Provided by: mold_2.30.0+dfsg-1build1_amd64 bug

NAME

       mold - a modern linker

SYNOPSIS

       mold [option...] file...

DESCRIPTION

       mold is a faster drop-in replacement for the default GNU ld(1).

   How to use
       See https://github.com/rui314/mold#how-to-use.

   Compatibility
       Mold  is  designed  to  be a drop-in replacement for the GNU linkers for linking user-land
       programs. If your user-land program cannot be built due to missing  command-line  options,
       please file a bug at https://github.com/rui314/mold/issues.

       Mold  supports  a  very limited set of linker script features, which is just sufficient to
       read /usr/lib/x86_64-linux-gnu/libc.so on Linux systems (on Linux, that file  is  contrary
       to  its  name  not  a  shared library but an ASCII linker script that loads a real libc.so
       file.)

       Beyond that, we have no plan to support any additional linker script features. The  linker
       script is an ad-hoc, over-designed, complex language which we believe needs to be replaced
       by a simpler mechanism. We have a plan to add a replacement for the linker script to  mold
       instead.

   Archive symbol resolution
       Traditionally,  Unix linkers are sensitive to the order in which input files appear on the
       command line. They process input  files  from  the  first  (leftmost)  file  to  the  last
       (rightmost)  file one-by-one. While reading input files, they maintain sets of defined and
       undefined symbols. When visiting an archive file (.a files), they pull out object files to
       resolve  as  many undefined symbols as possible and move on to the next input file. Object
       files that weren't pulled out will never have a chance for a second look.

       Due to this behavior, you usually have to add archive files at the end of a command  line,
       so that when a linker reaches archive files, it knows what symbols remain as undefined.

       If  you  put  archive  files at the beginning of a command line, a linker doesn't have any
       undefined symbols, and thus no object files will be pulled  out  from  archives.  You  can
       change  the  processing  order  by using the --start-group and --end-group options, though
       they make a linker slower.

       mold, as well as the LLVM lld(1) linker, takes a different approach. They  remember  which
       symbols  can  be  resolved  from archive files instead of forgetting them after processing
       each archive. Therefore, mold and lld(1) can "go back" in  a  command  line  to  pull  out
       object files from archives if they are needed to resolve remaining undefined symbols. They
       are not sensitive to the input file order.

       --start-group and --end-group are still accepted by mold and lld(1) for compatibility with
       traditional linkers, but they are silently ignored.

   Dynamic symbol resolution
       Some  Unix linker features are difficult to understand without comprehending the semantics
       of dynamic symbol resolution. Therefore, even though it's  not  specific  to  mold,  we'll
       explain it here.

       We  use  "ELF module" or just "module" as a collective term to refer to an executable or a
       shared library file in the ELF format.

       An ELF module may have lists of imported symbols and exported symbols, as well as  a  list
       of  shared library names from which imported symbols should be imported. The point is that
       imported symbols are not bound to any specific shared library until runtime.

       Here is how the Unix dynamic linker resolves dynamic symbols. Upon the  start  of  an  ELF
       program, the dynamic linker constructs a list of ELF modules which, as a whole, consist of
       a complete program. The executable file is always at the beginning of the list followed by
       its  dependent  shared libraries. An imported symbol is searched from the beginning of the
       list to the end. If two or more modules define the same symbol, the one that appears first
       in the list takes precedence over the others.

       This  Unix  semantics  are  contrary  to  systems  such  as  Windows that have a two-level
       namespace for dynamic symbols. On Windows, for example, dynamic symbols are represented as
       a  tuple  of (symbol-name, shared-library-name), so that each dynamic symbol is guaranteed
       to be resolved from some specific library.

       Typically, an ELF module that exports a symbol also imports the same symbol. Such a symbol
       is  usually resolved to itself, but that's not the case if a module that appears before it
       in the symbol search list provides another definition of the same symbol.

       Let's take malloc as an example. Assume that you define your version  of  malloc  in  your
       main executable file. Then, all malloc calls from any module are resolved to your function
       instead of the one in libc, because the executable is  always  at  the  beginning  of  the
       dynamic  symbol  search list. Note that even malloc calls within libc are resolved to your
       definition since libc exports and imports malloc. Therefore, by defining malloc  yourself,
       you can overwrite a library function, and the malloc in libc becomes dead code.

