[Bug lto/61123] With LTO, -fno-short-enums is ignored, resulting in ABI mis-matching in linking.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61123 --- Comment #8 from xuepeng guo xguo at gcc dot gnu.org --- Author: xguo Date: Tue Jul 29 07:11:02 2014 New Revision: 213147 URL: https://gcc.gnu.org/viewcvs?rev=213147root=gccview=rev Log: gcc/c-family/ 2014-07-29 Terry Guo terry@arm.com Backport mainline r211832 2014-06-20 Hale Wang hale.w...@arm.com PR lto/61123 * c.opt (fshort-enums): Add to LTO. * c.opt (fshort-wchar): Likewise. gcc/testsuite/ 2014-07-29 Terry Guo terry@arm.com Backport mainline r211832 2014-06-20 Hale Wang hale.w...@arm.com * gcc.target/arm/lto/: New folder to verify the LTO option. * gcc.target/arm/lto/pr61123-enum-size_0.c: New test case. * gcc.target/arm/lto/pr61123-enum-size_1.c: Likewise. * gcc.target/arm/lto/lto.exp: New exp file used to test LTO option. * lib/lto.exp (object-readelf): New procedure. Added: branches/ARM/embedded-4_8-branch/gcc/c-family/ChangeLog.arm branches/ARM/embedded-4_8-branch/gcc/testsuite/gcc.target/arm/lto/ branches/ARM/embedded-4_8-branch/gcc/testsuite/gcc.target/arm/lto/lto.exp branches/ARM/embedded-4_8-branch/gcc/testsuite/gcc.target/arm/lto/pr61123-enum-size_0.c branches/ARM/embedded-4_8-branch/gcc/testsuite/gcc.target/arm/lto/pr61123-enum-size_1.c Modified: branches/ARM/embedded-4_8-branch/gcc/c-family/c.opt branches/ARM/embedded-4_8-branch/gcc/testsuite/ChangeLog.arm branches/ARM/embedded-4_8-branch/gcc/testsuite/lib/lto.exp
[Bug lto/61123] With LTO, -fno-short-enums is ignored, resulting in ABI mis-matching in linking.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61123 Richard Biener rguenth at gcc dot gnu.org changed: What|Removed |Added Status|NEW |RESOLVED Resolution|--- |FIXED --- Comment #7 from Richard Biener rguenth at gcc dot gnu.org --- Fixed.
[Bug lto/61123] With LTO, -fno-short-enums is ignored, resulting in ABI mis-matching in linking.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61123 --- Comment #6 from Hale Wang Hale.Wang at arm dot com --- Thanks for Zhenqiang Chen's help. This bug is fixed. Refer to the link https://gcc.gnu.org/ml/gcc-patches/2014-06/msg01429.html
[Bug lto/61123] With LTO, -fno-short-enums is ignored, resulting in ABI mis-matching in linking.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61123 --- Comment #5 from zqchen at gcc dot gnu.org --- Author: zqchen Date: Fri Jun 20 04:52:11 2014 New Revision: 211832 URL: https://gcc.gnu.org/viewcvs?rev=211832root=gccview=rev Log: c-family/ChangeLog 2014-06-20 Hale Wang hale.w...@arm.com PR lto/61123 * c.opt (fshort-enums): Add to LTO. * c.opt (fshort-wchar): Likewise. testsuite/ChangeLog 2014-06-20 Hale Wang hale.w...@arm.com * gcc.target/arm/lto/: New folder to verify the LTO option. * gcc.target/arm/lto/pr61123-enum-size_0.c: New test case. * gcc.target/arm/lto/pr61123-enum-size_1.c: Likewise. * gcc.target/arm/lto/lto.exp: New exp file used to test LTO option. * lib/lto.exp (object-readelf): New procedure. Added: trunk/gcc/testsuite/gcc.target/arm/lto/ trunk/gcc/testsuite/gcc.target/arm/lto/lto.exp trunk/gcc/testsuite/gcc.target/arm/lto/pr61123-enum-size_0.c trunk/gcc/testsuite/gcc.target/arm/lto/pr61123-enum-size_1.c Modified: trunk/gcc/c-family/ChangeLog trunk/gcc/c-family/c.opt trunk/gcc/testsuite/ChangeLog trunk/gcc/testsuite/lib/lto.exp
[Bug lto/61123] With LTO, -fno-short-enums is ignored, resulting in ABI mis-matching in linking.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61123 Ramana Radhakrishnan ramana at gcc dot gnu.org changed: What|Removed |Added Status|UNCONFIRMED |NEW Last reconfirmed||2014-06-06 CC||ramana at gcc dot gnu.org Target Milestone|--- |4.10.0 Ever confirmed|0 |1
[Bug lto/61123] With LTO, -fno-short-enums is ignored, resulting in ABI mis-matching in linking.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61123 --- Comment #4 from Hale Wang Hale.Wang at arm dot com --- (In reply to Richard Biener from comment #3) It seems that Tag_ABI_PCS_wchar_t is emitted from the C-family frontends only via config/arm/arm-c.c (as opposed to any other Tags). Probably because the option is c-family specific. This code needs to move to generic handling (the option enum is shared across all frontends, so that's not a reason to keep it in a C specific file). Thanks very much for your comments. So this seems to be a separate issue that the Tag_ABI_PCS_wchar_t need to be moved to LTO frontend at least,but not only the C frontend. May be I need to creat another patch or bug description for this issue.
