On Wed, Nov 28, 2012 at 1:09 AM, Paolo Bonzini <bonz...@gnu.org> wrote:
> I cannot approve the collect2.c, gcc.c, opts.c, doc/invoke.texi. I'll
> include some comments anyway, since the patch needs some more work.
>
>> 2011-06-27 Doug Kwan <dougk...@google.com>
>>
>> Google ref 41164-p2
>> Backport upstream patch under review.
>>
>> 2011-01-19 Nick Clifton <ni...@redhat.com>
>> Matthias Klose <d...@debian.org>
>>
>> * configure.ac (gcc_cv_gold_srcdir): New cached variable -
>> contains the location of the gold sources.
>
> This is gcc_cv_ld_gold_srcdir in configure.ac. I prefer the name in the
> changelog.
I removed configure.ac change. We can create a separate patch
to select gold as the default linker. But this patch will only support
-fuse-ld=bfd and -fuse-ld=gold.
>> - static const char *const ld_suffix = "ld";
>> - static const char *const plugin_ld_suffix = PLUGIN_LD_SUFFIX;
>> - static const char *const real_ld_suffix = "real-ld";
>> + static const char *const ld_suffix = "ld";
>> + static const char *const gold_suffix = "ld.gold";
>> + static const char *const bfd_ld_suffix = "ld.bfd";
>> + static const char *const plugin_ld_suffix = PLUGIN_LD_SUFFIX;
>> + static const char *const real_ld_suffix = "real-ld";
>
> Please use an array for ld_suffix, gold_suffix, bfd_ld_suffix,
> plugin_ld_suffix. Similar for full_ld_suffix and friends.
Done.
>> - bool use_plugin = false;
>> + enum linker_select
>> + {
>> + DFLT_LINKER,
>> + PLUGIN_LINKER,
>> + GOLD_LINKER,
>> + BFD_LINKER
>> + } selected_linker = DFLT_LINKER;
>
> Please change the names to avoid the "DFLT" abbreviation. For example
> USE_DEFAULT_LD, USE_PLUGIN_LD, USE_GOLD, USE_LD.
Done.
>
>> AC_MSG_CHECKING(what linker to use)
>> if test "$gcc_cv_ld" = ../ld/ld-new$build_exeext \
>> || test "$gcc_cv_ld" = ../gold/ld-new$build_exeext; then
>> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
>> index 51b6e85..b78f698 100644
>> --- a/gcc/doc/invoke.texi
>> +++ b/gcc/doc/invoke.texi
>> @@ -425,7 +425,7 @@ Objective-C and Objective-C++ Dialects}.
>> -funit-at-a-time -funroll-all-loops -funroll-loops @gol
>> -funsafe-loop-optimizations -funsafe-math-optimizations -funswitch-loops
>> @gol
>> -fvariable-expansion-in-unroller -fvect-cost-model -fvpt -fweb @gol
>> --fwhole-program -fwpa -fuse-linker-plugin @gol
>> +-fwhole-program -fwpa -fuse-ld -fuse-linker-plugin @gol
>> --param @var{name}=@var{value}
>> -O -O0 -O1 -O2 -O3 -Os -Ofast -Og}
>>
>> @@ -8419,6 +8419,16 @@ the comparison operation before register allocation
>> is complete.
>>
>> Enabled at levels @option{-O}, @option{-O2}, @option{-O3}, @option{-Os}.
>>
>> +@item -fuse-ld=gold
>> +Use the @command{gold} linker instead of the default linker.
>> +This option is only necessary if GCC has been configured with
>> +@option{--enable-gold} and @option{--enable-ld=default}.
>
> This is not really clear. You could have built binutils separately,
> would -fuse-ld=gold work in that case? If not, I think that's a bug.
>
>> +@item -fuse-ld=bfd
>> +Use the @command{ld.bfd} linker instead of the default linker.
>> +This option is only necessary if GCC has been configured with
>> +@option{--enable-gold} and @option{--enable-ld}.
>
> Same concerns here.
Fixed.
>> @item -fcprop-registers
>> @opindex fcprop-registers
>> After register allocation and post-register allocation instruction
>> splitting,
>> diff --git a/gcc/exec-tool.in b/gcc/exec-tool.in
>> index 8a10775..46aaedc 100644
>> --- a/gcc/exec-tool.in
>> +++ b/gcc/exec-tool.in
>> @@ -1,6 +1,6 @@
>> #! /bin/sh
>>
>> -# Copyright (C) 2007, 2008, 2010 Free Software Foundation, Inc.
