LD.LLD(1)

💖 ld.lld(1) — bestie edition 💖

okay so you opened the General Commands Manual and landed on ld.lld(1), which is the whole entire vibe of this page. buckle up, we're doing a linker tour 🎀

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✨ NAME ✨

ld.lld — the ELF linker from the LLVM project. that's it. that's the name. iconic. 👑

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🦋 SYNOPSIS 🦋

ld.lld [options] objfile ...

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💅 DESCRIPTION 💅

so like, what even is a linker? bestie. a linker takes one or more object, archive, and library files and smooshes them together into one output file — which could be an executable, a shared library, or honestly another object file. it relocates code and data from the input files and resolves symbol references between them. that's the whole job. matchmaking, basically. 🫶

ld.lld is a drop-in replacement for the GNU BFD and gold linkers, no cap. it accepts most of the same command line arguments and linker scripts as GNU linkers do, so you can just swap it in and act natural. ✨

target support, and this is lowkey a lot: ld.lld currently supports i386, x86-64, ARM, AArch64, LoongArch, PowerPC32, PowerPC64, MIPS32, MIPS64, RISC-V, AMDGPU, Hexagon and SPARC V9 targets. also, ld.lld acts as a Microsoft link.exe-compatible linker if invoked as lld-link, and as macOS's ld if invoked as ld.ld64. and the best part — all these targets are always supported however ld.lld was built, so you can always use ld.lld as a native linker as well as a cross linker. main character energy fr fr 💜

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🌸 OPTIONS 🌸

many options have both a single-letter and a long form. when you're using the long form options — other than those beginning with the letter o — you may specify them using either one or two dashes preceding the option name. but long options beginning with o require two dashes, to avoid confusion with the -o path option. don't fight it, that's just the rules. 🎀

