LD(1)

💖 LD(1) — GNU Development Tools, and it's giving linker royalty 💖

okay so bestie, meet ld, aka The GNU linker. She's part of the GNU Development Tools lineup, and she is literally the final boss of compiling. No cap.

🌸 NAME 🌸

ld — The GNU linker. Periodt.

✨ SYNOPSIS ✨

ld [options] objfile ...

🦋 DESCRIPTION 🦋

ld combines a bunch of object and archive files, relocates their data, and ties up symbol references. Usually the last step in compiling a program is to run ld. It's giving "final girl" energy but for your build.

ld accepts Linker Command Language files written in a superset of AT&T's Link Editor Command Language syntax, to provide explicit and total control over the linking process. Like, you get to be the main character of your own link.

This man page does not describe the command language; see the ld entry in info for full details on the command language and on other aspects of the GNU linker. (iykyk — the man page is just the vibe check, not the whole novel.)

This version of ld uses the general purpose BFD libraries to operate on object files. This allows ld to read, combine, and write object files in many different formats---for example, COFF or a.out. Different formats may be linked together to produce any available kind of object file. She's flexible, she's iconic, she contains multitudes.

Aside from its flexibility, the GNU linker is more helpful than other linkers in providing diagnostic information. Many linkers abandon execution immediately upon encountering an error; whenever possible, ld continues executing, allowing you to identify other errors (or, in some cases, to get an output file in spite of the error). She doesn't just ghost you at the first red flag — she keeps going so you can see all the mess at once. 🫶

The GNU linker ld is meant to cover a broad range of situations, and to be as compatible as possible with other linkers. As a result, you have many choices to control its behavior. So many choices. A whole menu. A build-your-own-adventure, fr fr.

💅 OPTIONS 💅

The linker supports a plethora of command-line options, but in actual practice few of them are used in any particular context. For instance, a frequent use of ld is to link standard Unix object files on a standard, supported Unix system. On such a system, to link a file hello.o:

ld -o <output> /lib/crt0.o hello.o -lc

This tells ld to produce a file called output as the result of linking the file /lib/crt0.o with hello.o and the library libc.a, which will come from the standard search directories. (See the discussion of the -l option below.) Lowkey iconic behavior.

Some of the command-line options to ld may be specified at any point in the command line. However, options which refer to files, such as -l or -T, cause the file to be read at the point at which the option appears in the command line, relative to the object files and other file options. Repeating non-file options with a different argument will either have no further effect, or override prior occurrences (those further to the left on the command line) of that option. Options which may be meaningfully specified more than once are noted in the descriptions below. So like, order matters sometimes. Not always. The audacity.

Non-option arguments are object files or archives which are to be linked together. They may follow, precede, or be mixed in with command-line options, except that an object file argument may not be placed between an option and its argument. Do not separate the besties. 🥺

Usually the linker is invoked with at least one object file, but you can specify other forms of binary input files using -l, -R, and the script command language. If no binary input files at all are specified, the linker does not produce any output, and issues the message No input files. Empty-handed? She's not linking that.

If the linker cannot recognize the format of an object file, it will assume that it is a linker script. A script specified in this way augments the main linker script used for the link (either the default linker script or the one specified by using -T). This feature permits the linker to link against a file which appears to be an object or an archive, but actually merely defines some symbol values, or uses INPUT or GROUP to load other objects. Specifying a script in this way merely augments the main linker script, with the extra commands placed after the main script; use the -T option to replace the default linker script entirely, but note the effect of the INSERT command. It's giving "surprise, I'm a script" energy.

For options whose names are a single letter, option arguments must either follow the option letter without intervening whitespace, or be given as separate arguments immediately following the option that requires them. No space between letter and value unless you're doing the separate-argument thing. Got it? Slay.

For options whose names are multiple letters, either one dash or two can precede the option name; for example, -trace-symbol and --trace-symbol are equivalent. Note---there is one exception to this rule. Multiple letter options that start with a lower case 'o' can only be preceded by two dashes. This is to reduce confusion with the -o option. So for example -omagic sets the output file name to magic whereas --omagic sets the NMAGIC flag on the output. The one exception. The plot twist. 💀

Arguments to multiple-letter options must either be separated from the option name by an equals sign, or be given as separate arguments immediately following the option that requires them. For example, --trace-symbol foo and --trace-symbol=foo are equivalent. Unique abbreviations of the names of multiple-letter options are accepted. Short queen behavior, but make it unique.

Note---if the linker is being invoked indirectly, via a compiler driver (e.g. gcc) then all the linker command-line options should be prefixed by -Wl, (or whatever is appropriate for the particular compiler driver) like this:

gcc -Wl,--start-group foo.o bar.o -Wl,--end-group

This is important, because otherwise the compiler driver program may silently drop the linker options, resulting in a bad link. Confusion may also arise when passing options that require values through a driver, as the use of a space between option and argument acts as a separator, and causes the driver to pass only the option to the linker and the argument to the compiler. In this case, it is simplest to use the joined forms of both single- and multiple-letter options, such as:

gcc foo.o bar.o -Wl,-eENTRY -Wl,-Map=a.map

Here is a table of the generic command-line switches accepted by the GNU linker. (Imagine a cute lil table. We're doing bullets. Same energy.)

• @file — Read command-line options from file. The options read are inserted in place of the original @file option. If file does not exist, or cannot be read, then the option will be treated literally, and not removed. Options in file are separated by whitespace. A whitespace character may be included in an option by surrounding the entire option in either single or double quotes. Any character (including a backslash) may be included by prefixing the character to be included with a backslash. The file may itself contain additional @file options; any such options will be processed recursively. Recursive bestie behavior.
• -a keyword — This option is supported for HP/UX compatibility. The keyword argument must be one of the strings archive, shared, or default. -aarchive is functionally equivalent to -Bstatic, and the other two keywords are functionally equivalent to -Bdynamic. This option may be used any number of times.
• --audit AUDITLIB — Adds AUDITLIB to the DT_AUDIT entry of the dynamic section. AUDITLIB is not checked for existence, nor will it use the DT_SONAME specified in the library. If specified multiple times DT_AUDIT will contain a colon separated list of audit interfaces to use. If the linker finds an object with an audit entry while searching for shared libraries, it will add a corresponding DT_DEPAUDIT entry in the output file. This option is only meaningful on ELF platforms supporting the rtld-audit interface. ELF girlies only. 💅
• -b input-format, --format=input-format — ld may be configured to support more than one kind of object file. If your ld is configured this way, you can use the -b option to specify the binary format for input object files that follow this option on the command line. Even when ld is configured to support alternative object formats, you don't usually need to specify this, as ld should be configured to expect as a default input format the most usual format on each machine. input-format is a text string, the name of a particular format supported by the BFD libraries. (You can list the available binary formats with objdump -i.) You may want to use this option if you are linking files with an unusual binary format. You can also use -b to switch formats explicitly (when linking object files of different formats), by including -b input-format before each group of object files in a particular format. The default format is taken from the environment variable GNUTARGET. You can also define the input format from a script, using the command TARGET;
• -c MRI-commandfile, --mri-script=MRI-commandfile — For compatibility with linkers produced by MRI, ld accepts script files written in an alternate, restricted command language, described in the MRI Compatible Script Files section of GNU ld documentation. Introduce MRI script files with the option -c; use the -T option to run linker scripts written in the general-purpose ld scripting language. If MRI-cmdfile does not exist, ld looks for it in the directories specified by any -L options.
• -d, -dc, -dp — These three options are equivalent; multiple forms are supported for compatibility with other linkers. They assign space to common symbols even if a relocatable output file is specified (with -r). The script command FORCE_COMMON_ALLOCATION has the same effect.
• --depaudit AUDITLIB, -P AUDITLIB — Adds AUDITLIB to the DT_DEPAUDIT entry of the dynamic section. AUDITLIB is not checked for existence, nor will it use the DT_SONAME specified in the library. If specified multiple times DT_DEPAUDIT will contain a colon separated list of audit interfaces to use. This option is only meaningful on ELF platforms supporting the rtld-audit interface. The -P option is provided for Solaris compatibility.
• --enable-linker-version — Enables the LINKER_VERSION linker script directive, described in Output Section Data. If this directive is used in a linker script and this option has been enabled then a string containing the linker version will be inserted at the current point. Note - this location of this option on the linker command line is significant. It will only affect linker scripts that come after it on the command line, or which are built into the linker. Location, location, location.
• --disable-linker-version — Disables the LINKER_VERSION linker script directive, so that it does not insert a version string. This is the default.
• --enable-non-contiguous-regions — bestie, this one is the "no drama if it doesn't fit" flag 💅. Normally if an input section doesn't fit a matching output section, ld would just scream error at you. This option says chill, try the next matching output section, and only throw an error if no output section is large enough. It's giving "scattered memory regions? we can work with that" energy ✨. Useful when you've got several non-contiguous memory regions available and the input section doesn't care which one it gets. The order input sections are evaluated does not change, like:

MEMORY {
  MEM1 (rwx) : ORIGIN = 0x1000, LENGTH = 0x14
  MEM2 (rwx) : ORIGIN = 0x1000, LENGTH = 0x40
  MEM3 (rwx) : ORIGIN = 0x2000, LENGTH = 0x40
}
SECTIONS {
  mem1 : { *(.data.*); } > MEM1
  mem2 : { *(.data.*); } > MEM2
  mem3 : { *(.data.*); } > MEM3
}

with input sections:
.data.1: size 8
.data.2: size 0x10
.data.3: size 4

results in .data.1 affected to mem1, and .data.2 and .data.3
affected to mem2, even though .data.3 would fit in mem3.

So .data.1 ends up in mem1, and .data.2 plus .data.3 end up in mem2, even though .data.3 would fit in mem3. The vibes are non-contiguous, the order is still the order.

Heads up: this option is incompatible with INSERT statements because it changes the way input sections are mapped to output sections. So don't mix them, okay? 🫶

• --enable-non-contiguous-regions-warnings — this turns on warnings when --enable-non-contiguous-regions allows possibly unexpected matches in section mapping, which could potentially lead to silently discarding a section instead of failing because it doesn't fit any output region. Basically a "hey bestie, this match might be weird" alert 🚨.
• -e entry, --entry=entry — use entry as the explicit symbol for where your program starts executing, instead of the default entry point. If there's no symbol named entry, the linker will try to parse entry as a number and use that as the entry address. That number is interpreted in base 10; you can use a leading 0x for base 16, or a leading 0 for base 8. For i386 PE, entry can also be the original function name (without the leading underscore and/or the trailing stdcall @number when applicable). Iconic, honestly 👑.
• --exclude-libs lib,lib,... — specifies a list of archive libraries from which symbols should not be automatically exported. Library names can be delimited by commas or colons. --exclude-libs ALL excludes symbols in all archive libraries from automatic export. This option is only available for ELF and PE targeted ports of the linker. For PE targets, symbols explicitly listed in a .def file are still exported, regardless of this option. For ELF targeted ports, symbols affected by this option are treated as hidden. So they're lowkey invisible to the outside world 🙈.
• --exclude-modules-for-implib module,module,... — specifies a list of object files or archive members from which symbols should not be automatically exported, but which should be copied wholesale into the import library being generated during the link. Module names may be delimited by commas or colons, and must match exactly the filenames used by ld to open the files. For archive members, this is simply the member name; for object files, the name you list must include and match precisely any path used to specify the input file on the linker's command-line. Symbols explicitly listed in a .def file are still exported, regardless of this option. [This option is specific to PE targeted ports of the linker] 💅.
• -E, --export-dynamic, --no-export-dynamic — when you're creating a dynamically linked executable, -E or --export-dynamic makes the linker add all symbols to the dynamic symbol table. The dynamic symbol table is the set of symbols visible from dynamic objects at run time. Periodt.

If you don't use either of these options (or you use --no-export-dynamic to restore the default behavior), the dynamic symbol table will normally contain only those symbols referenced by some dynamic object mentioned in the link.

If you use "dlopen" to load a dynamic object that needs to refer back to symbols defined by the program, rather than some other dynamic object, then you'll probably need this option when linking the program itself. It's giving "main character needs to be seen" energy 🌟.

You can also use the dynamic list to control what symbols should be added to the dynamic symbol table if the output format supports it. See the description of --dynamic-list.

Note that this option is specific to ELF targeted ports. PE targets support a similar function to export all symbols from a DLL or EXE; see the description of --export-all-symbols below.

• --export-dynamic-symbol=glob — when creating a dynamically linked executable, symbols matching glob will be added to the dynamic symbol table. When creating a shared library, references to symbols matching glob will not be bound to the definitions within the shared library. This option is a no-op when creating a shared library and -Bsymbolic or --dynamic-list are not specified. This option is only meaningful on ELF platforms which support shared libraries. 🌈
• --export-dynamic-symbol-list=file — specify a --export-dynamic-symbol for each pattern in the file. The format of the file is the same as the version node without scope and node name. See VERSION for more information 📖.
• -EB — link big-endian objects. This affects the default output format. Big-endian besties, rise 🫶.
• -EL — link little-endian objects. This affects the default output format. Little-endian cuties, this one's for you 💖.
• -f name, --auxiliary=name — when creating an ELF shared object, set the internal DT_AUXILIARY field to the specified name. This tells the dynamic linker that the symbol table of the shared object should be used as an auxiliary filter on the symbol table of the shared object name.

If you later link a program against this filter object, then when you run the program, the dynamic linker will see the DT_AUXILIARY field. If the dynamic linker resolves any symbols from the filter object, it will first check whether there is a definition in the shared object name. If there is one, it will be used instead of the definition in the filter object. The shared object name need not exist. Thus the shared object name may be used to provide an alternative implementation of certain functions, perhaps for debugging or for machine-specific performance.

This option may be specified more than once. The DT_AUXILIARY entries will be created in the order in which they appear on the command line. It's giving "backup bestie" energy 😭.

• -F name, --filter=name — when creating an ELF shared object, set the internal DT_FILTER field to the specified name. This tells the dynamic linker that the symbol table of the shared object which is being created should be used as a filter on the symbol table of the shared object name.

If you later link a program against this filter object, then when you run the program, the dynamic linker will see the DT_FILTER field. The dynamic linker will resolve symbols according to the symbol table of the filter object as usual, but it will actually link to the definitions found in the shared object name. Thus the filter object can be used to select a subset of the symbols provided by the object name. Filtering, but make it fashion 💅.

Some older linkers used the -F option throughout a compilation toolchain for specifying object-file format for both input and output object files. The GNU linker uses other mechanisms for this purpose: the -b, --format, --oformat options, the "TARGET" command in linker scripts, and the "GNUTARGET" environment variable. The GNU linker will ignore the -F option when not creating an ELF shared object. Okay so don't come for GNU ld with old-toolchain expectations, bestie 🙈.