>> +# Copyright (C) 2007, 2008, 2010, 2011 Free Software Foundation, Inc.
>> # This file is part of GCC.
>>
>> # GCC is free software; you can redistribute it and/or modify
>> @@ -21,11 +21,13 @@
>>
>> ORIGINAL_AS_FOR_TARGET="@ORIGINAL_AS_FOR_TARGET@"
>> ORIGINAL_LD_FOR_TARGET="@ORIGINAL_LD_FOR_TARGET@"
>> +ORIGINAL_GOLD_FOR_TARGET="@ORIGINAL_GOLD_FOR_TARGET@"
>> ORIGINAL_PLUGIN_LD_FOR_TARGET="@ORIGINAL_PLUGIN_LD_FOR_TARGET@"
>> ORIGINAL_NM_FOR_TARGET="@ORIGINAL_NM_FOR_TARGET@"
>> exeext=@host_exeext@
>> fast_install=@enable_fast_install@
>> objdir=@objdir@
>> +version="1.1"
>
> Why is the -v behavior now required? Please remove it from this patch.
>
I rewrote exec-tool.in change. Now you get
# ./xgcc -B./ /tmp/x.c -fuse-ld=gold -v
...
./collect-ld --eh-frame-hdr -m elf_x86_64 -dynamic-linker
/lib64/ld-linux-x86-64.so.2 -fuse-ld=gold /lib/../lib64/crt1.o
/lib/../lib64/crti.o ./crtbegin.o -L. -L/lib/../lib64
-L/usr/lib/../lib64 /tmp/cclVWcGz.o -v -lgcc --as-needed -lgcc_s
--no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed ./crtend.o
/lib/../lib64/crtn.o
GNU gold (Linux/GNU Binutils 2.23.51.0.7.20121127) 1.11
/usr/local/bin/ld.gold: fatal error: -f/--auxiliary may not be used
without -shared
collect2: error: ld returned 1 exit status
This is because we pass everything to ld and ld.bfd/ld.gold doesn't
understand -fuse-ld=bfd/-fuse-ld=gold. It isn't a problem for collect2
since it will filter-out -fuse-ld=bfd/-fuse-ld=gold. I will submit a binutils
patch to ignore -fuse-ld=bfd/-fuse-ld=gold, similar to -flto options.
>> diff --git a/gcc/gcc.c b/gcc/gcc.c
>> index 13e93e5..1702d2c 100644
>> --- a/gcc/gcc.c
>> +++ b/gcc/gcc.c
>> @@ -705,6 +705,9 @@ proper position among the other output files. */
>> LINK_PLUGIN_SPEC \
>> "%{flto|flto=*:%<fcompare-debug*} \
>> %{flto} %{flto=*} %l " LINK_PIE_SPEC \
>> + "%{fuse-ld=gold:%{fuse-ld=bfd:%e-fuse-ld=gold and -fuse-ld=bfd may not
>> be used together}} \
>> + %{fuse-ld=gold:-use-gold} \
>> + %{fuse-ld=bfd:-use-ld}" \
>
> Why do we need to use separate spellings of the options in gcc and collect2?
>
This is a bug in the original patch. If we pass -fuse-ld=bfd/-fuse-ld=gold to
linker, linker will complain. -use-gold/-use-ld are valid linker options:
-u SYMBOL, --undefined SYMBOL
It is wrong to abuse -use-gold/-use-ld.
Here is the updated patch. OK for trunk?
Thanks.
--
H.J.
----
2012-11-28 Nick Clifton <ni...@redhat.com>
Matthias Klose <d...@debian.org>
Doug Kwan <dougk...@google.com>
H.J. Lu <hongjiu...@intel.com>
* collect2.c (main): Support -fuse-ld=bfd and -fuse-ld=gold.
* exec-tool.in: Likewise.
* common.opt: Add fuse-ld=bfd and fuse-ld=gold.
* gcc.c (LINK_COMMAND_SPEC): Pass -fuse-ld=* to collect2.
* opts.c (comman_handle_option): Ignore -fuse-ld=bfd and
-fuse-ld=gold.