• --allow-multiple-definition — do not error if a symbol is defined multiple times. the first definition will be used. (yes, first one wins, we don't argue about it)
• --allow-shlib-undefined — allow unresolved references in shared libraries. this one is enabled by default when linking a shared library. 🫶
• --apply-dynamic-relocs — apply link-time values for dynamic relocations.
• --as-needed — only set DT_NEEDED for shared libraries if they're actually used. minimal effort, minimal footprint ✨
• --auxiliary=value — set the DT_AUXILIARY field to the specified name.
• --Bdynamic, --dy — link against shared libraries.
• --Bstatic, --static, --dn — do not link against shared libraries.
• -Bno-symbolic — don't bind default visibility defined symbols locally for -shared (this is the default).
• -Bsymbolic — bind default visibility defined symbols locally for -shared. also sets the DF_SYMBOLIC flag. 💅
• -Bsymbolic-non-weak — bind default visibility defined STB_GLOBAL symbols locally for -shared.
• -Bsymbolic-functions — bind default visibility defined function symbols locally for -shared.
• -Bsymbolic-non-weak-functions — bind default visibility defined STB_GLOBAL function symbols locally for -shared.
• ---be8 — Write a Big Endian ELF File using BE8 format(AArch32 only) 👀 (yes that's three dashes, i'm not gaslighting you)
• --build-id=value — generate a build ID note. value may be one of fast, md5, sha1, tree, uuid, 0xhex-string, and none. tree is an alias for sha1. build-IDs of type fast, md5, sha1, and tree are calculated from the object contents. fast is not intended to be cryptographically secure — it's giving "good enough" energy, not "protect my diary" energy. 🔥
• --build-id — synonym for --build-id=sha1.
• --call-graph-profile-sort=algorithm — and algorithm may be:
  • none — ignore call graph profile.
  • hfsort — use hfsort.
  • cdsort — use cdsort (default). 👑
• --color-diagnostics=value — use colors in diagnostics. value may be one of always, auto, and never. auto enables color if and only if output is to a terminal. ✨
• --color-diagnostics — alias for --color-diagnostics=auto.
• --compress-debug-sections=value — compress DWARF debug sections. the sections remain uncompressed if compressed content would be larger. value may be:
  • none — no compression.
  • zlib — the default compression level is 1 (fastest) as the debug info usually compresses well at that level.
  • zstd — use the default compression level in zstd.
• --compress-sections=section-glob={none,zlib,zstd}[:level] — compress output sections that match the glob and do not have the SHF_ALLOC flag. the matched sections remain uncompressed if compressed content would be larger. the compression level is level (if specified) or a default speed-focused level. this is like a generalized --compress-debug-sections. 🎀
• --cref — output cross reference table. if -Map is specified, print to the map file.
• --debug-names — generate a merged .debug_names section.
• --default-script=file, -dT file — in the absence of --script, read this default linker script.
• --defsym=symbol=expression — define a symbol alias. expression may be another symbol or a linker script expression. for example, --defsym=foo=bar or --defsym=foo=bar+0x100. cute, right?
• --demangle — demangle symbol names. give those names their government name back 💅
• --disable-new-dtags — disable new dynamic tags.
• --discard-all, -x — delete all local symbols.
• --discard-locals, -X — delete temporary local symbols.
• --discard-none — keep all symbols in the symbol table. hoarder behaviour, valid.
• --dynamic-linker=value — specify the dynamic linker to be used for a dynamically linked executable. this is recorded in an ELF segment of type PT_INTERP.
• --dynamic-list=file — similar to --export-dynamic-symbol-list. when creating a shared object, implies -Bsymbolic but does not set DF_SYMBOLIC.
• --EB — Select the big-endian format in the OUTPUT_FORMAT command.
• --EL — Select the little-endian format in the OUTPUT_FORMAT command.
• --eh-frame-hdr — request creation of .eh_frame_hdr section and PT_GNU_EH_FRAME segment header.
• --emit-relocs, -q — generate relocations in the output.
• --enable-new-dtags — enable new dynamic tags.
• --enable-non-contiguous-regions — spill input sections to later matching output sections to avoid memory region overflow.
• --end-lib — end a grouping of objects that should be treated as if they were together in an archive.
• --entry=entry — name of entry point symbol.
• --error-limit=value — maximum number of errors to emit before stopping. a value of zero indicates that there is no limit. (zero = infinite chaos, got it 💀)
• --error-unresolved-symbols — report unresolved symbols as errors.
• --error-handing-script=script_path — call script script_path upon some error, with tag as first argument, and an extra parameter as second argument. the script is expected to return 0 on success. any other value is considered a generic error. tag may be missing-lib followed by the name of the missing library. undefined-symbol followed by the name of the undefined symbol. 📞 like a little emergency hotline for your link
• --execute-only — mark executable sections unreadable. this option is currently only supported on AArch64.
• --exclude-libs=value — exclude static libraries from automatic export.
• --export-dynamic, -E — put symbols in the dynamic symbol table.
