/usr/bin/ld64.lld

OVERVIEW: LLVM Linker

USAGE: /usr/bin/ld64.lld [options] file...

ADDITIONAL CONTENT:
  -add_empty_section <segment> <section>
                   Create an empty <section> in <segment>
  -filelist <file> Read names of files to link from <file>
  -sectcreate <segment> <section> <file>
                   Create <section> in <segment> from the contents of <file>
  -segcreate <segment> <section> <file>
                   Alias for -sectcreate

CREATING A BUNDLE:
  -bundle_loader <executable>
   Resolve undefined symbols from <executable>

DYNAMIC LIBRARIES (DYLIB):
  -compatibility_version <version>
                       Compatibility <version> of this library
  -current_version <version>
                       Current <version> of this library
  -dylib_install_name <name>
                       Alias for -install_name
  -dylinker_install_name <name>
                       Alias for -install_name
  -install_name <name> Set an internal install path in a dylib
  -mark_dead_strippable_dylib
                       Mark output dylib as dead-strippable: When a client links against it but does not use any of its symbols, the dylib will not be added to the client's list of needed dylibs

INTROSPECTING THE LINKER:
  -dependency_info <path> Dump dependency info
  -map <path>             Writes all symbols and their addresses to <path>
  -save-temps             Save intermediate LTO compilation results
  -t                      Log every file the linker loads: object, archive, and dylib
  -why_live <symbol>      Log a chain of references to <symbol>, for use with -dead_strip
  -why_load               Log why each object file is loaded from a static library
  -whyload                Alias for -why_load

LIBRARIES:
  -all_load              Load all members of all static archive libraries
  -force_load_swift_libs Apply -force_load to libraries listed in LC_LINKER_OPTIONS whose names start with 'swift'
  -force_load <path>     Load all members static archive library at <path>
  -framework <name>      Search for <name>.framework/<name> on the framework search path
  -F <dir>               Add dir to the framework search path
  -hidden-l<name>        Like -l<name>, but load all symbols with hidden visibility
  -load_hidden <path>    Load all symbols from static library with hidden visibility
  -L <dir>               Add dir to the library search path
  -l<name>               Search for lib<name>.dylib or lib<name>.a on the library search path
  -needed-l<name>        Like -l<name>, but link library even if its symbols are not used and -dead_strip_dylibs is active
  -needed_framework <name>
                         Like -framework <name>, but link <name> even if none of its symbols are used and -dead_strip_dylibs is active
  -needed_library <path> Like bare <path>, but link library even if its symbols are not used and -dead_strip_dylibs is active
  -noall_load            Don't load all static members from archives, this is the default, this negates -all_load
  -ObjC                  Load all members of static archives that are an Objective-C class or category.
  -reexport-l<name>      Like -l<name>, but export all symbols of <name> from newly created library
  -reexport_framework <name>
                         Like -framework <name>, but export all symbols of <name> from the newly created library
  -reexport_library <path>
                         Like bare <path>, but export all symbols of <path> from newly created library
  -search_dylibs_first   Search for lib<name>.dylib on first pass, then for lib<name>.a on second pass through search path (default for Xcode 3 and earlier)
  -search_paths_first    Search for lib<name>.dylib and lib<name>.a at each step in traversing search path (default for Xcode 4 and later)
  -syslibroot <rootdir>  Prepend <rootdir> to all library and framework search paths
  -weak-l<name>          Like -l<name>, but mark library and its references as weak imports
  -weak_framework <name> Like -framework <name>, but mark framework and its references as weak imports
  -weak_library <path>   Like bare <path>, but mark library and its references as weak imports
  -Z                     Remove standard directories from the library and framework search paths