• -fini=name — when creating an ELF executable or shared object, call NAME when the executable or shared object is unloaded, by setting DT_FINI to the address of the function. By default, the linker uses "_fini" as the function to call. Bye-bye function, but make it coded 💀.
• -g — ignored. Provided for compatibility with other tools. It's giving "I'm just here for the vibes" 🎀.
• -G value, --gpsize=value — set the maximum size of objects to be optimized using the GP register to size. This is only meaningful for object file formats such as MIPS ELF that support putting large and small objects into different sections. This is ignored for other object file formats. MIPS besties, this one's for you ✨.
• -h name, -soname=name — when creating an ELF shared object, set the internal DT_SONAME field to the specified name. When an executable is linked with a shared object which has a DT_SONAME field, then when the executable is run the dynamic linker will attempt to load the shared object specified by the DT_SONAME field rather than using the file name given to the linker. Name tags but for ELF shared objects 🏷️.
• -i — perform an incremental link (same as option -r). Incremental slay 🔥.
• -init=name — when creating an ELF executable or shared object, call NAME when the executable or shared object is loaded, by setting DT_INIT to the address of the function. By default, the linker uses "_init" as the function to call. Hello, initialization function 👋.
• -l namespec, --library=namespec — add the archive or object file specified by namespec to the list of files to link. This option may be used any number of times. If namespec is of the form :filename, ld will search the library path for a file called filename, otherwise it will search the library path for a file called libnamespec.a.

On systems which support shared libraries, ld may also search for files other than libnamespec.a. Specifically, on ELF and SunOS systems, ld will search a directory for a library called libnamespec.so before searching for one called libnamespec.a. (By convention, a .so extension indicates a shared library.) Note that this behavior does not apply to :filename, which always specifies a file called filename.

The linker will search an archive only once, at the location where it is specified on the command line. If the archive defines a symbol which was undefined in some object which appeared before the archive on the command line, the linker will include the appropriate file(s) from the archive. However, an undefined symbol in an object appearing later on the command line will not cause the linker to search the archive again.

See the -( option for a way to force the linker to search archives multiple times.

You may list the same archive multiple times on the command line. Library chaos, but controlled 💅.

This flavour of archive searching is just… the standard thing for Unix linkers. Lowkey universal, no cap. BUT — plot twist — if you're running ld on AIX, heads up: it does not behave like the AIX linker. Different vibe entirely. 💅

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• -L searchdir / --library-path=searchdir — Add the path searchdir to the list of paths ld will search for archive libraries and ld control scripts. Bestie, use this as many times as you want, there's no limit. ✨ The directories get searched in the exact order you specify them on the command line, and directories you specify on the command line get searched before the default directories. Every single -L option applies to every single -l option, no matter what order the options show up in — that's just the rule. But -L options do not affect how ld searches for a linker script, unless the -T option is specified. 🫶

If searchdir starts with = or $SYSROOT, that prefix gets replaced by the sysroot prefix — the one controlled by the --sysroot option, or the one specified when the linker was configured.

The default set of paths that gets searched (the ones you get without specifying -L) depends on which emulation mode ld is using, and in some cases also on how it was configured.

You can also specify paths in a link script with the SEARCH_DIR command. Directories specified that way are searched at the point where the linker script appears in the command line.

• -m emulation — Emulate the emulation linker. You can list the available emulations with the --verbose or -V options. 👑

If the -m option is not used, the emulation is taken from the LDEMULATION environment variable, if that is defined.

Otherwise, the default emulation depends upon how the linker was configured.

• --remap-inputs=pattern=filename / --remap-inputs-file=file — These options let you change the names of input files before the linker even attempts to open them. Sneaky, but iconic. The option --remap-inputs=foo.o=bar.o will cause any attempt to load a file called foo.o to instead try to load a file called bar.o. Wildcard patterns are permitted in the first filename, so --remap-inputs=foo*.o=bar.o will rename any input file that matches foo*.o to bar.o. 🌈

An alternative form of the option, --remap-inputs-file=filename, lets the remappings be read from a file. Each line in the file can contain a single remapping. Blank lines are ignored. Anything from a hash character (#) to the end of a line is considered a comment and is also ignored. The mapping pattern can be separated from the filename by whitespace or an equals (=) character.

The options can be specified multiple times. Their contents accumulate. The remappings will be processed in the order in which they occur on the command line, and if they come from a file, in the order in which they occur in the file. If a match is made, no further checking for that filename will be performed.

If the replacement filename is /dev/null or just NUL then the remapping will actually cause the input file to be ignored. This can be a convenient way to experiment with removing input files from a complicated build environment.

⚠️ This option is position dependent and only affects filenames that come after it on the command line. So check it:

ld foo.o --remap-inputs=foo.o=bar.o

Will have no effect 🙈, whereas:

ld --remap-inputs=foo.o=bar.o foo.o

Will rename the input file foo.o to bar.o. Ate. 💅

Note — these options also affect files referenced by INPUT statements in linker scripts. But since linker scripts are processed after the entire command line is read, the position of the remap options on the command line is not significant.

If the verbose option is enabled then any mappings that match will be reported, although again the verbose option needs to be enabled on the command line before the remapped filenames appear.

If the -Map or --print-map options are enabled then the remapping list will be included in the map output.

• -M / --print-map — Print a link map to the standard output. A link map is basically the receipts of the link, and it provides information about the link, including the following:
  • Where object files are mapped into memory.
  • How common symbols are allocated.
  • All archive members included in the link, with a mention of the symbol which caused the archive member to be brought in.
  • The values assigned to symbols.

Note — symbols whose values are computed by an expression which involves a reference to a previous value of the same symbol may not have correct result displayed in the link map. Why? Because the linker discards intermediate results and only retains the final value of an expression. Under such circumstances the linker will display the final value enclosed by square brackets. Thus, for example, a linker script containing:

foo = 1
foo = foo * 4
foo = foo + 8

will produce the following output in the link map if the -M option is used:

0x00000001                foo = 0x1
[0x0000000c]                foo = (foo * 0x4)
[0x0000000c]                foo = (foo + 0x8)

See Expressions for more information about expressions in linker scripts.

• How GNU properties are merged. 🧚

When the linker merges input .note.gnu.property sections into one output .note.gnu.property section, some properties are removed or updated. These actions are reported in the link map. For example:

Removed property 0xc0000002 to merge foo.o (0x1) and bar.o (not found)

This indicates that property 0xc0000002 is removed from output when merging properties in foo.o, whose property 0xc0000002 value is 0x1, and bar.o, which doesn't have property 0xc0000002.

Updated property 0xc0010001 (0x1) to merge foo.o (0x1) and bar.o (0x1)

This indicates that property 0xc0010001 value is updated to 0x1 in output when merging properties in foo.o, whose 0xc0010001 property value is 0x1, and bar.o, whose 0xc0010001 property value is 0x1.

• On some ELF targets, a list of fixups inserted by --relax:

foo.o: Adjusting branch at 0x00000008 towards "far" in section .text

This indicates that the branch at 0x00000008 in foo.o, targeting the symbol "far" in section .text, has been replaced by a trampoline. 🔥

• --print-map-discarded / --no-print-map-discarded — Print (or do not print) the list of discarded and garbage collected sections in the link map. Enabled by default.
• --print-map-locals / --no-print-map-locals — Print (or do not print) local symbols in the link map. Local symbols will have the text (local) printed before their name, and will be listed after all of the global symbols in a given section. Temporary local symbols (typically those that start with .L) will not be included in the output. Disabled by default.
• -n / --nmagic — Turn off page alignment of sections, and disable linking against shared libraries. If the output format supports Unix style magic numbers, mark the output as "NMAGIC".
• -N / --omagic — Set the text and data sections to be readable and writable. Also, do not page-align the data segment, and disable linking against shared libraries. If the output format supports Unix style magic numbers, mark the output as "OMAGIC".

Note: Although a writable text section is allowed for PE-COFF targets, it does not conform to the format specification published by Microsoft. 😭 Keep that in mind, bestie.

• --no-omagic — This option negates most of the effects of the -N option. It sets the text section to be read-only, and forces the data segment to be page-aligned.

⚠️ Note — this option does not enable linking against shared libraries. Use -Bdynamic for this.

• -o output / --output=output — Use output as the name for the program produced by ld; if this option is not specified, the name a.out is used by default. The script command OUTPUT can also specify the output file name. 💖

⚠️ Note — the linker will delete the output file before it starts to write to it. It will do this even if it turns out that the link cannot be completed due to errors. 💀

⚠️ Note — the linker will check to make sure that the output file name does not match the name of any of the input files, but that is all. In particular it will not complain if the output file might overwrite a source file or some other important file. Therefore in build systems it is recommended to use the -o option as the last option on the linker command line. For example consider:

ld -o $(EXE) $(OBJS)
ld $(OBJS) -o $(EXE)

If the EXE variable is not defined for some reason, the first version of the linker command could end up deleting one of the object files (the first one in the OBJS list) whereas the second version of the linker command will generate an error message and not delete anything. The second one is the main character. 🎀

• --dependency-file=depfile — Write a dependency file to depfile. This file contains a rule suitable for make describing the output file and all the input files that were read to produce it. The output is similar to the compiler's output with -M -MP. Note that there is no option like the compiler's -MM, to exclude "system files" (which is not a well-specified concept in the linker, unlike "system headers" in the compiler). So the output from --dependency-file is always specific to the exact state of the installation where it was produced, and should not be copied into distributed makefiles without careful editing. ✍️
• -O level — If level is a numeric value greater than zero ld optimizes the output. This might take significantly longer and therefore probably should only be enabled for the final binary. At the moment this option only affects ELF shared library generation. Future releases of the linker may make more use of this option. Also currently there is no difference in the linker's behaviour for different non-zero values of this option. Again this may change with future releases. ⭐

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But wait, if level is 0 or the string fast then ld gets lazy in the best way and skips the operations that are optional 💅 — you get a faster link, but at the cost of slower, bigger binaries. As of right now the only thing it skips is the combining of mergeable sections, but that might change later, so don't build your whole personality around it.

If level is the string default, or literally just the - character, then you get the linker's default behaviour: no optimizing, no skipping. Just vibes. ✨

• -plugin name — pull a plugin into the linking process 🫶. The name is the absolute filename of the plugin. Usually your compiler just adds this for you when you're using link time optimization, but bestie, you can absolutely add your own plugins if you want to.

Heads up though: compiler-originated plugins live somewhere different from where ar, nm and ranlib go looking for theirs. So if you want those commands to use a compiler-based plugin, you gotta copy it into the ${libdir}/bfd-plugins directory first. Good news: all gcc based linker plugins are backward compatible, so you only need to copy in the newest one. Queen behaviour. 👑

• --push-state — this one saves the current state of all the flags that govern input file handling, so you can restore them all later with one corresponding --pop-state. Snapshot, bestie 📸.

The options it covers are: -Bdynamic, -Bstatic, -dn, -dy, -call_shared, -non_shared, -static, -N, -n, --whole-archive, --no-whole-archive, --link-mapless, --no-link-mapless, -r, -Ur, --copy-dt-needed-entries, --no-copy-dt-needed-entries, --as-needed, --no-as-needed, and -a.

One target for this option is pkg-config specifications 📦. When you use it with the --libs option, all possibly needed libraries get listed and then possibly linked in all the time, which is not the move. It's way better to return something like this:

-Wl,--push-state,--as-needed -libone -libtwo -Wl,--pop-state

• --pop-state — undoes the effect of --push-state and restores the previous values of the flags governing input file handling. Rewind time, no time machine required 🦋.
• -q, --emit-relocs — leaves relocation sections and their contents in fully linked executables. Post link analysis and optimization tools might need this info to correctly modify executables. Downside: it makes your executables bigger. 😭

This option is currently only supported on ELF platforms.

• --force-dynamic — forces the output file to have dynamic sections. This one is specific to VxWorks targets 🎀.
• -r, --relocatable — generates relocatable output — i.e. it generates an output file that can in turn serve as input to ld. Everyone calls this partial linking. Side effect alert 🌸: in environments that support standard Unix magic numbers, this option also sets the output file's magic number to "OMAGIC". If you don't specify this option, an absolute file gets produced. And important 💀: when linking C++ programs, this option will not resolve references to constructors — to do that, use -Ur.

Here's the tea when an input file doesn't have the same format as the output file ☕: partial linking is only supported if that input file contains no relocations. Different output formats can have further restrictions; for example some "a.out"-based formats don't support partial linking with input files in other formats at all. Periodt.

When the relocatable output contains both contents that require link-time optimization (LTO) and contents that don't require LTO, a .gnu_object_only section will be created to contain a relocatable object file, as if -r is applied to all relocatable inputs which don't require LTO. When processing a relocatable input with a .gnu_object_only section, the linker will extract the .gnu_object_only section as a separate input.

Also ngl, since -r groups some sections from different input files together, there may be negative impacts on code size and locality in the final executable or shared library. Just so you know 🫶.

This option does the same thing as -i.

• -R filename, --just-symbols=filename — reads symbol names and their addresses from filename, but doesn't relocate it or include it in the output. This lets your output file refer symbolically to absolute locations of memory defined in other programs 👑. You can use this option more than once.

For compatibility with other ELF linkers: if the -R option is followed by a directory name instead of a file name, it's treated as the -rpath option. Sneaky but iconic.

• --rosegment, --no-rosegment — tries to make sure that only a single read-only, non-code segment gets created. Only useful when you're using it together with the -z separate-code option ✨. The resulting binaries should be smaller than if -z separate-code is used on its own. Without this option — or if --no-rosegment is specified — the -z separate-code option will create two read-only segments, one before the code segment and one after it.

The names of these options are misleading, but they were chosen so the linker stays compatible with the LLD and GOLD linkers. Blame the ancestors, not us 🙈.

These options are only supported by ELF targets.

• -s, --strip-all — omits all symbol information from the output file. Gone, deleted, not invited to the party 💅.
• -S, --strip-debug — omits debugger symbol information from the output file (but not all symbols). Some of them still get to stay 🌸.
• --strip-discarded, --no-strip-discarded — omits (or does not omit) global symbols defined in discarded sections. Enabled by default ⭐.
• -plugin-save-temps — stores the plugin "temporary" intermediate files permanently. No cleanup era, bestie 🎀.
• -t, --trace — prints the names of the input files as ld processes them 👀. If you pass -t twice, then members within archives get printed too. The -t output is genuinely useful for generating a list of all the object files and scripts involved in linking — for example when you're packaging files for a linker bug report. Do it for the scientists 🧚.
• -T scriptfile, --script=scriptfile — use scriptfile as the linker script. This script replaces ld's default linker script (rather than adding to it), unless the script contains "INSERT", so commandfile must specify everything necessary to describe the output file. It's giving full responsibility, no takebacks 😤.

If scriptfile doesn't exist in the current directory, "ld" looks for it in the directories specified by any preceding -L options.

Command line options that appear before the -T option can affect the script, but command line options that appear after it do not. Order matters, always has 🌈.

Multiple -T options will accumulate if they're augmenting the current script; otherwise the last, non-augmenting -T option will be used.

There are other ways of specifying linker scripts. See

• -dT scriptfile, --default-script=scriptfile — use scriptfile as the default linker script.

This is similar to the --script option, except that processing of the script is delayed until after the rest of the command line has been processed ⏳. This lets options placed after the --default-script option on the command line affect the behaviour of the linker script — which can be a big deal when the linker command line can't be directly controlled by the user (eg because the command line is being constructed by another tool, such as gcc).