[Bug lto/61123] With LTO, -fno-short-enums is ignored, resulting in ABI mis-matching in linking.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61123 --- Comment #3 from Richard Biener rguenth at gcc dot gnu.org --- It seems that Tag_ABI_PCS_wchar_t is emitted from the C-family frontends only via config/arm/arm-c.c (as opposed to any other Tags). Probably because the option is c-family specific. This code needs to move to generic handling (the option enum is shared across all frontends, so that's not a reason to keep it in a C specific file).
[Bug lto/61123] With LTO, -fno-short-enums is ignored, resulting in ABI mis-matching in linking.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61123
--- Comment #2 from Hale Wang Hale.Wang at arm dot com ---
(In reply to Richard Biener from comment #1)
All ABI changing options should be also enabled for LTO and they also deserve
handling in lto-opts.c (always stream, not only if explicitely set) and
lto-wrapper.c (diagnose mismatches and force a setting for the link stage).
At least enabling them for LTO is minimally required, like you suggest.
Hi Richard,
I was dealing with the fno-short-enum bug that LTO ignore the options of
fshort-enum and fshort-wchar(fshort-wchar is similar with fshort-enum). I tried
to fix this bug by adding these options to LTO group. And this solution works.
Right now, I am trying to add some test cases to report some error message for
these cases in the previous gcc versions. And these cases will be passed after
I add these options to LTO group.
For the option of fshort-enum, I catch the Tag_ABI_enum_size from the final
executable. And this test case can work very well now.
But for the option of fshort-wchar, if I compile the source files without
-flto option, I can catch the Tag_ABI_PCS_wchar_t from the final executable.
If I add the -flto option to the compile command, the Tag_ABI_PCS_wchar_t is
totally disappeared in the final executable.
So I think this is another bug which means the final executable file (or the
ABI) is different if we add -flto or not.
I generated a minimal example.I have two source files:
wchar_0.c:
#include stddef.h
wchar_t wc0[]=L”abc”;
const wchar_t wc1[]=L”abc”;
wchar_1.c:
#include stddef.h
wchar_t b0[]={ L”abc” };
const wchar_t b1[]={ L”abc” };
Firstly, I compile these files without “-flto”:
$ arm-none-eabi-gcc -fshort-wchar wchar_0.c wchar_1.c -Wl,-Ur -o
without_flto.o -nostdlib -Os
$ arm-none-eabi-readelf -A without_flto.o
Attribute Section: aeabi
File Attributes
Tag_CPU_name: ARM7TDMI
Tag_CPU_arch: v4T
Tag_ARM_ISA_use: Yes
Tag_THUMB_ISA_use: Thumb-1
Tag_ABI_PCS_wchar_t: 2
Tag_ABI_FP_denormal: Needed
Tag_ABI_FP_exceptions: Needed
Tag_ABI_FP_number_model: IEEE 754
Tag_ABI_align_needed: 8-byte
Tag_ABI_align_preserved: 8-byte, except leaf SP
Tag_ABI_enum_size: small
Tag_ABI_optimization_goals: Aggressive Size
Then I compile these files with –flto:
$ arm-none-eabi-gcc -fshort-wchar wchar_0.c wchar_1.c -Wl,-Ur -o
with_flto.o -nostdlib -Os –flto
$ arm-none-eabi-readelf -A with_flto.o
Attribute Section: aeabi
File Attributes
Tag_CPU_name: ARM7TDMI
Tag_CPU_arch: v4T
Tag_ARM_ISA_use: Yes
Tag_THUMB_ISA_use: Thumb-1
Tag_ABI_FP_denormal: Needed
Tag_ABI_FP_exceptions: Needed
Tag_ABI_FP_number_model: IEEE 754
Tag_ABI_align_needed: 8-byte
Tag_ABI_align_preserved: 8-byte, except leaf SP
Tag_ABI_enum_size: small
Tag_ABI_optimization_goals: Aggressive Size
So we can see the Tag_ABI_PCS_wchar_t attribute is totally disappeared.
What do you think about this?
[Bug lto/61123] With LTO, -fno-short-enums is ignored, resulting in ABI mis-matching in linking.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61123 Richard Biener rguenth at gcc dot gnu.org changed: What|Removed |Added Keywords||lto --- Comment #1 from Richard Biener rguenth at gcc dot gnu.org --- All ABI changing options should be also enabled for LTO and they also deserve handling in lto-opts.c (always stream, not only if explicitely set) and lto-wrapper.c (diagnose mismatches and force a setting for the link stage). At least enabling them for LTO is minimally required, like you suggest.
