On 2020-04-06, Martin Liška wrote:
On 4/6/20 12:32 AM, Fangrui Song wrote:
On 2020-03-11, Martin Liška wrote:
On 2/10/20 1:02 AM, Fangrui Song via gcc-patches wrote:
Hello.
Thank you for the patch. You haven't received a review because we are right now
in stage4 of the development cycle:
https://gcc.gnu.org/develop.html#stage4
Thanks for the review!
According to https://gcc.gnu.org/pipermail/gcc-patches/2020-April/543028.html "GCC
10.0 Status Report (2020-04-01)",
I guess GCC is not open for a new development cycle yet.
Yes, it's not opened, but I expect to be opened in 3 weeks from now.
I will just answer a few questions instead of uploading a new patch.
Sure, but don't hesitate to send a patch. It can sit here and wait for next
stage1 ;)
Thank you! I got around and updated the patch.
Tested locally with -fuse-ld=~/Stable/bin/ld.lld and
-fuse-ld=~/Dev/binutils-gdb/Debug/ld/ld-new
Anyway, I'm going to provide a review (even though I'm not maintainer of that).
Can you please describe your test-case why you need such option? When using
a different ld, I typically export PATH=/path/to/binutils and then run configure
and make.
I would hope -fuse-ld=ld.bfd and -fuse-ld=ld.gold were used instead of
-fuse-ld=bfd and -fuse-ld=gold, then it would be more natural to have
-fuse-ld=/abs/path/to/ld . https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55470
Well, problem with that is that the option values are used and we want to
preserve
backward compatibility of options (if possible). I mean we can't just rename
-fuse-ld=bfd to -fuse-ld=ld.bfd.
-fuse-ld=bfd, -fuse-ld=gold and -fuse-ld=lld are hard-coded in numerous
places. It is too late to change that.
One idea is to make
-fuse-ld=bfd
-fuse-ld=gold
-fuse-ld=lld
special. For any other value, e.g. -fuse-ld=foo or -fuse-ld=/abs/path, just
searches the
executable named "foo" (instead of "ld.foo") or /abs/path .
Yes, that seems feasible to me.
Does the scheme sound good? If it is agreed, I can make a similar change to
clang.
Yes, please send a patch and we can make another round of review process.
Thanks,
Martin
I noticed not ideal error message:
$ gcc -fuse-ld=pes /tmp/foo.c
collect2: fatal error: cannot find ‘ld’
compilation terminated.
while clang prints:
$clang -fuse-ld=pes /tmp/foo.c
clang-9.0: error: invalid linker name in argument '-fuse-ld=pes'
The rest of the patch is comment inline...
Thanks for all the comments.
PR driver/93645
* common.opt (-fuse-ld=): Delete -fuse-ld=[bfd|gold|lld]. Add -fuse-ld=.
* opts.c (common_handle_option): Handle OPT_fuse_ld_.
* gcc.c (driver_handle_option): Likewise.
* collect2.c (main): Likewise.
---
gcc/ChangeLog | 8 ++++++
gcc/collect2.c | 67 ++++++++++++++++++++++++---------------------
gcc/common.opt | 14 ++--------
gcc/doc/invoke.texi | 15 +++-------
gcc/gcc.c | 14 ++++------
gcc/opts.c | 4 +--
6 files changed, 57 insertions(+), 65 deletions(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index feb2d066d0b..6bcec12d841 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2020-02-09 Fangrui Song <mask...@google.com>
+
+ PR driver/93645
+ * common.opt (-fuse-ld=): Delete -fuse-ld=[bfd|gold|lld]. Add -fuse-ld=.
+ * opts.c (common_handle_option): Handle OPT_fuse_ld_.
+ * gcc.c (driver_handle_option): Likewise.
+ * collect2.c (main): Likewise.
+
2020-02-09 Uroš Bizjak <ubiz...@gmail.com>
* recog.c: Move pass_split_before_sched2 code in front of
diff --git a/gcc/collect2.c b/gcc/collect2.c
index 502d629141c..a3ef525a93b 100644
--- a/gcc/collect2.c
+++ b/gcc/collect2.c
@@ -859,18 +859,12 @@ main (int argc, char **argv)
{
USE_DEFAULT_LD,
USE_PLUGIN_LD,
- USE_GOLD_LD,
- USE_BFD_LD,
- USE_LLD_LD,
- USE_LD_MAX
+ USE_LD
} selected_linker = USE_DEFAULT_LD;
- static const char *const ld_suffixes[USE_LD_MAX] =
+ static const char *const ld_suffixes[USE_LD] =
{
"ld",
- PLUGIN_LD_SUFFIX,
- "ld.gold",
- "ld.bfd",
- "ld.lld"
+ PLUGIN_LD_SUFFIX
};
static const char *const real_ld_suffix = "real-ld";
static const char *const collect_ld_suffix = "collect-ld";
@@ -882,7 +876,7 @@ main (int argc, char **argv)
static const char *const strip_suffix = "strip";
static const char *const gstrip_suffix = "gstrip";
- const char *full_ld_suffixes[USE_LD_MAX];
+ const char *full_ld_suffixes[USE_LD];
#ifdef CROSS_DIRECTORY_STRUCTURE
/* If we look for a program in the compiler directories, we just use
the short name, since these directories are already system-specific.