• -u symbol, --undefined=symbol — forces symbol to be entered in the output file as an undefined symbol. Doing this may, for example, trigger linking of additional modules from standard libraries 👑. -u may be repeated with different option arguments to enter additional undefined symbols. This option is equivalent to the "EXTERN" linker script command.

If you're using this option to force additional modules to be pulled into the link, and it's an error for the symbol to remain undefined, then you should use the --require-defined option instead. Choose wisely bestie 🫶.

• --require-defined=symbol — requires that symbol is defined in the output file. This option is the same as --undefined, except that if symbol is not defined in the output file then the linker will issue an error and exit 💀. You can achieve the same effect in a linker script by using "EXTERN", "ASSERT" and "DEFINED" together. This option can be used multiple times to require additional symbols.
• -Ur — for programs that don't use constructors or destructors, or for ELF based systems, this option is equivalent to -r: it generates relocatable output — i.e., an output file that can in turn serve as input to ld. For other binaries though, -Ur is similar to -r but it also resolves references to constructors and destructors 🔥.

For those systems where -r and -Ur behave differently: it does not work to use -Ur on files that were themselves linked with -Ur. Once the constructor table has been built, it cannot be added to. Periodt. So use -Ur only for the last partial link, and -r for all the others 🎀.

• --orphan-handling=MODE — controls how orphan sections are handled. An orphan section is one that isn't specifically mentioned in a linker script. Cute little foundlings 🦋.

MODE can have any of the following values:

• "place" — orphan sections are placed into a suitable output section following the strategy described in Orphan Sections. The --unique option also affects how sections are placed.
• "discard" — all orphan sections are discarded, by placing them in the /DISCARD/ section.
• "warn" — the linker will place the orphan section as for "place" and also issue a warning.
• "error" — the linker will exit with an error if any orphan section is found.

The default if --orphan-handling is not given is "place" ⭐.

• --unique[=SECTION] — creates a separate output section for every input section matching SECTION, or — if the optional wildcard SECTION argument is missing — for every orphan input section. An orphan section is one not specifically mentioned in a linker script 🍼. You can use this option multiple times on the command line. It prevents the normal merging of input sections with the same name, overriding output section assignments in a linker script. Chaos, but make it organized 💅.
• -v, --version, -V — displays the version number for ld. The -V option also lists the supported emulations 👑. See also the description of the --enable-linker-version in Options,,Command-line Options, which can be used to insert the linker version string into a binary. Iconic.
• -x, --discard-all — deletes all local symbols. Bye bestie, you were loved 🌸.
• -X, --discard-locals — bestie, this one yeets every single temporary local symbol into the void 🗑️. We're talking the ones that start with whatever local label prefix your system decided to use — usually .L on ELF systems, or just L on old-school traditional a.out systems. Gone. Periodt.
• -y symbol, --trace-symbol=symbol — okay this is the detective mode 🔍. It prints the name of each linked file in which symbol appears. And the glow-up? You can hand it this option as many times as you want — it's giving unlimited slay. Heads up tho: on many systems you gotta prepend an underscore, iykyk.

Literally the use case: you've got an undefined symbol in your link and you're sitting there like "who is she and where did she come from 😭". This option tells you exactly where the reference is coming from. Main character energy.

• -Y path — adds path to the default library search path. This one exists purely for Solaris compatibility, so it's a little vintage moment 💅.
• -z keyword — the moment you've all been waiting for 👑. Here's every recognized keyword, no cap, no skips:

✨ -z KEYWORDS ✨

• call-nop=prefix-addr, call-nop=suffix-nop, call-nop=prefix-byte, call-nop=suffix-byte — these specify the 1-byte "NOP" padding when you're transforming an indirect call to a locally defined function, foo, via its GOT slot. The tea ☕:
  • call-nop=prefix-addr generates "0x67 call foo".
  • call-nop=suffix-nop generates "call foo 0x90".
  • call-nop=prefix-byte generates "byte call foo".
  • call-nop=suffix-byte generates "call foo byte".
  • Supported for i386 and x86_64.
• cet-report=none, cet-report=warning, cet-report=error — controls how we report the missing GNU_PROPERTY_X86_FEATURE_1_IBT and GNU_PROPERTY_X86_FEATURE_1_SHSTK properties in the input .note.gnu.property section. Breakdown:
  • cet-report=none — this is the default, and it makes the linker simply not report missing properties in input files. Be unbothered, stay unbothered 💅.
  • cet-report=warning — the linker issues a warning for missing properties in input files.
  • cet-report=error — the linker issues an error for missing properties in input files.
  • Also note: ibt will turn off the missing GNU_PROPERTY_X86_FEATURE_1_IBT property report, and shstk will turn off the missing GNU_PROPERTY_X86_FEATURE_1_SHSTK property report.
  • Supported for Linux/i386 and Linux/x86_64.
• combreloc, nocombreloc — combreloc combines multiple dynamic relocation sections and sorts them to improve dynamic symbol lookup caching (a little optimization moment ✨). Do not do this if nocombreloc, bestie — that's the whole vibe of nocombreloc.
• common, nocommon — common generates common symbols with STT_COMMON type during a relocatable link. Use STT_OBJECT type if nocommon. Pick your fighter 🥊.
• common-page-size=value — sets the page size most commonly used to value. Memory image layout gets optimized to minimize memory pages if your system is using pages of this size. Efficient queen 🎀.
• defs — reports unresolved symbol references from regular object files. And it does this even if the linker is creating a non-symbolic shared library. This option is the inverse of -z undefs, fr fr.
• dynamic-undefined-weak, nodynamic-undefined-weak — dynamic-undefined-weak makes undefined weak symbols dynamic when building a dynamic object, if they're referenced from a regular object file and not forced local by symbol visibility or versioning. nodynamic-undefined-weak says don't make them dynamic. If you give neither option, a target may default to either option being in force, or make some other selection of undefined weak symbols dynamic — so like, it's giving chaos, and not all targets support these options anyway 🙈.
• execstack — marks the object as requiring an executable stack. Spicy. 🌶️
• global — only meaningful when building a shared object. It makes the symbols defined by this shared object available for symbol resolution of subsequently loaded libraries. Sharing is caring 🫶.
• globalaudit — only meaningful when building a dynamic executable. It marks the executable as requiring global auditing by setting the "DF_1_GLOBAUDIT" bit in the "DT_FLAGS_1" dynamic tag. Global auditing requires that any auditing library defined via the --depaudit or -P command-line options be run for all dynamic objects loaded by the application. Very official, very serious 💜.
• ibtplt — generates Intel Indirect Branch Tracking (IBT) enabled PLT entries. Supported for Linux/i386 and Linux/x86_64.
• ibt — generates GNU_PROPERTY_X86_FEATURE_1_IBT in .note.gnu.property section to indicate compatibility with IBT. This also implies ibtplt. Supported for Linux/i386 and Linux/x86_64.
• indirect-extern-access, noindirect-extern-access —
  • indirect-extern-access generates GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS in .note.gnu.property section to indicate that the object file requires canonical function pointers and cannot be used with copy relocation. This option also implies noextern-protected-data and nocopyreloc. Supported for i386 and x86-64.
  • noindirect-extern-access removes GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS from the .note.gnu.property section.
• initfirst — only meaningful when building a shared object. It marks the object so that its runtime initialization will occur before the runtime initialization of any other objects brought into the process at the same time. Similarly, the runtime finalization of the object will occur after the runtime finalization of any other objects. It's giving priority boarding ✈️✨.
• interpose — specifies that the dynamic loader should modify its symbol search order so that symbols in this shared library interpose all other shared libraries not so marked. Respectfully, she's the moment 👑.
• unique, nounique — when generating a shared library or other dynamically loadable ELF object, unique marks it as one that should (by default) only ever be loaded once, and only in the main namespace (when using "dlmopen"). This is primarily used to mark fundamental libraries such as libc, libpthread et al, which don't usually function correctly unless they're the sole instances of themselves. This behaviour can be overridden by the "dlmopen" caller and does not apply to certain loading mechanisms (such as audit libraries). One of one 💅.
• lam-u48 — generates GNU_PROPERTY_X86_FEATURE_1_LAM_U48 in .note.gnu.property section to indicate compatibility with Intel LAM_U48. Supported for Linux/x86_64.
• lam-u57 — generates GNU_PROPERTY_X86_FEATURE_1_LAM_U57 in .note.gnu.property section to indicate compatibility with Intel LAM_U57. Supported for Linux/x86_64.
• lam-u48-report=none, lam-u48-report=warning, lam-u48-report=error — specifies how to report the missing GNU_PROPERTY_X86_FEATURE_1_LAM_U48 property in the input .note.gnu.property section:
  • lam-u48-report=none — the default. Linker does not report missing properties in input files.
  • lam-u48-report=warning — linker issues a warning for missing properties in input files.
  • lam-u48-report=error — linker issues an error for missing properties in input files.
  • Supported for Linux/x86_64.
• lam-u57-report=none, lam-u57-report=warning, lam-u57-report=error — specifies how to report the missing GNU_PROPERTY_X86_FEATURE_1_LAM_U57 property in the input .note.gnu.property section:
  • lam-u57-report=none — the default. Linker does not report missing properties in input files.
  • lam-u57-report=warning — linker issues a warning for missing properties in input files.
  • lam-u57-report=error — linker issues an error for missing properties in input files.
  • Supported for Linux/x86_64.
• lam-report=none, lam-report=warning, lam-report=error — specifies how to report the missing GNU_PROPERTY_X86_FEATURE_1_LAM_U48 and GNU_PROPERTY_X86_FEATURE_1_LAM_U57 properties in the input .note.gnu.property section:
  • lam-report=none — the default. Linker does not report missing properties in input files.
  • lam-report=warning — linker issues a warning for missing properties in input files.
  • lam-report=error — linker issues an error for missing properties in input files.
  • Supported for Linux/x86_64.
• lazy — when generating an executable or shared library, this marks it to tell the dynamic linker to defer function call resolution to the point when the function is called (that's lazy binding), rather than at load time. And plot twist: lazy binding is the default, so she's just being official about it 💅.
• loadfltr — specifies that the object's filters be processed immediately at runtime. No waiting, no queue 🌈.
• max-page-size=value — sets the maximum memory page size supported to value.
• mark-plt, nomark-plt — mark-plt marks PLT entries with dynamic tags, DT_X86_64_PLT, DT_X86_64_PLTSZ and DT_X86_64_PLTENT. And okay, important caveat time bestie:

Since this option stores a non-zero value in the r_addend field of R_X86_64_JUMP_SLOT relocations, the resulting executables and shared libraries are incompatible with dynamic linkers — such as those in older versions of glibc without the change to ignore r_addend in R_X86_64_GLOB_DAT and R_X86_64_JUMP_SLOT relocations — which don't ignore the r_addend field of R_X86_64_JUMP_SLOT relocations. Supported for x86_64.

• muldefs — allow multiple definitions. Chaos permitted 🫶.
• nocopyreloc — disables linker-generated .dynbss variables used in place of variables defined in shared libraries. Heads up: this may result in dynamic text relocations. Proceed with awareness 😌.
• nodefaultlib — specifies that the dynamic loader's search for dependencies of this object should ignore any default library search paths.
• nodelete — specifies that the object shouldn't be unloaded at runtime. She stays. Periodt 💅.
• nodlopen — specifies that the object is not available to "dlopen".
• nodump — specifies that the object can not be dumped by "dldump".
• noexecstack — marks the object as not requiring an executable stack.
• noextern-protected-data — don't treat protected data symbols as external when building a shared library. This option overrides the linker backend default, and it can be used to work around incorrect relocations against protected data symbols generated by the compiler. Key lore: updates on protected data symbols by another module aren't visible to the resulting shared library. Supported for i386 and x86-64.
• -z noreloc-overflow — turns off the relocation overflow check. Only do this if you know there's not gonna be a dynamic relocation overflow at run-time, bestie. Supported for x86_64. 💅
• -z memory-seal / -z nomemory-seal — tells the executable or shared library that all PT_LOAD segments should be sealed so nobody can mess with them anymore (like changing the protection flags, the segment size, or straight up removing the mapping). It's a security hardening that needs system support, okurrr. It spits out GNU_PROPERTY_MEMORY_SEAL in the .note.gnu.property section. 🎀
• -z now — when you're generating an executable or shared library, this marks it so the dynamic linker resolves all symbols when the program starts, or when the shared library gets loaded by dlopen, instead of being lazy and waiting until the function is first called. 🔥
• -z origin — says the object like, requires $ORIGIN handling in paths. 🦋
• -z pack-relative-relocs / -z nopack-relative-relocs — generates compact relative relocations in position-independent executables and shared libraries. It adds DT_RELR, DT_RELRSZ and DT_RELRENT entries to the dynamic section. It gets ignored when you're building position-dependent executable and relocatable output, so don't stress. nopack-relative-relocs is the default, which disables compact relative relocation. When linked against the GNU C Library, a GLIBC_ABI_DT_RELR symbol version dependency on the shared C Library gets added to the output. Supported for i386 and x86-64. ✨
• -z relro / -z norelro — creates an ELF PT_GNU_RELRO segment header in the object. This specifies a memory segment that should be made read-only after relocation, if it's supported. Heads up: specifying common-page-size smaller than the system page size will make this protection useless 😭. norelro means don't create that PT_GNU_RELRO segment at all.
• -z report-relative-reloc — reports the dynamic relative relocations that the linker generated. Supported for Linux/i386 and Linux/x86_64. 👑
• -z sectionheader / -z nosectionheader — generates the section header. nosectionheader means don't. sectionheader is the default, periodt.
• -z separate-code / -z noseparate-code — creates a separate code PT_LOAD segment header in the object. This specifies a memory segment that should contain only instructions and must be in wholly disjoint pages from any other data. noseparate-code means don't create that separate code PT_LOAD segment. 🌸
• -z shstk — generates GNU_PROPERTY_X86_FEATURE_1_SHSTK in the .note.gnu.property section to show compatibility with Intel Shadow Stack. Supported for Linux/i386 and Linux/x86_64. 🛡️ (not literally an emoji that exists but the vibe is there, iykyk)
• -z stack-size=value — picks a stack size for an ELF PT_GNU_STACK segment. Giving it zero will override any default non-zero sized PT_GNU_STACK segment creation. 💜
• -z start-stop-gc / -z nostart-stop-gc — okay so when --gc-sections is in effect, a reference from a retained section to __start_SECNAME or __stop_SECNAME makes all input sections named SECNAME get retained too — but only if SECNAME is representable as a C identifier and either __start_SECNAME or __stop_SECNAME is synthesized by the linker. -z start-stop-gc disables that whole effect, letting sections get garbage collected as if those special synthesized symbols were never defined. But listen: -z start-stop-gc has no effect on a definition of __start_SECNAME or __stop_SECNAME in an object file or linker script. That kind of definition will prevent the linker from providing a synthesized __start_SECNAME or __stop_SECNAME respectively, and therefore the special garbage-collection treatment for those references is off the table too.
• -z start-stop-visibility=value — sets the ELF symbol visibility for synthesized __start_SECNAME and __stop_SECNAME symbols. value has to be exactly default, internal, hidden, or protected. If you don't pass -z start-stop-visibility at all, protected is used for compatibility with historical practice. However — and this is important — it's highly recommended to use -z start-stop-visibility=hidden in new programs and shared libraries so these symbols don't get exported between shared objects, which is usually not what anyone intended anyway. 🙈
• -z text / -z notext / -z textoff — reports an error if DT_TEXTREL is set, i.e., if the position-independent or shared object has dynamic relocations in read-only sections. notext or textoff means don't report that error. 🍓
• -z undefs — do not report unresolved symbol references from regular object files, whether you're creating an executable or a shared library. This option is the inverse of -z defs. 💀
• -z unique-symbol / -z nounique-symbol — avoids duplicated local symbol names in the symbol string table. If unique-symbol is used, it appends "."number" to duplicated local symbol names. nounique-symbol is the default. 🧚
• -z x86-64-baseline, -z x86-64-v2, -z x86-64-v3, -z x86-64-v4 — specify the x86-64 ISA level needed in the .note.gnu.property section. x86-64-baseline generates GNU_PROPERTY_X86_ISA_1_BASELINE. x86-64-v2 generates GNU_PROPERTY_X86_ISA_1_V2. x86-64-v3 generates GNU_PROPERTY_X86_ISA_1_V3. x86-64-v4 generates GNU_PROPERTY_X86_ISA_1_V4. Supported for Linux/i386 and Linux/x86_64. ⭐
• -z isa-level-report=none, -z isa-level-report=all, -z isa-level-report=needed, -z isa-level-report=used — specify how to report x86-64 ISA levels in input relocatable files:
  • isa-level-report=none, which is the default, makes the linker not report x86-64 ISA levels in input files at all.
  • isa-level-report=all makes the linker report both needed and used x86-64 ISA levels in input files.
  • isa-level-report=needed makes the linker report needed x86-64 ISA levels in input files.
  • isa-level-report=used makes the linker report used x86-64 ISA levels in input files.