       These Unix semantics are tricky and sometimes considered harmful. For example, assume that
       you accidentally define atoi  as  a  global  function  in  your  executable  that  behaves
       completely  differently from the one in the C standard. Then, all atoi function calls from
       any modules (even function calls within libc) are redirected to your function  instead  of
       the one in libc, which will very likely cause a problem.

       That  is  a  somewhat surprising consequence for an accidental name conflict. On the other
       hand, this semantic is sometimes useful  because  it  allows  users  to  override  library
       functions without rebuilding modules containing them.

       Whether  good  or bad, you should keep these semantics in mind to understand Unix linkers'
       behaviors.

   Build reproducibility
       mold's output is deterministic. That is, if you pass the same object files  and  the  same
       command-line  options to the same version of mold, it is guaranteed that mold produces the
       bit-by-bit identical output. The linker's internal  randomness,  such  as  the  timing  of
       thread scheduling or iteration orders of hash tables, doesn't affect the output.

       mold  does  not  have  any  host-specific  default  settings.  This is contrary to the GNU
       linkers, for which some configurable  values,  such  as  system-dependent  library  search
       paths, are hard-coded. mold depends only on its command-line arguments.

MOLD-SPECIFIC OPTIONS

       --chroot=dir
              Set dir as the root directory.

       --color-diagnostics=[ auto | always | never ]
              Show diagnostic messages in color using ANSI escape sequences. auto means that mold
              prints out messages in color only if the standard output is  connected  to  a  TTY.
              Default is auto.

       --color-diagnostics
              Synonym for --color-diagnostics=auto.

       --no-color-diagnostics
              Synonym for --color-diagnostics=never.

       --fork, --no-fork
              Spawn  a  child  process  and  let  it  do the actual linking. When linking a large
              program, the OS kernel can take a few hundred  milliseconds  to  terminate  a  mold
              process. --fork hides that latency. By default, it does fork.

       --perf Print performance statistics.

       --print-dependencies
              Print out dependency information for input files.

              Each  line  of the output for this option shows which file depends on which file to
              use a specific symbol. This option is useful for debugging why some object file  in
              a  static archive got linked or why some shared library is kept in an output file's
              dependency list even with --as-needed.

       --repro
              Archive input files, as well as a text file containing command line options,  in  a
              tar  file so that you can run mold with the exact same inputs again. This is useful
              for reporting a bug with a reproducer. The output filename  is  path/to/output.tar,
              where path/to/output is an output filename specified by -o.

       --reverse-sections
              Reverse the order of input sections before assigning them the offsets in the output
              file.

              This option is useful for finding bugs that depend on the initialization  order  of
              global  objects. In C++, constructors of global objects in a single source file are
              guaranteed to be executed in the source order, but there's no such guarantee across
              compilation  units.  Usually,  constructors  are executed in the order given to the
              linker, but depending on it is a mistake.

              By reversing the order of input sections using --reverse-sections, you  can  easily
              test that your program works in the reversed initialization order.

       --run command arg...
              Run command with mold /usr/bin/ld. Specifically, mold runs a given command with the
              LD_PRELOAD environment set to  intercept  exec(3)  family  functions  and  replaces
              argv[0] with itself if it is ld, ld.gold, or ld.lld.

       --shuffle-sections, --shuffle-sections=number
              Randomize the output by shuffling the order of input sections before assigning them
              the offsets in the output file. If a number is given, it's used as a seed  for  the
              random  number  generator, so that the linker produces the same output for the same
              seed. If no seed is given, a random number is used as a seed.

              This option is useful for benchmarking. Modern CPUs are sensitive  to  a  program's
              memory  layout.  A  seemingly benign change in program layout, such as a small size
              increase of a function in the  middle  of  a  program,  can  affect  the  program's
              performance. Therefore, even if you write new code and get a good benchmark result,
              it is hard to say whether the new code improves the program's  performance;  it  is
              possible that the new memory layout happens to perform better.

              By  running  a  benchmark  multiple  times  with  randomized  memory  layouts using
              --shuffle-sections, you can isolate your program's real performance number from the
              randomness caused by memory layout changes.

       --stats
              Print input statistics.

       --thread-count=count
              Use count number of threads.

       --threads, --no-threads
              Use  multiple threads. By default, mold uses as many threads as the number of cores
              or 32, whichever is smaller. The reason it is capped at 32 is because mold  doesn't
              scale  well  beyond  that  point.  To  use  only  one  thread, pass --no-threads or
              --thread-count=1.