• --export-dynamic-symbol=glob — (executable) put matched non-local defined symbols to the dynamic symbol table. (shared object) references to matched non-local STV_DEFAULT symbols shouldn't be bound to definitions within the shared object even if they would otherwise be due to -Bsymbolic, -Bsymbolic-functions or --dynamic-list. iykyk.
• --export-dynamic-symbol-list=file — read a list of dynamic symbol patterns from file. apply --export-dynamic-symbol on each pattern.
• --fatal-warnings — treat warnings as errors. no chill mode. 😭
• --filter=value, -F value — set the DT_FILTER field to the specified value.
• --fini=symbol — specify a finalizer function.
• --force-group-allocation — only meaningful for -r. section groups are discarded. if two section group members are placed to the same output section, combine their relocations as well.
• --format=input-format, -b input-format — specify the format of the inputs following this option. input-format may be one of binary, elf, and default. default is a synonym for elf.
• --gc-sections — enable garbage collection of unused sections. spring cleaning for your binary 🧚
• --gdb-index — generate .gdb_index section.
• --hash-style=value — specify hash style. value may be sysv, gnu, or both. both is the default.
• --help — print a help message. always there for you 🫶
• --icf=all — enable identical code folding.
• --icf=safe — enable safe identical code folding.
• --icf=none — disable identical code folding.
• --ignore-data-address-equality — ignore address equality of data. C/C++ requires each data to have a unique address. this option allows lld to do unsafe optimization that breaks the requirement: create copies of read-only data or merge two or more read-only data that happen to have the same value. ⚠️ unsafe, bestie, it says so right there
• --ignore-function-address-equality — ignore address equality of functions. this option allows non-PIC calls to a function with non-default visibility in a shared object. the function may have different addresses within the executable and within the shared object. ⚠️ same energy, be careful
• --image-base=value — set the base address to value.
• --init=symbol — specify an initializer function.
• --keep-unique=symbol — do not fold symbol during ICF.
• -l libName, --library=libName — root name of library to use.
• -L dir, --library-path=dir — add a directory to the library search path.
• --lto-aa-pipeline=value — AA pipeline to run during LTO. used in conjunction with --lto-newpm-passes.
• --lto-newpm-passes=value — passes to run during LTO.
• --lto-Oopt-level — optimization level for LTO.
• --lto-partitions=value — number of LTO codegen partitions.
• -m value — set target emulation.
• --Map=file, -M file — print a link map to file.
• --nmagic, -n — do not page align sections, link against static libraries.
• --no-allow-shlib-undefined — do not allow unresolved references in shared libraries. this option is enabled by default when linking an executable. 👑
• --no-as-needed — always set DT_NEEDED for shared libraries.
• --no-color-diagnostics — do not use colors in diagnostics.
• --no-demangle — do not demangle symbol names.
• --no-dynamic-linker — inhibit output of an .interp section.
• --no-fortran-common — okay so normally the linker goes digging through archive members looking for definitions that could override COMMON symbols, and this says nope, don't do that. 💅
• --no-gc-sections — turns off the garbage collection of unused sections. Like, nothing gets swept away anymore. 🗑️
• --no-gnu-unique — disables STB_GNU_UNIQUE symbol binding. byeee 👋
• --no-merge-exidx-entries — stops the linker from merging .ARM.exidx entries. no grouping today bestie 🎀
• --no-nmagic — page align sections. that's it, that's the whole vibe 📐
• --no-omagic — do not set the text data sections to be writable, and page align sections. 💖
• --no-relax — disables target-specific relaxations. and for x86-64 specifically, this kills the R_X86_64_GOTPCRELX and R_X86_64_REX_GOTPCRELX GOT optimization. no chill, no relax 😤
• --no-rosegment — do not put read-only non-executable sections in their own segment. they gotta share, sorry 🫶
• --undefined-version — do not report version scripts that refer to undefined symbols. like, let it slide ✨
• --no-undefined — report unresolved symbols even if the linker is creating a shared library. it's giving strict parent energy 💀
• --no-warn-mismatch — do not reject unknown section types. live and let live ig 🌸
• --no-warn-symbol-ordering — do not warn about problems with the symbol ordering file or the call graph profile. silence is golden 🤫
• --no-warnings, -w — suppress warnings AND cancel --fatal-warnings. two-for-one slay 👑
• --no-whole-archive — restores the default behavior of loading archive members. back to factory settings bestie 🎀
• --no-pie, --no-pic-executable — do not create a position independent executable. ✨
• --noinhibit-exec — retain the executable output file whenever it is still usable. keep it, it's still cute 💅
• --nostdlib — only search directories specified on the command line. no default paths, we're going custom 🦋
• -o path — write the output executable, library, or object to path. if you don't specify it, a.out is used as a default. main character output file fr fr 📁
• -Ovalue — optimize output file size. value may be:
  • 0 — disable string merging.
  • 1 — enable string merging.
  • 2 — enable string tail merging.