Supported for Linux/i386 and Linux/x86_64. 🌈

Other keywords are ignored for Solaris compatibility. (so, like, don't worry about them 💅)

---

• --gnu-tls-tag / --no-gnu-tls-tag — adds a GLIBC_ABI_GNU_TLS version tag dependency in output programs and shared libraries when linking against glibc, but only if input relocatable object files call ___tls_get_addr. Heads up: the output will fail to load and run at run-time against glibc that doesn't define the GLIBC_ABI_GNU_TLS version tag 😭. Unless it's disabled by the --disable-gnu-tls-tag configure option at linker build time, when no options are specified the linker will add the GLIBC_ABI_GNU_TLS version tag dependency if inputs have a ___tls_get_addr call and libc.so defines the GLIBC_ABI_GNU_TLS version tag. Supported for Linux/i386. 🎀
• --gnu2-tls-tag / --no-gnu2-tls-tag — adds a GLIBC_ABI_GNU2_TLS version tag dependency in output programs and shared libraries when linking against glibc if input relocatable object files have R_386_TLS_DESC_CALL or R_X86_64_TLSDESC_CALL relocation. Same deal: the output will fail to load and run at run-time against glibc that doesn't define the GLIBC_ABI_GNU2_TLS version tag 💀. Unless disabled by the --disable-gnu2-tls-tag configure option at linker build time, when no options are specified the linker will add the GLIBC_ABI_GNU2_TLS version tag dependency if inputs have R_386_TLS_DESC_CALL or R_X86_64_TLSDESC_CALL relocation and libc.so defines the GLIBC_ABI_GNU2_TLS version tag. Supported for Linux/i386 and Linux/x86_64. ✨

---

• -( archives -) and --start-group archives --end-group — okay so archives here should be a list of archive files. They can be either explicit file names, or -l options.

The specified archives get searched over and over until no new undefined references are created. Normally an archive is searched only once, in the order it appears on the command line. So if a symbol in that archive is needed to resolve an undefined symbol referred to by an object in an archive that shows up later on the command line, the linker just wouldn't be able to resolve that reference 😭. By grouping the archives, they all get searched repeatedly until all possible references are resolved. slay.

This option is not allowed within a --start-lib/--end-lib option pair.

Using this option has a significant performance cost. It's best to use it only when there are unavoidable circular references between two or more archives. fr fr, don't just do this for fun.

• --start-lib objects --end-lib — objects here should be a list of object files.

The specified objects are treated as if they were members of an archive whose name has been placed at the location of --start-lib on the command line. All the usual linker archive handling properties and command line options apply to that artificial archive. 💖

This option may be used multiple times, and in that case each set of objects specified gets treated as an individual archive. Nesting this option is not allowed though.

Options that affect archive processing are not allowed between --start-lib and --end-lib, because it would make zero sense to apply them midway through handling an archive. These options include: -(/--start-group, -)/--end-group, --whole-archive, and --no-whole-archive, as well as --pop-state where it would change the state of the --whole-archive setting. 🚫

• --accept-unknown-input-arch / --no-accept-unknown-input-arch — tells the linker to accept input files whose architecture can't be recognised. The whole assumption here is that the user knows what they're doing and deliberately wants to link in these unknown input files. 👀 This was actually the default behaviour of the linker before release 2.14. From release 2.14 onwards, the default became to reject such input files, and so --accept-unknown-input-arch was added to bring the old behaviour back. 🌸
• --as-needed, --no-as-needed — okay so bestie, this one is about ELF DT_NEEDED tags for dynamic libraries that show up on the command line after --as-needed itself. Normally? The linker is extra and adds a DT_NEEDED tag for literally every dynamic library mentioned on the command line, whether it's actually needed or not 🙈. What --as-needed does is make a DT_NEEDED tag get emitted only for a library that, at that point in the link, satisfies a non-weak undefined symbol reference from a regular object file — or, if the library isn't found in the DT_NEEDED lists of other needed libraries, a non-weak undefined symbol reference from another needed dynamic library. And the way that object files or libraries appearing on the command line after the library in question don't affect whether that library is seen as needed? Very "similar to the rules for extraction of object files from archives" energy fr fr. Then --no-as-needed just restores the default behaviour, no drama 💅.

Note: on Linux based systems, --as-needed also has an affect on the behaviour of the --rpath and --rpath-link options. Go read the description of --rpath-link for the details, iykyk.

• --add-needed, --no-add-needed — these two are deprecated 😭 and it's purely because their names were too similar to --as-needed and --no-as-needed — confusing, honestly. They got replaced by --copy-dt-needed-entries and --no-copy-dt-needed-entries. So use those instead, bestie.
• -assert keyword — this option is just… ignored, for SunOS compatibility. That's it. Nothing happens. Slay, I guess 🎀.
• -Bdynamic, -dy, -call_shared — link against dynamic libraries ✨. Heads up: this is only meaningful on platforms where shared libraries are actually supported, and on those platforms it's normally the default. The different variants exist for compatibility with various systems. Oh and you can use this option multiple times on the command line — it affects library searching for -l options that follow it. Order matters, periodt 👑.
• -Bgroup — this sets the "DF_1_GROUP" flag in the "DT_FLAGS_1" entry in the dynamic section. What that does is make the runtime linker handle lookups in this object and its dependencies only inside the group. Also, --unresolved-symbols=report-all is implied. Only meaningful on ELF platforms which support shared libraries 🦋.
• -Bstatic, -dn, -non_shared, -static — do not link against shared libraries. Again, only meaningful on platforms for which shared libraries are supported, and the different variants are for compatibility with various systems. You can use it multiple times on the command line — it affects library searching for -l options which follow it. It also implies --unresolved-symbols=report-all. Fun fact: this option can be used with -shared 💀 — doing so means a shared library is being created, but all of the library's external references must be resolved by pulling in entries from static libraries. Iconic combo honestly.
• -Bsymbolic — when you're creating a shared library, this binds references to global symbols to the definition within the shared library, if any. Normally a program linked against a shared library can override the definition within that shared library — this shuts that down. Only meaningful on ELF platforms which support shared libraries 🌸.
• -Bsymbolic-functions — same vibe as -Bsymbolic but specifically for global function symbols: bind those references to the definition within the shared library, if any. Only meaningful on ELF platforms which support shared libraries ✨.
• -Bno-symbolic — this one can cancel previously specified -Bsymbolic and -Bsymbolic-functions. Undo button, but make it linker 🫶.
• --dynamic-list=dynamic-list-file — tells the linker the name of a dynamic list file. Typically used when creating shared libraries, to specify a list of global symbols whose references shouldn't be bound to the definition within the shared library — or when creating dynamically linked executables, to specify a list of symbols which should be added to the symbol table in the executable. Only meaningful on ELF platforms which support shared libraries 💜. The format of the dynamic list is the same as the version node without scope and node name — see VERSION for more info.
• --dynamic-list-data — includes all global data symbols into the dynamic list. Simple, effective, we love her 💖.
• --dynamic-list-cpp-new — provides the builtin dynamic list for C++ operator new and delete. Mainly useful for building shared libstdc++. Niche but valid 🎀.
• --dynamic-list-cpp-typeinfo — provides the builtin dynamic list for C++ runtime type identification (RTTI, bestie). 🌈
• --check-sections, --no-check-sections — this asks the linker not to check section addresses after they've been assigned, to see if there are any overlaps. Normally the linker does perform this check, and if it finds overlaps it produces suitable error messages. The linker does know about, and does make allowances for, sections in overlays. The default behaviour comes back if you use --check-sections on the command line. Also: section overlap is usually not checked for relocatable links — you can force checking in that case with --check-sections 💅.
• --copy-dt-needed-entries, --no-copy-dt-needed-entries — this affects how dynamic libraries referred to by DT_NEEDED tags inside ELF dynamic libraries mentioned on the command line get treated. Normally the linker won't add a DT_NEEDED tag to the output binary for each library mentioned in a DT_NEEDED tag in an input dynamic library. But with --copy-dt-needed-entries specified on the command line, any dynamic libraries that follow it will have their DT_NEEDED entries added 🔥. Default behaviour comes back with --no-copy-dt-needed-entries.

It also has an effect on the resolution of symbols in dynamic libraries. With --copy-dt-needed-entries, dynamic libraries mentioned on the command line get recursively searched — following their DT_NEEDED tags to other libraries — in order to resolve symbols required by the output binary. With the default setting though, the searching of dynamic libraries that follow it stops with the dynamic library itself, and no DT_NEEDED links get traversed to resolve symbols. 🦋

• --cref — outputs a cross reference table. If a linker map file is being generated, the cross reference table is printed to the map file; otherwise it's printed on standard output. The format of the table is intentionally simple so it can be easily processed by a script if necessary, and the symbols are printed out sorted by name. For each symbol you get a list of file names: if the symbol is defined, the first file listed is the location of the definition. If the symbol is defined as a common value, then any files where this happens appear next. And finally, any files that reference the symbol are listed. Chef's kiss table, honestly 👑.
• --ctf-variables, --no-ctf-variables — so the CTF debuginfo format supports a section which encodes the names and types of variables found in the program that do not appear in any symbol table. Those variables clearly can't be looked up by address by conventional debuggers, so the space used for their types and names is usually just wasted — the types are usually small, but the names are often not 😭. --ctf-variables causes the generation of such a section, and the default behaviour can be restored with --no-ctf-variables ✨.
• --ctf-share-types=method — adjusts the method used to share types between translation units in CTF. The methods are:
  • share-unconflicted — put all types that do not have ambiguous definitions into the shared dictionary, where debuggers can easily access them, even if they only occur in one translation unit. This is the default. 💖
  • share-duplicated — put only types that occur in multiple translation units into the shared dictionary; types with only one definition go into per-translation-unit dictionaries. Types with ambiguous definitions in multiple translation units always go into per-translation-unit dictionaries. This tends to make the CTF larger, but may reduce the amount of CTF in the shared dictionary. For very large projects this may speed up opening the CTF and save memory in the CTF consumer at runtime 🧚.
• --no-define-common — inhibits the assignment of addresses to common symbols. The script command "INHIBIT_COMMON_ALLOCATION" has the same effect. What it's for: the --no-define-common option allows you to decouple the decision to assign addresses to Common symbols from the choice of the output file type — otherwise a non-Relocatable output type forces assigning addresses to Common symbols. Using --no-define-common allows Common symbols that are referenced from a shared library to be assigned addresses only in the main program. That eliminates the unused duplicate space in the shared library, and also prevents any possible confusion over resolving to the wrong duplicate when there are many dynamic modules with specialized search paths for runtime symbol resolution. Clean ✨.
• --force-group-allocation — causes the linker to place section group members like normal input sections, and to delete the section groups. This is the default behaviour for a final link, but this option can be used to change the behaviour of a relocatable link (-r). The script command "FORCE_GROUP_ALLOCATION" has the same effect 🌸.
• --defsym=symbol=expression — creates a global symbol in the output file, containing the absolute address given by expression. You can use this option as many times as necessary to define multiple symbols on the command line. A limited form of arithmetic is supported for the expression in this context: you can give a hexadecimal constant or the name of an existing symbol, or use "+" and "-" to add or subtract hexadecimal constants or symbols. If you need more elaborate expressions, consider using the linker command language from a script 💅. And a very important note: there should be no white space between symbol, the equals sign ("="), and expression. Type it tight, bestie 🎀.

so like, the linker goes through --defsym arguments and -T arguments in order, okay? Put --defsym before -T and the symbol gets defined before the linker script from -T is even processed. Put --defsym after -T and the symbol gets defined after the linker script has already been processed. 💅 And yes bestie this matters, because expressions inside the linker script that use those --defsym symbols will see them or not depending on where you put stuff. Which order is "correct"? Depends entirely on what you're trying to achieve. Main character energy, your call. ✨

• --demangle[=style], --no-demangle — these control whether symbol names get demangled in error messages and other output. When the linker is told to demangle, it tries to show you symbol names in a readable way: it strips leading underscores (if the object file format uses them) and converts C++ mangled symbol names into user-readable names. Different compilers have different mangling styles, so the optional style argument lets you pick the right demangling style for your compiler. The linker demangles by default unless the environment variable COLLECT_NO_DEMANGLE is set. These options exist to override that default. 🎀
• -Ifile, --dynamic-linker=file — sets the name of the dynamic linker. This is only meaningful when you're generating dynamically linked ELF executables. The default dynamic linker is normally correct, so don't use this unless you genuinely know what you're doing. 👑
• --no-dynamic-linker — when producing an executable file, omits the request for a dynamic linker to be used at load-time. This is only meaningful for ELF executables that contain dynamic relocations, and it usually requires entry point code that's capable of processing those relocations. 👀
• --embedded-relocs — similar to the --emit-relocs option, except the relocs are stored in a target-specific section. Only the BFIN, CR16 and M68K targets support this one. 🦋
• --disable-multiple-abs-defs — don't allow multiple definitions with symbols included in filename invoked by -R or --just-symbols. 🚫
• --fatal-warnings, --no-fatal-warnings — treat all warnings as errors. You can get the default behaviour back with --no-fatal-warnings. 💀
• -w, --no-warnings — don't display any warning or error messages. This overrides --fatal-warnings if it's been enabled. Use it when you already know the output binary won't work but you still need to create it anyway. no thoughts, just vibes 🙈
• --force-exe-suffix — makes sure an output file has a .exe suffix.