* doc/invoke.texi: Document Da-fuse-ld=bfd and -fuse-ld=gold.
diff --git a/gcc/collect2.c b/gcc/collect2.c
index 49c4030..19bdc29 100644
--- a/gcc/collect2.c
+++ b/gcc/collect2.c
@@ -842,8 +842,21 @@ maybe_run_lto_and_relink (char **lto_ld_argv,
char **object_lst,
int
main (int argc, char **argv)
{
- static const char *const ld_suffix = "ld";
- static const char *const plugin_ld_suffix = PLUGIN_LD_SUFFIX;
+ enum linker_select
+ {
+ USE_DEFAULT_LD,
+ USE_PLUGIN_LD,
+ USE_GOLD_LD,
+ USE_BFD_LD,
+ USE_LD_MAX
+ } selected_linker = USE_DEFAULT_LD;
+ static const char *const ld_suffixes[USE_LD_MAX] =
+ {
+ "ld",
+ PLUGIN_LD_SUFFIX,
+ "ld.gold",
+ "ld.bfd"
+ };
static const char *const real_ld_suffix = "real-ld";
static const char *const collect_ld_suffix = "collect-ld";
static const char *const nm_suffix = "nm";
@@ -854,16 +867,13 @@ 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];
#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.
But it we look for a program in the system directories, we need to
qualify the program name with the target machine. */
- const char *const full_ld_suffix =
- concat(target_machine, "-", ld_suffix, NULL);
- const char *const full_plugin_ld_suffix =
- concat(target_machine, "-", plugin_ld_suffix, NULL);
const char *const full_nm_suffix =
concat (target_machine, "-", nm_suffix, NULL);
const char *const full_gnm_suffix =
@@ -877,13 +887,11 @@ main (int argc, char **argv)
const char *const full_gstrip_suffix =
concat (target_machine, "-", gstrip_suffix, NULL);
#else
- const char *const full_ld_suffix = ld_suffix;
- const char *const full_plugin_ld_suffix = plugin_ld_suffix;
- const char *const full_nm_suffix = nm_suffix;
- const char *const full_gnm_suffix = gnm_suffix;
#ifdef LDD_SUFFIX
const char *const full_ldd_suffix = ldd_suffix;
#endif
+ const char *const full_nm_suffix = nm_suffix;
+ const char *const full_gnm_suffix = gnm_suffix;
const char *const full_strip_suffix = strip_suffix;
const char *const full_gstrip_suffix = gstrip_suffix;
#endif /* CROSS_DIRECTORY_STRUCTURE */
@@ -900,6 +908,7 @@ main (int argc, char **argv)
char **ld1_argv;
const char **ld1;
bool use_plugin = false;
+ bool use_collect_ld = false;
/* 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
@@ -919,6 +928,15 @@ main (int argc, char **argv)
int first_file;
int num_c_args;
char **old_argv;
+ int i;
+
+ for (i = 0; i < USE_LD_MAX; i++)
+ full_ld_suffixes[i]
+#ifdef CROSS_DIRECTORY_STRUCTURE
+ = concat(target_machine, "-", ld_suffixes[i], NULL);
+#else
+ = ld_suffixes[i];
+#endif
p = argv[0] + strlen (argv[0]);
while (p != argv[0] && !IS_DIR_SEPARATOR (p[-1]))
@@ -980,7 +998,6 @@ main (int argc, char **argv)
are called. We also look for the -flto or -flto-partition=none
flag to know
what LTO mode we are in. */
{
- int i;
bool no_partition = false;
for (i = 1; argv[i] != NULL; i ++)
@@ -998,7 +1015,14 @@ main (int argc, char **argv)
{
use_plugin = true;
lto_mode = LTO_MODE_NONE;
+ 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;
+
#ifdef COLLECT_EXPORT_LIST
/* since -brtl, -bexport, -b64 are not position dependent
also check for them here */
@@ -1095,21 +1119,18 @@ main (int argc, char **argv)
ld_file_name = find_a_file (&cpath, real_ld_suffix);
/* Likewise for `collect-ld'. */
if (ld_file_name == 0)
- ld_file_name = find_a_file (&cpath, collect_ld_suffix);
+ {
+ ld_file_name = find_a_file (&cpath, collect_ld_suffix);
+ 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,
- use_plugin
- ? plugin_ld_suffix
- : ld_suffix);
+ ld_file_name = find_a_file (&cpath, ld_suffixes[selected_linker]);
/* 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,
- use_plugin
- ? full_plugin_ld_suffix
- : full_ld_suffix);
+ ld_file_name = find_a_file (&path, full_ld_suffixes[selected_linker]);
#ifdef REAL_NM_FILE_NAME
nm_file_name = find_a_file (&path, REAL_NM_FILE_NAME);
@@ -1266,6 +1287,13 @@ main (int argc, char **argv)
"configuration");
#endif
}
+ else if (!use_collect_ld
+ && strncmp (arg, "-fuse-ld=", 9) == 0)
+ {
+ /* Do not pass -fuse-ld={bfd|gold} to the linker. */
+ ld1--;
+ ld2--;
+ }
#ifdef TARGET_AIX_VERSION
else
{
diff --git a/gcc/common.opt b/gcc/common.opt
index 4c8bd11..7b36ba3 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -2171,6 +2171,12 @@ funwind-tables
Common Report Var(flag_unwind_tables) Optimization
Just generate unwind tables for exception handling
+fuse-ld=bfd
+Common Var(flag_use_ld_bfd) Negative(fuse-ld=gold) Undocumented
+
+fuse-ld=gold
+Common Var(flag_use_ld_gold) Negative(fuse-ld=bfd) Undocumented
+
fuse-linker-plugin
Common Undocumented
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 51b6e85..3558f43 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -425,7 +425,7 @@ Objective-C and Objective-C++ Dialects}.
