| Message ID | 20200702193449.cz6bhplp5kvdmkkd@google.com |
|---|---|
| State | New |
| Headers | show |
| Series | Add -fld-path= to specify an arbitrary executable as the linker | expand |
On 7/2/20 9:34 PM, Fāng-ruì Sòng wrote: > On 2020-07-01, Fāng-ruì Sòng wrote: >> On 2020-07-01, Martin Liška wrote: >>> On 6/30/20 5:32 PM, Fāng-ruì Sòng wrote: >>>> There is some concern about clang's -fuse-ld=path >>>> http://lists.llvm.org/pipermail/cfe-dev/2020-June/065710.html and use >>>> of COMPILER_PATH vs PATH. >>>> Shall we introduce another option like -fld-path=path (PATH is used, >>>> COMPILER_PATH is not used)? >>> >>> I would recommend first landing a patch to LLVM and then we can do >>> a corresponding change to GCC. >>> >>> Martin >> >> Thank a lot for you welcoming words! This is what I intend to add for clang: https://reviews.llvm.org/D83015 >> >> I'll create a GCC patch superseding this one later. > > Attached the new patch. Thank you for the update patch: > From e7f86cdcaf03e4ddb98d0df9d07894d9ffb7d91a Mon Sep 17 00:00:00 2001 > From: Fangrui Song <maskray@google.com> > Date: Thu, 2 Jul 2020 12:26:09 -0700 > Subject: [PATCH] Add -fld-path= to specify an arbitrary executable as the > linker > > The value can be either a relative path (relative to a COMPILER_PATH > directory or a PATH directory) or an absolute path. -fld-path= > complements -fuse-ld={bfd,gold,lld} which specifies the linker flavor. > > PR driver/93645 > * common.opt (-fld-path=): Add -fld-path= > * opts.c (common_handle_option): Handle OPT_fld_path_. > * gcc.c (driver_handle_option): Likewise. > * collect2.c (main): Likewise. > * doc/invoke.texi: Document -fld-path=. > --- > gcc/collect2.c | 57 ++++++++++++++++++++++++++++++++------------- > gcc/common.opt | 4 ++++ > gcc/doc/invoke.texi | 6 +++++ > gcc/gcc.c | 2 +- > gcc/opts.c | 1 + > 5 files changed, 53 insertions(+), 17 deletions(-) > > diff --git a/gcc/collect2.c b/gcc/collect2.c > index f8a5ce45994..efa652f7f82 100644 > --- a/gcc/collect2.c > +++ b/gcc/collect2.c > @@ -844,6 +844,7 @@ main (int argc, char **argv) > const char **ld1; > bool use_plugin = false; > bool use_collect_ld = false; > + const char *ld_path = NULL; > > /* The kinds of symbols we will have to consider when scanning the > outcome of a first pass link. This is ALL to start with, then might > @@ -961,12 +962,21 @@ main (int argc, char **argv) > if (selected_linker == USE_DEFAULT_LD) > selected_linker = USE_PLUGIN_LD; > } > - else if (strcmp (argv[i], "-fuse-ld=bfd") == 0) > - selected_linker = USE_BFD_LD; > - else if (strcmp (argv[i], "-fuse-ld=gold") == 0) > - selected_linker = USE_GOLD_LD; > - else if (strcmp (argv[i], "-fuse-ld=lld") == 0) > - selected_linker = USE_LLD_LD; > + else if (strncmp (argv[i], "-fuse-ld=bfd", 9) == 0 > + && selected_linker != USE_LD_MAX) > + { This does not seem correct to me. You match -fuse-ld=bfd and then test other option values in the following block. > + if (strcmp (argv[i] + 9, "bfd") == 0) > + selected_linker = USE_BFD_LD; > + else if (strcmp (argv[i] + 9, "gold") == 0) > + selected_linker = USE_GOLD_LD; > + else if (strcmp (argv[i] + 9, "lld") == 0) > + selected_linker = USE_LLD_LD; > + } > + else if (strncmp (argv[i], "-fld-path=", 10) == 0) > + { > + ld_path = argv[i] + 10; > + selected_linker = USE_LD_MAX; > + } > else if (strncmp (argv[i], "-o", 2) == 0) > { > /* Parse the output filename if it's given so that we can make > @@ -1117,14 +1127,27 @@ main (int argc, char **argv) > ld_file_name = find_a_file (&cpath, collect_ld_suffix, X_OK); > use_collect_ld = ld_file_name != 0; > } > - /* Search the compiler directories for `ld'. We have protection against > - recursive calls in find_a_file. */ > - if (ld_file_name == 0) > - ld_file_name = find_a_file (&cpath, ld_suffixes[selected_linker], X_OK); > - /* Search the ordinary system bin directories > - for `ld' (if native linking) or `TARGET-ld' (if cross). */ > - if (ld_file_name == 