Basically: if a successfully built, fully linked output file doesn't have a .exe or .dll suffix, this option forces the linker to copy the output file to one of the same name with a .exe suffix. This is useful when you're using unmodified Unix makefiles on a Microsoft Windows host, because some versions of Windows won't run an image unless it ends in a .exe suffix. 💅

• --gc-sections, --no-gc-sections — enables garbage collection of unused input sections. It's ignored on targets that don't support it. The default behaviour (not doing this garbage collection) comes back if you specify --no-gc-sections on the command line. Heads up: garbage collection for COFF and PE format targets is supported, but the implementation is currently considered to be experimental. 🧪

--gc-sections decides which input sections are used by examining symbols and relocations. The section containing the entry symbol and all sections containing symbols undefined on the command-line get kept, and so do sections containing symbols referenced by dynamic objects. Note that when you're building shared libraries, the linker must assume that any visible symbol is referenced. Once this initial set of sections has been determined, the linker recursively marks as used any section referenced by their relocations. See --entry, --undefined, and --gc-keep-exported. 🔍

You can set this option when doing a partial link (that's enabled with -r). In that case, the root of symbols kept must be explicitly specified either by one of the options --entry, --undefined, or --gc-keep-exported, or by an "ENTRY" command in the linker script.

As a GNU extension, ELF input sections marked with the "SHF_GNU_RETAIN" flag will not be garbage collected. 🛡️

• --print-gc-sections, --no-print-gc-sections — lists all sections removed by garbage collection. The listing is printed on stderr. This option is only effective if garbage collection has been enabled (yes bestie, the stray ) is in the original, i don't make the rules) via the --gc-sections) option. The default behaviour (not listing the sections that get removed) comes back if you specify --no-print-gc-sections on the command line. 📝
• --gc-keep-exported — when --gc-sections is enabled, this option prevents garbage collection of unused input sections that contain global symbols having default or protected visibility. It's meant for executables where unreferenced sections would otherwise be garbage collected regardless of the external visibility of the contained symbols. Note this option has no effect when linking shared objects, since it's already the default behaviour there. And it's only supported for ELF format targets. 🌈
• --print-output-format — prints the name of the default output format (possibly influenced by other command-line options). This is the string that would appear in an "OUTPUT_FORMAT" linker script command. ⭐
• --print-memory-usage — prints used size, total size and used size of memory regions created with the MEMORY command. This is super useful on embedded targets for a quick view of how much free memory you've got. The output format has one headline and one line per region, and it's both human readable and easily parsable by tools. Here's an example of the output:

        Memory region         Used Size  Region Size  %age Used
                     ROM:        256 KB         1 MB     25.00%
                     RAM:          32 B         2 GB      0.00%

Note: if you want to find out about the memory usage of the linker itself, then the --stats option will do this. 🍓

• --help — prints a summary of the command-line options on the standard output and exits. 🫶
• --target-help — prints a summary of all target-specific options on the standard output and exits. 🎯
• -Map=mapfile — prints a link map to the file mapfile. See the description of the -M option, above. If mapfile is just the character - then the map gets written to stdout.

Specifying a directory as mapfile makes the linker map get written as a file inside the directory. Normally the name of the file inside the directory is computed as the basename of the output file with .map appended. If, however, the special character % is used, then this gets replaced by the full path of the output file. Additionally, if there are any characters after the % symbol, then .map will no longer be appended. Behold, the sacred texts:

-o foo.exe -Map=bar                  [Creates ./bar]
-o ../dir/foo.exe -Map=bar           [Creates ./bar]
-o foo.exe -Map=../dir               [Creates ../dir/foo.exe.map]
-o ../dir2/foo.exe -Map=../dir       [Creates ../dir/foo.exe.map]
-o foo.exe -Map=%                    [Creates ./foo.exe.map]
-o ../dir/foo.exe -Map=%             [Creates ../dir/foo.exe.map]
-o foo.exe -Map=%.bar                [Creates ./foo.exe.bar]
-o ../dir/foo.exe -Map=%.bar         [Creates ../dir/foo.exe.bar]
-o ../dir2/foo.exe -Map=../dir/%     [Creates ../dir/../dir2/foo.exe.map]
-o ../dir2/foo.exe -Map=../dir/%.bar [Creates ../dir/../dir2/foo.exe.bar]

It is an error to specify more than one % character. 🚨

If the map file already exists, then it will be overwritten by this operation. 💖

• --no-keep-memory — ld normally optimizes for speed over memory usage by caching the symbol tables of input files in memory. This option tells ld to optimize for memory usage instead, by rereading the symbol tables as necessary. You might need this if ld runs out of memory space while linking a large executable. 😭
• --no-undefined, -z defs — report unresolved symbol references from regular object files. This happens even if the linker is creating a non-symbolic shared library. The switch --[no-]allow-shlib-undefined controls the behaviour for reporting unresolved references found in shared libraries being linked in.

The effects of this option can be reverted by using -z undefs. ↩️

• --allow-multiple-definition, -z muldefs — normally when a symbol is defined multiple times, the linker reports a fatal error. These options allow multiple definitions, and the first definition will be used. 💀
• --allow-shlib-undefined, --no-allow-shlib-undefined — allows or disallows undefined symbols in shared libraries. This switch is similar to --no-undefined, except it determines the behaviour when the undefined symbols are in a shared library rather than a regular object file. It does not affect how undefined symbols in regular object files are handled.

The default behaviour is to report errors for any undefined symbols referenced in shared libraries if the linker is being used to create an executable, but to allow them if the linker is being used to create a shared library. 🤔

The reasons for allowing undefined symbol references in shared libraries specified at link time are that:

• A shared library specified at link time may not be the same as the one that is available at load time, so the symbol might actually be resolvable at load time.
• There are some operating systems, eg BeOS and HPPA, where undefined symbols in shared libraries are normal.

The BeOS kernel, for example, patches shared libraries at load time to select whichever function is most appropriate for the current architecture. This is used, for example, to dynamically select an appropriate memset function. 🌸

• --error-handling-script=scriptname — bestie, if you pass this, the linker will run scriptname every single time it hits an error 😭. rn only two kinds of error are supported: missing symbols and missing libraries. Two args get passed to the script: the keyword "undefined-symbol" or missing-lib" plus the name of the undefined symbol or missing library. The whole point is so your script can be like "hey, try looking here for that thing ✨" and then after the script finishes, the normal linker error message still shows up. Also: whether this option even exists is controlled by a configure-time switch, so some builds just… won't have it 💀.
• --no-undefined-version — normally, if a symbol has an undefined version, the linker just ignores it (iconic, unbothered). This option says nope 🙅‍♀️ — symbols with an undefined version are disallowed and you get a fatal error instead.
• --default-symver — makes a default symbol version (the soname) and uses it for unversioned exported symbols. slay 💅.
• --default-imported-symver — same energy, but for unversioned imported symbols. creates and uses a default symbol version (the soname) 🎀.
• --no-warn-mismatch — so normally ld gets mad if you try to link input files that don't match, like they were compiled for different processors or different endiannesses. This option tells ld to just silently allow those possible errors 🙈. > Use this with care, okay? Only in cases where you've taken some special action that makes those linker errors inappropriate — otherwise you're just vibing in the danger zone 💀.
• --no-warn-search-mismatch — normally ld throws a warning if it finds an incompatible library during a library search. This one silences the warning. shhh 🤫.
• --no-whole-archive — turns off the effect of the --whole-archive option for the archive files that come after it. 🚫 Not allowed inside a --start-lib/--end-lib option pair, periodt.
• --no-link-mapless — rejects archives that lack an index, a.k.a. a symbol map, for all the subsequent archives mentioned on the command line. If it hits a file like that, boom, link error 💥. This is the traditional behavior.
• --noinhibit-exec — keeps the executable output file whenever it's still usable. Normally the linker just refuses to produce an output file if it hits errors during the link — it dips out without writing anything the second it issues any error whatsoever. This option says "no bestie, stay, we can still use this" 🫶.
• -nostdlib — only search library directories that you explicitly put on the command line. Library directories specified in linker scripts (yes, including linker scripts specified on the command line) are ignored. bye 👋.
• --oformat=output-format — ld can be configured to support more than one kind of object file. If yours is, you can use --oformat to pick the binary format for the output object file. fr fr though, even when alt object formats are supported you usually don't need this, because ld should already be configured to default to the most usual format on each machine. output-format is a text string — the name of a particular format supported by the BFD libraries. (You can list the available binary formats with objdump -i.) The script command "OUTPUT_FORMAT" can also specify the output format, but this option overrides it. 👑
• --out-implib file — creates an import library in file corresponding to the executable the linker is generating (eg. a DLL or ELF program). This import library (which should be called "*.dll.a" or "*.a" for DLLs) can be used to link clients against the generated executable 🎀. This behavior means you get to skip a separate import library creation step (eg. "dlltool" for DLLs) — iconic, saves a whole step. Only available for the PE and ELF targeted ports of the linker tho.
• -pie, --pic-executable — creates a position independent executable ✨. Currently only supported on ELF platforms. PIEs get relocated by the dynamic linker to whatever virtual address the OS feels like choosing for them, which can vary between invocations (main character energy, refuses to be pinned down 💅). They're marked ET_DYN in the ELF file header, but they differ from shared libraries in a bunch of ways — in particular, defined symbols in a PIE by default can not be overridden by another object like they can in a shared library.
• -no-pie — creates a position dependent executable. This is the default, bestie.
• -qmagic — this option is ignored, for Linux compatibility. it's giving ghost town 👻.
• -Qy — this option is ignored, for SVR4 compatibility. same vibe 🙈.
• --relax, --no-relax — an option with machine dependent effects. Only supported on a few targets.

On some platforms, --relax performs target-specific, global optimizations that become possible once the linker resolves addressing in the program — stuff like relaxing address modes, synthesizing new instructions, selecting shorter versions of current instructions, and combining constant values 🔥.

On some platforms, these link-time global optimizations may make symbolic debugging of the resulting executable impossible 😭. This is known to be the case for the Matsushita MN10200 and MN10300 family of processors.

On platforms where the feature is supported, --no-relax disables it.

On platforms where the feature is not supported, both --relax and --no-relax are accepted, but ignored. cute, they just sit there 🫠.

• --retain-symbols-file=filename — retains only the symbols listed in the file filename, discarding all the others. filename is just a flat file with one symbol name per line 📝. This is especially useful in environments (like VxWorks) where a huge global symbol table gets accumulated gradually, so it conserves run-time memory.

Heads up: --retain-symbols-file does not discard undefined symbols, or symbols needed for relocations.

You may only specify --retain-symbols-file once on the command line. And it overrides -s and -S. one at a time, periodt 💅.

• -rpath=dir — adds a directory to the runtime library search path 🦋. Used when linking an ELF executable with shared objects. All -rpath arguments get concatenated and passed to the runtime linker, which uses them to locate shared objects at runtime.

-rpath is also used when locating shared objects that are needed by shared objects explicitly included in the link; see the description of the -rpath-link option. Searching -rpath this way is only supported by native linkers and cross linkers that have been configured with the --with-sysroot option.

If -rpath is not used when linking an ELF executable, the contents of the environment variable "LD_RUN_PATH" will be used if it's defined.

-rpath may also be used on SunOS 🌞. By default on SunOS, the linker forms a runtime search path out of all the -L options it's given. If a -rpath option is used, the runtime search path gets formed exclusively using the -rpath options, ignoring the -L options. This can be useful when using gcc, which adds many -L options that may be on NFS mounted file systems.

For compatibility with other ELF linkers, if the -R option is followed by a directory name rather than a file name, it's treated as the -rpath option. iykyk 💜.

• -rpath-link=dir — when using ELF or SunOS, one shared library may require another. This happens when an "ld -shared" link includes a shared library as one of the input files.

When the linker hits a dependency like that during a non-shared, non-relocatable link, it'll automatically try to locate the required shared library and include it in the link, if it wasn't explicitly included. In that case, several directories get searched, as described below 👇. The -rpath-link option specifies the first set of directories to search. You can give it a sequence of directory names either as a list separated by colons, or by appearing multiple times. either way bestie, your call ✨.

The tokens $ORIGIN and $LIB can appear in these search directories. They get replaced by: the full path to the directory containing the program or shared object, for $ORIGIN; and either lib — for 32-bit binaries — or lib64 — for 64-bit binaries — for $LIB. 🌈

The alternative forms of these tokens — ${ORIGIN} and ${LIB} — can also be used. The token $PLATFORM is not supported 🚫.

--rpath-link should be used with caution, because it overrides the search path that may have been hard compiled into a shared library. In that case it's possible to unintentionally use a different search path than the runtime linker would have used. 💀

When additional shared libraries are required, the linker searches directories in the order listed below to find them. But note — this only applies to additional libraries needed to satisfy already included shared libraries. It does not apply to libraries included via the -l command line option. Searches for -l libraries only happen in directories specified by the -L option. okay okay, got it? 👑

1. Any directories specified by -rpath-link options.
2. Any directories specified by -rpath options. The difference between -rpath and -rpath-link is that directories specified by -rpath options are included in the executable and used at runtime, whereas -rpath-link is only effective at link time. Searching -rpath this way is only supported by native linkers and cross linkers that have been configured with the --with-sysroot option.
3. On an ELF system, for native linkers, if the -rpath and -rpath-link options were not used, search the contents of the environment variable "LD_RUN_PATH".
4. On SunOS, if the -rpath option was not used, search any directories specified using -L options.
5. For a native linker, search the contents of the environment variable "LD_LIBRARY_PATH".
6. For a native ELF linker, the directories in "DT_RUNPATH" or "DT_RPATH" of a shared library are searched for shared libraries needed by it. The "DT_RPATH" entries are ignored if "DT_RUNPATH" entries exist. 🎀

7. On a Linux system, if the file /etc/ld.so.conf exists, then the list of directories found in that file. 💅 Quick lil' note though bestie: the path to this file gets the "sysroot" value slapped on the front if that's defined, and then any "prefix" string too if the linker was configured with the --prefix=<path> option.
8. For a native linker on a FreeBSD system, any directories specified by the _PATH_ELF_HINTS macro (it lives in the elf-hints.h header file, iykyk).
9. Any directories specified by a SEARCH_DIR command in a linker script handed over on the command line, and yes that includes scripts given via -T — but not -dT.
10. The default directories, which are normally /lib and /usr/lib.
11. Any directories specified by a plugin's LDPT_SET_EXTRA_LIBRARY_PATH. 🧚
12. Any directories specified by a SEARCH_DIR command in a default linker script.