-O1 is the default. the way that 1 just quietly runs the whole show 😌

• --oformat=format — specify the format for the output object file. the only supported format is binary, which produces output with no ELF header. just so you know — it's the only one, no other options, periodt 💀
• --omagic, -N — set the text and data sections to be readable and writable, do not page align sections, and link against static libraries. chaotic but make it work 🔥
• --opt-remarks-filename file — write optimization remarks in YAML format to file. 📝
• --opt-remarks-passes pass-regex — filter optimization remarks by only allowing the passes matching pass-regex. only the chosen ones get through 👑
• --opt-remarks-with-hotness — include hotness information in the optimization remarks file. 🔥 literally hotness, no cap
• --orphan-handling=mode — control how orphan sections are handled. an orphan section is one not specifically mentioned in a linker script. mode may be:
  • place — place orphan sections in suitable output sections.
  • warn — place orphan sections as for place and also report a warning.
  • error — place orphan sections as for place and also report an error.

place is the default. taking care of the little orphan sections 🥺💖

• --pack-dyn-relocs=format — pack dynamic relocations in the given format. format may be:
  • none — do not pack. dynamic relocations are encoded in SHT_REL(A).
  • android — pack dynamic relocations in SHT_ANDROID_REL(A).
  • relr — pack relative relocations in SHT_RELR, and the rest of dynamic relocations in SHT_REL(A).
  • android+relr — pack relative relocations in SHT_RELR, and the rest of dynamic relocations in SHT_ANDROID_REL(A).

none is the default. and heads up — if --use-android-relr-tags is specified, use SHT_ANDROID_RELR instead of SHT_RELR. 📦✨

• --pic-veneer — always generate position independent thunks. 🧚
• --pie, --pic-executable — create a position independent executable. the PIE of it all 🥧💅
• --power10-stubs=mode — whether to use Power10 instructions in call stubs for R_PPC64_REL24_NOTOC and TOC/NOTOC interworking. mode may be:
  • yes — (default) use.
  • auto — currently the same as yes.
  • no — don't use.