0) > - ld_file_name = find_a_file (&path, full_ld_suffixes[selected_linker], X_OK); > + if (selected_linker == USE_LD_MAX) > + { > + /* If -fld-path= does not contain a slash, search for the command using > + the PATH environment variable. */ We also support file systems like Windows where the comment about a slash will be misleading. You can just mention relative vs. absolute path. > + if (lbasename (ld_path) == ld_path) Does it really return the same pointer? Maybe strcmp can be needed? > + ld_file_name = find_a_file (&path, ld_path, X_OK); > + else if (file_exists (ld_path)) > + ld_file_name = ld_path; > + } > + else > + { > + /* Search the compiler directories for `ld'. We have protection against > + recursive calls in find_a_file. */ > + if (ld_file_name == 0) > + ld_file_name = find_a_file (&cpath, ld_suffixes[selected_linker], X_OK); > + /* Search the ordinary system bin directories > + for `ld' (if native linking) or `TARGET-ld' (if cross). */ > + if (ld_file_name == 0) > + ld_file_name = > + find_a_file (&path, full_ld_suffixes[selected_linker], X_OK); > + } > > #ifdef REAL_NM_FILE_NAME > nm_file_name = find_a_file (&path, REAL_NM_FILE_NAME, X_OK); > @@ -1297,9 +1320,11 @@ main (int argc, char **argv) > #endif > } > else if (!use_collect_ld > - && strncmp (arg, "-fuse-ld=", 9) == 0) > + && (strncmp (arg, "-fuse-ld=", 9) == 0 || > + strncmp (arg, "-fld-path=", 10) == 0)) > { > - /* Do not pass -fuse-ld={bfd|gold|lld} to the linker. */ > + /* Do not pass -fuse-ld={bfd|gold|lld} or -fld-path= to the > + linker. */ > ld1--; > ld2--; > } > diff --git a/gcc/common.opt b/gcc/common.opt > index df8af365d1b..d5dfbb5c9c6 100644 > --- a/gcc/common.opt > +++ b/gcc/common.opt > @@ -2919,6 +2919,10 @@ fuse-ld=lld > Common Driver Negative(fuse-ld=lld) > Use the lld LLVM linker instead of the default linker. > > +fld-path= > +Common Driver Joined > +Use the specified executable instead of the default linker. > + > fuse-linker-plugin > Common Undocumented Var(flag_use_linker_plugin) > > diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi > index e21d8a5217b..bfb6222f96b 100644 > --- a/gcc/doc/invoke.texi > +++ b/gcc/doc/invoke.texi > @@ -14651,6 +14651,12 @@ Use the @command{gold} linker instead of the default linker. > @opindex fuse-ld=lld > Use the LLVM @command{lld} linker instead of the default linker. > > +@item -fld-path=@var{linker} > +@opindex fld-path=linker > +Use the specified executable named @var{linker} instead of the default linker. > +If @var{linker} does not contain any slash character, the linker will be > +searched for using @env{PATH}. This option overrides @option{-fuse-ld=}. The slash comment applies here as well. Martin > + > @cindex Libraries > @item -l@var{library} > @itemx -l @var{library} > diff --git a/gcc/gcc.c b/gcc/gcc.c > index c0eb3c10cfd..a57a3d0aec4 100644 > --- a/gcc/gcc.c > +++ b/gcc/gcc.c > @@ -1077,7 +1077,7 @@ proper position among the other output files. */ > LINK_PLUGIN_SPEC \ > "%{flto|flto=*:%<fcompare-debug*} \ > %{flto} %{fno-lto} %{flto=*} %l " LINK_PIE_SPEC \ > - "%{fuse-ld=*:-fuse-ld=%*} " LINK_COMPRESS_DEBUG_SPEC \ > + "%{fuse-ld=*:-fuse-ld=%*} %{fld-path=*:-fld-path=%*} " LINK_COMPRESS_DEBUG_SPEC \ > "%X %{o*} %{e*} %{N} %{n} %{r}\ > %{s} %{t} %{u*} %{z} %{Z} %{!nostdlib:%{!r:%{!nostartfiles:%S}}} \ > %{static|no-pie|static-pie:} %@{L*} %(mfwrap) %(link_libgcc) " \ > diff --git a/gcc/opts.c b/gcc/opts.c > index 340d99434b3..c4507d53abc 100644 > --- a/gcc/opts.c > +++ b/gcc/opts.c > @@ -2750,6 +2750,7 @@ common_handle_option (struct gcc_options *opts, > case OPT_fuse_ld_bfd: > case OPT_fuse_ld_gold: > case OPT_fuse_ld_lld: > + case OPT_fld_path_: > case OPT_fuse_linker_plugin: > /* No-op. Used by the driver and passed to us because it starts with f.*/ > break; > -- > 2.27.0.383.g050319c2ae-goog >