---

⚠️ Extra caveat time, and it's Linux-specific so pay attention — if --as-needed is active, and a shared library gets located that would normally satisfy the search, but that library does not have a DT_NEEDED tag for libc.so, and then there's another shared library later on in the set of search directories that also satisfies the search, and that second shared library does have a DT_NEEDED tag for libc.so — then the second library gets picked instead of the first. The way that it just swaps them out. 🙈

And if the required shared library isn't found at all? The linker just issues a warning and keeps going with the link. Casual. 😭

--section-ordering-file=script

This option augments the current linker script with extra mapping of input sections to output sections. The file has to use the exact same syntax for SECTIONS that normal linker scripts use, but honestly it should not do anything other than place input sections into output sections. @pxref{SECTIONS}

Second constraint, bestie, and it's important: the section ordering script can only reference output sections that are already defined by whichever linker script is currently in use. (Ie the default linker script, or a script you specified on the command line.) But here's the slay — the whole benefit of the section ordering script is that input sections get mapped to the start of the output sections, so you can guarantee the ordering of sections inside the output section. ✨

For example, imagine the default linker script looks like this:

SECTIONS {
  .text : { *(.text.hot) ; *(.text .text.*) }
  .data : { *(.data.big) ; *(.data .data.*) }
  }

Then if a section ordering file like this is used:

  .text : { *(.text.first) ; *(.text.z*) }
  .data : { foo.o(.data.first) ; *(.data.small) }

That would be equivalent to a linker script like this:

SECTIONS {
  .text : { *(.text.first) ; *(.text.z*) ; *(.text.hot) ; *(.text .text.*) }
  .data : { foo.o(.data.first) ; *(.data.small) ; *(.data.big) ; *(.data .data.*) }
  }

The advantage of the section ordering file is that you can order the sections that matter to you without having to worry about any other sections, or memory regions, or literally anything else. 🎀

-shared / -Bshareable

Create a shared library. This is currently only supported on ELF, XCOFF and SunOS platforms. On SunOS, the linker will automatically create a shared library if the -e option isn't used and there are undefined symbols in the link. 👑

--sort-common, --sort-common=ascending, --sort-common=descending

Tells ld to sort the common symbols by alignment, either ascending or descending, when it places them in the appropriate output sections. The symbol alignments it cares about are sixteen-byte or larger, eight-byte, four-byte, two-byte, and one-byte. This is all to prevent gaps between symbols because of alignment constraints. And if you don't specify a sorting order? Descending is assumed. Periodt.

--sort-section=name

Applies SORT_BY_NAME to every wildcard section pattern in the linker script. 🌸

--sort-section=alignment

Applies SORT_BY_ALIGNMENT to every wildcard section pattern in the linker script. 🌸

--spare-dynamic-tags=count

Specifies how many empty slots to leave in the .dynamic section of ELF shared objects. Those empty slots may be needed by post processing tools, like the prelinker. Default is 5.

--split-by-file[=size]

Similar to --split-by-reloc but it creates a new output section for each input file once size is reached. size defaults to a size of 1 if you don't give it one.

--split-by-reloc[=count]

Tries to create extra sections in the output file so that no single output section in the file contains more than count relocations. This is the move when you're generating huge relocatable files to download into certain real time kernels using the COFF object file format — because COFF literally cannot represent more than 65535 relocations in a single section. 💀

Note that this will fail to work with object file formats that don't support arbitrary sections. Also, the linker will not split up individual input sections for redistribution, so if a single input section contains more than count relocations, one output section will end up containing that many relocations. count defaults to a value of 32768.

--stats[=filename]

Computes and displays statistics about what the linker did — think execution time and memory usage. 📊

If the optional filename argument isn't supplied, then only basic information gets reported, and it goes to the standard error output stream. If filename is supplied, then extended information gets written to the named file. If filename is set to just the - symbol, then the extended information goes to the standard output stream. And if filename starts with + then the file is opened in append mode instead of overwrite mode. Cute.

If the -Map option has been enabled, then the information also gets recorded in the map file as well. Note: if both the --stats option and the -Map option have been given filename arguments and they match, then the information is only written out once, not twice. No dupes here bestie.

If the LD_STATS environment variable is defined then this behaves like the --stats option. If the variable's value is a string, then that gets used as the name of a file into which the information should be recorded. Otherwise the information gets sent to the standard output stream. Using the environment variable lets stats be recorded without having to alter the linker's command line. Note: if both the environment variable and the --stats option are used, then --stats takes precedence. ✨

The extended information reported includes the cpu time used and, if the getrusage() system library call is available, then maximum set size and the user and system run times as well. In addition, if the mallinfo or mallinfo2 system library calls are available, then the total memory usage is reported.

The information is displayed for individual parts of the linking process, which are referred to as phases. And note — individual phases can contain or overlap with each other, so do not assume that the overall resources used by the linker is the sum of the resources used by the individual phases. 🙈

In addition, the information is also reported for a special phase called ALL, which covers the entire linking process.

When extended information is being reported, the linker version, command line arguments and linker start time are also included. This makes it easier to deal with multiple links being invoked by a build system, and to identify exactly which arguments were responsible for producing the statistics that get reported. 👑

The extended output looks something like this:

Stats: linker version: (GNU Binutils) 2.44.50.20250401
Stats: linker started: Wed Apr  2 09:36:41 2025
Stats: args: ld -z norelro -z nomemory-seal -z no-separate-code -o a.out [...]

Stats: phase               cpu time       rss      user time    system time     memory
Stats: name                (microsec)   (KiB)      (seconds)      (seconds)      (KiB)
Stats: ALL                   390082    217740              0              0   25219440
Stats: ctf processing            12         0              0              0          0
Stats: string merge            1324         0              0              0     406544
Stats: parsing                  349       288              0              0     119792
Stats: plugins                    1         0              0              0          0
Stats: processing files      259616    214524              0              0   31569120
Stats: write                 116493         0              0              0      48096

--no-stats

Disables the reporting of usage statistics, in case it got enabled via the --stats command line option or the LD_STATS environment variable. 🚫

--sysroot=directory

Uses directory as the location of the sysroot, overriding the configure-time default. Heads up: this option is only supported by linkers that were configured using --with-sysroot. 🌈

--task-link

This is used by COFF/PE based targets to create a task-linked object file where all of the global symbols have been converted to statics. 🫶

--traditional-format

For some targets, the output of ld is different in some ways from the output of some existing linker. This switch asks ld to use the traditional format instead. 💅

For example, on SunOS, ld combines duplicate entries in the symbol string table. This can shrink the size of an output file with full debugging information by over 30 percent. Unfortunately, the SunOS dbx program can not read the resulting program (gdb has no trouble, though 😌). The --traditional-format switch tells ld to not combine duplicate entries.

• --section-start=sectionname=org — pins a section in the output file to the exact absolute address you hand it in org. You can drop this option as many times as you want to place multiple sections, like a lil parking attendant for sections 🅿️✨. Heads up though: org must be a single hexadecimal integer, and for compatibility with other linkers you're allowed to leave off the leading 0x you'd normally slap on hex values. Also, tiny but mighty: there should be no white space between sectionname, the equals sign ("="), and org. None. Zero. Nada. 💅
• --image-base=org — depends on your flavor of binary, bestie:
  • When you're using ELF, this is the same as -Ttext-segment, with both options effectively setting the base address of the ELF executable.
  • When you're using PE, org becomes the base address of your program or dll. It's the lowest memory location that gets used when your program or dll is loaded. To cut down on the need to relocate and to boost your dlls' performance, each one should have a unique base address and not overlap any other dlls. The default is 0x400000 for executables, and 0x10000000 for dlls 🫶
• -Tbss=org, -Tdata=org, -Ttext=org — same thing as --section-start, except the sectionname is basically baked in: ".bss", ".data" or ".text" respectively. Shortcut szn 🌸
• -Ttext-segment=org — when you're creating an ELF executable, this sets the address of the first byte of the first segment. And listen: when -pie is used together with -Ttext-segment=org, the output executable gets marked ET_EXEC so that the address of the first byte of the text segment is guaranteed to be org at run time. Locked in 🔒
• -Trodata-segment=org — when you're creating an ELF executable or shared object for a target where the read-only data lives in its own segment, separate from the executable text, this sets the address of the first byte of the read-only data segment 📍
• -Tldata-segment=org — when you're creating an ELF executable or shared object for the x86-64 medium memory model, this sets the address of the first byte of the ldata segment 💜
• --unresolved-symbols=method — this is you deciding how to handle unresolved symbols, and you've got four possible values for method:
  • ignore-all — do not report any unresolved symbols. blissful ignorance, honestly iconic 🙈
  • report-all — report all unresolved symbols. This is the default.
  • ignore-in-object-files — report unresolved symbols that are contained in shared libraries, but ignore them if they come from regular object files.
  • ignore-in-shared-libs — report unresolved symbols that come from regular object files, but ignore them if they come from shared libraries. This one's useful when you're creating a dynamic binary and you already know that all the shared libraries it should be referencing are included on the linker's command line ✨

The behaviour for shared libraries on their own can also be controlled by the --[no-]allow-shlib-undefined option.

Normally the linker will generate an error message for each reported unresolved symbol, but the option --warn-unresolved-symbols can change this into a warning instead 🌈

• --dll-verbose, --verbose[=NUMBER] — these spill the tea: display the version number for ld and list the linker emulations supported, display which input files can and cannot be opened, and display the linker script being used by the linker. And if the optional NUMBER argument is > 1, plugin symbol status will also be displayed 👑 (very "tell me everything" of them)
• --version-script=version-scriptfile — specify the name of a version script to the linker. This is typically used when creating shared libraries, to specify additional info about the version hierarchy for the library being created. Real talk though: this option is only fully supported on ELF platforms which support shared libraries; see VERSION. It is partially supported on PE platforms, which can use version scripts to filter symbol visibility in auto-export mode: any symbols marked local in the version script will not be exported 🦋
• --warn-common — warns you when a common symbol gets combined with another common symbol or with a symbol definition. Unix linkers allow this somewhat sloppy practice, but linkers on some other operating systems do not. This option lets you find potential problems from combining global symbols. Unfortunately, some C libraries use this practice, so you may get some warnings about symbols in the libraries as well as in your programs 😭 (it's not you, bestie, it's the libs)

There are three kinds of global symbols, illustrated here by C examples:

• int i = 1; — a definition, which goes in the initialized data section of the output file.
• extern int i; — an undefined reference, which does not allocate space. There must be either a definition or a common symbol for the variable somewhere.
• int i; — a common symbol. If there are only (one or more) common symbols for a variable, it goes in the uninitialized data area of the output file. The linker merges multiple common symbols for the same variable into a single symbol. If they are of different sizes, it picks the largest size. The linker turns a common symbol into a declaration, if there is a definition of the same variable.

Now — the --warn-common option can produce five kinds of warnings. Each warning consists of a pair of lines: the first describes the symbol just encountered, and the second describes the previous symbol encountered with the same name. One or both of the two symbols will be a common symbol 🎀

1. Turning a common symbol into a reference, because there is already a definition for the symbol.

<file>(<section>): warning: common of `<symbol>'
   overridden by definition
<file>(<section>): warning: defined here

2. Turning a common symbol into a reference, because a later definition for the symbol is encountered. This is the same as the previous case, except that the symbols are encountered in a different order.

<file>(<section>): warning: definition of `<symbol>'
   overriding common
<file>(<section>): warning: common is here

3. Merging a common symbol with a previous same-sized common symbol.

<file>(<section>): warning: multiple common
   of `<symbol>'
<file>(<section>): warning: previous common is here

4. Merging a common symbol with a previous larger common symbol.

<file>(<section>): warning: common of `<symbol>'
   overridden by larger common
<file>(<section>): warning: larger common is here

5. Merging a common symbol with a previous smaller common symbol. This is the same as the previous case, except that the symbols are encountered in a different order.

<file>(<section>): warning: common of `<symbol>'
   overriding smaller common
<file>(<section>): warning: smaller common is here

• --warn-constructors — warns you if any global constructors are used. This is only useful for a few object file formats, ngl. For formats like COFF or ELF, the linker cannot detect the use of global constructors, so don't expect it to catch what it literally can't see 💀
• --warn-execstack, --warn-execstack-objects, --no-warn-execstack — on ELF platforms the linker may generate warning messages if it's asked to create an output file that contains an executable stack. There are three possible states:
  1. Do not generate any warnings.
  2. Always generate warnings, even if the executable stack is requested via the -z execstack command line option.
  3. Only generate a warning if an object file requests an executable stack, but not if the -z execstack option is used.

The default state depends upon how the linker was configured when it was built. The --no-warn-execstack option always puts the linker into the no-warnings state. The --warn-execstack option puts the linker into the warn-always state. The --warn-execstack-objects option puts the linker into the warn-for-object-files-only state ⭐

Note: ELF format input files can specify that they need an executable stack by having a .note.GNU-stack section with the executable bit set in its section flags. They can specify that they do not need an executable stack by having the same section, but without the executable flag bit set. If an input file does not have a .note.GNU-stack section then the default behaviour is target specific. For some targets, the absence of such a section implies that an executable stack is required. This is often a problem for hand crafted assembler files 😬

• --error-execstack, --no-error-execstack — if the linker is going to generate a warning message about an executable stack, then the --error-execstack option will instead change that warning into an error. But note — this option does not change the linker's execstack warning generation state. Use --warn-execstack or --warn-execstack-objects to set a specific warning state 💅

The --no-error-execstack option will restore the default behaviour of generating warning messages 🫶

• --warn-multiple-gp — warns you if multiple global pointer values are required in the output file. This is only meaningful for certain processors, such as the Alpha. Specifically: some processors put large-valued constants in a special section, and a special register (the global pointer) points into the middle of this section, so that constants can be loaded efficiently via a base-register relative addressing mode. Since the offset in base-register relative mode is fixed and relatively small (e.g., 16 bits), this limits the maximum size of the constant pool. So in large programs, it's often necessary to use multiple global pointer values in order to be able to address all possible constants. This option causes a warning to be issued whenever this case occurs 🔥
• --warn-once — only warn once for each undefined symbol, rather than once per module which refers to it. Because bestie, we get it, we heard you the first time 😌
• --warn-rwx-segments, --no-warn-rwx-segments — warns you if the linker creates a loadable, non-zero sized segment that has all three of the read, write and execute permission flags set. Such a segment represents a potential security vulnerability 🚨 In addition, warnings will be generated if a thread local storage segment is created with the execute permission flag set, regardless of whether or not it has the read and/or write flags set.

okay so these warnings? they're on by default. if you wanna ✂️ cut them off, hit up --no-warn-rwx-segments, and if you miss them, --warn-rwx-segments brings them right back bb 🫶

---

• --error-rwx-segments, --no-error-rwx-segments — bestie this one upgrades a warning to a whole ERROR 😭 If the linker is about to give you a warning message about an executable segment, a writeable segment, or an executable TLS segment, then --error-rwx-segments turns that lil warning into a full error instead. And --no-error-rwx-segments? It restores the default behaviour of just... warning. Chill vibes back.

⚠️ note bestie!! --error-rwx-segments does not turn those warnings on by itself. Those warnings are either enabled by default (if the linker was configured that way), or via the --warn-rwx-segments command line option. two separate levers, okay? 💅

• --warn-section-align — Warns you if the address of an output section changed because of alignment 🚨 Typically the alignment gets set by an input section. The address will only be changed if it wasn't explicitly specified — like, if the "SECTIONS" command doesn't specify a start address for the section. no start address, no promises 🤷‍♀️
• --warn-textrel — Warns if the linker adds DT_TEXTREL to a position-independent executable or shared object. iykyk ✨
• --warn-alternate-em — Warns if an object has alternate ELF machine code. that's it, that's the whole thing 🦋
• --warn-unresolved-symbols — So when the linker is about to report an unresolved symbol (peep the --unresolved-symbols option for that), it'll normally generate an error. This option makes it generate a warning instead. downgrade arc ✨
• --error-unresolved-symbols — This restores the linker's default behaviour of generating errors when it's reporting unresolved symbols. back to being dramatic 💅
• --whole-archive — For each archive mentioned on the command line after the --whole-archive option, include every object file in the archive in the link, rather than searching the archive for the required object files 👑 This is normally used to turn an archive file into a shared library, forcing every object to be included in the resulting shared library. This option may be used more than once.

not allowed within a --start-lib/--end-lib option pair. periodt.