LLD-SPECIFIC:
  --bp-compression-sort-startup-functions
                          Order startup functions to improve compressed size in addition to startup time
  --bp-compression-sort=[none,function,data,both]
                          Order sections to improve compressed size
  --bp-startup-sort=[none,function]
                          Order sections based on profile data to improve startup time
  --call-graph-profile-sort
                          Reorder sections with call graph profile (default)
  --check-category-conflicts
                          Check for conflicts between category & class methods
  --codegen-data-generate-path=<cgdata>
                          Write the CG data to the specified path <cgdata>.
  --color-diagnostics=[auto,always,never]
                          Use colors in diagnostics (default: auto)
  --color-diagnostics     Alias for --color-diagnostics=always
  --compression-sort-startup-functions
                          Deprecated. Please use --bp-compression-sort-startup-functions
  --compression-sort=[none,function,data,both]
                          Deprecated. Please use --bp-compression-sort=
  --cs-profile-generate   Perform context sensitive PGO instrumentation
  --cs-profile-path=<value>
                          Context sensitive profile file path
  --dead-strip-duplicates Do not error on duplicate symbols that will be dead stripped.
  --deduplicate-strings   Enable string deduplication
  --disable_verify        Do not verify LLVM modules during LTO
  --error-limit=<value>   Maximum number of errors to print before exiting (default: 20)
  --help-hidden           Display help for hidden options
  --icf=[none,safe,safe_thunks,all]
                          Set level for identical code folding (default: none). Possible values:
                            none        - Disable ICF
                            safe        - Only folds non-address significant functions (as described by `__addrsig` section)
                            safe_thunks - Like safe, but replaces address-significant functions with thunks
                            all         - Fold all identical functions
  --ignore-auto-link-option=<value>
                          Ignore a single auto-linked library or framework. Useful to ignore invalid options that ld64 ignores
  --irpgo-profile-sort=<profile>
                          Deprecated. Please use --irpgo-profile and --bp-startup-sort=function
  --irpgo-profile=<profile>
                          Read the IRPGO <profile> for use with --bp-startup-sort and other profile-guided optimizations
  --keep-icf-stabs<value> Generate STABS entries for symbols folded by ICF. These entries can then be used by dsymutil to discover the address range where folded symbols are located.
  --load-pass-plugin=<value>
                          Load passes from plugin library
  --lto-CGO<cgopt-level>  Set codegen optimization level for LTO (default: 2)
  --lto-debug-pass-manager
                          Debug new pass manager
  --lto-newpm-passes=<value>
                          Passes to run during LTO
  --lto-O<opt-level>      Set optimization level for LTO (default: 2)
  --no-bp-compression-sort-startup-functions
                          Do not order startup function for compression
  --no-call-graph-profile-sort
                          Do not reorder sections with call graph profile
  --no-color-diagnostics  Alias for --color-diagnostics=never
  --no-compression-sort-startup-functions
                          Deprecated. Please use --no-bp-compression-sort-startup-functions
  --no-deduplicate-strings
                          Disable string deduplication. This helps uncover cases of comparing string addresses instead of equality and might have a link time performance benefit.
  --no-pgo-warn-mismatch  turn off warnings about profile cfg mismatch
  --no-warn-duplicate-rpath
                          Do not warn if the same -rpath is specified multiple times
  --no-warn-dylib-install-name
                          Do not warn on -install_name if -dylib is not passed (default)
  --no-warn-thin-archive-missing-members
                          Do not warn on missing object files referenced by thin archives
  -no_objc_category_merging
                          Do not merge Objective-C categories
  -objc_category_merging  Merge Objective-C categories that share the same base class
  --pgo-warn-mismatch     turn on warnings about profile cfg mismatch (default)
  --print-dylib-search    Print which paths lld searched when trying to find dylibs
  --print-symbol-order=<value>
                          Print a symbol order specified by --call-graph-profile-sort into the specified file
  --reproduce=<value>     Write tar file containing inputs and command to reproduce link
  --strict-auto-link      Always warn for missing frameworks or libraries if they are loaded via LC_LINKER_OPTIONS
  --thinlto-cache-policy=<value>
                          Pruning policy for the ThinLTO cache
  --thinlto-jobs=<value>  Number of ThinLTO jobs. Default to --threads=
  --threads=<value>       Number of threads. '1' disables multi-threading. By default all available hardware threads are used
  --time-trace-granularity=<value>
                          Minimum time granularity (in microseconds) traced by time profiler
  --time-trace=<file>     Record time trace to <file>
  --time-trace            Record time trace to file next to output
  --verbose-bp-section-orderer
                          Print information on how many sections were ordered by balanced partitioning and a measure of the expected number of page faults
  --version               Display the version number and exit
  --warn-duplicate-rpath  Warn if the same -rpath is specified multiple times (default)
  --warn-dylib-install-name
                          Warn on -install_name if -dylib is not passed
  --warn-thin-archive-missing-members
                          Warn on missing object files referenced by thin archives (default)