       --quick-exit, --no-quick-exit
              Use or do not use quick_exit to exit.

GNU-COMPATIBLE OPTIONS

       --help Report usage information to stdout and exit.

       -v, --version
              Report version information to stdout.

       -V     Report version and target information to stdout.

       -E, --export-dynamic, --no-export-dynamic
              When creating an executable, using the -E option causes all global  symbols  to  be
              put  into  the dynamic symbol table, so that the symbols are visible from other ELF
              modules at runtime.

              By default, or if --no-export-dynamic is given, only symbols that are referenced by
              DSOs at link-time are exported from an executable.

       -F libname, --filter=libname
              Set the DT_FILTER dynamic section field to libname.

       -I file, --dynamic-linker=file, --no-dynamic-linker
              Set   the  dynamic  linker  path  to  file.  If  no  -I  option  is  given,  or  if
              --no-dynamic-linker is given, no dynamic linker path is set to an output file. This
              is  contrary  to  the  GNU  linkers which set a default dynamic linker path in that
              case. This difference doesn't usually make  any  difference  because  the  compiler
              driver always passes -I to the linker.

       -L dir, --library-path=dir
              Add  dir to the list of library search paths from which mold searches libraries for
              the -l option.

              Unlike the GNU linkers, mold does not have default search  paths.  This  difference
              doesn't  usually  make any difference because the compiler driver always passes all
              necessary search paths to the linker.

       -M, --print-map
              Write a map file to stdout.

       -N, --omagic, --no-omagic
              Force mold to emit an output file with an old-fashioned memory  layout.  First,  it
              makes  the first data segment not aligned to a page boundary. Second, text segments
              are marked as writable if the option is given.

       -S, --strip-debug
              Omit .debug_* sections from the output file.

       -T file, --script=file
              Read linker script from file.

       -X, --discard-locals
              Discard temporary local symbols to reduce the sizes of the  symbol  table  and  the
              string table. Temporary local symbols are local symbols starting with .L. Compilers
              usually generate such symbols for unnamed program elements such as string  literals
              or floating-point literals.

       -e symbol, --entry=symbol:

       -f shlib, --auxiliary=shlib
              Set the DT_AUXILIARY dynamic section field to shlib.

       -h libname, --soname=libname
              Set  the  DT_SONAME  dynamic  section  field  to  libname. This option is used when
              creating a shared object file. Typically, when you create libfoo.so,  you  want  to
              pass --soname=foo to a linker.

       -l libname
              Search for liblibname.so or liblibname.a from library search paths.

       -m target
              Choose a target.

       -o file, --output=file
              Use file as the output file name instead of the default name a.out.

       -r, --relocatable
              Instead  of  generating an executable or a shared object file, combine input object
              files to generate another object file that can be used as an input to a linker.

       --relocatable-merge-sections
              By default, mold doesn't merge input sections by name  when  merging  input  object
              files into a single output object file for -r. For example, .text.foo and .text.bar
              aren't merged for -r even though they  are  merged  into  .text  according  to  the
              default section merging rules.

              This  option changes the behavior so that mold merges input sections by name by the
              default section merging rules.

       -s, --strip-all
              Omit .symtab section from the output file.

       -u symbol, --undefined=symbol
              If symbol remains as an undefined symbol after reading all  object  files,  and  if
              there  is  a  static archive that contains an object file defining symbol, pull out
              the object file and link it so that  the  output  file  contains  a  definition  of
              symbol.

       -y symbol, --trace-symbol=symbol
              Trace references to symbol.

       --Bdynamic
              Link against shared libraries.

       --Bstatic
              Do not link against shared libraries.

       --Bsymbolic
              When creating a shared library, make global symbols export-only (i.e. do not import
              the same symbol). As a result,  references  within  a  shared  library  are  always
              resolved  locally,  negating  symbol  override  at  runtime.  See  "Dynamic  symbol
              resolution" for more information about symbol imports and exports.

       --Bsymbolic-functions
              This option has the same effect as --Bsymbolic but works only for function symbols.
              Data symbols remain being both imported and exported.

       --Bno-symbolic
              Cancel --Bsymbolic and --Bsymbolic-functions.

       --Map=file
              Write map file to file.

       --Tbss=address
              Alias for --section-start=.bss=address.

       --Tdata=address
              Alias for --section-start=.data=address.