⚡ power10 energy, literally

• --print-gc-sections — list removed unused sections. snitch on the garbage 🗑️👀
• --print-icf-sections — list identical folded sections. twinning fr 👯
• --print-map — print a link map to the standard output. 🗺️
• --print-archive-stats=file — write archive usage statistics to the specified file. it prints the numbers of members and fetched members for each archive. receipts, bestie 🧾
• --push-state — save the current state of --as-needed, --static, and --whole-archive. bookmark it 🔖
• --pop-state — restore the states saved by --push-state. un-bookmark it, we're back 🫶
• ---relax-gp — enable global pointer relaxation for RISC-V. (yes, that's three dashes, that's literally how it's written, don't come for me) 🌈
• --relocatable, -r — create relocatable object file. 🔄
• --remap-inputs=from-glob=to-file — input files matching from-glob are mapped to to-file. use /dev/null to ignore an input file. bye felicia 👋
• --remap-inputs-file=file — remap input files based on patterns in file. each line in the remap file is of the format from-glob=to-file or a comment starting with #. 📄
• --reproduce=path — write a tar file to path, containing all the input files needed to reproduce the link, a text file called response.txt containing the command line options and a text file called version.txt containing the output of ld.lld --version. the archive when unpacked can be used to re-run the linker with the same options and input files. time capsule core 🎁✨
• --retain-symbols-file=file — retain only the symbols listed in the file. keep the chosen ones, drop the rest 💅
• --rpath=value, -R value — add a DT_RUNPATH to the output. 🛣️
• --rsp-quoting=value — quoting style for response files. the supported values are windows and posix. 🪟🐧
• --script=file, -T file — read linker script from file. if multiple linker scripts are given, they are processed as if they were concatenated in the order they appeared on the command line. 📜
• --section-start=section=address — set address of section. 📍
• --shared, --Bsharable — build a shared object. (yes, --Bsharable, that's the spelling, keep it moving) 🫶
• --shuffle-sections=seed — shuffle matched sections using the given seed before mapping them to the output sections. if -1, reverse the section order. if 0, use a random seed. 🎲 no cap, it actually shuffles
• --soname=value, -h value — set DT_SONAME to value. 🏷️
• --sort-common — this option is ignored for GNU compatibility. it's just there for the vibes 🙈
• --sort-section=value — specifies sections sorting rule when linkerscript is used. 🗂️
• --start-lib — start a grouping of objects that should be treated as if they were together in an archive. 👯♀️
• --strip-all, -s — strip all symbols. implies --strip-debug. ✂️
• --strip-debug, -S — strip debugging information. 🐛✂️
• --symbol-ordering-file=file — lay out sections in the order specified by file. 📋
• --sysroot=value — set the system root. 🌳
• --target1-abs — interpret R_ARM_TARGET1 as R_ARM_ABS32. 🎯
• --target1-rel — interpret R_ARM_TARGET1 as R_ARM_REL32. 🎯
• --target2=type — interpret R_ARM_TARGET2 as type, where type is one of rel, abs, or got-rel. 🎯
• --Tbss=value — same as --section-start with .bss as the sectionname. 📍
• --Tdata=value — same as --section-start with .data as the sectionname. 📍
• --Ttext=value — same as --section-start with .text as the sectionname. 📍
• --thinlto-cache-dir=value — path to ThinLTO cached object file directory. 📂
• --thinlto-cache-policy=value — pruning policy for the ThinLTO cache. 🌿✂️
• --thinlto-jobs=value — number of ThinLTO jobs. 💼
• --threads=N — number of threads. all (default) means all of concurrent threads supported. 1 disables multi-threading. 🧵🧵🧵
• --fat-lto-objects — use the .llvm.lto section, which contains LLVM bitcode, in fat LTO object files to perform LTO. 🍔
• --no-fat-lto-objects — ignore the .llvm.lto section in relocatable object files (default). 🚫🍔
• --time-trace — record time trace. ⏱️
• --time-trace-file=file — write time trace output to file. ⏱️📄
• --time-trace-granularity=value — minimum time granularity (in microseconds) traced by time profiler. ⏱️🔍
• --trace — print the names of the input files. 🗣️
• --trace-symbol=symbol, -y symbol — trace references to symbol. 🔎
• --undefined=symbol, -u symbol — if symbol is not defined after symbol resolution, and there's a static library that contains an object file defining the symbol, load the member to include the object file in the output file. the rescue mission 🦸
• --undefined-glob=pattern — synonym for --undefined, except that it takes a glob pattern. in a glob pattern, * matches zero or more characters, ? matches any single character, and [...] matches the characters within brackets. all symbols that match a given pattern are handled as if they were given as arguments of --undefined. 🌐
• --unique — creates a separate output section for every orphan input section. everyone gets their own room 🚪
• --unresolved-symbols=value — determine how to handle unresolved symbols. ❓
• --use-android-relr-tags — use SHT_ANDROID_RELR / DT_ANDROID_RELR* tags instead of SHT_RELR / DT_RELR*. 🤖
• -v, -V — display the version number and proceed with linking if object files are specified. 🏷️
• --version — display the version number and exit. 🚪
• --verbose — verbose mode. it's giving yapper 🗣️💬
• --version-script=file — read version script from file. 📜
• --warn-backrefs — warn about reverse or cyclic dependencies to or between static archives. this can be used to ensure linker invocation remains compatible with traditional Unix-like linkers. ⚠️
• --warn-backrefs-exclude=glob — glob describing an archive (or an object file within --start-lib) which should be ignored for --warn-backrefs. 🙈
• --warn-common — warn about duplicate common symbols. ⚠️👯
• --warn-ifunc-textrel — okay so this one warns about using ifunc symbols in conjunction with text relocations. Older versions of the glibc library (2.28 and earlier) has a bug that causes the segment that includes ifunc symbols to be marked as not executable when they are relocated. As a result, although the program compiles and links successfully, it gives a segmentation fault when the instruction pointer reaches an ifunc symbol. Use -warn-ifunc-textrel to let lld give a warning if the code may include ifunc symbols, may do text relocations and be linked with an older glibc version. Otherwise, there is no need to use it, as the default value does not give a warning. This flag has been introduced in late 2018, has no counter part in ld and gold linkers, and may be removed in the future.