On 2020-07-03, Martin Liška wrote: >On 7/2/20 9:34 PM, Fāng-ruì Sòng wrote: >>On 2020-07-01, Fāng-ruì Sòng wrote: >>>On 2020-07-01, Martin Liška wrote: >>>>On 6/30/20 5:32 PM, Fāng-ruì Sòng wrote: >>>>>There is some concern about clang's -fuse-ld=path >>>>>http://lists.llvm.org/pipermail/cfe-dev/2020-June/065710.html and use >>>>>of COMPILER_PATH vs PATH. >>>>>Shall we introduce another option like -fld-path=path (PATH is used, >>>>>COMPILER_PATH is not used)? >>>> >>>>I would recommend first landing a patch to LLVM and then we can do >>>>a corresponding change to GCC. >>>> >>>>Martin >>> >>>Thank a lot for you welcoming words! This is what I intend to add for clang: https://reviews.llvm.org/D83015 >>> >>>I'll create a GCC patch superseding this one later. >> >>Attached the new patch. > >Thank you for the update patch: > >>From e7f86cdcaf03e4ddb98d0df9d07894d9ffb7d91a Mon Sep 17 00:00:00 2001 >>From: Fangrui Song <maskray@google.com> >>Date: Thu, 2 Jul 2020 12:26:09 -0700 >>Subject: [PATCH] Add -fld-path= to specify an arbitrary executable as the >> linker >> >>The value can be either a relative path (relative to a COMPILER_PATH >>directory or a PATH directory) or an absolute path. -fld-path= >>complements -fuse-ld={bfd,gold,lld} which specifies the linker flavor. >> >> PR driver/93645 >> * common.opt (-fld-path=): Add -fld-path= >> * opts.c (common_handle_option): Handle OPT_fld_path_. >> * gcc.c (driver_handle_option): Likewise. >> * collect2.c (main): Likewise. >> * doc/invoke.texi: Document -fld-path=. >>--- >> gcc/collect2.c | 57 ++++++++++++++++++++++++++++++++------------- >> gcc/common.opt | 4 ++++ >> gcc/doc/invoke.texi | 6 +++++ >> gcc/gcc.c | 2 +- >> gcc/opts.c | 1 + >> 5 files changed, 53 insertions(+), 17 deletions(-) >> >>diff --git a/gcc/collect2.c b/gcc/collect2.c >>index f8a5ce45994..efa652f7f82 100644 >>--- a/gcc/collect2.c >>+++ b/gcc/collect2.c >>@@ -844,6 +844,7 @@ main (int argc, char **argv) >> const char **ld1; >> bool use_plugin = false; >> bool use_collect_ld = false; >>+ const char *ld_path = NULL; >> /* The kinds of symbols we will have to consider when scanning the >> outcome of a first pass link. This is ALL to start with, then might >>@@ -961,12 +962,21 @@ main (int argc, char **argv) >> if (selected_linker == USE_DEFAULT_LD) >> selected_linker = USE_PLUGIN_LD; >> } >>- else if (strcmp (argv[i], "-fuse-ld=bfd") == 0) >>- selected_linker = USE_BFD_LD; >>- else if (strcmp (argv[i], "-fuse-ld=gold") == 0) >>- selected_linker = USE_GOLD_LD; >>- else if (strcmp (argv[i], "-fuse-ld=lld") == 0) >>- selected_linker = USE_LLD_LD; >>+ else if (strncmp (argv[i], "-fuse-ld=bfd", 9) == 0 >>+ && selected_linker != USE_LD_MAX) >>+ { > >This does not seem correct to me. You match -fuse-ld=bfd and then >test other option values in the following block. This is correct but I probably should use: - strncmp (argv[i], "-fuse-ld=bfd", 9) == 0 + strncmp (argv[i], "-fuse-ld=", 9) == 0 >>+ if (strcmp (argv[i] + 9, "bfd") == 0) >>+ selected_linker = USE_BFD_LD; >>+ else if (strcmp (argv[i] + 9, "gold") == 0) >>+ selected_linker = USE_GOLD_LD; >>+ else if (strcmp (argv[i] + 9, "lld") == 0) >>+ selected_linker = USE_LLD_LD; >>+ } >>+ else if (strncmp (argv[i], "-fld-path=", 10) == 0) >>+ { >>+ ld_path = argv[i] + 10; >>+ selected_linker = USE_LD_MAX; >>+ } >> else if (strncmp (argv[i], "-o", 2) == 0) >> { >> /* Parse the output filename if it's given so that we can make >>@@ -1117,14 +1127,27 @@ main (int argc, char **argv) >> ld_file_name = find_a_file (&cpath, collect_ld_suffix, X_OK); >> use_collect_ld = ld_file_name != 0; >> } >>- /* Search the compiler directories for `ld'. We have protection against >>- recursive calls in find_a_file. */ >>- if (ld_file_name == 0) >>- ld_file_name = find_a_file (&cpath, ld_suffixes[selected_linker], X_OK); >>- /* Search the ordinary system bin directories >>- for `ld' (if native linking) or `TARGET-ld' (if cross). */ >>- if (ld_file_name == 0) >>- ld_file_name = find_a_file (&path, full_ld_suffixes[selected_linker], X_OK); >>+ if (selected_linker == USE_LD_MAX) >>+ { >>+ /* If -fld-path= does not contain a slash, search for the command using >>+ the PATH environment variable. */ > >We also support file systems like Windows where the comment about a slash will be misleading. >You can just mention relative vs. absolute path. The behavior is modeled after https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html Command Search and Execution e. Otherwise, the command shall be searched for using the PATH environment variable as described in XBD Environment Variables : is performed if "the command name does not contain any <slash> characters". For your suggestion, I think 'word' can mean a relative path as well, along with 'rel\path' and 'rel/path'. Should I say If -fld-path= does not contain a path component separator (e.g. slash), search for the command using ? >>+ if (lbasename (ld_path) == ld_path) > >Does it really return the same pointer? Maybe strcmp can be needed? lbasename returns a const char * referencing a place of the string. lto-wrapper.s has a similar use case: 1542: if (!dumppfx || lbasename (dumppfx) == dumppfx) >>+ ld_file_name = find_a_file (&path, ld_path, X_OK); >>+ else if (file_exists (ld_path)) >>+ ld_file_name = ld_path; >>+ } >>+ else >>+ { >>+ /* Search the compiler directories for `ld'. We have protection against >>+ recursive calls in find_a_file. */ >>+ if (ld_file_name == 0) >>+ ld_file_name = find_a_file (&cpath, ld_suffixes[selected_linker], X_OK); >>+ /* Search the ordinary system bin directories >>+ for `ld' (if native linking) or `TARGET-ld' (if cross). */ >>+ if (ld_file_name == 0) >>+ ld_file_name = >>+ find_a_file (&path, full_ld_suffixes[selected_linker], X_OK); >>+ } >> #ifdef REAL_NM_FILE_NAME >> nm_file_name = find_a_file (&path, REAL_NM_FILE_NAME, X_OK); >>@@ -1297,9 +1320,11 @@ main (int argc, char **argv) >> #endif >> } >> else if (!use_collect_ld >>- && strncmp (arg, "-fuse-ld=", 9) == 0) >>+ && (strncmp (arg, "-fuse-ld=", 9) == 0 || >>+ strncmp (arg, "-fld-path=", 10) == 0)) >> { >>- /* Do not pass -fuse-ld={bfd|gold|lld} to the linker. */ >>+ /* Do not pass -fuse-ld={bfd|gold|lld} or -fld-path= to the >>+ linker. */ >> ld1--; >> ld2--; >> } >>diff --git a/gcc/common.opt b/gcc/common.opt >>index df8af365d1b..d5dfbb5c9c6 100644 >>--- a/gcc/common.opt >>+++ b/gcc/common.opt >>@@ -2919,6 +2919,10 @@ fuse-ld=lld >> Common Driver Negative(fuse-ld=lld) >> Use the lld LLVM linker instead of the default linker. >>+fld-path= >>+Common Driver Joined >>+Use the specified executable instead of the default linker. >>+ >> fuse-linker-plugin >> Common Undocumented Var(flag_use_linker_plugin) >>diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi >>index e21d8a5217b..bfb6222f96b 100644 >>--- a/gcc/doc/invoke.texi >>+++ b/gcc/doc/invoke.texi >>@@ -14651,6 +14651,12 @@ Use the @command{gold} linker instead of the default linker. >> @opindex fuse-ld=lld >> Use the LLVM @command{lld} linker instead of the default linker. >>+@item -fld-path=@var{linker} >>+@opindex fld-path=linker >>+Use the specified executable named @var{linker} instead of the default linker. >>+If @var{linker} does not contain any slash character, the linker will be >>+searched for using @env{PATH}. This option overrides @option{-fuse-ld=}. > >The slash comment applies here as well. > >Martin Ack. Will update when I get a clarification regarding the previous comment. >>+ >> @cindex Libraries >> @item -l@var{library} >> @itemx -l @var{library} >>diff --git a/gcc/gcc.c b/gcc/gcc.c >>index c0eb3c10cfd..a57a3d0aec4 100644 >>--- a/gcc/gcc.c >>+++ b/gcc/gcc.c >>@@ -1077,7 +1077,7 @@ proper position among the other output files. */ >> LINK_PLUGIN_SPEC \ >> "%{flto|flto=*:%<fcompare-debug*} \ >> %{flto} %{fno-lto} %{flto=*} %l " LINK_PIE_SPEC \ >>- "%{fuse-ld=*:-fuse-ld=%*} " LINK_COMPRESS_DEBUG_SPEC \ >>+ "%{fuse-ld=*:-fuse-ld=%*} %{fld-path=*:-fld-path=%*} " LINK_COMPRESS_DEBUG_SPEC \ >> "%X %{o*} %{e*} %{N} %{n} %{r}\ >> %{s} %{t} %{u*} %{z} %{Z} %{!nostdlib:%{!r:%{!nostartfiles:%S}}} \ >> %{static|no-pie|static-pie:} %@{L*} %(mfwrap) %(link_libgcc) " \ >>diff --git a/gcc/opts.c b/gcc/opts.c >>index 340d99434b3..c4507d53abc 100644 >>--- a/gcc/opts.c >>+++ b/gcc/opts.c >>@@ -2750,6 +2750,7 @@ common_handle_option (struct gcc_options *opts, >> case OPT_fuse_ld_bfd: >> case OPT_fuse_ld_gold: >> case OPT_fuse_ld_lld: >>+ case OPT_fld_path_: >> case OPT_fuse_linker_plugin: >> /* No-op. Used by the driver and passed to us because it starts with f.*/ >> break; >>-- >>2.27.0.383.g050319c2ae-goog >>
