LD(1)

💖 ld(1) — The GNU linker — GNU Development Tools 💖

✨ NAME ✨

ld — The GNU linker. Bestie, this is the link-up phase. 🫶

🌸 SYNOPSIS 🌸

ld [options] objfile ...

🦋 DESCRIPTION 🦋

Okay so ld is out here combining a bunch of object and archive files, relocating their data, and tying up symbol references. Usually the last step in compiling a program is literally running ld. 💅

ld accepts Linker Command Language files written in a superset of AT&T's Link Editor Command Language syntax, which gives you explicit and total control over the linking process. Iconic. 👑

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.

This version of ld uses the general purpose BFD libraries to operate on object files. That means it can 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. Slay. ✨

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). Not it being forgiving AND useful 😭💖

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. Choices are the moment. 🎀

💅 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.) We love a standard search directory moment. 🌈

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. iykyk. 👀

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. Respect the boundary, bestie. 💀

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.

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. Plot twist in file format form. 🌀

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.

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. Sneaky little lowercase o. 🙈

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 queens win. 👑

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

Okay bestie, here’s the lineup of generic command-line switches accepted by the GNU linker — table energy, but make it cute. 🎀

• @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 file energy, we love to see it. 🌀

• -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 besties 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. Retro compatibility slay. 🎀
• -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. Look at her serving cross-platform. 💅
• --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 matters, bestie. 📍

• --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 a whole vibe. Normally if an input section doesn't fit into a matching output section, the linker just screams and dies. With this flag, it doesn't. Instead it keeps trying to drop the input section into subsequent matching output sections, and only throws an error if literally no output section is big enough. Iconic for when you've got several non-contiguous memory regions chilling and your input section doesn't care which one it lands in. 🫶

Just know the order in which input sections are evaluated doesn't change. Like for example:

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.

Heads up bestie: this option is incompatible with INSERT statements, because it changes the way input sections are mapped to output sections. So no mixing, okay? 💀

• --enable-non-contiguous-regions-warnings — turns on warnings for when --enable-non-contiguous-regions lets through possibly-unexpected matches in the section mapping. Why do you care? Because those sneaky matches could literally lead to a section getting silently discarded instead of failing properly just because it doesn't fit any output region. 😭 So yeah, maybe turn this on, iykyk.
• -e entry, --entry=entry — use entry as the explicit symbol for where your program starts executing, instead of whatever the default entry point is. If there's no symbol actually 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 — but 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 without the trailing stdcall @number when applicable). Slay.
• --exclude-libs lib,lib,... — gives you a list of archive libraries whose symbols should not be automatically exported. Names can be delimited by commas or colons, either one, we're flexible 💅. Saying --exclude-libs ALL excludes symbols in all archive libraries from automatic export. Only available for the i386 PE targeted port of the linker and for ELF targeted ports. For i386 PE, symbols explicitly listed in a .def file are still exported regardless of this option. For ELF targeted ports, symbols affected by this option get treated as hidden. ✨
• --exclude-modules-for-implib module,module,... — specifies a list of object files or archive members whose symbols should not be automatically exported, but which should still be copied wholesale into the import library being generated during the link. Names may be delimited by commas or colons, and they must match exactly the filenames used by ld to open the files. For archive members this is simply the member name, but for object files the name you list has to include and match precisely any path used to specify the input file on the linker's command line. Only available for the i386 PE targeted port. Symbols explicitly listed in a .def file are still exported regardless of this option. No cap, exact means exact. 🔍
• -E, --export-dynamic, --no-export-dynamic — when you're creating a dynamically linked executable, using -E or --export-dynamic makes the linker add all symbols to the dynamic symbol table. Btw the dynamic symbol table is the set of symbols visible from dynamic objects at run time. 👑

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

Now — 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), you will probably need this option when linking the program itself. Fr fr.

You can also use the dynamic list to control which symbols get added to the dynamic symbol table, if the output format supports it. See the description of --dynamic-list.

Note that this option is ELF-targeted-ports specific. 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 get 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. Only meaningful on ELF platforms which support shared libraries. ✨
• --export-dynamic-symbol-list=file — specifies a --export-dynamic-symbol for each pattern in the file. The file format is the same as the version node without scope and node name. See VERSION for more info. 📄
• -EB — link big-endian objects. This affects the default output format.
• -EL — link little-endian objects. This affects the default output format. (Yes bestie, they're siblings. 💖)
• -f name, --auxiliary=name — when creating an ELF shared object, sets 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. 🎀

So 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 it resolves any symbols from the filter object, it'll first check whether there's a definition in the shared object name. If there is one, that gets used instead of the definition in the filter object. And get this — the shared object name doesn't even need to exist. 😭 Thus name may be used to provide an alternative implementation of certain functions, maybe for debugging or for machine-specific performance.

This option may be specified more than once. The DT_AUXILIARY entries get created in the order in which they appear on the command line. Periodt.

• -F name, --filter=name — when creating an ELF shared object, sets the internal DT_FILTER field to the specified name. This tells the dynamic linker that the symbol table of the shared object 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. It'll resolve symbols according to the symbol table of the filter object as usual, but it'll actually link to the definitions found in the shared object name. So the filter object can be used to select a subset of the symbols provided by the object name. Ate. ✨

Some older linkers used -F 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 just ignore -F when not creating an ELF shared object. 🙈

• -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. 🫶
• -g — ignored. It's just here for compatibility with other tools. That's it, that's the whole personality. 💀
• -G value, --gpsize=value — sets the maximum size of objects to be optimized using the GP register to value. Only meaningful for object file formats like MIPS ELF that support putting large and small objects into different sections. Ignored for other object file formats. 🌸
• -h name, -soname=name — when creating an ELF shared object, sets the internal DT_SONAME field to the specified name. When an executable is linked with a shared object that has a DT_SONAME field, then when the executable runs, 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. Iconic behavior honestly. 👑
• -i — perform an incremental link (same as option -r). 💫
• -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. 🎀
• -l namespec, --library=namespec — adds the archive or object file specified by namespec to the list of files to link. You can use this option any number of times, go off. If namespec is of the form :filename, ld will search the library path for a file called filename; otherwise it searches the library path for a file called libnamespec.a. 🦋

On systems that 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 means 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's specified on the command line. If the archive defines a symbol that was undefined in some object appearing before the archive on the command line, the linker will include the appropriate file(s) from the archive. But an undefined symbol in an object appearing later on the command line will not cause the linker to search the archive again. That's just how it is bestie. 😭

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. Living your truth. 💅

okay so this whole archive-searchy thing? total standard behaviour for Unix linkers, everyone's doing it. but if you're running ld on AIX, be aware — it does not match the behaviour of the AIX linker. different vibes entirely. 💅

• -L searchdir, --library-path=searchdir — adds the path searchdir to the list of paths ld will search for archive libraries and ld control scripts. you can use this option literally as many times as you want. the directories get searched in the order you specified them on the command line, and dirs you specify on the command line get searched before the default directories. also — and this is the part people always get wrong — all -L options apply to all -l options, no matter what order the options appear in. but -L options do not affect how ld searches for a linker script unless the -T option is specified. noted. 📝 if searchdir begins with = or $SYSROOT, then that prefix gets replaced by the sysroot prefix — the one controlled by the --sysroot option, or specified when the linker was configured. ✨ the default set of paths that get searched (when you don't specify them with -L) depends on which emulation mode ld is using, and in some cases also on how it was configured. so like... it depends. 🙈 you can also specify the paths inside a link script with the "SEARCH_DIR" command. directories specified that way get searched at the point in which the linker script appears on the command line. 🎀
• -m emulation — emulate the emulation linker. you can list all the available emulations with the --verbose or -V options. 👑 if -m isn't used, the emulation gets taken from the LDEMULATION environment variable (if that's defined). otherwise? the default emulation depends on how the linker was configured. that's it, that's the rule. 🦋
• --remap-inputs=pattern=filename, --remap-inputs-file=file — these options let you change the names of input files before the linker even tries to open them. so --remap-inputs=foo.o=bar.o makes any attempt to load a file called foo.o instead try to load one called bar.o. slay. 💅 wildcard patterns are allowed in the first filename too, so --remap-inputs=foo*.o=bar.o renames any input file matching foo*.o to bar.o. ✨ the alternative form, --remap-inputs-file=filename, lets you read the remappings out of a file. each line in the file can hold a single remapping. blank lines get ignored. anything from a hash character (#) to the end of a line counts as a comment and is also ignored. the mapping pattern can be separated from the filename by whitespace or an equals (=) character. 🎀 you can specify these options multiple times — their contents accumulate. remappings get processed in the order they occur on the command line, and if they come from a file, in the order they occur in that file. once a match is made, no further checking for that filename happens. periodt. if the replacement filename is /dev/null or just NUL, then the remapping actually causes the input file to be ignored. lowkey a convenient way to experiment with removing input files from a complicated build environment. 🧚