• --warn-unresolved-symbols — Report unresolved symbols as warnings. periodt.
• --whole-archive — Force load of all members in a static library. the whole squad, no skips.
• --why-extract=file — Print to a file about why archive members are extracted. receipts, bestie.
• --wrap=symbol — Redirect symbol references to __wrap_symbol, and __real_symbol references to symbol. the way this swaps your references is lowkey iconic.
• -z option — Linker option extensions. the little sub-menu of chaos:
  • dead-reloc-in-nonalloc=section_glob=value — Resolve a relocation in a matched non-SHF_ALLOC section referencing a discarded symbol to value. Accepts globs, in the event of a section matching more than one option, the last option takes precedence. An order of least specific to most specific match is recommended. vibe check: globs.
  • execstack — Make the main stack executable. Stack permissions are recorded in the PT_GNU_STACK segment.
  • bti-report=[none|warning|error] — Specify how to report the missing GNU_PROPERTY_AARCH64_FEATURE_1_BTI property. none is the default, linker will not report the missing property otherwise will be reported as a warning or an error. ngl, default is chill.
  • cet-report=[none|warning|error] — Specify how to report the missing GNU_PROPERTY_X86_FEATURE_1_IBT or GNU_PROPERTY_X86_FEATURE_1_SHSTK properties. none is the default, linker will not report the missing property otherwise will be reported as a warning or an error.
  • pauth-report=[none|warning|error] — Specify how to report the missing GNU_PROPERTY_AARCH64_FEATURE_PAUTH property. none is the default, linker will not report the missing property otherwise will be reported as a warning or an error.
  • force-bti — Force enable AArch64 BTI instruction in PLT, warn if Input ELF file does not have GNU_PROPERTY_AARCH64_FEATURE_1_BTI property. no cap.
  • force-ibt — Force enable Intel Indirect Branch Tracking in PLT, warn if an input ELF file does not have GNU_PROPERTY_X86_FEATURE_1_IBT property.
  • global — Sets the DF_1_GLOBAL flag in the DYNAMIC section. Different loaders can decide how to handle this flag on their own.
  • ifunc-noplt — Do not emit PLT entries for ifunc symbols. Instead, emit text relocations referencing the resolver. This is an experimental optimization and only suitable for standalone environments where text relocations do not have the usual drawbacks. This option must be combined with the -z notext option. experimental, so don't @ me.
  • initfirst — Sets the DF_1_INITFIRST flag to indicate the module should be initialized first.
  • interpose — Set the DF_1_INTERPOSE flag to indicate to the runtime linker that the object is an interposer. During symbol resolution interposers are searched after the application but before other dependencies.
  • lrodata-after-bss — Place .lrodata after .bss.
  • muldefs — Do not error if a symbol is defined multiple times. The first definition will be used. This is a synonym for --allow-multiple-definition. first one wins, periodt.
  • nocombreloc — Disable combining and sorting multiple relocation sections.
  • nocopyreloc — Disable the creation of copy relocations.
  • nodefaultlib — Set the DF_1_NODEFLIB flag to indicate that default library search paths should be ignored.
  • nodelete — Set the DF_1_NODELETE flag to indicate that the object cannot be unloaded from a process.
  • nodlopen — Set the DF_1_NOOPEN flag to indicate that the object may not be opened by dlopen(3).
  • nognustack — Do not emit the PT_GNU_STACK segment. bye segment.
  • norelro — Do not indicate that portions of the object should be mapped read-only after initial relocation processing. The object will omit the PT_GNU_RELRO segment.
  • notext — Allow relocations against read-only segments. Sets the DT_TEXTREL flag in the DYNAMIC section.
  • now — Set the DF_BIND_NOW flag to indicate that the run-time loader should perform all relocation processing as part of object initialization. By default relocations may be performed on demand. on demand is the default vibe.
  • origin — Set the DF_ORIGIN flag to indicate that the object requires $ORIGIN processing. iykyk.
  • pac-plt — AArch64 only, use pointer authentication in PLT. AArch64 only, bestie.
  • pack-relative-relocs — Similar to -pack-dyn-relocs=relr , but synthesizes the GLIBC_ABI_DT_RELR version dependency if there is a GLIBC_2.* version dependency. glibc ld.so rejects loading a dynamically linked object without the GLIBC_ABI_DT_RELR version dependency. glibc said no entry without the version dependency.
  • rel — Use REL format for dynamic relocations.
  • rela — Use RELA format for dynamic relocations.
  • retpolineplt — Emit retpoline format PLT entries as a mitigation for CVE-2017-5715. CVE-2017-5715 said not today.
  • rodynamic — Make the .dynamic section read-only. The DT_DEBUG tag will not be emitted.
  • separate-loadable-segments, separate-code, noseparate-code — Specify whether two adjacent PT_LOAD segments are allowed to overlap in pages. noseparate-code (default) allows overlap. separate-code allows overlap between two executable segments, or two non-executable segments. separate-loadable-segments disallows overlap. pages are fighting.
  • shstk — x86 only, use shadow stack. x86 only, shadow stack slay.
  • stack-size=size — Set the main thread's stack size to size. The stack size is recorded as the size of the size. PT_GNU_STACK program segment. yes, that's the wording, bestie.
  • start-stop-gc — Don't let __start_/__stop_ references retain the associated C identifier name sections (default). default behavior, no notes.
  • nostart-stop-gc — Let __start_/__stop_ references retain the associated C identifier name sections.
  • text — Do not allow relocations against read-only segments. This is the default. this is the default, periodt.
  • wxneeded — Create a PT_OPENBSD_WXNEEDED segment.