On 7/3/20 7:18 PM, Fāng-ruì Sòng wrote: > > On 2020-07-03, Martin Liška wrote: >> On 7/2/20 9:34 PM, Fāng-ruì Sòng wrote: >>> On 2020-07-01, Fāng-ruì Sòng wrote: >>>> On 2020-07-01, Martin Liška wrote: >>>>> On 6/30/20 5:32 PM, Fāng-ruì Sòng wrote: >>>>>> There is some concern about clang's -fuse-ld=path >>>>>> http://lists.llvm.org/pipermail/cfe-dev/2020-June/065710.html and use >>>>>> of COMPILER_PATH vs PATH. >>>>>> Shall we introduce another option like -fld-path=path (PATH is used, >>>>>> COMPILER_PATH is not used)? >>>>> >>>>> I would recommend first landing a patch to LLVM and then we can do >>>>> a corresponding change to GCC. >>>>> >>>>> Martin >>>> >>>> Thank a lot for you welcoming words! This is what I intend to add for clang: https://reviews.llvm.org/D83015 >>>> >>>> I'll create a GCC patch superseding this one later. >>> >>> Attached the new patch. >> >> Thank you for the update patch: >> >>> From e7f86cdcaf03e4ddb98d0df9d07894d9ffb7d91a Mon Sep 17 00:00:00 2001 >>> From: Fangrui Song <maskray@google.com> >>> Date: Thu, 2 Jul 2020 12:26:09 -0700 >>> Subject: [PATCH] Add -fld-path= to specify an arbitrary executable as the >>> linker >>> >>> The value can be either a relative path (relative to a COMPILER_PATH >>> directory or a PATH directory) or an absolute path. -fld-path= >>> complements -fuse-ld={bfd,gold,lld} which specifies the linker flavor. >>> >>> PR driver/93645 >>> * common.opt (-fld-path=): Add -fld-path= >>> * opts.c (common_handle_option): Handle OPT_fld_path_. >>> * gcc.c (driver_handle_option): Likewise. >>> * collect2.c (main): Likewise. >>> * doc/invoke.texi: Document -fld-path=. >>> --- >>> gcc/collect2.c | 57 ++++++++++++++++++++++++++++++++------------- >>> gcc/common.opt | 4 ++++ >>> gcc/doc/invoke.texi | 6 +++++ >>> gcc/gcc.c | 2 +- >>> gcc/opts.c | 1 + >>> 5 files changed, 53 insertions(+), 17 deletions(-) >>> >>> diff --git a/gcc/collect2.c b/gcc/collect2.c >>> index f8a5ce45994..efa652f7f82 100644 >>> --- a/gcc/collect2.c >>> +++ b/gcc/collect2.c >>> @@ -844,6 +844,7 @@ main (int argc, char **argv) >>> const char **ld1; >>> bool use_plugin = false; >>> bool use_collect_ld = false; >>> + const char *ld_path = NULL; >>> /* The kinds of symbols we will have to consider when scanning the >>> outcome of a first pass link. This is ALL to start with, then might >>> @@ -961,12 +962,21 @@ main (int argc, char **argv) >>> if (selected_linker == USE_DEFAULT_LD) >>> selected_linker = USE_PLUGIN_LD; >>> } >>> - else if (strcmp (argv[i], "-fuse-ld=bfd") == 0) >>> - selected_linker = USE_BFD_LD; >>> - else if (strcmp (argv[i], "-fuse-ld=gold") == 0) >>> - selected_linker = USE_GOLD_LD; >>> - else if (strcmp (argv[i], "-fuse-ld=lld") == 0) >>> - selected_linker = USE_LLD_LD; >>> + else if (strncmp (argv[i], "-fuse-ld=bfd", 9) == 0 >>> + && selected_linker != USE_LD_MAX) >>> + { >> >> This does not seem correct to me. You match -fuse-ld=bfd and then >> test other option values in the following block. > > This is correct but I probably should use: > > - strncmp (argv[i], "-fuse-ld=bfd", 9) == 0 > + strncmp (argv[i], "-fuse-ld=", 9) == 0 Yes, that would be much better. > > >>> + if (strcmp (argv[i] + 9, "bfd") == 0) >>> + selected_linker = USE_BFD_LD; >>> + else if (strcmp (argv[i] + 9, "gold") == 0) >>> + selected_linker = USE_GOLD_LD; >>> + else if (strcmp (argv[i] + 