@@ -924,6 +918,7 @@ main (int argc, char **argv)
const char **ld1;
bool use_plugin = false;
bool use_collect_ld = false;
+ const char *use_ld = 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
@@ -948,7 +943,7 @@ main (int argc, char **argv)
#endif
int i;
- for (i = 0; i < USE_LD_MAX; i++)
+ for (i = 0; i < USE_LD; i++)
full_ld_suffixes[i]
#ifdef CROSS_DIRECTORY_STRUCTURE
= concat (target_machine, "-", ld_suffixes[i], NULL);
@@ -1041,12 +1036,11 @@ 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))
+ {
+ use_ld = argv[i] + 9;
+ selected_linker = USE_LD;
+ }
else if (strncmp (argv[i], "-o", 2) == 0)
{
/* Parse the output filename if it's given so that we can make
@@ -1152,8 +1146,7 @@ main (int argc, char **argv)
/* Maybe we know the right file to use (if not cross). */
ld_file_name = 0;
#ifdef DEFAULT_LINKER
- if (selected_linker == USE_BFD_LD || selected_linker == USE_GOLD_LD ||
- selected_linker == USE_LLD_LD)
+ if (!ld_file_name && selected_linker == USE_LD)
{
char *linker_name;
# ifdef HOST_EXECUTABLE_SUFFIX
@@ -1168,15 +1161,13 @@ main (int argc, char **argv)
if (! strcmp (&default_linker[len], HOST_EXECUTABLE_SUFFIX))
{
default_linker[len] = '\0';
- linker_name = concat (default_linker,
- &ld_suffixes[selected_linker][2],
+ linker_name = concat (default_linker, ".", use_ld,
HOST_EXECUTABLE_SUFFIX, NULL);
}
}
This piece of code (added by commit b78e932d513b7d3373bc5e1aab456dda737d07d0 PR
driver/59321) is a bit complex.
The new patch does not touch it.
if (linker_name == NULL)
# endif
- linker_name = concat (DEFAULT_LINKER,
- &ld_suffixes[selected_linker][2],
+ linker_name = concat (DEFAULT_LINKER, ".", use_ld,
NULL);
if (access (linker_name, X_OK) == 0)
ld_file_name = linker_name;
@@ -1197,14 +1188,28 @@ 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) {
+ /* Search the compiler directories for `ld'. We have protection against
+ recursive calls in find_a_file. */
+ if (!ld_file_name)
+ 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)
+ ld_file_name = find_a_file(&path, full_ld_suffixes[selected_linker],
X_OK);
+ } else if (IS_ABSOLUTE_PATH(use_ld) && access(use_ld, X_OK) == 0) {
+ ld_file_name = use_ld;
+ } else {
+ const char *linker_name = concat("ld.", use_ld, NULL);
This leads to strange searches like:
$ strace -f -s512 gcc -fuse-ld=/x/y/z/pes /tmp/foo.c 2>&1 | grep pes
...
[pid 24295] stat("/home/marxin/bin/ld./x/y/z/pes", 0x7fffffffd1f0) = -1 ENOENT
(No such file or directory)
[pid 24295] stat("/usr/local/bin/ld./x/y/z/pes", 0x7fffffffd1f0) = -1 ENOENT
(No such file or directory)
Moreover, before the patch we only searched for suffixes 'ld.bfd', 'ld.gold'
and 'ld.gold'. Now it
searches also for:
$ strace ... gcc -fuse-ld=xyz
...
[pid 24893] stat("/home/marxin/bin/ld.xyz", 0x7fffffffd200) = -1 ENOENT (No
such file or directory)
+ if (!ld_file_name)
+ ld_file_name = find_a_file(&cpath, linker_name, X_OK);
+ if (!ld_file_name) {
+#ifdef CROSS_DIRECTORY_STRUCTURE
+ linker_name = concat(target_machine, "-", linker_name, NULL);
+#endif
+ ld_file_name = find_a_file(&path, linker_name, X_OK);
+ }
+ }
#ifdef REAL_NM_FILE_NAME
nm_file_name = find_a_file (&path, REAL_NM_FILE_NAME, X_OK);
diff --git a/gcc/common.opt b/gcc/common.opt
index 5692cd04374..a76ed6434bb 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -2859,17 +2859,9 @@ funwind-tables
Common Report Var(flag_unwind_tables) Optimization
Just generate unwind tables for exception handling.