       --Ttext=address
              Alias for --section-start=.text=address.

       --allow-multiple-definition
              Normally,  the  linker  reports an error if there are more than one definition of a
              symbol. This option changes the default behavior so that it doesn't report an error
              for duplicate definitions and instead use the first definition.

       --as-needed, --no-as-needed
              By  default,  shared libraries given to the linker are unconditionally added to the
              list of required libraries in an  output  file.  However,  shared  libraries  after
              --as-needed are added to the list only when at least one symbol is actually used by
              the output file. In other words, shared libraries after --as-needed are  not  added
              to the list of needed libraries if they are not needed by a program.

              The --no-as-needed option restores the default behavior for subsequent files.

       --build-id=[ md5 | sha1 | sha256 | uuid | 0xhexstring | none ]
              Create  a  .note.gnu.build-id section containing a byte string to uniquely identify
              an output file. sha256 compute a 256-bit cryptographic hash of an output  file  and
              set  it  to build-id. md5 and sha1 compute the same hash but truncate it to 128 and
              160 bits, respectively, before setting it to build-id. uuid sets a  random  128-bit
              UUID. 0xhexstring sets hexstring.

       --build-id
              Synonym for --build-id=sha256.

       --no-build-id
              Synonym for --build-id=none.

       --compress-debug-sections=[ zlib | zlib-gabi | zstd | none ]
              Compress  DWARF  debug  info (.debug_* sections) using the zlib or zstd compression
              algorithm. zlib-gabi is an alias for zlib.

       --defsym=symbol=value
              Define symbol as an alias for value.

              value is either an integer (in decimal or hexadecimal with 0x prefix) or  a  symbol
              name.  If  an  integer is given as a value, symbol is defined as an absolute symbol
              with the given value.

       --default-symver
              Use soname as a symbol version and append that version to all symbols.

       --demangle, --no-demangle
              Demangle C++ and Rust symbols in log messages.

       --dependency-file=file
              Write a dependency file to file. The contents of the written file  is  readable  by
              make(1),  which defines only one rule with the linker's output file as a target and
              all input files as its prerequisites. Users are expected to include  the  generated
              dependency  file into a Makefile to automate the dependency management. This option
              is analogous to the compiler's -MM -MF options.

       --dynamic-list=file
              Read a list of dynamic symbols from  file.  Same  as  --export-dynamic-symbol-list,
              except  that  it  implies  --Bsymbolic.  If  file  does  not  exist  in the current
              directory, it is searched from library search paths for the sake  of  compatibility
              with GNU ld.

       --eh-frame-hdr, --no-eh-frame-hdr
              Create .eh_frame_hdr section.

       --emit-relocs
              The  linker  usually  "consumes"  relocation  sections. That is, the linker applies
              relocations to other sections, and relocation sections themselves are discarded.

              The --emit-relocs instructs the linker to leave relocation sections in  the  output
              file.  Some  post-link binary analysis or optimization tools such as LLVM Bolt need
              them.

       --enable-new-dtags, --disable-new-dtags
              By default, mold emits DT_RUNPATH for --rpath.  If  you  pass  --disable-new-dtags,
              mold emits DT_RPATH for --rpath instead.

       --execute-only
              Traditionally,  most  processors  require both executable and readable bits to 1 to
              make the page executable, which allows machine code to be read as data at  runtime.
              This  is  actually what an attacker often does after gaining a limited control of a
              process to find pieces of machine code they can use to gain the full control of the
              process.  As a mitigation, some recent processors allows "execute-only" pages. If a
              page is execute-only, you can call a function there as long as you know its address
              but can't read it as data.

              This  option  marks text segments execute-only. This option currently works only on
              some ARM64 processors.

       --exclude-libs=libraries ...
              Mark all symbols in the given libraries hidden.

       --export-dynamic-symbol=symbol
              Put symbols matching symbol in the dynamic symbol  table.  symbol  may  be  a  glob
              pattern   in   the   same   syntax   as  for  the  --export-dynamic-symbol-list  or
              --version-script options.

       --export-dynamic-symbol-list=file
              Read a list of dynamic symbols from file.

       --fatal-warnings, --no-fatal-warnings
              Treat warnings as errors.

       --fini=symbol
              Call symbol at unload-time.

       --gc-sections, --no-gc-sections
              Remove unreferenced sections.