9, "lld") == 0) >>> + selected_linker = USE_LLD_LD; >>> + } >>> + else if (strncmp (argv[i], "-fld-path=", 10) == 0) >>> + { >>> + ld_path = argv[i] + 10; >>> + selected_linker = USE_LD_MAX; >>> + } >>> else if (strncmp (argv[i], "-o", 2) == 0) >>> { >>> /* Parse the output filename if it's given so that we can make >>> @@ -1117,14 +1127,27 @@ main (int argc, char **argv) >>> ld_file_name = find_a_file (&cpath, collect_ld_suffix, X_OK); >>> use_collect_ld = ld_file_name != 0; >>> } >>> - /* Search the compiler directories for `ld'. We have protection against >>> - recursive calls in find_a_file. */ >>> - if (ld_file_name == 0) >>> - ld_file_name = find_a_file (&cpath, ld_suffixes[selected_linker], X_OK); >>> - /* Search the ordinary system bin directories >>> - for `ld' (if native linking) or `TARGET-ld' (if cross). */ >>> - if (ld_file_name == 0) >>> - ld_file_name = find_a_file (&path, full_ld_suffixes[selected_linker], X_OK); >>> + if (selected_linker == USE_LD_MAX) >>> + { >>> + /* If -fld-path= does not contain a slash, search for the command using >>> + the PATH environment variable. */ >> >> We also support file systems like Windows where the comment about a slash will be misleading. >> You can just mention relative vs. absolute path. > > The behavior is modeled after > https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html Command Search and Execution > > e. Otherwise, the command shall be searched for using the PATH environment variable as described in XBD Environment Variables : > > is performed if "the command name does not contain any <slash> characters". > > For your suggestion, I think 'word' can mean a relative path as well, along with 'rel\path' and 'rel/path'. > > Should I say > If -fld-path= does not contain a path component separator (e.g. slash), search for the command using > > ? Seems file to me. > >>> + if (lbasename (ld_path) == ld_path) >> >> Does it really return the same pointer? Maybe strcmp can be needed? > > lbasename returns a const char * referencing a place of the string. > lto-wrapper.s has a similar use case: Fine then. > > 1542: if (!dumppfx || lbasename (dumppfx) == dumppfx) > >>> + ld_file_name = find_a_file (&path, ld_path, X_OK); >>> + else if (file_exists (ld_path)) >>> + ld_file_name = ld_path; >>> + } >>> + else >>> + { >>> + /* Search the compiler directories for `ld'. We have protection against >>> + recursive calls in find_a_file. */ >>> + if (ld_file_name == 0) >>> + ld_file_name = find_a_file (&cpath, ld_suffixes[selected_linker], X_OK); >>> + /* Search the ordinary system bin directories >>> + for `ld' (if native linking) or `TARGET-ld' (if cross). */ >>> + if (ld_file_name == 0) >>> + ld_file_name = >>> + find_a_file (&path, full_ld_suffixes[selected_linker], X_OK); >>> + } >>> #ifdef REAL_NM_FILE_NAME >>> nm_file_name = find_a_file (&path, REAL_NM_FILE_NAME, X_OK); >>> @@ -1297,9 +1320,11 @@ main (int argc, char **argv) >>> #endif >>> } >>> else if (!use_collect_ld >>> - && strncmp (arg, "-fuse-ld=", 9) == 0) >>> + && (strncmp (arg, "-fuse-ld=", 9) == 0 || >>> + strncmp (arg, "-fld-path=", 10) == 0)) >>> { >>> - /* Do not pass -fuse-ld={bfd|gold|lld} to the linker. */ >>> + /* Do not pass -fuse-ld={bfd|gold|lld} or -fld-path= to the >>> + linker. */ >>> ld1--; >>> ld2--; >>> } >>> diff --git a/gcc/common.opt b/gcc/common.opt >>> index df8af365d1b..d5dfbb5c9c6 100644 >>> --- a/gcc/common.opt >>> +++ b/gcc/common.opt >>> @@ -2919,6 +2919,10 @@ fuse-ld=lld >>> Common Driver Negative(fuse-ld=lld) >>> Use the lld LLVM linker instead of the default linker. >>> +fld-path= >>> +Common Driver Joined >>> +Use the specified executable instead of the default linker. >>> + >>> fuse-linker-plugin >>> Common Undocumented Var(flag_use_linker_plugin) >>> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi >>> index e21d8a5217b..bfb6222f96b 100644 >>> --- a/gcc/doc/invoke.texi >>> +++ b/gcc/doc/invoke.texi >>> @@ -14651,6 +14651,12 @@ Use the @command{gold} linker instead of the default linker. >>> @opindex fuse-ld=lld >>> Use the LLVM @command{lld} linker instead of the default linker. >>> +@item -fld-path=@var{linker} >>> +@opindex fld-path=linker >>> +Use the specified executable named @var{linker} instead of the default linker. >>> +If @var{linker} does not contain any slash character, the linker will be >>> +searched for using @env{PATH}. This option overrides @option{-fuse-ld=}. >> >> The slash comment applies here as well. >> >> Martin > > Ack. Will update when I get a clarification regarding the previous comment. Thanks, Martin > >>> + >>> @cindex Libraries >>> @item -l@var{library} >>> @itemx -l @var{library} >>> diff --git a/gcc/gcc.c b/gcc/gcc.c >>> index c0eb3c10cfd..a57a3d0aec4 100644 >>> --- a/gcc/gcc.c >>> +++ b/gcc/gcc.c >>> @@ -1077,7 +1077,7 @@ proper position among the other output files. */ >>> LINK_PLUGIN_SPEC \ >>> "%{flto|flto=*:%<fcompare-debug*} \ >>> %{flto} %{fno-lto} %{flto=*} %l " LINK_PIE_SPEC \ >>> - "%{fuse-ld=*:-fuse-ld=%*} " LINK_COMPRESS_DEBUG_SPEC \ >>> + "%{fuse-ld=*:-fuse-ld=%*} %{fld-path=*:-fld-path=%*} " LINK_COMPRESS_DEBUG_SPEC \ >>> "%X %{o*} %{e*} %{N} %{n} %{r}\ >>> %{s} %{t} %{u*} %{z} %{Z} %{!nostdlib:%{!r:%{!nostartfiles:%S}}} \ >>> %{static|no-pie|static-pie:} %@{L*} %(mfwrap) %(link_libgcc) " \ >>> diff --git a/gcc/opts.c b/gcc/opts.c >>> index 340d99434b3..c4507d53abc 100644 >>> --- a/gcc/opts.c >>> +++ b/gcc/opts.c >>> @@ -2750,6 +2750,7 @@ common_handle_option (struct gcc_options *opts, >>> case OPT_fuse_ld_bfd: >>> case OPT_fuse_ld_gold: >>> case OPT_fuse_ld_lld: >>> + case OPT_fld_path_: >>> case OPT_fuse_linker_plugin: >>> /* No-op. Used by the driver and passed to us because it starts with f.*/ >>> break; >>> -- >>> 2.27.0.383.g050319c2ae-goog >>>
From e7f86cdcaf03e4ddb98d0df9d07894d9ffb7d91a Mon Sep 17 00:00:00 2001
From: Fangrui Song <maskray@google.com>
Date: Thu, 2 Jul 2020 12:26:09 -0700
Subject: [PATCH] Add -fld-path= to specify an arbitrary executable as the
linker
The value can be either a relative path (relative to a COMPILER_PATH
directory or a PATH directory) or an absolute path. -fld-path=
complements -fuse-ld={bfd,gold,lld} which specifies the linker flavor.
PR driver/93645
* common.opt (-fld-path=): Add -fld-path=
* opts.c (common_handle_option): Handle OPT_fld_path_.
* gcc.c (driver_handle_option): Likewise.
* collect2.c (main): Likewise.
* doc/invoke.texi: Document -fld-path=.
---
gcc/collect2.c | 57 ++++++++++++++++++++++++++++++++-------------
gcc/common.opt | 4 ++++
gcc/doc/invoke.texi | 6 +++++
gcc/gcc.c | 2 +-
gcc/opts.c | 1 +
5 files changed, 53 insertions(+), 17 deletions(-)
diff --git a/gcc/collect2.c b/gcc/collect2.c
index f8a5ce45994..efa652f7f82 100644
--- a/gcc/collect2.c
+++ b/gcc/collect2.c
@@ -844,6 +844,7 @@ main (int argc, char **argv)
const char **ld1;
bool use_plugin = false;
bool use_collect_ld = false;
+ const char *ld_path = NULL;
/* The kinds of symbols we will have to consider when scanning the
outcome of a first pass link. This is ALL to start with, then might
@@ -961,12 +962,21 @@ main (int argc, char **argv)
if (selected_linker == USE_DEFAULT_LD)
selected_linker = USE_PLUGIN_LD;
}
- else if (strcmp (argv[i], "-fuse-ld=bfd") == 0)
- selected_linker = USE_BFD_LD;
- else if (strcmp (argv[i], "-fuse-ld=gold") == 0)
- selected_linker = USE_GOLD_LD;
- else if (strcmp (argv[i], "-fuse-ld=lld") == 0)
- selected_linker = USE_LLD_LD;
+ else if (strncmp (argv[i], "-fuse-ld=bfd", 9) == 0
+ && selected_linker != USE_LD_MAX)
+ {
+ if (strcmp (argv[i] + 9, "bfd") == 0)
+ selected_linker = USE_BFD_LD;
+ else if (strcmp (argv[i] + 9, "gold") == 0)
+ selected_linker = USE_GOLD_LD;
+ else if (strcmp (argv[i] + 9, "lld") == 0)
+ selected_linker = USE_LLD_LD;
+ }
+ else if (strncmp (argv[i], "-fld-path=", 10) == 0)
+ {
+ ld_path = argv[i] + 10;
+ selected_linker = USE_LD_MAX;
+ }
else if (strncmp (argv[i], "-o", 2) == 0)