MAIN EXECUTABLE:
  -export_dynamic       Preserve all global symbols during LTO and when dead-stripping executables
  -no_pie               Do not build a position independent executable
  -pagezero_size <size> Size of unreadable segment at address zero is hex <size> (default is 4KB on 32-bit and 4GB on 64-bit)
  -pie                  Build a position independent executable (default)

OBSOLETE:
  -lto_library <path> Obsolete. LLD supports LTO directly, without using an external dylib.
  -sectorder <segname> <sectname> <orderfile>
                      Obsolete. Replaced by more general -order_file option

OPTIMIZATIONS:
  -dead_strip         Remove unreachable functions and data
  -interposable       Indirects access to all exported symbols in an image
  -no_deduplicate     Disable code deduplication (synonym for `--icf=none')
  -no_implicit_dylibs Do not optimize public dylib transitive symbol references
  -order_file <file>  Layout functions and data according to specification in <file>

OPTIONS:
  -demangle   Demangle symbol names in diagnostics
  --end-lib   End a grouping of objects that should be treated as if they were together in an archive
  -O <value>  Optimize output file size
  --start-lib Start a grouping of objects that should be treated as if they were together in an archive

OUTPUT KIND:
  -arch <arch_name> The architecture (e.g. ppc, ppc64, i386, x86_64)
  -bundle           Produce a bundle
  -dylib            Produce a shared library
  -dynamic          Link dynamically (default)
  -execute          Produce a main executable (default)
  -o <path>         The name of the output file (default: `a.out')

RARELY USED:
  -adhoc_codesign         Write an ad-hoc code signature to the output file (default for arm64 binaries)
  -allowable_client <name>
                          Specify <name> of a dylib, framework, or executable that is allowed to link to this dylib
  -application_extension  Mark output as safe for use in an application extension, and validate that linked dylibs are safe
  -arch_errors_fatal      Escalate to errors any warnings about inputs whose architecture does not match the -arch option
  -arch_multiple          Augment error and warning messages with the architecture name
  -cache_path_lto <path>  Use <path> as a directory for the incremental LTO cache
  -client_name <name>     Specifies a <name> this client should match with the -allowable_client <name> in an explicitly linked dylib
  -data_const             Force migration of readonly data into __DATA_CONST segment
  -dead_strip_dylibs      Remove dylibs that are unreachable by the entry point or exported symbols
  -dyld_env <dyld_env_var>
                          Specifies a LC_DYLD_ENVIRONMENT variable value pair.
  -e <symbol>             Make <symbol> the entry point of an executable (default is "start" from crt1.o)
  -fatal_warnings         Treat warnings as errors
  -final_output <name>    Specify dylib install name if -install_name is not used; used by compiler driver for multiple -arch arguments
  -headerpad_max_install_names
                          Allocate extra space so all load-command paths can expand to MAXPATHLEN via install_name_tool
  -headerpad <size>       Allocate hex <size> extra space for future expansion of the load commands via install_name_tool (default is 0x20)
  -ignore_auto_link       Ignore LC_LINKER_OPTIONs
  -max_relative_cache_size_lto <percent>
                          Limit the incremental LTO cache growth to <percent> of free disk, space
  -mcpu <value>           Processor family target for LTO code generation
  -mllvm <value>          Options to pass to LLVM
  -no-deduplicate-symbol-strings
                          Do not deduplicate strings in the symbol string table. Might result in larger binaries but slightly faster link times.
  -no_adhoc_codesign      Do not write an ad-hoc code signature to the output file (default for x86_64 binaries)
  -no_application_extension
                          Disable application extension functionality (default)
  -no_data_const          Block migration of readonly data away from __DATA segment
  -no_dtrace_dof          Disable dtrace-dof processing (default).
  -no_function_starts     Do not create table of function start addresses
  -no_uuid                Do not generate the LC_UUID load command
  -objc_stubs_fast        Produce larger stubs for Objective-C method calls with fewer jumps (default).
  -objc_stubs_small       Produce smaller stubs for Objective-C method calls with more jumps.
  -object_path_lto <path> Retain any temporary mach-o file in <path> that would otherwise be deleted during LTO
  -prune_after_lto <seconds>
                          Remove LTO cache entries after <seconds>
  -prune_interval_lto <seconds>
                          Prune the incremental LTO cache after <seconds> (-1 disables pruning)
  -rename_section <from_segment> <from_section> <to_segment> <to_section>
                          Rename <from_segment>/<from_section> as <to_segment>/<to_section>
  -rename_segment <from_segment> <to_segment>
                          Rename <from_segment> as <to_segment>
  -reproducible           Make the output reproducible by removing timestamps and other non-deterministic data. This is the default behavior.
  -sectalign <segment> <section> <boundary>
                          Align <section> within <segment> to hex power-of-2 <boundary>
  -segprot <segment> <max> <init>
                          Specifies the <max> and <init> virtual memory protection of <segment> as r/w/x/-seg_addr_table path
  -sub_library <name>     Re-export the dylib as <name>
  -sub_umbrella <name>    Re-export the framework as <name>
  -umbrella <name>        Re-export this dylib through the umbrella framework <name>
  -v                      Print the linker version and search paths in addition to linking
  -w                      Suppress all warnings