       --gdb-index
              Create a .gdb_index section to speed up GNU debugger. To  use  this,  you  need  to
              compile source files with the -ggnu-pubnames compiler flag.

       --hash-style=[ sysv | gnu | both | none ]
              Set hash style.

       --icf=[ safe | all | none ], --no-icf
              It  is  not  uncommon for a program to contain many identical functions that differ
              only in name. For example,  a  C++  template  std::vector  is  very  likely  to  be
              instantiated  to  the identical code for std::vector<int> and std::vector<unsigned>
              because the container cares only about the size of the  parameter  type.  Identical
              Code  Folding  (ICF)  is  a  size optimization to identify and merge such identical
              functions.

              If --icf=all is given, mold tries to merge all identical  functions.  This  reduces
              the  size of the output most, but it is not a "safe" optimization. It is guaranteed
              in C and C++ that two pointers pointing  two  different  functions  will  never  be
              equal,  but  --icf=all  breaks  that assumption as two identical functions have the
              same address after merging. So a care must be taken when you  use  this  flag  that
              your program does not depend on the function pointer uniqueness.

              --icf=safe  is a flag to merge functions only when it is safe to do so. That is, if
              a program does not take an address of a function, it is safe to merge that function
              with  other  function, as you cannot compare a function pointer with something else
              without taking an address of a function.

              --icf=safe needs to be used with a compiler  that  supports  .llvm_addrsig  section
              which  contains  the  information  as to what symbols are address-taken. LLVM/Clang
              supports that section by default. Since GCC does not support it yet, you cannot use
              --icf=safe with GCC (it doesn't do any harm but can't optimize at all.)

              --icf=none and --no-icf disables ICF.

       --ignore-data-address-equality
              Make  ICF  to merge not only functions but also data. This option should be used in
              combination with --icf=all.

       --image-base=addr
              Set the base address to addr.

       --init=symbol
              Call symbol at load-time.

       --no-undefined
              Report undefined symbols (even with --shared).

       --noinhibit-exec
              Create an output file even if errors occur.

       --pack-dyn-relocs=[ relr | none ]
              If relr is specified, all R_*_RELATIVE relocations are put into  .relr.dyn  section
              instead   of  .rel.dyn  or  .rela.dyn  section.  Since  .relr.dyn  section  uses  a
              space-efficient encoding scheme, specifying this flag can reduce the  size  of  the
              output. This is typically most effective for position-independent executable.

              Note  that  a  runtime loader has to support .relr.dyn to run executables or shared
              libraries linked with --pack-dyn-relocs=relr. As of 2022,  only  ChromeOS,  Android
              and Fuchsia support it.

       --package-metadata=string
              Embed  string  to  a .note.package section. This option is intended to be used by a
              package management command such as rpm(8) to embed metadata regarding a package  to
              each executable file.

       --pie, --pic-executable, --no-pie, --no-pic-executable
              Create a position-independent executable.

       --print-gc-sections, --no-print-gc-sections
              Print removed unreferenced sections.

       --print-icf-sections, --no-print-icf-sections
              Print folded identical sections.

       --push-state, --pop-state
              --push-state  saves  the  current values of --as-needed, --whole-archive, --static,
              and --start-lib. The saved values can be restored by pop-state.

              --push-state and --pop-state pairs can nest.

              These options are useful when you want to construct  linker  command  line  options
              programmatically. For example, if you want to link libfoo.so by as-needed basis but
              don't want to change the global state of --as-needed, you can  append  --push-state
              --as-needed -lfoo --pop-state to the linker command line options.

       --relax, --no-relax
              Rewrite  machine  instructions  with  more efficient ones for some relocations. The
              feature is enabled by default.

       --require-defined=symbol
              Like --undefined, except the new symbol must be defined by the end of the link.

       --retain-symbols-file=file
              Keep only symbols listed in file. file is a text file containing a symbol  name  on
              each line. mold discards all local symbols as well as global symbol that are not in
              file. Note that this option removes symbols only from .symtab section and does  not
              affect .dynsym section, which is used for dynamic linking.

       --rpath=dir
              Add dir to runtime search paths.

       --section-start=section=address
              Set  address  to  section.  address  is a hexadecimal number that may start with an
              optional 0x.

       --shared, --Bshareable
              Create a share library.

       --spare-dynamic-tags=number
              Reserve the given number of tags in .dynamic section.

       --spare-program-headers=number
              Reserve the given number of entries in the program header.