Two notes when using this option from gcc:

1. gcc doesn't know about this option, so you have to use -Wl,-whole-archive.
2. don't forget to use -Wl,-no-whole-archive after your list of archives, because gcc will add its own list of archives to your link and you may not want this flag to affect those as well 💀

• --link-mapless — Accepts archives that lack an index aka symbol map, for all the subsequent archives referred on the command line. If that index is missing, one gets made internally on the fly, at a performance cost 🐢 This is the default.
• --wrap=symbol — Use a wrapper function for symbol 🌯 Any undefined reference to symbol will be resolved to "__wrap_symbol". Any undefined reference to "__real_symbol" will be resolved to symbol.

This can be used to provide a wrapper for a system function. The wrapper function should be called "__wrap_symbol". If it wishes to call the system function, it should call "__real_symbol".

Here is a trivial example:

        void *
        __wrap_malloc (size_t c)
        {
          printf ("malloc called with %zu\n", c);
          return __real_malloc (c);
        }

If you link other code with this file using --wrap malloc, then all calls to "malloc" will call the function "__wrap_malloc" instead. The call to "__real_malloc" in "__wrap_malloc" will call the real "malloc" function.

You may wish to provide a "__real_malloc" function as well, so that links without the --wrap option will succeed. If you do this, you should not put the definition of "__real_malloc" in the same file as "__wrap_malloc" — if you do, the assembler may resolve the call before the linker has a chance to wrap it to "malloc". sneaky lil ordering issue, watch out 😭

Only undefined references are replaced by the linker. So, translation unit internal references to symbol are not resolved to "__wrap_symbol". In the next example, the call to "f" in "g" is not resolved to "__wrap_f" :

        int
        f (void)
        {
          return 123;
        }

        int
        g (void)
        {
          return f();
        }

• --eh-frame-hdr, --no-eh-frame-hdr — Request (--eh-frame-hdr) or suppress (--no-eh-frame-hdr) the creation of .eh_frame_hdr section and ELF PT_GNU_EH_FRAME segment header 🌈
• --no-ld-generated-unwind-info — Request creation of .eh_frame unwind info for linker generated code sections like PLT 🧚 This option is on by default if linker generated unwind info is supported.
• --discard-sframe — Discards .sframe stack trace info from the output 🗑️ This option also prohibits the creation of SFrame stack trace data for linker generated code sections like PLT. This option is off by default.
• --enable-new-dtags, --disable-new-dtags — This linker can create the new dynamic tags in ELF. But the older ELF systems may not understand them 😬 If you specify --enable-new-dtags, the new dynamic tags will be created as needed and older dynamic tags will be omitted. If you specify --disable-new-dtags, no new dynamic tags will be created. By default, the new dynamic tags are not created. Note that those options are only available for ELF systems 🦋
• --hash-size=number — Sets the default size of the linker's hash tables to a prime number close to number 🔢 Increasing this value can reduce the length of time it takes the linker to perform its tasks, at the expense of increasing the linker's memory requirements. Similarly reducing this value can reduce the memory requirements at the expense of speed. The default value is 4051 under normal circumstances and 1021 if the --reduce-memory-overheads command line option is used ✨
• --hash-style=style — Sets the type of linker's hash table(s) 🍓 style can be either "sysv" for classic ELF .hash section, "gnu" for new style GNU .gnu.hash section or "both" for both the classic ELF .hash and new style GNU .gnu.hash hash tables. The default depends upon how the linker was configured, but for most Linux based systems it will be "both".
• --compress-debug-sections=none, --compress-debug-sections=zlib, --compress-debug-sections=zlib-gnu, --compress-debug-sections=zlib-gabi, --compress-debug-sections=zstd — On ELF platforms, these options control how DWARF debug sections are compressed using zlib 🫧

--compress-debug-sections=none doesn't compress DWARF debug sections. --compress-debug-sections=zlib-gnu compresses DWARF debug sections and renames them to begin with .zdebug instead of .debug. --compress-debug-sections=zlib-gabi also compresses DWARF debug sections, but rather than renaming them it sets the SHF_COMPRESSED flag in the sections' headers ✅

The --compress-debug-sections=zlib option is an alias for --compress-debug-sections=zlib-gabi.

--compress-debug-sections=zstd compresses DWARF debug sections using zstd ⚡

Note that this option overrides any compression in input debug sections, so if a binary is linked with --compress-debug-sections=none for example, then any compressed debug sections in input files will be uncompressed before they are copied into the output binary. no sneaky compression hiding through the pipeline, bestie 💅

The default compression behaviour varies depending upon the target involved and the configure options used to build the toolchain 🛠️ The default can be determined by examining the output from the linker's --help option.

• --reduce-memory-overheads — This option reduces memory requirements at ld runtime, at the expense of linking speed 🐌 This was introduced to select the old O(n^2) algorithm for link map file generation, rather than the new O(n) algorithm which uses about 40% more memory for symbol storage.

Another effect of the switch is to set the default hash table size to 1021, which again saves memory at the cost of lengthening the linker's run time. This is not done however if the --hash-size switch has been used 🙅‍♀️

The --reduce-memory-overheads switch may be also be used to enable other tradeoffs in future versions of the linker 🔮 (yes, it says "may be also be", we don't fix manpage prose around here, we respect it ✨)

• --max-cache-size=size — ld normally caches the relocation information and symbol tables of input files in memory with unlimited size 🧠 This option sets the maximum cache size to size. Note — if the --no-keep-memory command line option has been used then the linker acts as if the maximum cache size has been set to 0 — ie nothing is retained. zero. nada. zilch.
• --build-id, --build-id=style — Request the creation of a .note.gnu.build-id ELF note section or a .buildid COFF section 🎀 The contents of the note are unique bits identifying this linked file. style can be:
  • "uuid" to use 128 random bits
  • "sha1" to use a 160-bit SHA1 hash
  • "md5" to use a 128-bit MD5 hash
  • "xx" to use a 128-bit XXHASH on the normative parts of the output contents
  • "0xhexstring" to use a chosen bit string specified as an even number of hexadecimal digits ("-" and ":" characters between digit pairs are ignored)

If style is omitted, "sha1" is used ⭐

The "md5", "sha1", and "xx" styles produces an identifier that is always the same in an identical output file, but are almost certainly unique among all nonidentical output files. It is not intended to be compared as a checksum for the file's contents 🚫 A linked file may be changed later by other tools, but the build ID bit string identifying the original linked file does not change. it's an identity, not a checksum bestie, big difference 💖

Passing "none" for style disables the setting from any "--build-id" options earlier on the command line 🚫✨

• --package-metadata=JSON — bestie, this one asks for a .note.package ELF note section to be created ✨. The contents of that note are in JSON format, per the package metadata specification. Wanna know more? Go peek at https://systemd.io/ELF_PACKAGE_METADATA/ 🫶

The JSON argument supports percent-encoding, plus this little %[string] notation (where string is the name from HTML's Named Character References): %[comma] for ,, %[lbrace] for {, %[quot] for ", %[rbrace] for }, and %[space] for a space character 🎀

If the JSON argument is missing or empty, that disables the creation of the metadata note — but only if some earlier --package-metadata occurrence had switched it on, okay? And if the linker got built with libjansson, then the JSON string will actually be validated 💅

---

Okay so now we're entering PE linker territory and it's giving whole other personality 🌈

The PE linker supports the -shared option, which makes the output a dynamically linked library (DLL) instead of a normal executable. You should name the output "*.dll" when you use this option, fr fr. On top of that, the linker fully supports standard "*.def" files — and you can specify them on the linker command line just like an object file ✨ (and honestly? it should come before the archives it exports symbols from, so those symbols actually get linked in, same as a normal object file would) 👑

On top of the options that every target has in common, the PE linker supports extra command-line options that are specific to the PE target. And heads up: options that take values can be separated from their values by either a space or an equals sign 👯

• --add-stdcall-alias — if you give it, symbols with a stdcall suffix (@nn) get exported as-is and also with the suffix stripped off 💅 [This option is specific to PE targeted ports of the linker]
• --base-file file — use file as the name of a file in which to save the base addresses of all the relocations needed for generating DLLs with dlltool 📁 [This option is specific to PE targeted ports of the linker]
• --dll — create a DLL instead of a regular executable. You can also use -shared, or just specify a "LIBRARY" in a given ".def" file 🎀 [This option is specific to PE targeted ports of the linker]
• --enable-long-section-names
• --disable-long-section-names — so the PE variants of the COFF object format added an extension that lets you use section names longer than eight characters (eight being the normal COFF limit, no cap). By default these names are only allowed in object files, because fully-linked executable images don't carry the COFF string table you need to support the longer names 📚. As a GNU extension, you can allow their use in executable images too, or — probably pointlessly! — disallow it in object files, by using these two options 🙈. Executable images generated with these long section names are slightly non-standard, carrying as they do a string table, and may produce confusing output when examined with non-GNU PE-aware tools, like file viewers and dumpers 💀. BUT: GDB relies on PE long section names to find Dwarf-2 debug info sections in an executable image at runtime, so if neither option shows up on the command line, ld will enable long section names — overriding the default and technically correct behaviour — when it finds debug information present while linking an executable image and not stripping symbols 👑 [This option is specific to PE targeted ports of the linker]
• --enable-stdcall-fixup
• --disable-stdcall-fixup — if the link finds a symbol it can't resolve, it'll attempt "fuzzy linking": hunting for another defined symbol that differs only in the format of the symbol name (cdecl vs stdcall) and resolving it by linking to that match 🧚. Like, the undefined symbol "_foo" might get linked to the function "_foo@12", or the undefined symbol "_bar@16" might get linked to the function "_bar". When the linker pulls this off, it prints a warning, since it normally should have failed to link — but sometimes import libraries generated from third-party dlls need this feature just to be usable 😭. If you specify --enable-stdcall-fixup, the feature is fully enabled and warnings are not printed. If you specify --disable-stdcall-fixup, the feature is disabled and such mismatches count as errors ❌ [This option is specific to PE targeted ports of the linker]
• --leading-underscore
• --no-leading-underscore — for most targets the default symbol-prefix is an underscore, and it's defined in the target's description. With this option you can disable/enable that default underscore symbol-prefix 🔄 [This option is specific to PE targeted ports of the linker]
• --export-all-symbols — if given, all global symbols in the objects used to build a DLL will be exported by the DLL 👑. Note that this is the default if there otherwise wouldn't be any exported symbols at all. When symbols are explicitly exported via DEF files, or implicitly exported via function attributes, the default is to not export anything else unless this option is given, okay? 💅 And note: the symbols "DllMain@12", "DllEntryPoint@0", "DllMainCRTStartup@12", and "impure_ptr" will not be automatically exported. Also, symbols imported from other DLLs won't be re-exported, and neither will symbols specifying the DLL's internal layout — things like those beginning with "_head_" or ending with "_iname" 🚫. On top of that, no symbols from "libgcc", "libstd++", "libmingw32", or "crtX.o" will be exported. Symbols whose names begin with "__rtti_" or "__builtin_" won't be exported either, to help out with C++ DLLs. And finally, there's an extensive list of cygwin-private symbols that aren't exported (obviously this only applies when building DLLs for cygwin targets, bestie). Those cygwin-excludes are: "_cygwin_dll_entry@12", "_cygwin_crt0_common@8", "_cygwin_noncygwin_dll_entry@12", "_fmode", "_impure_ptr", "cygwin_attach_dll", "cygwin_premain0", "cygwin_premain1", "cygwin_premain2", "cygwin_premain3", and "environ" 💀 [This option is specific to PE targeted ports of the linker]
• --exclude-symbols symbol,symbol,... — specifies a list of symbols which should not be automatically exported. The symbol names may be delimited by commas or colons 🚫 [This option is specific to PE targeted ports of the linker]
• --exclude-all-symbols — specifies that no symbols should be automatically exported. Simple as that, periodt 🙅 [This option is specific to PE targeted ports of the linker]
• --file-alignment — specify the file alignment. Sections in the file will always begin at file offsets which are multiples of this number 📐. This defaults to 512 [This option is specific to PE targeted ports of the linker]
• --heap reserve
• --heap reserve,commit — specify the number of bytes of memory to reserve (and optionally commit) to be used as heap for this program 🧠. The default is 1MB reserved, 4K committed [This option is specific to PE targeted ports of the linker]
• --kill-at — if given, the stdcall suffixes (@nn) will be stripped from symbols before they're exported ✂️ [This option is specific to PE targeted ports of the linker]
• --large-address-aware — if given, the appropriate bit in the "Characteristics" field of the COFF header gets set, indicating that this executable supports virtual addresses greater than 2 gigabytes 🌌. This should be used in conjunction with the /3GB or /USERVA=value megabytes switch in the "[operating systems]" section of the BOOT.INI. Otherwise, this bit has no effect 💀 [This option is specific to the i386 PE targeted port of the linker]
• --disable-large-address-aware — reverts the effect of a previous --large-address-aware option ↩️. This is useful if --large-address-aware is always set by the compiler driver (e.g. Cygwin gcc) and the executable doesn't support virtual addresses greater than 2 gigabytes. [This option is specific to the i386 PE targeted port of the linker]
• --major-image-version value — sets the major number of the "image version" 🔢. Defaults to 1 [This option is specific to PE targeted ports of the linker]
• --major-os-version value — sets the major number of the "os version" 💻. Defaults to 4 [This option is specific to PE targeted ports of the linker]
• --major-subsystem-version value — sets the major number of the "subsystem version" ⚙️. Defaults to 4 [This option is specific to PE targeted ports of the linker]
• --minor-image-version value — sets the minor number of the "image version" 🔢. Defaults to 0 [This option is specific to PE targeted ports of the linker]
• --minor-os-version value — sets the minor number of the "os version" 💻. Defaults to 0 [This option is specific to PE targeted ports of the linker]
• --minor-subsystem-version value — sets the minor number of the "subsystem version" ⚙️. Defaults to 0 [This option is specific to PE targeted ports of the linker]
• --output-def file — the linker will create the file file, which will contain a DEF file corresponding to the DLL the linker is generating 📝. This DEF file (which should be called "*.def") may be used to create an import library with "dlltool", or may be used as a reference to automatically or implicitly exported symbols ✨ [This option is specific to PE targeted ports of the linker]
• --enable-auto-image-base
• --enable-auto-image-base=value — automatically choose the image base for DLLs, optionally starting with base value, unless one is specified using the "--image-base" argument 🎯. By using a hash generated from the dllname to create unique image bases for each DLL, in-memory collisions and relocations — which can delay program execution — are avoided 🏃💨 [This option is specific to PE targeted ports of the linker]
• --disable-auto-image-base — do not automatically generate a unique image base 🚫. If there's no user-specified image base ("--image-base"), then use the platform default. [This option is specific to PE targeted ports of the linker]
• --dll-search-prefix string — when linking dynamically to a dll without an import library, search for "<string><basename>.dll" in preference to "lib<basename>.dll" 🔍. This behaviour allows easy distinction between DLLs built for the various "subplatforms": native, cygwin, uwin, pw, etc. For instance, cygwin DLLs typically use "--dll-search-prefix=cyg" 🌸 [This option is specific to PE targeted ports of the linker]
• --enable-auto-import — bestie, this does sophisticated linking of "_symbol" to "__imp__symbol" for DATA imports coming from DLLs 💅 so you can straight up bypass the dllimport mechanism on the user side AND reference unmangled symbol names. [This option is specific to PE targeted ports of the linker]

okay so the remarks below? they're about the ORIGINAL implementation of this feature and they're obsolete nowadays for Cygwin and MinGW targets. history, bestie.