heads up: this option is position dependent and only affects filenames that come after it on the command line. so this: ld foo.o --remap-inputs=foo.o=bar.o does nothing. whereas this: ld --remap-inputs=foo.o=bar.o foo.o renames the input file foo.o to bar.o. main character ordering, honestly. 💀

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 isn't significant there. 🙈 if the verbose option is enabled, any mappings that match will get reported — although again, the verbose option needs to be enabled on the command line before the remaped filenames appear. (yes, "remaped". that's how it's spelled in the source. leave her alone. 😭) and if -Map or --print-map is enabled, the remapping list gets included in the map output. 🌸

• -M, --print-map — prints a link map to the standard output. a link map gives you the tea ☕ about the link, including:
  • 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 that caused the archive member to be brought in.
  • the values assigned to symbols. note — symbols whose values are computed by an expression involving a reference to a previous value of the same symbol may not have the correct result displayed in the link map. that's because the linker discards intermediate results and only keeps the final value of an expression. in that situation the linker displays the final value enclosed by square brackets. so 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 get 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 the 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 the 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. iconic behaviour ngl. 🔥

• --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 get the text (local) printed before their name, and get listed after all of the global symbols in a given section. temporary local symbols (typically the ones that start with .L) will not be included in the output. disabled by default. 🙈
• -n, --nmagic — turns off page alignment of sections, and disables linking against shared libraries. if the output format supports Unix style magic numbers, the output gets marked as "NMAGIC". no frills, all vibes. 💅
• -N, --omagic — sets the text and data sections to be readable and writable. also: don't page-align the data segment, and disable linking against shared libraries. if the output format supports Unix style magic numbers, the output gets marked 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. so like, you can, but Microsoft will side-eye you. 😭

• --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 that. don't skip that step bestie. 🫶
• -o output, --output=output — uses output as the name for the program produced by ld. if this option isn't specified, the name a.out is the 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 does this even if it turns out the link can't be completed due to errors. so yeah. she's committed. 💀 note — the linker checks to make sure the output file name doesn't match the name of any of the input files, but that is all. in particular it won't complain if the output file might overwrite a source file or some other important file. that's why in build systems it's recommended to use -o as the last option on the linker command line. for example, consider: ld -o $(EXE) $(OBJS) ld $(OBJS) -o $(EXE) if the EXE variable isn't 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. so please, put -o last. for me. 🥺🌸

• --dependency-file=depfile — writes 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's 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. ngl, respect the honesty. 💅

• -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, but future releases of the linker may make more use of it. also, currently there's no difference in the linker's behaviour for different non-zero values of this option — again, this may change with future releases. so like, it's giving "we have plans". 👀✨
• -plugin name — ok so this one pulls a plugin into the linking process 🧩 The name param is the absolute filename of the plugin. Usually the compiler adds this automatically for you when it's doing link time optimization, but like… you can absolutely add your own plugins if you want to. Your link, your rules 💅

One thing tho, bestie, heads up: the place where compiler-originated plugins live is not the same place ar, nm and ranlib look for their plugins. So for those commands to actually use a compiler-based plugin, it has to be copied into the ${libdir}/bfd-plugins directory first. Good news? All gcc based linker plugins are backward compatible, so literally just copy in the newest one and you're golden ✨

• --push-state — this is the save-point of your linker life 🎀 It preserves the current state of all the flags that govern input file handling, so you can restore every single one of them with a matching --pop-state.

The options it covers (iconic list, no skips): -Bdynamic, -Bstatic, -dn, -dy, -call_shared, -non_shared, -static, -N, -n, --whole-archive, --no-whole-archive, -r, -Ur, --copy-dt-needed-entries, --no-copy-dt-needed-entries, --as-needed, --no-as-needed, and -a.

One target for this option: specs for pkg-config 🫶 When it's used with the --libs option, all possibly needed libraries get listed and then possibly linked with all the time. 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, restoring the previous values of the flags that govern input file handling. The un-save. The ctrl-Z. The "jk bestie" 😌
• -q, --emit-relocs — leaves relocation sections and their contents in fully linked executables. Post-link analysis and optimization tools might need this info to perform correct modifications of executables. Downside? Bigger executables. It's giving "paying in binary size" 💀

Currently this option is only supported on ELF platforms.

• --force-dynamic — forces the output file to have dynamic sections. This one's specific to VxWorks targets, iykyk 🌸
• -r, --relocatable — generates relocatable output, i.e. an output file that can in turn serve as input to ld. People call this partial linking 🧚 Side effect: 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 is produced. And when you're linking C++ programs, this option will not resolve references to constructors — to do that, use -Ur.

When an input file doesn't have the same format as the output file, partial linking is only supported if that input file doesn't contain any 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 🙈

When the relocatable output contains both contents which require link-time optimization (LTO) and contents which 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. And when processing a relocatable input with a .gnu_object_only section, the linker will extract the .gnu_object_only section as a separate input 👑

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. Not a vibe, just facts.

This option does the same thing as -i.

• -R filename, --just-symbols=filename — reads symbol names and their addresses from filename, but does not 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 may use this option more than once.

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. Sneaky little shape-shifter, love that for them 💜

• --rosegment, --no-rosegment — attempts to ensure that only a single read-only, non-code segment is created 🌸 Only useful when used in conjunction 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 the options are misleading, but they were chosen so the linker stays compatible with the LLD and GOLD linkers. Blame history, not us 😭

These options are only supported by ELF targets.

• -s, --strip-all — omit all symbol information from the output file. Gone. Poof. Nothing left but vibes 🎀
• -S, --strip-debug — omit debugger symbol information from the output file (but not all symbols). The selective declutter, we respect it ⭐
• --strip-discarded, --no-strip-discarded — omit (or don't omit) global symbols defined in discarded sections. Enabled by default, so the stripping is already happening unless you say otherwise 💅
• -plugin-save-temps — stores the plugin's "temporary" intermediate files permanently. Yeah. Permanently. They're not temps anymore, they're residents 💀
• -t, --trace — prints the names of the input files as ld processes them 👀 If -t is given twice, members within archives are also printed. The -t output is genuinely useful for generating a list of all the object files and scripts involved in linking — like when you're packaging files for a linker bug report. Chef's kiss for debugging, fr fr 🔥
• -T scriptfile, --script=scriptfile — uses scriptfile as the linker script 📜 This script replaces ld's default linker script (rather than adding to it) — unless the script contains "INSERT", in which case commandfile must specify everything necessary to describe the output file.