{
/* Parse the output filename if it's given so that we can make
@@ -1117,14 +1127,27 @@ main (int argc, char **argv)
ld_file_name = find_a_file (&cpath, collect_ld_suffix, X_OK);
use_collect_ld = ld_file_name != 0;
}
- /* Search the compiler directories for `ld'. We have protection against
- recursive calls in find_a_file. */
- if (ld_file_name == 0)
- ld_file_name = find_a_file (&cpath, ld_suffixes[selected_linker], X_OK);
- /* Search the ordinary system bin directories
- for `ld' (if native linking) or `TARGET-ld' (if cross). */
- if (ld_file_name == 0)
- ld_file_name = find_a_file (&path, full_ld_suffixes[selected_linker], X_OK);
+ if (selected_linker == USE_LD_MAX)
+ {
+ /* If -fld-path= does not contain a slash, search for the command using
+ the PATH environment variable. */
+ if (lbasename (ld_path) == ld_path)
+ ld_file_name = find_a_file (&path, ld_path, X_OK);
+ else if (file_exists (ld_path))
+ ld_file_name = ld_path;
+ }
+ else
+ {
+ /* Search the compiler directories for `ld'. We have protection against
+ recursive calls in find_a_file. */
+ if (ld_file_name == 0)
+ ld_file_name = find_a_file (&cpath, ld_suffixes[selected_linker], X_OK);
+ /* Search the ordinary system bin directories
+ for `ld' (if native linking) or `TARGET-ld' (if cross). */
+ if (ld_file_name == 0)
+ ld_file_name =
+ find_a_file (&path, full_ld_suffixes[selected_linker], X_OK);
+ }
#ifdef REAL_NM_FILE_NAME
nm_file_name = find_a_file (&path, REAL_NM_FILE_NAME, X_OK);
@@ -1297,9 +1320,11 @@ main (int argc, char **argv)
#endif
}
else if (!use_collect_ld
- && strncmp (arg, "-fuse-ld=", 9) == 0)
+ && (strncmp (arg, "-fuse-ld=", 9) == 0 ||
+ strncmp (arg, "-fld-path=", 10) == 0))
{
- /* Do not pass -fuse-ld={bfd|gold|lld} to the linker. */
+ /* Do not pass -fuse-ld={bfd|gold|lld} or -fld-path= to the
+ linker. */
ld1--;
ld2--;
}
diff --git a/gcc/common.opt b/gcc/common.opt
index df8af365d1b..d5dfbb5c9c6 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -2919,6 +2919,10 @@ fuse-ld=lld
Common Driver Negative(fuse-ld=lld)
Use the lld LLVM linker instead of the default linker.
+fld-path=
+Common Driver Joined
+Use the specified executable instead of the default linker.
+
fuse-linker-plugin
Common Undocumented Var(flag_use_linker_plugin)
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index e21d8a5217b..bfb6222f96b 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -14651,6 +14651,12 @@ Use the @command{gold} linker instead of the default linker.
@opindex fuse-ld=lld
Use the LLVM @command{lld} linker instead of the default linker.
+@item -fld-path=@var{linker}
+@opindex fld-path=linker
+Use the specified executable named @var{linker} instead of the default linker.
+If @var{linker} does not contain any slash character, the linker will be
+searched for using @env{PATH}. This option overrides @option{-fuse-ld=}.
+
@cindex Libraries
@item -l@var{library}
@itemx -l @var{library}
diff --git a/gcc/gcc.c b/gcc/gcc.c
index c0eb3c10cfd..a57a3d0aec4 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -1077,7 +1077,7 @@ proper position among the other output files. */
LINK_PLUGIN_SPEC \
"%{flto|flto=*:%<fcompare-debug*} \
%{flto} %{fno-lto} %{flto=*} %l " LINK_PIE_SPEC \
- "%{fuse-ld=*:-fuse-ld=%*} " LINK_COMPRESS_DEBUG_SPEC \
+ "%{fuse-ld=*:-fuse-ld=%*} %{fld-path=*:-fld-path=%*} " LINK_COMPRESS_DEBUG_SPEC \
"%X %{o*} %{e*} %{N} %{n} %{r}\
%{s} %{t} %{u*} %{z} %{Z} %{!nostdlib:%{!r:%{!nostartfiles:%S}}} \
%{static|no-pie|static-pie:} %@{L*} %(mfwrap) %(link_libgcc) " \
diff --git a/gcc/opts.c b/gcc/opts.c
index 340d99434b3..c4507d53abc 100644
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -2750,6 +2750,7 @@ common_handle_option (struct gcc_options *opts,
case OPT_fuse_ld_bfd:
case OPT_fuse_ld_gold:
case OPT_fuse_ld_lld:
+ case OPT_fld_path_:
case OPT_fuse_linker_plugin:
/* No-op. Used by the driver and passed to us because it starts with f.*/
break;
--
2.27.0.383.g050319c2ae-goog