From 042394387ecf67d0d4e57004f8c499d037dacf52 Mon Sep 17 00:00:00 2001
From: Fangrui Song <maskray@google.com>
Date: Fri, 24 Jul 2020 22:50:26 -0700
Subject: [PATCH v3] Add --ld-path= to specify an arbitrary executable as the
linker
If the value does not contain any path component separator (e.g. a
slash), the linker will be searched for using COMPILER_PATH followed by
PATH. Otherwise, it is either an absolute path or a path relative to the
current working directory.
--ld-path= complements and overrides -fuse-ld={bfd,gold,lld}. If in the
future, we want to make dfferent linker option decisions we can let
-fuse-ld= represent the linker flavor and --ld-path= the linker path.
PR driver/93645
* common.opt (--ld-path=): Add --ld-path=
* opts.c (common_handle_option): Handle OPT__ld_path_.
* gcc.c (driver_handle_option): Likewise.
* collect2.c (main): Likewise.
* doc/invoke.texi: Document --ld-path=.
---
Changes in v2:
* Renamed -fld-path= to --ld-path= (clang 12.0.0 new option).
The option does not affect code generation and is not a language feature,
-f* is not suitable.
---
gcc/collect2.c | 62 +++++++++++++++++++++++++++++++++++----------
gcc/common.opt | 4 +++
gcc/doc/invoke.texi | 9 +++++++
gcc/gcc.c | 2 +-
gcc/opts.c | 1 +
5 files changed, 63 insertions(+), 15 deletions(-)
@@ -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=", 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], "--ld-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 +1127,33 @@ 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 --ld-path= does not contain a path component separator, search for
+ the command using cpath, then using path. Otherwise the value is
+ either an absolute path or a path relative to the current working
+ directory. */
+ if (lbasename (ld_path) == ld_path)
+ {
+ ld_file_name = find_a_file (&cpath, ld_path, X_OK);
+ if (ld_file_name == NULL)
+ 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 == NULL)
+ 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 == NULL)
+ 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);
@@ -1461,6 +1490,11 @@ main (int argc, char **argv)
ld2--;
#endif
}
+ else if (strncmp (arg, "--ld-path=", 10) == 0)
+ {
+ ld1--;
+ ld2--;
+ }
else if (strncmp (arg, "--sysroot=", 10) == 0)
target_system_root = arg + 10;
else if (strcmp (arg, "--version") == 0)
@@ -2940,6 +2940,10 @@ fuse-ld=lld
Common Driver Negative(fuse-ld=lld)
Use the lld LLVM linker instead of the default linker.
+-ld-path=
+Common Driver Joined
+Use the specified executable instead of the default linker.
+
fuse-linker-plugin
Common Undocumented Var(flag_use_linker_plugin)
@@ -14718,6 +14718,15 @@ 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 --ld-path=@var{linker}
+@opindex -ld-path=linker
+Use the specified executable named @var{linker} instead of the default linker.
+If @var{linker} does not contain any path component separator (e.g. a slash),
+the linker will be searched for using @env{COMPILER_PATH} followed by
+@env{PATH}. Otherwise, it is either an absolute path or a path relative to the
+current working directory. If @option{-fuse-ld=} is also specified, the linker
+path is specified by @option{--ld-path=}.
+
@cindex Libraries
@item -l@var{library}
@itemx -l @var{library}
@@ -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=%*} %{-ld-path=*:--ld-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) " \
@@ -2755,6 +2755,7 @@ common_handle_option (struct gcc_options *opts,
dc->max_errors = value;
break;
+ case OPT__ld_path_:
case OPT_fuse_ld_bfd:
case OPT_fuse_ld_gold:
case OPT_fuse_ld_lld:
--
2.28.0.rc0.142.g3c755180ce-goog