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, bestie 🫶

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 — uses scriptfile as the default linker script 🌈

This option 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. That's the whole point — it 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. (e.g. because the command line is being constructed by another tool, such as gcc.) Very "let the tools cook" energy 👑

• -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 to force additional modules to be pulled into the link, and it's an error for the symbol to remain undefined, then use --require-defined instead. Different tool for a different job 💅

• --require-defined=symbol — requires that symbol is defined in the output file. Same as --undefined except that if symbol isn't defined in the output file, the linker will issue an error and exit 😭 The exact same effect can be achieved in a linker script by using "EXTERN", "ASSERT" and "DEFINED" together. This option can be used multiple times to require additional symbols. No pressure, just consequences 🎀
• -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, the -Ur option 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. Use -Ur only for the last partial link, and -r for the others. Periodt. 🔥

• --orphan-handling=MODE — controls how orphan sections are handled. An orphan section is one not specifically mentioned in a linker script 🧚

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 option --unique 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 isn't 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 may 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. Breaking up the group chat, respectfully 💅
• -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. Flex those creds 👑
• -x, --discard-all — deletes all local symbols. Every last one. Bye 👋
• -X, --discard-locals — deletes all temporary local symbols 🫶 (These symbols start with system-specific local label prefixes — typically .L for ELF systems, or L for traditional a.out systems.)
• -y symbol, --trace-symbol=symbol — prints the name of each linked file in which symbol appears 👀 This option may be given any number of times. On many systems it's necessary to prepend an underscore.

This option is a lifesaver when you've got an undefined symbol in your link but you genuinely have no idea where the reference is coming from. Detective mode activated 🔍✨

---

• -Y path — drops path onto the default library search path ✨ this one's literally just vibes for Solaris compat, it exists so Solaris builds feel seen 💅
• -z keyword — okay bestie, this is the big one, the keyword buffet 🍓 the recognized keywords are:
  • call-nop=prefix-addr
  • call-nop=suffix-nop
  • call-nop=prefix-byte
  • call-nop=suffix-byte — these four tell the linker what 1-byte "NOP" padding to use when it transforms an indirect call to a locally defined function, foo, via its GOT slot 🎀
    • 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 — these control how the linker tattles on missing GNU_PROPERTY_X86_FEATURE_1_IBT and GNU_PROPERTY_X86_FEATURE_1_SHSTK properties in the input .note.gnu.property section 👀
    • cet-report=none, which is the default, makes the linker not report missing properties in input files (peace, silence, no drama 🌸).
    • cet-report=warning makes the linker issue a warning for missing properties in input files.
    • cet-report=error makes the linker issue an error for missing properties in input files.
    • heads up: 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 🔥 don't do this if you picked nocombreloc.
  • common
  • nocommon — common generates common symbols with STT_COMMON type during a relocatable link. Use STT_OBJECT type if you said nocommon.
  • common-page-size=value — sets the page size most commonly used to value. The memory image layout gets optimized to minimize memory pages if the system is using pages of this size 🦋
  • 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.
  • dynamic-undefined-weak
  • nodynamic-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 💫 don't make them dynamic if you chose nodynamic-undefined-weak. If neither option is given, a target may default to either option being in force, or make some other selection of undefined weak symbols dynamic. Not all targets support these options, so like... no promises 🫶
  • execstack — marks the object as requiring an executable stack 🫣
  • global — this one's only meaningful when building a shared object. It makes the symbols defined by this shared object available for symbol resolution of subsequently loaded libraries 👑
  • globalaudit — only meaningful when building a dynamic executable. This 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.
  • 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 — 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.
    • and noindirect-extern-access removes GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS from .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. main character scheduling, honestly.
  • 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 💁‍♀️
  • 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 do not usually function correctly unless they are 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).
  • 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 — controls how the linker reports the missing GNU_PROPERTY_X86_FEATURE_1_LAM_U48 property in the input .note.gnu.property section 🧐
    • lam-u48-report=none, which is the default, makes the linker not report missing properties in input files.
    • lam-u48-report=warning makes the linker issue a warning for missing properties in input files.
    • lam-u48-report=error makes the linker issue 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 — same deal but for the missing GNU_PROPERTY_X86_FEATURE_1_LAM_U57 property in the input .note.gnu.property section 🌸
    • lam-u57-report=none, which is the default, makes the linker not report missing properties in input files.
    • lam-u57-report=warning makes the linker issue a warning for missing properties in input files.
    • lam-u57-report=error makes the linker issue an error for missing properties in input files. Supported for Linux/x86_64.
  • lam-report=none
  • lam-report=warning
  • lam-report=error — the two-for-one combo 💖 these control reporting for 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, which is the default, makes the linker not report missing properties in input files.
    • lam-report=warning makes the linker issue a warning for missing properties in input files.
    • lam-report=error makes the linker issue an error for missing properties in input files. Supported for Linux/x86_64.
  • lazy — when generating an executable or shared library, marks it to tell the dynamic linker to defer function call resolution to the point when the function is called (lazy binding), rather than at load time 😴 lazy binding is the default, so it's giving "I'll do it when I get there" energy.
  • loadfltr — specifies that the object's filters be processed immediately at runtime ⚡
  • max-page-size=value — sets the maximum memory page size supported to value 📏
  • mark-plt
  • nomark-plt — marks PLT entries with dynamic tags, DT_X86_64_PLT, DT_X86_64_PLTSZ and DT_X86_64_PLTENT 🏷️

okay, caution 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 — allows multiple definitions 🤝
• nocopyreloc — disables linker generated .dynbss variables used in place of variables defined in shared libraries. May result in dynamic text relocations 🫠
• 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 🚫
• 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 ✨ it can be used to work around incorrect relocations against protected data symbols generated by compiler. Updates on protected data symbols by another module aren't visible to the resulting shared library 👀 Supported for i386 and x86-64.
• noreloc-overflow — disables the relocation overflow check. You can use this to disable the relocation overflow check if there will be no dynamic relocation overflow at run-time 🦋 Supported for x86_64.
• memory-seal
• nomemory-seal — instructs the executable or shared library that all PT_LOAD segments should be sealed to avoid further manipulation (such as changing the protection flags, the segment size, or removing the mapping) 🔐 this is a security hardening that requires system support. It generates GNU_PROPERTY_MEMORY_SEAL in .note.gnu.property section 🎀

• now — when you're generating an executable or a shared library, this stamps it so the dynamic linker resolves all the symbols right when the program starts (or when dlopen loads the shared lib), instead of being lazy and waiting until the function is actually called. No procrastination era 💅
• origin — says the object needs $ORIGIN handling in its paths. ✨
• pack-relative-relocs, 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 a position-dependent executable or relocatable output. nopack-relative-relocs is the default, which disables compact relative relocation. When you link against the GNU C Library, a GLIBC_ABI_DT_RELR symbol version dependency on the shared C Library is added to the output. Supported for i386 and x86-64. 🎀
• relro, 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. ⚠️ Specifying common-page-size smaller than the system page size will render this protection ineffective — like, actually useless, bestie. Don't create an ELF PT_GNU_RELRO segment if norelro.
• report-relative-reloc — reports dynamic relative relocations generated by the linker. Supported for Linux/i386 and Linux/x86_64. 🦋
• sectionheader, nosectionheader — generates a section header. Don't generate a section header if nosectionheader is used. sectionheader is the default. 🌸
• separate-code, 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. Don't create a separate code PT_LOAD segment if noseparate-code is used. 🔥
• shstk — generates GNU_PROPERTY_X86_FEATURE_1_SHSTK in the .note.gnu.property section to indicate compatibility with Intel Shadow Stack. Supported for Linux/i386 and Linux/x86_64. 👑
• stack-size=value — specifies a stack size for an ELF PT_GNU_STACK segment. Specifying zero will override any default non-zero sized PT_GNU_STACK segment creation. (yes, zero means "no segment for you", not "default" 🙈)
• start-stop-gc, nostart-stop-gc — when --gc-sections is in effect, a reference from a retained section to __start_SECNAME or __stop_SECNAME causes all input sections named SECNAME to also be retained, 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 this effect, allowing sections to be garbage collected as if the special synthesized symbols were not defined. -z start-stop-gc has no effect on a definition of __start_SECNAME or __stop_SECNAME in an object file or linker script. Such a definition will prevent the linker providing a synthesized __start_SECNAME or __stop_SECNAME respectively, and therefore the special treatment by garbage collection for those references. 🧚
• start-stop-visibility=value — specifies the ELF symbol visibility for synthesized __start_SECNAME and __stop_SECNAME symbols. value must be exactly default, internal, hidden, or protected. If no -z start-stop-visibility option is given, protected is used for compatibility with historical practice. However, it's highly recommended to use -z start-stop-visibility=hidden in new programs and shared libraries so that these symbols are not exported between shared objects, which is not usually what's intended. 💡
• text, notext, 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. Don't report an error if notext or textoff. 😤
• undefs — do not report unresolved symbol references from regular object files, either when creating an executable or when creating a shared library. This option is the inverse of -z defs. 🫶
• unique-symbol, nounique-symbol — avoids duplicated local symbol names in the symbol string table. Appends "."number" to duplicated local symbol names if unique-symbol is used. nounique-symbol is the default. 💜
• x86-64-baseline, x86-64-v2, x86-64-v3, x86-64-v4 — specifies 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. ⭐
• isa-level-report=none, isa-level-report=all, isa-level-report=needed, isa-level-report=used — specifies how to report x86-64 ISA levels in input relocatable files. isa-level-report=none, which is the default, will make the linker not report x86-64 ISA levels in input files. isa-level-report=all will make the linker report needed and used x86-64 ISA levels in input files. isa-level-report=needed will make the linker report needed x86-64 ISA levels in input files. isa-level-report=used will make 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. (iykyk 💀)