-fuse-ld=bfd
-Common Driver Negative(fuse-ld=gold)
-Use the bfd linker instead of the default linker.
-
-fuse-ld=gold
-Common Driver Negative(fuse-ld=bfd)
-Use the gold linker instead of the default linker.
-
-fuse-ld=lld
-Common Driver Negative(fuse-ld=lld)
-Use the lld LLVM linker instead of the default linker.
+fuse-ld=
+Common Driver Joined
+-fuse-ld=[bfd|gold|lld|<absolute path>] Use the specified linker.
fuse-linker-plugin
Common Undocumented Var(flag_use_linker_plugin)
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 35b341e759f..c2dd410c88f 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -14128,17 +14128,10 @@ uses @samp{nolto-rel}. To maintain whole program
optimization, it is
recommended to link such objects into static library instead. Alternatively it
is possible to use H.J. Lu's binutils with support for mixed objects.
-@item -fuse-ld=bfd
-@opindex fuse-ld=bfd
-Use the @command{bfd} linker instead of the default linker.
-
-@item -fuse-ld=gold
-@opindex fuse-ld=gold
-Use the @command{gold} linker instead of the default linker.
-
-@item -fuse-ld=lld
-@opindex fuse-ld=lld
-Use the LLVM @command{lld} linker instead of the default linker.
+@item -fuse-ld=@var{linker}
+@opindex fuse-ld=linker
+If @var{linker} is an absolute path, use it instead of the default linker;
+otherwise use @command{ld.@var{linker}}.
You should somehow mention the special values bfd,gold and ldd.
@cindex Libraries
@item -l@var{library}
diff --git a/gcc/gcc.c b/gcc/gcc.c
index effc384f3ef..f9a6f10502d 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -3989,12 +3989,8 @@ driver_handle_option (struct gcc_options *opts,
do_save = false;
break;
- case OPT_fuse_ld_bfd:
- use_ld = ".bfd";
- break;
-
- case OPT_fuse_ld_gold:
- use_ld = ".gold";
+ case OPT_fuse_ld_:
+ use_ld = arg;
break;
case OPT_fcompare_debug_second:
@@ -7903,20 +7899,20 @@ driver::maybe_print_and_exit () const
if (! strcmp (&default_linker[len], HOST_EXECUTABLE_SUFFIX))
{
default_linker[len] = '\0';
- ld = concat (default_linker, use_ld,
+ ld = concat (default_linker, ".", use_ld,
HOST_EXECUTABLE_SUFFIX, NULL);
}
}
if (ld == NULL)
# endif
- ld = concat (DEFAULT_LINKER, use_ld, NULL);
+ ld = concat (DEFAULT_LINKER, ".", use_ld, NULL);
if (access (ld, X_OK) == 0)
{
printf ("%s\n", ld);
return (0);
}
#endif
- print_prog_name = concat (print_prog_name, use_ld, NULL);
+ print_prog_name = concat (print_prog_name, ".", use_ld, NULL);
In gcc.c you will probably have similar issues.
}
char *newname = find_a_file (&exec_prefixes, print_prog_name, X_OK, 0);
printf ("%s\n", (newname ? newname : print_prog_name));
diff --git a/gcc/opts.c b/gcc/opts.c
index 7affeb41a96..f50d365d517 100644
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -2763,9 +2763,7 @@ common_handle_option (struct gcc_options *opts,
dc->max_errors = value;
break;
- case OPT_fuse_ld_bfd:
- case OPT_fuse_ld_gold:
- case OPT_fuse_ld_lld:
+ case OPT_fuse_ld_:
case OPT_fuse_linker_plugin:
/* No-op. Used by the driver and passed to us because it starts with f.*/
break;
>From 72049b927b6cee8c3acb2d56b2a403d9f0946807 Mon Sep 17 00:00:00 2001
From: Fangrui Song <mask...@google.com>
Date: Tue, 19 May 2020 12:21:26 -0700
Subject: [PATCH] Add -fuse-ld= to specify an arbitrary executable as the
linker
The value can be either an absolute path or a relative path.
Unlike -fuse-ld={bfd,gold,lld}, -fuse-ld= does not add a prefix `ld.`
PR driver/93645
* common.opt (-fuse-ld=): Add -fuse-ld=.
* opts.c (common_handle_option): Handle OPT_fuse_ld_.
* gcc.c (driver_handle_option): Likewise.
* collect2.c (main): Likewise.
* doc/invoke.texi: Document -fuse-ld=.