       --start-lib, --end-lib
              Handle object files between --start-lib and --end-lib as if they were in an archive
              file.  That means object files between them are linked only when they are needed to
              resolve undefined symbols. The options are useful if you want to link object  files
              only when they are needed but want to avoid the overhead of running ar(3).

       --static
              Do not link against shared libraries.

       --sysroot=dir
              Set target system root directory to dir.

       --trace
              Print name of each input file.

       --undefined-version, --no-undefined-version
              By  default,  mold  warns  on  a  symbol  specified  by  a  version  script  or  by
              --export-dynamic-symbol if it is not  defined.  You  can  silence  the  warning  by
              --undefined-version.

       --unique=pattern
              Don't merge input sections that match the given glob pattern pattern.

       --unresolved-symbols=[    report-all    |    ignore-all    |    ignore-in-object-files   |
       ignore-in-shared-libs ]
              How to handle undefined symbols.

       --version-script=file
              Read version script from file. If file does not exist in the current directory,  it
              is searched from library search paths for the sake of compatibility with GNU ld.

       --warn-common, --no-warn-common
              Warn about common symbols.

       --warn-once
              Only  warn  once  for  each  undefined  symbol  instead of warn for each relocation
              referring an undefined symbol.

       --warn-unresolved-symbols, --error-unresolved-symbols
              Normally,   the   linker    reports    an    error    for    unresolved    symbols.
              --warn-unresolved-symbols      option      turns     it     into     a     warning.
              --error-unresolved-symbols option restores the default behavior.

       --whole-archive, --no-whole-archive
              When archive files (.a files) are given to the linker, only object files  that  are
              needed to resolve undefined symbols are extracted from them and linked to an output
              file. --whole-archive changes that behavior for subsequent  archives  so  that  the
              linker  extracts  all object files and links them to an output. For example, if you
              are creating a shared object file and you want to include all  archive  members  to
              the  output,  you  should  pass  --whole-archive.  --no-whole-archive  restores the
              default behavior for subsequent archives.

       --wrap=symbol
              Make symbol be resolved to __wrap_symbol. The original symbol can  be  resolved  as
              __real_symbol. This option is typically used for wrapping an existing function.

       -z cet-report=[ warning | error | none ]
              Intel  Control-flow  Enforcement  Technology  (CET)  is a new x86 feature available
              since Tiger Lake which is released in 2020. It defines new instructions  to  harden
              security  to  protect  programs  from  control  hijacking attacks. You can tell the
              compiler to use the feature by specifying the -fcf-protection flag.

              -z cet-report flag is used to make sure that all object files were compiled with  a
              correct  -fcf-protection  flag.  If  warning  or error are given, mold prints out a
              warning or an error message if an object file was not compiled  with  the  compiler
              flag.

              mold       looks       for       GNU_PROPERTY_X86_FEATURE_1_IBT       bit       and
              GNU_PROPERTY_X86_FEATURE_1_SHSTK bit in  .note.gnu.property  section  to  determine
              whether or not an object file was compiled with -fcf-protection.

       -z now, -z lazy
              By  default,  functions  referring to other ELF modules are resolved by the dynamic
              linker when they are called for the first time. -z now marks  an  executable  or  a
              shared  library file so that all dynamic symbols are resolved when a file is loaded
              to memory. -z lazy restores the default behavior.

       -z origin
              Mark object requiring immediate $ORIGIN processing at runtime.

       -z ibt Turn  on  GNU_PROPERTY_X86_FEATURE_1_IBT  bit  in  .note.gnu.property  section   to
              indicate that the output uses IBT-enabled PLT. This option implies -z ibtplt.

       -z ibtplt
              Generate  Intel  Branch  Tracking (IBT)-enabled PLT which is the default on x86-64.
              This is the default.

       -z execstack, -z noexecstack
              By default, the pages for the stack area (i.e.  the  pages  where  local  variables
              reside)  are not executable for security reasons. -z execstack makes it executable.
              -z noexecstack restores the default behavior.

       -z keep-text-section-prefix, -z nokeep-text-section-prefix
              Keep .text.hot, .text.unknown, .text.unlikely,  .text.startup,  and  .text.exit  as
              separate sections in the final binary instead of merging them as .text.

       -z relro, -z norelro
              Some  sections  such as .dynamic have to be writable only during an executable or a
              shared library file is being loaded to memory. Once the dynamic linker finishes its
              job,  such  sections  won't  be  mutated by anyone. As a security mitigation, it is
              preferred to make such segments read-only during program execution.

