diff options
Diffstat (limited to 'docs/ld.lld.1')
| -rw-r--r-- | docs/ld.lld.1 | 55 |
1 files changed, 51 insertions, 4 deletions
diff --git a/docs/ld.lld.1 b/docs/ld.lld.1 index 0fdfe0ae7e899..d1ce4a3517f4d 100644 --- a/docs/ld.lld.1 +++ b/docs/ld.lld.1 @@ -3,7 +3,7 @@ .\" .\" This man page documents only lld's ELF linking support, obtained originally .\" from FreeBSD. -.Dd July 30, 2018 +.Dd September 26, 2018 .Dt LD.LLD 1 .Os .Sh NAME @@ -13,6 +13,7 @@ .Nm ld.lld .Op Ar options .Ar objfile ... + .Sh DESCRIPTION A linker takes one or more object, archive, and library files, and combines them into an output file (an executable, a shared library, or another object @@ -25,7 +26,21 @@ is a drop-in replacement for the GNU BFD and gold linkers. It accepts most of the same command line arguments and linker scripts as GNU linkers. .Pp -These options are available: +.Nm +currently supports i386, x86-64, ARM, AArch64, PowerPC32, PowerPC64, +MIPS32, MIPS64, RISC-V, AMDGPU, Hexagon and SPARC V9 targets. +.Nm +acts as a Microsoft link.exe-compatible linker if invoked as +.Nm lld-link +and as macOS's ld if invoked as +.Nm ld.ld64. +All these targets are always supported however +.Nm +was built, so you can always use +.Nm +as a native linker as well as a cross linker. + +.Sh OPTIONS .Bl -tag -width indent .It Fl -allow-multiple-definition Do not error if a symbol is defined multiple times. @@ -144,6 +159,9 @@ Maximum number of errors to emit before stopping. A value of zero indicates that there is no limit. .It Fl -error-unresolved-symbols Report unresolved symbols as errors. +.It Fl -execute-only +Mark executable sections unreadable. This option is currently only +supported on AArch64. .It Fl -exclude-libs Ns = Ns Ar value Exclude static libraries from automatic export. .It Fl -export-dynamic , Fl E @@ -297,6 +315,8 @@ Include hotness information in the optimization remarks file. Create a position independent executable. .It Fl -print-gc-sections List removed unused sections. +.It Fl -print-icf-sections +List identical folded sections. .It Fl -print-map Print a link map to the standard output. .It Fl -push-state @@ -304,7 +324,7 @@ Save the current state of .Fl -as-needed , .Fl -static , and -.Fl -while-archive. +.Fl -whole-archive. .It Fl -pop-state Undo the effect of .Fl -push-state. @@ -426,6 +446,17 @@ This can be used to ensure linker invocation remains compatible with traditional Unix-like linkers. .It Fl -warn-common Warn about duplicate common symbols. +.It Fl -warn-ifunc-textrel +Warn about using ifunc symbols in conjunction with text relocations. +Older versions of 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 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. .It Fl -warn-unresolved-symbols Report unresolved symbols as warnings. .It Fl -whole-archive @@ -440,10 +471,22 @@ Make the main stack executable. Stack permissions are recorded in the .Dv PT_GNU_STACK segment. +.It Cm global +Sets the +.Dv DF_1_GLOBAL flag in the +.Dv DYNAMIC +section. +Different loaders can decide how to handle this flag on their own. .It Cm initfirst Sets the .Dv DF_1_INITFIRST flag to indicate the module should be initialized first. +.It Cm interpose +Set the +.Dv 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. .It Cm muldefs Do not error if a symbol is defined multiple times. The first definition will be used. @@ -453,6 +496,10 @@ This is a synonym for Disable combining and sorting multiple relocation sections. .It Cm nocopyreloc Disable the creation of copy relocations. +.It Cm nodefaultlib +Set the +.Dv DF_1_NODEFLIB +flag to indicate that default library search paths should be ignored. .It Cm nodelete Set the .Dv DF_1_NODELETE @@ -460,7 +507,7 @@ flag to indicate that the object cannot be unloaded from a process. .It Cm nodlopen Set the .Dv DF_1_NOOPEN -flag to indcate that the object may not be opened by +flag to indicate that the object may not be opened by .Xr dlopen 3 . .It Cm norelro Do not indicate that portions of the object shold be mapped read-only |