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✨ ENVIRONMENT VARIABLES ✨

• LLD_REPRODUCE — Create a reproduce tarball with the specified filename. If --reproduce is specified, --reproduce takes precedence. tarball time, bestie.
• LLD_VERSION — ld.lld creates a section named .comment containing the LLD version string. The version string can be overridden by this environment variable, which is useful to eliminate differences in the binary caused by LLD version number differences. version string but make it customizable.

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💖 IMPLEMENTATION NOTES 💖

okay so this is the tea.

ld.lld's handing of archive files (those with a .a file extension) is different from traditional linkers used on Unix-like systems. (yes, the source says handing — we're keeping it, it's iconic. 💅)

Traditional linkers maintain a set of undefined symbols during linking. The linker processes each file in the order in which it appears on the command line, until the set of undefined symbols becomes empty. An object file is linked into the output object when it is encountered, with its undefined symbols added to the set. Upon encountering an archive file a traditional linker searches the objects contained therein, and processes those that satisfy symbols in the unresolved set.

Handling mutually dependent archives may be awkward when using a traditional linker. Archive files may have to be specified multiple times, or the special command line options --start-group and --end-group may be used to have the linker loop over the files in the group until no new symbols are added to the set.

ld.lld records all symbols found in objects and archives as it iterates over command line arguments. When ld.lld encounters an undefined symbol that can be resolved by an object file contained in a previously processed archive file, it immediately extracts and links it into the output object.

With certain archive inputs ld.lld may produce different results compared to traditional linkers. In practice, large bodies of third party software have been linked with ld.lld without material issues.

The --warn-backrefs option may be used to identify a linker invocation that may be incompatible with traditional Unix-like linker behavior.

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This page is from Debian, dated Jul 25, 2023, and it's LD.LLD(1) — go link something iconic. 💖✨