---

• --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, if input relocatable object files call ___tls_get_addr. Heads up: the output will fail to load and run at run-time against glibc which 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 warning energy as above: the output will fail to load and run at run-time against glibc which doesn't define the GLIBC_ABI_GNU2_TLS version tag. Unless it's 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 -), --start-group archives --end-group — the archives should be a list of archive files. They may be either explicit file names, or -l options.

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

Real talk though: 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. 💀

• --accept-unknown-input-arch, --no-accept-unknown-input-arch — tells the linker to accept input files whose architecture it can't even recognise. The assumption is that the user knows what they're doing and deliberately wants to link in these unknown input files. This was the default behaviour of the linker before release 2.14. The default behaviour from release 2.14 onwards is to reject such input files, and so the --accept-unknown-input-arch option was added to restore the old behaviour. 🎀
• --as-needed, --no-as-needed — this option affects ELF DT_NEEDED tags for dynamic libraries mentioned on the command line after the --as-needed option. Normally the linker adds a DT_NEEDED tag for each dynamic library mentioned on the command line, regardless of whether the library is actually needed or not. --as-needed causes a DT_NEEDED tag to only be emitted 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 is not found in the DT_NEEDED lists of other needed libraries, a non-weak undefined symbol reference from another needed dynamic library. Object files or libraries appearing on the command line after the library in question do not affect whether the library is seen as needed. This is similar to the rules for extraction of object files from archives. --no-as-needed restores the default behaviour. ✨

Note: on Linux based systems the --as-needed option also has an affect on the behaviour of the --rpath and --rpath-link options. See the description of --rpath-link for more details. 👀

• --add-needed, --no-add-needed — these two options have been deprecated because of the similarity of their names to the --as-needed and --no-as-needed options. They have been replaced by --copy-dt-needed-entries and --no-copy-dt-needed-entries. (rest in peace besties 🪦)
• -assert keyword — this option is ignored for SunOS compatibility. 💅
• -Bdynamic, -dy, -call_shared — link against dynamic libraries. This is only meaningful on platforms for which shared libraries are supported. This option is normally the default on such platforms. The different variants of this option are for compatibility with various systems. You may use this option multiple times on the command line: it affects library searching for -l options which follow it. 🌸
• -Bgroup — sets the "DF_1_GROUP" flag in the "DT_FLAGS_1" entry of the dynamic section ✨ basically it tells the runtime linker "bestie, lookups in this object and its dependencies happen only inside the group, no wandering off". It implies --unresolved-symbols=report-all. Ngl this one only makes sense on ELF platforms that support shared libraries, so don't come for me if you're on something else 💅
• -Bstatic, -dn, -non_shared, -static — the "no shared libs for you" squad 🚫 don't link against shared libraries. Only meaningful on platforms where shared libraries are even a thing. The different variants exist purely for compatibility with various systems (yes, all four, they're the same vibe, different fonts). You can use this option multiple times on the command line — it affects library searching for the -l options that follow it. It also implies --unresolved-symbols=report-all. And plot twist: it can be used with -shared 😳 which means you're creating a shared library but all of the library's external references must be resolved by pulling in entries from static libraries.
• -Bsymbolic — when creating a shared library, bind references to global symbols to the definition within the shared library, if there is one. Normally a program linked against a shared library can override the definition inside that shared library — this shuts that down. Only meaningful on ELF platforms which support shared libraries 🦋
• -Bsymbolic-functions — same energy as -Bsymbolic but scoped to global function symbols only: bind references to them to the definition within the shared library, if any 🎯 Only meaningful on ELF platforms which support shared libraries.
• -Bno-symbolic — the undo button 💅 cancels previously specified -Bsymbolic and -Bsymbolic-functions.
• --dynamic-list=dynamic-list-file — hands the linker the name of a dynamic list file. Typically used when creating shared libraries to list global symbols whose references shouldn't be bound to the definition within the shared library, or when creating dynamically linked executables to list symbols that should be added to the executable's symbol table. 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 — peep VERSION for more info 👀
• --dynamic-list-data — include all global data symbols in the dynamic list. All of them. Every last one 🫶
• --dynamic-list-cpp-new — provides the builtin dynamic list for C++ operator new and delete. Mainly useful for building shared libstdc++ 🔥
• --dynamic-list-cpp-typeinfo — provides the builtin dynamic list for C++ runtime type identification ✨
• --check-sections, --no-check-sections — asks the linker not to check section addresses after they've been assigned, to see if anything overlaps. Normally the linker does perform this check and, if it finds overlaps, produces suitable error messages 👑 the linker also knows about overlays and makes allowances for sections in them. Default behaviour comes back with --check-sections. Also, section overlap isn't usually checked for relocatable links — you can force checking in that case with --check-sections.
• --copy-dt-needed-entries, --no-copy-dt-needed-entries — this one's about how dynamic libraries referred to by DT_NEEDED tags inside ELF dynamic libraries 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 on the command line, any dynamic libraries that follow it get their DT_NEEDED entries added 📋 default behaviour is restored with --no-copy-dt-needed-entries.

It also affects symbol resolution 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 — to resolve symbols required by the output binary. With the default setting, searching of the dynamic libraries that follow 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 table goes to the map file; otherwise it's printed on standard output. The format is intentionally simple so a script can process it easily if needed. Symbols are printed sorted by name, and for each symbol you get a list of file names: if the symbol is defined, the first file listed is where the definition lives; if it's defined as a common value, any files where that happens come next; and finally, any files that reference the symbol are listed. Chef's kiss organization, fr fr ✨
• --ctf-variables, --no-ctf-variables — okay so the CTF debuginfo format supports a section encoding the names and types of variables in the program that don't 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 wasted — types are usually small but names often are not. --ctf-variables causes generation of such a section. Default behaviour is 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 don't 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 this buys you: it decouples the decision to assign addresses to Common symbols from the choice of output file type — otherwise a non-Relocatable output type forces assigning addresses to Common symbols. Using --no-define-common lets Common symbols referenced from a shared library get addresses assigned 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. Iconic honestly.
• --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 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. Use it as many times as you need to define multiple symbols on the command line. A limited form of arithmetic is supported for expression here: you can give a hexadecimal constant or the name of an existing symbol, or use "+" and "-" to add or subtract hexadecimal constants or symbols. Need more elaborate expressions? Consider using the linker command language from a script, bestie. Note: there should be no white space between symbol, the equals sign ("="), and expression ⚠️

Also, the linker processes --defsym arguments and -T arguments in order: putting --defsym before -T defines the symbol before the linker script from -T is processed, while putting --defsym after -T defines it after the linker script has been processed. This difference has consequences for expressions within the linker script that use the --defsym symbols — which order is correct depends on what you're trying to achieve 🦋