---
gcc/ChangeLog | 9 +++++++++
gcc/collect2.c | 34 ++++++++++++++++++++++------------
gcc/common.opt | 4 ++++
gcc/doc/invoke.texi | 4 ++++
gcc/opts.c | 1 +
5 files changed, 40 insertions(+), 12 deletions(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 703b6349516..19506bf0884 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2020-05-19 Fangrui Song <mask...@google.com>
+
+ PR driver/93645
+ * common.opt (-fuse-ld=): Add -fuse-ld=.
+ * opts.c (common_handle_option): Handle OPT_fuse_ld_.
+ * gcc.c (driver_handle_option): Likewise.
+ * collect2.c (main): Likewise.
+ * doc/invoke.texi: Document -fuse-ld=.
+
2020-05-19 Jozef Lawrynowicz <joze...@mittosystems.com>
* doc/sourcebuild.texi: Document new short_eq_int, ptr_eq_short,
diff --git a/gcc/collect2.c b/gcc/collect2.c
index f8a5ce45994..e04892cb91f 100644
--- a/gcc/collect2.c
+++ b/gcc/collect2.c
@@ -782,15 +782,16 @@ main (int argc, char **argv)
USE_GOLD_LD,
USE_BFD_LD,
USE_LLD_LD,
+ USE_LD,
USE_LD_MAX
} selected_linker = USE_DEFAULT_LD;
- static const char *const ld_suffixes[USE_LD_MAX] =
+ static const char *const ld_suffixes[USE_LD] =
{
"ld",
PLUGIN_LD_SUFFIX,
"ld.gold",
"ld.bfd",
- "ld.lld"
+ "ld.lld",
};
static const char *const real_ld_suffix = "real-ld";
static const char *const collect_ld_suffix = "collect-ld";
@@ -802,7 +803,7 @@ main (int argc, char **argv)
static const char *const strip_suffix = "strip";
static const char *const gstrip_suffix = "gstrip";
- const char *full_ld_suffixes[USE_LD_MAX];
+ const char *full_ld_suffixes[USE_LD];
#ifdef CROSS_DIRECTORY_STRUCTURE
/* If we look for a program in the compiler directories, we just use
the short name, since these directories are already system-specific.
@@ -844,6 +845,7 @@ main (int argc, char **argv)
const char **ld1;
bool use_plugin = false;
bool use_collect_ld = false;
+ const char *use_ld = 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
@@ -868,7 +870,7 @@ main (int argc, char **argv)
#endif
int i;
- for (i = 0; i < USE_LD_MAX; i++)
+ for (i = 0; i < USE_LD; i++)
full_ld_suffixes[i]
#ifdef CROSS_DIRECTORY_STRUCTURE
= concat (target_machine, "-", ld_suffixes[i], NULL);
@@ -967,6 +969,11 @@ main (int argc, char **argv)
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))
+ {
+ use_ld = argv[i] + 9;
+ selected_linker = USE_LD;
+ }
else if (strncmp (argv[i], "-o", 2) == 0)
{
/* Parse the output filename if it's given so that we can make
@@ -1119,12 +1126,16 @@ main (int argc, char **argv)
}
/* 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) {
+ ld_file_name = find_a_file (&cpath, use_ld, X_OK);
+ } else {
+ 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);
@@ -1296,8 +1307,7 @@ main (int argc, char **argv)
"configuration");
#endif
}
- else if (!use_collect_ld
- && strncmp (arg, "-fuse-ld=", 9) == 0)
+ else if (strncmp (arg, "-fuse-ld=", 9) == 0)
{
/* Do not pass -fuse-ld={bfd|gold|lld} to the linker. */
ld1--;
diff --git a/gcc/common.opt b/gcc/common.opt
index 4464049fc1f..6408d042d8c 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -2908,6 +2908,10 @@ fuse-ld=lld
Common Driver Negative(fuse-ld=lld)
Use the lld LLVM linker instead of the default linker.
+fuse-ld=
+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 7217e27151d..30a2fc4fa53 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -14304,6 +14304,10 @@ 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 -fuse-ld=@var{linker}
+@opindex fuse-ld=linker
+Use the specified executable named @var{linker} instead of the default linker.
+
@cindex Libraries
@item -l@var{library}
@itemx -l @var{library}
diff --git a/gcc/opts.c b/gcc/opts.c
index ec3ca0720f9..522a196ab0f 100644
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -2785,6 +2785,7 @@ common_handle_option (struct gcc_options *opts,
case OPT_fuse_ld_bfd:
case OPT_fuse_ld_gold:
case OPT_fuse_ld_lld:
+ case OPT_fuse_ld_:
case OPT_fuse_linker_plugin:
/* No-op. Used by the driver and passed to us because it starts with f.*/
break;
--
2.26.2.761.g0e0b3e54be-goog