              -z relro puts such sections into a special segment called relro. The dynamic linker
              makes a relro segment read-only after it finishes its job.

              By default, mold generates a relro segment. -z norelro disables the feature.

       -z sectionheader, -z nosectionheader
              -z  nosectionheader  tell  the  linker  to omit the section header. By default, the
              linker does not omit the section header.

       -z separate-loadable-segments, -z separate-code, -z noseparate-code
              If one memory page contains multiple segments, the page protection bits are set  in
              such  a  way  that the needed attributes (writable or executable) are satisfied for
              all segments. This usually happens at a boundary of two segments with two different
              attributes.

              separate-loadable-segments adds paddings between segments with different attributes
              so that they do not share the same page. This is the default.

              separate-code adds paddings only between executable and non-executable segments.

              noseparate-code does not add any paddings between segments.

       -z defs, -z nodefs
              Report undefined symbols (even with --shared).

       -z shstk
              Enforce  shadow  stack   by   turning   GNU_PROPERTY_X86_FEATURE_1_SHSTK   bit   in
              .note.gnu.property  output  section.  Shadow  stack  is  part of Intel Control-flow
              Enforcement Technology (CET), which is available since Tiger Lake (2020).

       -z text, -z notext, -z textoff
              mold by default reports an error if dynamic relocations are  created  in  read-only
              sections.  If  -z  notext  or  -z  textoff  are  given,  mold  creates such dynamic
              relocations without reporting an error. -z text restores the default behavior.

       -z max-page-size=number
              Some CPU ISAs support multiple different memory page sizes. This  option  specifies
              the  maximum page size that an output binary can run on. The default value is 4 KiB
              for i386, x86-64, and RISC-V, and 64 KiB for ARM64.

       -z nodefaultlib
              Make the dynamic loader ignore default search paths.

       -z nodelete
              Mark DSO non-deletable at runtime.

       -z nodlopen
              Mark DSO not available to dlopen(3). This option makes it possible for  the  linker
              to  optimize  thread-local  variable  accesses  by  rewriting instructions for some
              targets.

       -z nodump
              Mark DSO not available to dldump(3).

       -z nocopyreloc
              Do not create copy relocations.

       -z initfirst
              Mark DSO to be initialized first at runtime.

       -z interpose
              Mark object to interpose all DSOs but executable.

       -(, -), -EL, -Onumber, --allow-shlib-undefined, --dc, --dp, --end-group,  --no-add-needed,
       --no-allow-shlib-undefined,  --no-copy-dt-needed-entries, --no-fatal-warnings, --nostdlib,
       --rpath-link=Ar dir, --sort-common,  --sort-section,  --start-group,  --warn-constructors,
       --warn-once,    --fix-cortex-a53-835769,   --fix-cortex-a53-843419,   -z   combreloc,   -z
       common-page-size, -z nocombreloc
              Ignored

ENVIRONMENT VARIABLES

       MOLD_JOBS
              If this variable is set to 1, only one mold process will run at a time.  If  a  new
              mold  process  is  initiated  while another is already active, the new process will
              wait until the active one completes before starting.

              The primary reason for this environment variable is to minimize peak memory  usage.
              Since  mold  is  designed  to  operate with high parallelism, running multiple mold
              instances simultaneously may not be beneficial. If you execute N instances of  mold
              concurrently,  it  could  require  N  times the time and N times the memory. On the
              other hand, running them one after the other might still take N times  longer,  but
              the peak memory usage would be the same as running just a single instance.

              If  your  build system invokes multiple linker processes simultaneously and some of
              them often get killed due to out-of-memory errors, you might consider setting  this
              environment variable to 1 to see if it addresses the OOM issue.

              Currently, any value other than 1 is silently ignored.

       MOLD_DEBUG
              If this variable is set to a non-empty string, mold embeds its command-line options
              in the output file's .comment section.

       MOLD_REPRO
              Setting this variable to a non-empty string has the  same  effect  as  passing  the
              --repro option.

SEE ALSO

       gold(1), ld(1), elf(5), ld.so(8)

AUTHOR

       Rui Ueyama ruiu@cs.stanford.edu

BUGS

       Report bugs to https://github.com/rui314/mold/issues.

                                          November 2023                                   MOLD(1)