• --demangle[=style], --no-demangle — control whether to demangle symbol names in error messages and other output. When told to demangle, the linker tries to present symbol names readably: 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 one for your compiler. The linker demangles by default unless the environment variable COLLECT_NO_DEMANGLE is set — these options override the default ✨
• -Ifile, --dynamic-linker=file — sets the name of the dynamic linker. Only meaningful when generating dynamically linked ELF executables. The default dynamic linker is normally correct — don't use this unless you know what you're doing 🙈 (she's serious about this one)
• --no-dynamic-linker — when producing an executable file, omit the request for a dynamic linker to be used at load-time. Only meaningful for ELF executables containing dynamic relocations, and usually requires entry point code capable of processing those relocations 🫶
• --embedded-relocs — similar to the --emit-relocs option except the relocs are stored in a target-specific section. Only supported by the BFIN, CR16 and M68K targets 💅
• --disable-multiple-abs-defs — do not allow multiple definitions with symbols included in filename invoked by -R or --just-symbols. Simple as that 🔥
• --fatal-warnings, --no-fatal-warnings — treat all warnings as errors 😤 default behaviour comes back with --no-fatal-warnings.
• -w, --no-warnings — bestie, this one just says "shhh 🤫" to all warnings and error messages. No output, nothing. And yes, it hard-overrides --fatal-warnings if you had that on. When is it valid? When you already know the output binary won't work but you still need to create it anyway. Chaos, but documented chaos 💅
• --force-exe-suffix — forces your output file to have a .exe suffix, periodt. If a fully linked output file comes out without a .exe or .dll suffix, this makes the linker copy the output file to one with a .exe suffix bolted on. Iconic use case: running unmodified Unix makefiles on a Microsoft Windows host, because some Windows versions literally won't run an image unless it ends in .exe. Not a vibe, but here we are 🪟
• --gc-sections, --no-gc-sections — garbage collection for unused input sections ✨. It gets ignored on targets that don't support it, so no drama there. Want the default behaviour back (i.e. not doing the collection)? Just pass --no-gc-sections on the command line. Heads up though: garbage collection for COFF and PE format targets is supported, but the implementation is currently considered experimental 🙈.

How does --gc-sections actually decide what's used? It examines symbols and relocations, like the little detective it is 🔍. Kept: the section containing the entry symbol, all sections containing symbols undefined on the command-line, and sections containing symbols referenced by dynamic objects. Also note: when building shared libraries, the linker must assume any visible symbol is referenced. Once that initial set is locked in, the linker recursively marks as used any section referenced by their relocations. See --entry, --undefined, and --gc-keep-exported.

This option can be set during a partial link (enabled with -r). In that case the root of symbols kept has to be explicitly specified, either by one of --entry, --undefined, or --gc-keep-exported, or by a "ENTRY" command in the linker script.

GNU extension moment 👑: ELF input sections marked with the "SHF_GNU_RETAIN" flag will not be garbage collected. Protected. Cherished.

• --print-gc-sections, --no-print-gc-sections — lists every section that garbage collection removed, printed on stderr 🗑️. Only effective if garbage collection has actually been enabled via the --gc-sections) option. Want the default back (not listing the removed sections)? Pass --no-print-gc-sections on the command line.
• --gc-keep-exported — when --gc-sections is enabled, this prevents garbage collection of unused input sections that contain global symbols having default or protected visibility 🛡️. Meant for executables where unreferenced sections would otherwise get collected regardless of the external visibility of the symbols inside them. Ngl, it has no effect when linking shared objects, because that's already the default behaviour there. Only supported for ELF format targets.
• --print-output-format — prints the name of the default output format (possibly influenced by other command-line options). It's the same string that would show up in an "OUTPUT_FORMAT" linker script command. Cute little preview 🎀
• --print-memory-usage — prints used size, total size and used size of memory regions created with the MEMORY command. Super useful on embedded targets for a quick peek at how much free memory you've got left 🧠✨. Output format = one headline plus one line per region, and it's both human readable and easily parsable by tools. Example:

        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 actually want to know the memory usage of the linker itself, that's what the --stats option is for.

• --help — prints a summary of the command-line options to standard output and exits. The classic "help me bestie" move 🫶
• --target-help — same energy, but prints a summary of all target-specific options to 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 goes to stdout 💜

Special directory behaviour incoming: if you specify a directory as mapfile, the linker writes the map as a file inside that directory. Normally the filename inside the directory is computed as the basename of the output file with .map appended. But if you use the special character %, it gets replaced by the full path of the output file. And if there are any characters after the % symbol, then .map is no longer appended. Behold, the lore:

         -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]

🚨 Specifying more than one % character is an error. And if the map file already exists, this operation will overwrite it. Fair warning, bestie.

• --no-keep-memory — ld normally optimizes for speed over memory usage by caching the symbol tables of input files in memory. This option flips that: it optimizes for memory usage instead, rereading symbol tables as needed 😮‍💨. Might be required if ld runs out of memory while linking a large executable.
• --no-undefined, -z defs — reports unresolved symbol references from regular object files 📢. It does this 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. And 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. First come, first served, no cap.
• --allow-shlib-undefined, --no-allow-shlib-undefined — allows or disallows undefined symbols in shared libraries. Similar to --no-undefined, except this one decides the behaviour when the undefined symbols live in a shared library rather than a regular object file. It does not affect how undefined symbols in regular object files are handled.

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

Why allow undefined symbol references in shared libraries specified at link time? Two reasons, bestie:

• A shared library specified at link time may not be the same as the one available at load time, so the symbol might actually be resolvable at load time. Timeline ✨
• 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 — used, for example, to dynamically select an appropriate memset function. Main character energy for the kernel honestly 👑

• --error-handling-script=scriptname — if provided, the linker invokes scriptname whenever an error is encountered 🐛. Currently though, only two kinds of error are supported: missing symbols and missing libraries. Two arguments get passed to script: the keyword "undefined-symbol" or missing-lib" and the name of the undefined symbol or missing library. The intention? The script gives the user suggestions about where that symbol or library might be found 🔎. After the script finishes, the normal linker error message still gets displayed.

Availability of this option is controlled by a configure time switch, so it may not be present in specific implementations 🙈.

• --no-undefined-version — normally when a symbol has an undefined version, the linker just ignores it. This option disallows symbols with undefined version, and a fatal error gets issued instead ⚠️.
• --default-symver — creates and uses a default symbol version (the soname) for unversioned exported symbols 🏷️
• --default-imported-symver — same but for unversioned imported symbols. Matching set, slay 💅
• --no-warn-mismatch — normally ld errors out if you try to link together input files that are mismatched for some reason — maybe they were compiled for different processors or different endiannesses 😵‍💫. This option tells ld to silently permit such possible errors.

🚨 Use this one with care, and only in cases where you've taken some special action that ensures the linker errors are actually inappropriate. Don't just vibe-check it on and walk away.

• --no-warn-search-mismatch — normally ld warns if it finds an incompatible library during a library search. This silences that warning 🤐.
• --no-whole-archive — turns off the effect of the --whole-archive option for subsequent archive files 🚫📚
• --noinhibit-exec — retains the executable output file whenever it's still usable. Normally the linker won't produce an output file if it hits errors during the link process — it exits without writing one when it issues any error whatsoever. This option says "girl, keep the file anyway" 💾
• -nostdlib — only searches library directories explicitly specified on the command line. Library directories specified in linker scripts (including linker scripts specified on the command line) are straight-up ignored 🙅‍♀️
• --oformat=output-format — okay so ld can be built to support more than one kind of object file. If yours is like that, this flag lets you pick the binary format for the output object file. Even when ld supports alternative object formats, you usually don’t need to touch this — ld should already 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 — create 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) may be used to link clients against the generated executable; this behaviour makes it possible to skip a separate import library creation step (eg. "dlltool" for DLLs). This option is only available for the i386 PE and ELF targetted ports of the linker. 🎀
• -pie, --pic-executable — create a position independent executable. This is currently only supported on ELF platforms. Position independent executables are relocated by the dynamic linker to the virtual address the OS chooses for them, which can vary between invocations. They are marked ET_DYN in the ELF file header, but differ from shared libraries in a number of ways. In particular, defined symbols in a PIE by default can not be overridden by another object as they can be in a shared library. 💅
• -no-pie — create a position dependent executable. This is the default. 🫶
• -qmagic — this option is ignored for Linux compatibility. literally ignored, no cap.
• -Qy — this option is ignored for SVR4 compatibility. also just vibing in the ignored corner.
• --relax, --no-relax — an option with machine dependent effects. This option is only supported on a few targets.