-funit-at-a-time -funroll-all-loops -funroll-loops @gol
-funsafe-loop-optimizations -funsafe-math-optimizations -funswitch-loops @gol
-fvariable-expansion-in-unroller -fvect-cost-model -fvpt -fweb @gol
--fwhole-program -fwpa -fuse-linker-plugin @gol
+-fwhole-program -fwpa -fuse-ld=@var{linker} -fuse-linker-plugin @gol
--param @var{name}=@var{value}
-O -O0 -O1 -O2 -O3 -Os -Ofast -Og}
@@ -8419,6 +8419,12 @@ the comparison operation before register
allocation is complete.
Enabled at levels @option{-O}, @option{-O2}, @option{-O3}, @option{-Os}.
+@item -fuse-ld=gold
+Use the @command{gold} linker instead of the default linker.
+
+@item -fuse-ld=bfd
+Use the @command{ld.bfd} linker instead of the default linker.
+
@item -fcprop-registers
@opindex fcprop-registers
After register allocation and post-register allocation instruction splitting,
diff --git a/gcc/exec-tool.in b/gcc/exec-tool.in
index 8a10775..8f9ae27 100644
--- a/gcc/exec-tool.in
+++ b/gcc/exec-tool.in
@@ -36,13 +36,28 @@ case "$invoked" in
dir=gas
;;
collect-ld)
- # when using a linker plugin, gcc will always pass '-plugin' as the
- # first or second option to the linker.
- if test x"$1" = "x-plugin" || test x"$2" = "x-plugin"; then
- original=$ORIGINAL_PLUGIN_LD_FOR_TARGET
- else
- original=$ORIGINAL_LD_FOR_TARGET
- fi
+ # Check -fuse-ld=bfd and -fuse-ld=gold
+ case " $* " in
+ *\ -fuse-ld=bfd\ *)
+ if test -x ${ORIGINAL_LD_FOR_TARGET}.bfd; then
+ original=${ORIGINAL_LD_FOR_TARGET}.bfd;
+ fi
+ ;;
+ *\ -fuse-ld=gold\ *)
+ if test -x ${ORIGINAL_LD_FOR_TARGET}.gold; then
+ original=${ORIGINAL_LD_FOR_TARGET}.gold;
+ fi
+ ;;
+ *)
+ # when using a linker plugin, gcc will always pass '-plugin' as the
+ # first or second option to the linker.
+ if test x"$1" = "x-plugin" || test x"$2" = "x-plugin"; then
+ original=$ORIGINAL_PLUGIN_LD_FOR_TARGET
+ else
+ original=$ORIGINAL_LD_FOR_TARGET
+ fi
+ ;;
+ esac
prog=ld-new$exeext
dir=ld
id=ld
diff --git a/gcc/gcc.c b/gcc/gcc.c
index 13e93e5..e0fee40 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -705,7 +705,8 @@ proper position among the other output files. */
LINK_PLUGIN_SPEC \
"%{flto|flto=*:%<fcompare-debug*} \
%{flto} %{flto=*} %l " LINK_PIE_SPEC \
- "%X %{o*} %{e*} %{N} %{n} %{r}\
+ "%{fuse-ld=*:-fuse-ld=%*}\
+ %X %{o*} %{e*} %{N} %{n} %{r}\
%{s} %{t} %{u*} %{z} %{Z} %{!nostdlib:%{!nostartfiles:%S}}\
%{static:} %{L*} %(mfwrap) %(link_libgcc) %o\
%{fopenmp|ftree-parallelize-loops=*:%:include(libgomp.spec)%(link_gomp)}\
diff --git a/gcc/opts.c b/gcc/opts.c
index b3a9afe..ff1b51e 100644
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -1753,6 +1753,8 @@ 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_linker_plugin:
/* No-op. Used by the driver and passed to us because it starts with f.*/
break;
