| Message ID | ydd36u9k7fg.fsf@CeBiTec.Uni-Bielefeld.DE |
|---|---|
| State | New |
| Headers | show |
| Series | [libgcc] Use v2 map syntax in libgcc-unwind.map if Solaris ld supports it | expand |
On 9/16/18 5:28 AM, Rainer Orth wrote: > Currently, the libgcc-unwind.map file generated for use with Solaris ld > > http://gcc.gnu.org/ml/gcc-patches/2014-01/msg01088.html > > uses the v1 linker map file syntax because both that's supported > everywhere. However, with ld -z guidance, newer versions of ld warn > about this: > > ld: guidance: version 2 mapfile syntax recommended: ./libgcc-unwind.map > > Since it is easy to detect if ld supports v2 map syntax (introduced in > Solaris 11 and later backported to some Solaris 10 patches) and the > mapfile is generated at build time, the following patch performs this > check and generates a v2 mapfile if ld supports it. > > While testing the patch, I found that the arg to AC_TRY_COMMAND needed > quoting to avoid the embedded commas in -Wl,-M,... ended the command. > Shouldn't the other uses of AC_TRY_COMMAND receive the same quoting for > safety and consistency? > > Bootstrapped on i386-pc-solaris2.10 (with older v1-only ld) and > i386-pc-solaris2.11 without regressions. > > Ok for mainline? OK with a suitable ChangeLog. Jeff
Hi Jeff, > On 9/16/18 5:28 AM, Rainer Orth wrote: >> Currently, the libgcc-unwind.map file generated for use with Solaris ld >> >> http://gcc.gnu.org/ml/gcc-patches/2014-01/msg01088.html >> >> uses the v1 linker map file syntax because both that's supported >> everywhere. However, with ld -z guidance, newer versions of ld warn >> about this: >> >> ld: guidance: version 2 mapfile syntax recommended: ./libgcc-unwind.map >> >> Since it is easy to detect if ld supports v2 map syntax (introduced in >> Solaris 11 and later backported to some Solaris 10 patches) and the >> mapfile is generated at build time, the following patch performs this >> check and generates a v2 mapfile if ld supports it. >> >> While testing the patch, I found that the arg to AC_TRY_COMMAND needed >> quoting to avoid the embedded commas in -Wl,-M,... ended the command. >> Shouldn't the other uses of AC_TRY_COMMAND receive the same quoting for >> safety and consistency? >> >> Bootstrapped on i386-pc-solaris2.10 (with older v1-only ld) and >> i386-pc-solaris2.11 without regressions. >> >> Ok for mainline? > OK with a suitable ChangeLog. thanks, installed. However, the ChangeLog entry already was in the original patch submission. Rainer
# HG changeset patch # Parent 6e22c7ec2252ccb001d91cccbacc5378de003e7c Use v2 map syntax in libgcc-unwind.map if Solaris ld supports it diff --git a/libgcc/Makefile.in b/libgcc/Makefile.in --- a/libgcc/Makefile.in +++ b/libgcc/Makefile.in @@ -44,6 +44,7 @@ enable_vtable_verify = @enable_vtable_ve enable_decimal_float = @enable_decimal_float@ fixed_point = @fixed_point@ with_aix_soname = @with_aix_soname@ +solaris_ld_v2_maps = @solaris_ld_v2_maps@ enable_execute_stack = @enable_execute_stack@ unwind_header = @unwind_header@ md_unwind_header = @md_unwind_header@ diff --git a/libgcc/config/t-slibgcc-sld b/libgcc/config/t-slibgcc-sld --- a/libgcc/config/t-slibgcc-sld +++ b/libgcc/config/t-slibgcc-sld @@ -8,12 +8,23 @@ ifeq ($(enable_shared),yes) # Linker mapfile to enforce direct binding to libgcc_s unwinder # (PR target/59788). +# Emit v2 mapfile syntax if possible, otherwise ld -z guidance complains +# every time the mapfile is used. libgcc-unwind.map: libgcc-std.ver +ifeq ($(solaris_ld_v2_maps),yes) + @(echo '$$mapfile_version 2'; \ + echo "SYMBOL_SCOPE {"; \ + for f in `grep _Unwind_ $< | sort`; do \ + echo " $$f { FLAGS = EXTERN DIRECT };"; \ + done; \ + echo "};" ) > $@ +else @(echo "{"; \ for f in `grep _Unwind_ $< | sort`; do \ echo " $$f = EXTERN DIRECT;"; \ done; \ echo "};" ) > $@ +endif # Copy libgcc-unwind.map to the place where gcc will look for it at build-time. install-libgcc-unwind-map-forbuild: libgcc-unwind.map diff --git a/libgcc/configure.ac b/libgcc/configure.ac --- a/libgcc/configure.ac +++ b/libgcc/configure.ac @@ -459,6 +459,21 @@ EOF ;; esac +# Check if Solaris linker support v2 linker mapfile syntax. +# Link with -nostartfiles -nodefaultlibs since neither are present while +# building libgcc. +case ${host} in +*-*-solaris2*) + solaris_ld_v2_maps=no + echo 'int main(void) {return 0;}' > conftest.c + echo '$mapfile_version 2' > conftest.map + if AC_TRY_COMMAND([${CC-cc} -nostartfiles -nodefaultlibs -Wl,-M,conftest.map -o conftest conftest.c 1>&AS_MESSAGE_LOG_FD]); then + solaris_ld_v2_maps=yes + fi + ;; +esac +AC_SUBST(solaris_ld_v2_maps) + # Check if xtensa target is configured for windowed ABI and thus needs to use # custom unwind code. # This is after config.host so we can augment tmake_file.