On some platforms the --relax option performs target specific, global optimizations that become possible when the linker resolves addressing in the program, such as relaxing address modes, synthesizing new instructions, selecting shorter version 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, the option --no-relax will disable it.

On platforms where the feature is not supported, both --relax and --no-relax are accepted, but ignored.

• --retain-symbols-file=filename — retain only the symbols listed in the file filename, discarding all others. filename is simply a flat file, with one symbol name per line. This option is especially useful in environments (such as VxWorks) where a large global symbol table is accumulated gradually, to conserve run-time memory. 🧚

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

You may only specify --retain-symbols-file once in the command line. It overrides -s and -S.

• -rpath=dir — add a directory to the runtime library search path. This is used when linking an ELF executable with shared objects. All -rpath arguments are concatenated and passed to the runtime linker, which uses them to locate shared objects at runtime.

The -rpath option is also used when locating shared objects which are needed by shared objects explicitly included in the link; see the description of the -rpath-link option. Searching -rpath in this way is only supported by native linkers and cross linkers which 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 is defined.

The -rpath option may also be used on SunOS. By default, on SunOS, the linker will form a runtime search path out of all the -L options it is given. If a -rpath option is used, the runtime search path will be formed exclusively using the -rpath options, ignoring the -L options. This can be useful when using gcc, which adds many -L options which 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 is treated as the -rpath option. 🌸

• -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 encounters such a dependency when doing a non-shared, non-relocatable link, it will automatically try to locate the required shared library and include it in the link, if it is not included explicitly. In such a case, several directories are searched as described below. The -rpath-link option specifies the first set of directories to search. This option may specify a sequence of directory names either by providing a list of names separated by colons, or by appearing multiple times.

The tokens $ORIGIN and $LIB can appear in these search directories. They will be replaced by the full path to the directory containing the program or shared object in the case of $ORIGIN and either lib - for 32-bit binaries - or lib64 - for 64-bit binaries - in the case of $LIB.

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

bestie, be careful: the --rpath-link option should be used with caution as it overrides the search path that may have been hard compiled into a shared library. In such a case it is possible to unintentionally use a different search path than the runtime linker would have used. 💀

When additional shared libraries are required, the linker will search directories in the order listed below in order to find them. Note however that this only applies to additional libraries needed to satisfy already included shared libraries. It does not apply to libraries that are included via the -l command line option. Searches for -l libraries are only conducted in directories specified by the -L option.

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 the -rpath-link option is only effective at link time. Searching -rpath in this way is only supported by native linkers and cross linkers which 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. For a linker for a Linux system, if the file /etc/ld.so.conf exists, the list of directories found in that file. Note: the path to this file is prefixed with the "sysroot" value, if that is defined, and then any "prefix" string 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 defined in the elf-hints.h header file.
9. Any directories specified by a "SEARCH_DIR" command in a linker script given on the command line, including scripts specified by -T (but not -dT).
10. The default directories, normally /lib and /usr/lib.
11. Any directories specified by a plugin LDPT_SET_EXTRA_LIBRARY_PATH.
12. Any directories specified by a "SEARCH_DIR" command in a default linker script.

Note however on Linux based systems there is an additional caveat: If the --as-needed option is active and a shared library is located which would normally satisfy the search and this library does not have DT_NEEDED tag for libc.so and there is a shared library later on in the set of search directories which also satisfies the search and this second shared library does have a DT_NEEDED tag for libc.so then the second library will be selected instead of the first. 🙈

If the required shared library is not found, the linker will issue a warning and continue with the link.

• --section-ordering-file=script — this option is used to augment the current linker script with additional mapping of input sections to output sections. This file must use the same syntax for "SECTIONS" as is used in normal linker scripts, but it should not do anything other than place input sections into output sections. @pxref{SECTIONS} ✨

A second constraint on the section ordering script is that it 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 specified on the command line). The benefit of the section ordering script however is that the input sections are mapped to the start of the output sections, so that they can ensure the ordering of sections in the output section. For example, imagine that 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) }

This 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.*) }
  }

and like — the whole point of the section ordering file is that you get to order the sections that actually matter to you, without having to worry about any other sections, or memory regions, or literally anything else. it's giving ✨main character energy✨ for your sections. 🎀

• -shared, -Bshareable — makes a shared library. rn this is only supported on ELF, XCOFF and SunOS platforms. and on SunOS the linker will just automatically create a shared library if you're not using -e and there are undefined symbols in the link. she does it herself, no notes. 💅
• --sort-common, --sort-common=ascending, --sort-common=descending — tells ld to sort the common symbols by alignment, ascending or descending, when it places them into the appropriate output sections. the alignments it considers are sixteen-byte or larger, eight-byte, four-byte, two-byte, and one-byte. why? to prevent gaps between symbols due to alignment constraints. if you don't specify a sorting order, descending is assumed. default slay. 🫶
• --sort-section=name — applies "SORT_BY_NAME" to all wildcard section patterns in the linker script. all of them. 📛
• --sort-section=alignment — same idea but applies "SORT_BY_ALIGNMENT" to all wildcard section patterns in the linker script. 📐
• --spare-dynamic-tags=count — picks 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 when size is reached. if you don't give one, size defaults to a size of 1. 📂
• --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. super useful when you're generating huge relocatable files for downloading into certain real time kernels with the COFF object file format, since COFF cannot represent more than 65535 relocations in a single section. ⚠️ but bestie, note: this will fail to work with object file formats which do not 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 contain that many relocations. count defaults to 32768. 🫠
• --stats[=filename] — computes and displays statistics about what the linker got up to, like execution time and memory usage. 📊

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

if the -Map option has been enabled then the information is also recorded in the map file as well. note: if both the --stats option and the -Map options have been given filename arguments and they match, then the information will only be written out once, not twice. we do not do duplicates here. 💅

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'll be used as the name of a file into which the information should be recorded. otherwise the information goes 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 the --stats option 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. note that individual phases can contain or overlap with each other, so it should not be assumed that the overall resources used by the linker is the sum of the resources used by the individual phases. overlapping phases, we contain multitudes. 🌈

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 handle the situation where multiple links are being invoked by a build system, and to identify exactly which arguments were responsible for producing the statistics that are reported. iykyk. 🕵️

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 — turns off the reporting of usage statistics, should it have been enabled via the --stats command line option or the LD_STATS environment variable. the undo button. 🙈
• --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. no configure flag, no sysroot, no cap. 🚫
• --task-link — 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, and this switch asks ld to use the traditional format instead. 🕰️

example time: on SunOS, ld combines duplicate entries in the symbol string table. this can reduce 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). the --traditional-format switch tells ld to not combine duplicate entries. one little flag, one big debugging-session save. 😭

• --section-start=sectionname=org — locates a section in the output file at the absolute address given by org. you may use this option as many times as necessary to locate multiple sections in the command line. org must be a single hexadecimal integer; for compatibility with other linkers, you may omit the leading 0x usually associated with hexadecimal values. 📍

note: there should be no white space between sectionname, the equals sign ("="), and org. not even one. i'm watching. 👀