SYMBOL RESOLUTION:
  -alias <symbol_name> <alternate_name>
                         Create a symbol alias with default global visibility
  -exported_symbols_list <file>
                         Symbols specified in <file> remain global, while others become private externs
  -exported_symbol <symbol>
                         <symbol> remains global, while others become private externs
  -flat_namespace        Resolve symbols from all dylibs, both direct and transitive. Do not record source libraries: dyld must re-search at runtime and use the first definition found
  -no_exported_symbols   Don't export any symbols from the binary, useful for main executables that don't have plugins
  -rpath <path>          Add <path> to dyld search list for dylibs with load path prefix `@rpath/'
  -twolevel_namespace    Make dyld look up symbols by (dylib,name) pairs (default)
  -undefined <treatment> Handle undefined symbols according to <treatment>: error, warning, suppress, or dynamic_lookup (default is error)
  -unexported_symbols_list <file>
                         Global symbols specified in <file> become private externs
  -unexported_symbol <symbol>
                         Global <symbol> becomes private extern
  -U <symbol>            Allow <symbol> to have no definition
  -u <symbol>            Require that <symbol> be defined for the link to succeed

SYMBOL TABLE:
  -add_ast_path <path> AST paths will be emitted as STABS
  -non_global_symbols_no_strip_list <path>
                       Specify in <path> the non-global symbols that should remain in the output symbol table
  -non_global_symbols_strip_list <path>
                       Specify in <path> the non-global symbols that should be removed from the output symbol table
  -oso_prefix <path>   Remove the prefix <path> from OSO symbols in the debug map
  -S                   Strip debug information (STABS or DWARF) from the output
  -x                   Exclude non-global symbols from the output symbol table

UNDOCUMENTED:
  -data_in_code_info    Emit data-in-code information (default)
  -encryptable          Generate the LC_ENCRYPTION_INFO load command
  -fixup_chains         Emit chained fixups
  -function_starts      Create table of function start addresses (default)
  -ignore_optimization_hints
                        Ignore Linker Optimization Hints
  -init_offsets         Store __TEXT segment offsets of static initializers
  -no_data_in_code_info Do not emit data-in-code information
  -no_encryption        Do not generate the LC_ENCRYPTION_INFO load command
  -no_fixup_chains      Emit fixup information as classic dyld opcodes
  -no_objc_relative_method_lists
                        Don't emit relative method lists (use traditional representation)
  -objc_relative_method_lists
                        Emit relative method lists (more compact representation)

VERSION TARGETING:
  -macos_version_min <version>
   Oldest macOS version for which linked output is usable
  -platform_version <platform> <min_version> <sdk_version>
   Platform (e.g., macos, ios, tvos, watchos, xros, bridgeos, mac-catalyst, ios-sim, tvos-sim, watchos-sim, xros-sim, driverkit) and version numbers