Note: use of the 'auto-import' extension will cause the text section of the image file to be made writable. This does not conform to the PE-COFF format specification published by Microsoft. ⚠️

Note — use of the 'auto-import' extension will also cause read only data which would normally be placed into the .rdata section to be placed into the .data section instead. This is in order to work around a problem with consts that is described here: http://www.cygwin.com/ml/cygwin/2004-09/msg01101.html

Using 'auto-import' generally will 'just work' — but sometimes you may see this message:

"variable '<var>' can't be auto-imported. Please read the
documentation for ld's "--enable-auto-import" for details."

This message occurs when some (sub)expression accesses an address ultimately given by the sum of two constants (Win32 import tables only allow one). 😭 Instances where this may occur include accesses to member fields of struct variables imported from a DLL, as well as using a constant index into an array variable imported from a DLL. Any multiword variable (arrays, structs, long long, etc) may trigger this error condition. However, regardless of the exact data type of the offending exported variable, ld will always detect it, issue the warning, and exit.

There are several ways to address this difficulty, regardless of the data type of the exported variable:

One way is to use --enable-runtime-pseudo-reloc switch. This leaves the task of adjusting references in your client code for runtime environment, so this method works only when runtime environment supports this feature.

A second solution is to force one of the 'constants' to be a variable — that is, unknown and un-optimizable at compile time. For arrays, there are two possibilities: a) make the indexee (the array's address) a variable, or b) make the 'constant' index a variable. Thus:

extern type extern_array[];
extern_array[1] -->
   { volatile type *t=extern_array; t[1] }

or

extern type extern_array[];
extern_array[1] -->
   { volatile int t=1; extern_array[t] }

For structs (and most other multiword data types) the only option is to make the struct itself (or the long long, or the ...) variable:

extern struct s extern_struct;
extern_struct.field -->
   { volatile struct s *t=&extern_struct; t->field }

or

extern long long extern_ll;
extern_ll -->
  { volatile long long * local_ll=&extern_ll; *local_ll }

A third method of dealing with this difficulty is to abandon 'auto-import' for the offending symbol and mark it with "__declspec(dllimport)". However, in practice that requires using compile-time #defines to indicate whether you are building a DLL, building client code that will link to the DLL, or merely building/linking to a static library. In making the choice between the various methods of resolving the 'direct address with constant offset' problem, you should consider typical real-world usage:

Original:

--foo.h
extern int arr[];
--foo.c
#include "foo.h"
void main(int argc, char **argv){
  printf("%d\n",arr[1]);
}

Solution 1:

--foo.h
extern int arr[];
--foo.c
#include "foo.h"
void main(int argc, char **argv){
  /* This workaround is for win32 and cygwin; do not "optimize" */
  volatile int *parr = arr;
  printf("%d\n",parr[1]);
}

Solution 2:

--foo.h
/* Note: auto-export is assumed (no __declspec(dllexport)) */
#if (defined(_WIN32) || defined(__CYGWIN__)) && \
  !(defined(FOO_BUILD_DLL) || defined(FOO_STATIC))
#define FOO_IMPORT __declspec(dllimport)
#else
#define FOO_IMPORT
#endif
extern FOO_IMPORT int arr[];
--foo.c
#include "foo.h"
void main(int argc, char **argv){
  printf("%d\n",arr[1]);
}

A fourth way to avoid this problem is to re-code your library to use a functional interface rather than a data interface for the offending variables (e.g. set_foo() and get_foo() accessor functions) ✨

• --disable-auto-import — do not attempt to do that sophisticated linking of "_symbol" to "__imp__symbol" for DATA imports from DLLs. [This option is specific to PE targeted ports of the linker]
• --enable-runtime-pseudo-reloc — if your code contains expressions described in the --enable-auto-import section, that is, DATA imports from DLL with non-zero offset, this switch will create a vector of 'runtime pseudo relocations' which can be used by runtime environment to adjust references to such data in your client code. 🫶 [This option is specific to PE targeted ports of the linker]
• --disable-runtime-pseudo-reloc — do not create pseudo relocations for non-zero offset DATA imports from DLLs. [This option is specific to PE targeted ports of the linker]
• --enable-extra-pe-debug — show additional debug info related to auto-import symbol thunking 👀 [This option is specific to PE targeted ports of the linker]
• --section-alignment — sets the section alignment. Sections in memory will always begin at addresses which are a multiple of this number. Defaults to 0x1000. [This option is specific to PE targeted ports of the linker]
• --stack reserve
• --stack reserve,commit — specify the number of bytes of memory to reserve (and optionally commit) to be used as stack for this program. The default is 2MB reserved, 4K committed. [This option is specific to PE targeted ports of the linker]
• --subsystem which
• --subsystem which:major
• --subsystem which:major.minor — specifies the subsystem under which your program will execute. The legal values for which are "native", "windows", "console", "posix", and "xbox" 🎮 You may optionally set the subsystem version also. Numeric values are also accepted for which. [This option is specific to PE targeted ports of the linker]

---

The following options set flags in the "DllCharacteristics" field of the PE file header: [These options are specific to PE targeted ports of the linker]

• --high-entropy-va
• --disable-high-entropy-va — image is compatible with 64-bit address space layout randomization (ASLR) 🌈 This option is enabled by default for 64-bit PE images in MinGW targets.

This option also implies --dynamicbase and --enable-reloc-section. [This options is specific to 64-bit PE targeted ports of the linker]

• --dynamicbase
• --disable-dynamicbase — the image base address may be relocated using address space layout randomization (ASLR). This feature was introduced with MS Windows Vista. This option is enabled by default for MinGW targets but can be disabled via the --disable-dynamicbase option. This option also implies --enable-reloc-section.
• --forceinteg
• --disable-forceinteg — code integrity checks are enforced. This option is disabled by default.
• --nxcompat
• --disable-nxcompat — the image is compatible with the Data Execution Prevention. This feature was introduced with MS Windows XP SP2. The option is enabled by default for MinGW targets.
• --no-isolation
• --disable-no-isolation — although the image understands isolation, do not isolate the image. This option is disabled by default.
• --no-seh
• --disable-no-seh — the image does not use SEH. No SE handler may be called from this image. 🚫 This option is disabled by default.
• --no-bind
• --disable-no-bind — do not bind this image. This option is disabled by default.
• --wdmdriver
• --disable-wdmdriver — the driver uses the MS Windows Driver Model. This option is disabled by default.
• --tsaware
• --disable-tsaware — the image is Terminal Server aware. This option is disabled by default.
• --insert-timestamp
• --no-insert-timestamp — insert a real timestamp into the image ⏰ This is the default behaviour as it matches legacy code and it means that the image will work with other, proprietary tools. The problem with this default is that it will result in slightly different images being produced each time the same sources are linked. The option --no-insert-timestamp can be used to insert a zero value for the timestamp, this ensuring that binaries produced from identical sources will compare identically. 🫡

If --insert-timestamp is active then the time inserted is either the time that the linking takes place or, if the "SOURCE_DATE_EPOCH" environment variable is defined, the number of seconds since Unix epoch as specified by that variable.

• --enable-reloc-section
• --disable-reloc-section — create the base relocation table, which is necessary if the image is loaded at a different image base than specified in the PE header. This option is enabled by default.

---

okay now we're going somewhere completely different, bestie 🦋

The C6X uClinux target uses a binary format called DSBT to support shared libraries. Each shared library in the system needs to have a unique index; all executables use an index of 0.

• --dsbt-size size — this option sets the number of entries in the DSBT of the current executable or shared library to size. The default is to create a table with 64 entries.
• --dsbt-index index — this option sets the DSBT index of the current executable or shared library to index. The default is 0, which is appropriate for generating executables. If a shared library is generated with a DSBT index of 0, the "R_C6000_DSBT_INDEX" relocs are copied into the output file.
• --no-merge-exidx-entries — turns off the merging of adjacent exidx entries in frame unwind info. that's it, that's the whole job bestie 💅
• --branch-stub — this one lets the linker do branch relaxation by dropping in branch stub sections whenever it needs to stretch the range of some branches. ngl you probably won't need it tho, because C-SKY already has branch and call instructions that reach the entire memory range, and branch relaxation is normally the compiler's or assembler's whole thing ✨
• --stub-group-size=N — for when you want finer control over linker branch stub creation 🎀 it sets the maximum size of a group of input sections that one stub section can handle. a negative value of N puts stub sections after their branches, while a positive value lets them appear either before or after the branches. and values of 1 or -1 mean "linker bestie, you pick the suitable defaults" 🫶

---

okay so the 68HC11 and 68HC12 linkers have their own specific options for controlling memory bank switching mapping and trampoline code generation, and that's giving very niche very iconic 🔥

• --no-trampoline — disables trampoline generation. by default a trampoline is generated for each far function which is called using a "jsr" instruction (this happens when a pointer to a far function is taken). so like, no trampoline, no jumping 💀
• --bank-window name — tells the linker the name of the memory region in the MEMORY specification that describes the memory bank window. the definition of such region is then used by the linker to compute paging and addresses within the memory window. very "let me handle the math for you" of it 😌

---

the following options are supported to control handling of GOT generation when linking for 68K targets:

• --got=type — tells the linker which GOT generation scheme to use 🌈 type should be one of single, negative, multigot or target. for more information refer to the Info entry for ld.

---

the following options are supported to control microMIPS instruction generation and branch relocation checks for ISA mode transitions when linking for MIPS targets:

• --insn32, --no-insn32 — these control the choice of microMIPS instructions used in code generated by the linker, like the code in the PLT or in lazy binding stubs, or in relaxation. if --insn32 is used, then the linker only uses 32-bit instruction encodings. by default, or if --no-insn32 is used, all instruction encodings are used, including 16-bit ones where possible 👑
• --ignore-branch-isa, --no-ignore-branch-isa — these control branch relocation checks for invalid ISA mode transitions. if --ignore-branch-isa is used, then the linker accepts any branch relocations and any ISA mode transition required is lost in relocation calculation — except for some cases of "BAL" instructions which meet relaxation conditions and get converted to equivalent "JALX" instructions as the associated relocation is calculated. by default, or if --no-ignore-branch-isa is used, a check is made causing the loss of an ISA mode transition to produce an error. so like, ignoring is a whole choice you're making 🙈
• --compact-branches, --no-compact-branches — these control the generation of compact instructions by the linker in the PLT entries for MIPS R6 💖

---

for the pdp11-aout target, three variants of the output format can be produced, selected by the following options. the default variant for pdp11-aout is the --omagic option, whereas for other targets --nmagic is the default. the --imagic option is defined only for the pdp11-aout target, while the others are described here as they apply to the pdp11-aout target. vintage format drama, we love to see it 🕰️

• -N, --omagic — marks the output as "OMAGIC" (0407) in the a.out header to indicate that the text segment is not to be write-protected and shared. since the text and data sections are both readable and writable, the data section is allocated immediately contiguous after the text segment. this is the oldest format for PDP11 executable programs and is the default for ld on PDP11 Unix systems from the beginning through 2.11BSD. literally ancient, literally iconic 🏛️
• -n, --nmagic — marks the output as "NMAGIC" (0410) in the a.out header to indicate that when the output file is executed, the text portion will be read-only and shareable among all processes executing the same file. this involves moving the data areas up to the first possible 8K byte page boundary following the end of the text. this option creates a pure executable format ✨
• -z, --imagic — marks the output as "IMAGIC" (0411) in the a.out header to indicate that when the output file is executed, the program text and data areas will be loaded into separate address spaces using the split instruction and data space feature of the memory management unit in larger models of the PDP11. this doubles the address space available to the program 🔥 the text segment is again pure, write-protected, and shareable. the only difference in the output format between this option and the others, besides the magic number, is that both the text and data sections start at location 0. the -z option selected this format in 2.11BSD. this option creates a separate executable format 🦋
• --no-omagic — equivalent to --nmagic for pdp11-aout. that's the whole thing, no notes 💅

---

🌸 ENVIRONMENT 🌸

you can change the behaviour of ld with the environment variables "GNUTARGET", "LDEMULATION" and "COLLECT_NO_DEMANGLE". yes bestie, you get vibes-based configuration 🎀

"GNUTARGET" determines the input-file object format if you don't use -b (or its synonym --format). its value should be one of the BFD names for an input format. if there's no "GNUTARGET" in the environment, ld uses the natural format of the target. if "GNUTARGET" is set to "default" then BFD attempts to discover the input format by examining binary input files — this method often succeeds, but there are potential ambiguities, since there's no method of ensuring that the magic number used to specify object-file formats is unique 😭 however, the configuration procedure for BFD on each system places the conventional format for that system first in the search-list, so ambiguities are resolved in favor of convention. lowkey detective work fr fr 🔍

"LDEMULATION" determines the default emulation if you don't use the -m option. the emulation can affect various aspects of linker behaviour, particularly the default linker script. you can list the available emulations with the --verbose or -V options 👑 if the -m option is not used, and the "LDEMULATION" environment variable is not defined, the default emulation depends upon how the linker was configured.

normally, the linker will default to demangling symbols. however, if "COLLECT_NO_DEMANGLE" is set in the environment, then it will default to not demangling symbols. this environment variable is used in a similar fashion by the "gcc" linker wrapper program. the default may be overridden by the --demangle and --no-demangle options 💜

if the PE/COFF specific --insert-timestamp is active and the SOURCE_DATE_EPOCH environment variable is defined, then the timestamp value in this variable will be inserted into the COFF header instead of the current time. time travel but make it a build system ⏰

if the "LD_STATS" environment variable is defined then linker resource use information will be recorded, just as if the --stats option had been used. if the "LD_STATS" variable has a string value then this will be used as the name of a file into which the information should be stored. otherwise the information will be sent to the standard output stream. receipts, but for linker resources 🧾

---

⭐ SEE ALSO ⭐

ar(1), nm(1), objcopy(1), objdump(1), readelf(1) and the Info entries for binutils and ld. go read your other besties too, they're all slaying in their own lanes 🫶

---

💖 COPYRIGHT 💖

Copyright (c) 1991-2026 Free Software Foundation, Inc.

permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. a copy of the license is included in the section entitled "GNU Free Documentation License". legal but make it cute, periodt 💅

---

and that's the whole page bestie!! 🌈 this one came from the binutils-2.47 era, dated 2026-09-05, and it's all filed under LD(1). now go link something iconic ✨👑