• --image-base=org — when using ELF, same as -Ttext-segment, with both options effectively setting the base address of the ELF executable. 🧬

when using PE, use value as the base address of your program or dll. this is the lowest memory location that will be used when your program or dll is loaded. to reduce the need to relocate and improve performance of your dlls, each 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 as --section-start, with .bss, .data or .text as the sectionname. the shortcut trio. ⚡
• -Ttext-segment=org — when creating an ELF executable, it will set the address of the first byte of the first segment. note that when -pie is used with -Ttext-segment=org, the output executable is marked ET_EXEC so that the address of the first byte of the text segment will be guaranteed to be org at run time. guaranteed. certified. signed off. 🖊️
• -Trodata-segment=org — when creating an ELF executable or shared object for a target where the read-only data is in its own segment separate from the executable text, it will set the address of the first byte of the read-only data segment. 📚
• -Tldata-segment=org — when creating an ELF executable or shared object for x86-64 medium memory model, it will set the address of the first byte of the ldata segment. niche but iconic. 🦋
• --unresolved-symbols=method — decides how to handle unresolved symbols. there are four possible values for method:
  • ignore-all — do not report any unresolved symbols. see no evil. 🙈
  • 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 can be useful when creating a dynamic binary and it is known that all the shared libraries that 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 to a warning. gentle parenting mode. 🍼

• --dll-verbose, --verbose[=NUMBER] — bestie, this one is basically the linker’s little “hi, here’s what’s up” mode ✨. It displays the version number for ld and lists the linker emulations supported. It also shows which input files can and cannot be opened, and it displays the linker script being used by the linker. If the optional NUMBER argument is greater than 1, plugin symbol status will also be displayed. Very “tell me everything” main character energy 💅.
• --version-script=version-scriptfile — okay so this specifies the name of a version script to the linker 🎀. This is typically used when creating shared libraries to specify additional information about the version hierarchy for the library being created. 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. Noted, bestie 🫶.
• --warn-common — warn when a common symbol is 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 allows you to 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 giving “your fave is problematic” but for symbol merging 😭.

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.

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 — warn if any global constructors are used. This is only useful for a few object file formats. For formats like COFF or ELF, the linker can not detect the use of global constructors. So like… don’t expect magic where there isn’t any, bestie 🙈.
• --warn-execstack, --warn-execstack-objects, --no-warn-execstack — on ELF platforms the linker may generate warning messages if it is 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. Pick your vibe 🌈.

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, then absence of such a section implies that an executable stack is required. This is often a problem for hand crafted assembler files. Hand crafted?? In this economy?? 💀

• --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. 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. So it’s a glow-up from “warning” to “error,” not a whole personality transplant 🎀.
• --warn-multiple-gp — warn 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. 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. Thus, in large programs, it is 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. Big program problems, honestly 😭.
• --warn-once — only warn once for each undefined symbol, rather than once per module which refers to it. We love a “say it once and move on” queen 👑.
• --warn-rwx-segments, --no-warn-rwx-segments — warn 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. These warnings are enabled by default. They can be disabled via the --no-warn-rwx-segments option and re-enabled via the --warn-rwx-segments option. Security girlies stay winning 🔥.
• --error-rwx-segments, --no-error-rwx-segments — if the linker is going to generate a warning message about an executable, writeable segment, or an executable TLS segment, then the --error-rwx-segments option will turn this warning into an error instead. The --no-error-rwx-segments option will restore the default behaviour of just generating a warning message.

Note — the --error-rwx-segments option does not by itself turn on warnings about these segments. These warnings are either enabled by default, if the linker was configured that way, or via the --warn-rwx-segments command line option. Don’t skip steps, bestie 💅.

• --warn-section-align — warn if the address of an output section is changed because of alignment. Typically, the alignment will be set by an input section. The address will only be changed if it not explicitly specified; that is, if the "SECTIONS" command does not specify a start address for the section. It’s giving “who moved my section” energy ⭐.
• --warn-textrel — warn if the linker adds DT_TEXTREL to a position-independent executable or shared object. Keep an eye on that, bestie 👀.
• --warn-alternate-em — warn if an object has alternate ELF machine code. Little warning, big awareness 🦋.
• --warn-unresolved-symbols — if the linker is going to report an unresolved symbol (see the option --unresolved-symbols) it will normally generate an error. This option makes it generate a warning instead. Soft launch the problem, I guess 😭.
• --error-unresolved-symbols — this restores the linker’s default behaviour of generating errors when it is reporting unresolved symbols. Back to business, no cap 🎀.
• --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. It’s the “everyone is invited” option, fr fr 🫶.

Two notes when using this option from gcc: First, gcc doesn’t know about this option, so you have to use -Wl,-whole-archive. Second, 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. Do not forget the cleanup, bestie, I’m begging 😭.

• --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. It’s literally the “call me by your name” of linker symbols 💅.

Here is a trivial example:

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

So like, if you link other code with this file using --wrap malloc, then all calls to malloc will call the function __wrap_malloc instead. And the call to __real_malloc inside __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. But bestie, 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. 😭

Only undefined references are replaced by the linker. So, translation unit internal references to a 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 the .eh_frame_hdr section and the 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 — discard .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 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 these options are only available for ELF systems. 👑
• --hash-size=number — set 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 — set the type of the linker's hash table(s). style can be either sysv for the classic ELF .hash section, gnu for the new style GNU .gnu.hash section, or both for both the classic ELF .hash and the 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. 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 also be used to enable other tradeoffs in future versions of the linker. 🌸
• --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. 🔥
• --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, or xx to use a 128-bit XXHASH on the normative parts of the output contents; or 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 produce 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. Passing none for style disables the setting from any --build-id options earlier on the command line. 🌈
• --package-metadata=JSON — request the creation of a .note.package ELF note section. The contents of the note are in JSON format, as per the package metadata specification. For more information see: https://systemd.io/ELF_PACKAGE_METADATA/ The JSON argument supports percent-encoding and the following %[string] encodings (where string refers to the name in HTML's Named Character References): %[comma] for ,, %[lbrace] for {, %[quot] for ", %[rbrace] for }, and %[space] for the space character. If the JSON argument is missing/empty, then this will disable the creation of the metadata note, if one had been enabled by an earlier occurrence of the --package-metadata option. If the linker has been built with libjansson, then the JSON string will be validated. 🧚

---

The i386 PE linker supports the -shared option, which causes the output to be a dynamically linked library (DLL) instead of a normal executable. You should name the output *.dll when you use this option. In addition, the linker fully supports the standard *.def files, which may be specified on the linker command line like an object file (in fact, it should precede archives it exports symbols from, to ensure that they get linked in, just like a normal object file). 💖

In addition to the options common to all targets, the i386 PE linker supports additional command-line options that are specific to the i386 PE target. Options that take values may be separated from their values by either a space or an equals sign. ⭐

