[v2] gcc: Use ld -r when checking for HAVE_LD_RO_RW_SECTION_MIXING
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Commit Message
Fall back to ld -r if ld -shared fails during configure. The check for
HAVE_LD_RO_RW_SECTION_MIXING can fail on targets where ld does not
support shared objects, even though the answer to the test should be
'read-write'. One such target is riscv64-unknown-elf. Failing this test
results in a libgcc crtbegin.o which has a writable .eh_frame section
leading to the default linker scripts placing the .eh_frame section in a
writable memory segment, or a linker warning when using ld scripts that
place .eh_frame unconditionally in ROM.
gcc/ChangeLog:
* configure: Regenerate.
* configure.ac: Use ld -r in the check for HAVE_LD_RO_RW_SECTION_MIXING
Signed-off-by: Joakim Nohlgård <joakim@nohlgard.se>
---
gcc/configure.ac | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
Comments
On 12/5/22 06:43, Joakim Nohlgård wrote:
> Fall back to ld -r if ld -shared fails during configure. The check for
> HAVE_LD_RO_RW_SECTION_MIXING can fail on targets where ld does not
> support shared objects, even though the answer to the test should be
> 'read-write'. One such target is riscv64-unknown-elf. Failing this test
> results in a libgcc crtbegin.o which has a writable .eh_frame section
> leading to the default linker scripts placing the .eh_frame section in a
> writable memory segment, or a linker warning when using ld scripts that
> place .eh_frame unconditionally in ROM.
>
> gcc/ChangeLog:
>
> * configure: Regenerate.
> * configure.ac: Use ld -r in the check for HAVE_LD_RO_RW_SECTION_MIXING
Thanks. I've pushed this to the trunk.
jeff
@@ -3152,16 +3152,19 @@ elif test x$gcc_cv_as != x -a x$gcc_cv_ld != x -a x$gcc_cv_objdump != x ; then
echo '.byte 0' >> conftest3.s
if $gcc_cv_as -o conftest1.o conftest1.s > /dev/null 2>&1 \
&& $gcc_cv_as -o conftest2.o conftest2.s > /dev/null 2>&1 \
- && $gcc_cv_as -o conftest3.o conftest3.s > /dev/null 2>&1 \
- && $gcc_cv_ld -shared -o conftest1.so conftest1.o \
- conftest2.o conftest3.o > /dev/null 2>&1; then
- gcc_cv_ld_ro_rw_mix=`$gcc_cv_objdump -h conftest1.so \
- | sed -e '/myfoosect/!d' -e N`
- if echo "$gcc_cv_ld_ro_rw_mix" | grep CONTENTS > /dev/null; then
- if echo "$gcc_cv_ld_ro_rw_mix" | grep READONLY > /dev/null; then
- gcc_cv_ld_ro_rw_mix=read-only
- else
- gcc_cv_ld_ro_rw_mix=read-write
+ && $gcc_cv_as -o conftest3.o conftest3.s > /dev/null 2>&1; then
+ if $gcc_cv_ld -shared -o conftest1.so conftest1.o \
+ conftest2.o conftest3.o > /dev/null 2>&1 \
+ || $gcc_cv_ld -r -o conftest1.so conftest1.o \
+ conftest2.o conftest3.o > /dev/null 2>&1; then
+ gcc_cv_ld_ro_rw_mix=`$gcc_cv_objdump -h conftest1.so \
+ | sed -e '/myfoosect/!d' -e N`
+ if echo "$gcc_cv_ld_ro_rw_mix" | grep CONTENTS > /dev/null; then
+ if echo "$gcc_cv_ld_ro_rw_mix" | grep READONLY > /dev/null; then
+ gcc_cv_ld_ro_rw_mix=read-only
+ else
+ gcc_cv_ld_ro_rw_mix=read-write
+ fi
fi
fi
fi