• --add-stdcall-alias — if given, symbols with a stdcall suffix (@nn) will be exported as-is and also with the suffix stripped. [This option is specific to the i386 PE targeted port 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 is an i386 PE specific option] 🫶
• --dll — create a DLL instead of a regular executable. You may also use -shared or specify a LIBRARY in a given .def file. [This option is specific to the i386 PE targeted port of the linker] 💅
• --enable-long-section-names, --disable-long-section-names — the PE variants of the COFF object format add an extension that permits the use of section names longer than eight characters, the normal limit for COFF. By default, these names are only allowed in object files, as fully-linked executable images do not carry the COFF string table required to support the longer names. As a GNU extension, it is possible to allow their use in executable images as well, or to (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 generate confusing output when examined with non-GNU PE-aware tools, such as file viewers and dumpers. However, GDB relies on the use of PE long section names to find Dwarf-2 debug information sections in an executable image at runtime, and so if neither option is specified on the command-line, ld will enable long section names, overriding the default and technically correct behaviour, when it finds the presence of debug information while linking an executable image and not stripping symbols. [This option is valid for all PE targeted ports of the linker] 🦋
• --enable-stdcall-fixup, --disable-stdcall-fixup — okay so this one's about ~fuzzy linking~ 💅. If the link finds a symbol it literally cannot resolve, it'll go hunting for another defined symbol that differs only in the format of the symbol name (cdecl vs stdcall) and resolve it by linking to the 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 little move it prints a warning, because normally it should have failed to link — but sometimes import libraries generated from third-party dlls lowkey need this feature to be usable. Pass --enable-stdcall-fixup and the feature is fully enabled, no warnings printed. Pass --disable-stdcall-fixup and it's disabled, and such mismatches are straight-up errors. [This option is specific to the i386 PE targeted port of the linker]
• --leading-underscore, --no-leading-underscore — for most targets the default symbol-prefix is an underscore, defined in the target's description. This option lets you disable/enable that default underscore symbol-prefix. ✨
• --export-all-symbols — give this and all global symbols in the objects used to build a DLL get exported by the DLL. 🫶 Note that this is the default if there otherwise wouldn't be any exported symbols at all. But 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. Heads up on what does not get auto-exported: the symbols DllMain@12, DllEntryPoint@0, DllMainCRTStartup@12, and impure_ptr. Also symbols imported from other DLLs won't be re-exported, and neither will symbols specifying the DLL's internal layout 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_ stay unexported too, to help with C++ DLLs. And finally there's an extensive list of cygwin-private symbols that aren't exported (obviously this applies only when building DLLs for cygwin targets) — these 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 the i386 PE targeted port of the linker]
• --exclude-symbols symbol,symbol,... — specifies a list of symbols that should not be automatically exported. The symbol names may be delimited by commas or colons. [This option is specific to the i386 PE targeted port of the linker]
• --exclude-all-symbols — specifies no symbols should be automatically exported. That's it, that's the whole vibe. 🙈 [This option is specific to the i386 PE targeted port 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. Defaults to 512. [This option is specific to the i386 PE targeted port 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 the i386 PE targeted port of the linker]
• --kill-at — if given, the stdcall suffixes (@nn) will be stripped from symbols before they are exported. Slay, no more suffix. 💅 [This option is specific to the i386 PE targeted port of the linker]
• --large-address-aware — if given, the appropriate bit in the Characteristics field of the COFF header is set to indicate 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 PE targeted ports of the linker]
• --disable-large-address-aware — reverts the effect of a previous --large-address-aware option. Genuinely useful if --large-address-aware is always set by the compiler driver (e.g. Cygwin gcc) and the executable does not support virtual addresses greater than 2 gigabytes. [This option is specific to PE targeted ports of the linker]
• --major-image-version value — sets the major number of the image version. Defaults to 1. [This option is specific to the i386 PE targeted port of the linker]
• --major-os-version value — sets the major number of the os version. Defaults to 4. [This option is specific to the i386 PE targeted port of the linker]
• --major-subsystem-version value — sets the major number of the subsystem version. Defaults to 4. [This option is specific to the i386 PE targeted port of the linker]
• --minor-image-version value — sets the minor number of the image version. Defaults to 0. [This option is specific to the i386 PE targeted port of the linker]
• --minor-os-version value — sets the minor number of the os version. Defaults to 0. [This option is specific to the i386 PE targeted port of the linker]
• --minor-subsystem-version value — sets the minor number of the subsystem version. Defaults to 0. [This option is specific to the i386 PE targeted port 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 the i386 PE targeted port 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. Iconic behaviour honestly. ⭐ [This option is specific to the i386 PE targeted port 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 the i386 PE targeted port 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 the i386 PE targeted port of the linker]
• --enable-auto-import — does sophisticated linking of _symbol to __imp__symbol for DATA imports from DLLs, thus making it possible to bypass the dllimport mechanism on the user side and to reference unmangled symbol names. [This option is specific to the i386 PE targeted port of the linker]

The following remarks pertain to the original implementation of the feature and are obsolete nowadays for Cygwin and MinGW targets.

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 }

Okay bestie, real talk — this next bit is the "our data symbol got a constant offset and everything's on fire" saga. Buckle up 💅

A third method of dealing with this difficulty is to abandon 'auto-import' for the offending symbol and mark it with __declspec(dllimport). However — and this is the annoying part — 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. So when you're choosing 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 dodge this whole 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). Iconic, honestly 👑

---

• --disable-auto-import — do not attempt to do sophisticated linking of "_symbol" to "__imp__symbol" for DATA imports from DLLs. [This option is specific to the i386 PE targeted port 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 the runtime environment to adjust references to such data in your client code. [This option is specific to the i386 PE targeted port 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 the i386 PE targeted port of the linker]
• --enable-extra-pe-debug — show additional debug info related to auto-import symbol thunking. [This option is specific to the i386 PE targeted port 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 the i386 PE targeted port 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 the i386 PE targeted port 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 the i386 PE targeted port 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. 🫶

• --dynamicbase / --disable-dynamicbase — the image base address may be relocated using address space layout randomization (ASLR). This feature was introduced with MS Windows Vista for i386 PE targets. 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 for i386 PE targets. 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. 😭 (reproducible builds girlies, this one's for you)

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.

---

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.

The --no-merge-exidx-entries switch disables the merging of adjacent exidx entries in frame unwind info. 🧚

• --branch-stub — this option enables linker branch relaxation by inserting branch stub sections when needed to extend the range of branches. This option is usually not required since C-SKY supports branch and call instructions that can access the full memory range and branch relaxation is normally handled by the compiler or assembler.
• --stub-group-size=N — this option allows finer control of linker branch stub creation. It sets the maximum size of a group of input sections that can be handled by one stub section. A negative value of N locates stub sections after their branches, while a positive value allows stub sections to appear either before or after the branches. Values of 1 or -1 indicate that the linker should choose suitable defaults.

---

The 68HC11 and 68HC12 linkers support specific options to control the memory bank switching mapping and trampoline code generation. 🌈

• --no-trampoline — this option disables the generation of trampoline. 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).
• --bank-window name — this option indicates to 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.

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

• --got=type — this option 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 options control the choice of microMIPS instructions used in code generated by the linker, such as that in the PLT or 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 options 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 are 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. 💀 (yes, it will yell at you, and honestly? deserved)
• --compact-branches / --no-compact-branches — these options control the generation of compact instructions by the linker in the PLT entries for MIPS R6.

Okay bestie, one last little pdp11 detour before we wrap — because the pdp11-aout target is out here living its own best life with three whole flavours of output format. You pick one with the options below. Lowkey important: the default variant for pdp11-aout is --omagic, whereas for every other target --nmagic is the default. And --imagic is defined only for the pdp11-aout target — the other two are described here as they apply to the pdp11-aout target. Iykyk. 💅

• -N, --omagic — stamps the output as "OMAGIC" (0407) in the a.out header, which tells the world the text segment is not to be write-protected and shared. Since text and data are both readable and writable, the data section gets allocated immediately contiguous after the text segment. This is literally the oldest format for PDP11 executable programs, and it's been the default for ld on PDP11 Unix systems from the very beginning all the way through 2.11BSD. Iconic behavior. 👑
• -n, --nmagic — stamps the output as "NMAGIC" (0410) in the a.out header, meaning that when the output file is executed, the text portion will be read-only and shareable among all processes executing that same file. The catch? It 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 — stamps the output as "IMAGIC" (0411) in the a.out header, meaning 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. That doubles the address space available to the program, bestie. 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. Short and sweet, fr fr.

---

🌸 ENVIRONMENT 🌸

You can absolutely change how ld behaves with the environment variables "GNUTARGET", "LDEMULATION" and "COLLECT_NO_DEMANGLE". Let's go through them, one bestie at a time. 💜

"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 — and this method often succeeds, but there are potential ambiguities, since there is 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. Slay, honestly.

"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. Reproducible builds said what? 🔥

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. And if the "LD_STATS" variable has a string value, then this will 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. Note that "this will used as the name" is exactly how the page says it, so don't come for me, I'm just the messenger. 🙈

---

👀 SEE ALSO 👀

Go read ar(1), nm(1), objcopy(1), objdump(1), readelf(1) and the Info entries for binutils and ld. Your group chat of tools, basically. 🎀

---

📜 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".

---

And that's the whole page, bestie — every last crumb of it. This icon is from binutils-2.46.1, dated 2026-06-08, and it's the LD(1) manual page, so go forth and link things. Periodt. 💅✨🎀