Successfully identified regression in *gcc* in CI configuration
tcwg_gnu_cross_build/master-arm. So far, this commit has regressed CI
configurations:
- tcwg_gnu_cross_build/master-arm
Culprit:
<cut>
commit caf81d3b57501b1f58dcd9b1ef9d7b4bc76f4ab1
Author: Sebastian Huber <sebastian.hu...@embedded-brains.de>
Date: Tue Aug 17 09:53:43 2021 +0200
Use __builtin_trap() for abort() if inhibit_libc
abort() is used in gcc_assert() and gcc_unreachable() which is used by
target
libraries such as libgcov.a. This patch changes the abort() definition
under
certain conditions. If inhibit_libc is defined and abort is not already
defined, then abort() is defined to __builtin_trap().
The inhibit_libc define is usually defined if GCC is built for targets
running
in embedded systems which may optionally use a C standard library. If
inhibit_libc is defined, then there may be still a full featured abort()
available. abort() is a heavy weight function which depends on signals and
file streams. For statically linked applications, this means that a
dependency
on gcc_assert() pulls in the support for signals and file streams. This
could
prevent using gcov to test low end targets for example. Using
__builtin_trap()
avoids these dependencies if the target implements a "trap" instruction.
The
application or operating system could use a trap handler to react to failed
GCC
runtime checks which caused a trap.
gcc/
* tsystem.h (abort): Define abort() if inhibit_libc is defined and
it
is not already defined.
</cut>
Results regressed to (for first_bad == caf81d3b57501b1f58dcd9b1ef9d7b4bc76f4ab1)
# reset_artifacts:
-10
# true:
0
# build_abe binutils:
1
# First few build errors in logs:
# 00:01:44 cc1: error: no include path in which to search for stdc-predef.h
# 00:02:05
/home/tcwg-buildslave/workspace/tcwg_gnu_1/abe/snapshots/gcc.git~master/libgcc/unwind-arm-common.inc:55:24:
error: macro passed 1 arguments, but takes just 0
# 00:02:05 make[2]: ***
[/home/tcwg-buildslave/workspace/tcwg_gnu_1/abe/snapshots/gcc.git~master/libgcc/static-object.mk:17:
unwind-arm.o] Error 1
# 00:02:06 make[1]: *** [Makefile:12484: all-target-libgcc] Error 2
# 00:02:06 make: *** [Makefile:953: all] Error 2
from (for last_good == d7e56b084d0b230ae5ee280f569d679fa0f09f4d)
# reset_artifacts:
-10
# true:
0
# build_abe binutils:
1
# build_abe stage1:
2
# build_abe linux:
3
# build_abe glibc:
4
# build_abe stage2:
5
# build_abe gdb:
6
# build_abe qemu:
7
Artifacts of last_good build:
https://ci.linaro.org/job/tcwg_gnu_cross_build-bisect-master-arm/1/artifact/artifacts/build-d7e56b084d0b230ae5ee280f569d679fa0f09f4d/
Artifacts of first_bad build:
https://ci.linaro.org/job/tcwg_gnu_cross_build-bisect-master-arm/1/artifact/artifacts/build-caf81d3b57501b1f58dcd9b1ef9d7b4bc76f4ab1/
Build top page/logs:
https://ci.linaro.org/job/tcwg_gnu_cross_build-bisect-master-arm/1/
Configuration details:
Reproduce builds:
<cut>
mkdir investigate-gcc-caf81d3b57501b1f58dcd9b1ef9d7b4bc76f4ab1
cd investigate-gcc-caf81d3b57501b1f58dcd9b1ef9d7b4bc76f4ab1
git clone https://git.linaro.org/toolchain/jenkins-scripts
mkdir -p artifacts/manifests
curl -o artifacts/manifests/build-baseline.sh
https://ci.linaro.org/job/tcwg_gnu_cross_build-bisect-master-arm/1/artifact/artifacts/manifests/build-baseline.sh
--fail
curl -o artifacts/manifests/build-parameters.sh
https://ci.linaro.org/job/tcwg_gnu_cross_build-bisect-master-arm/1/artifact/artifacts/manifests/build-parameters.sh
--fail
curl -o artifacts/test.sh
https://ci.linaro.org/job/tcwg_gnu_cross_build-bisect-master-arm/1/artifact/artifacts/test.sh
--fail
chmod +x artifacts/test.sh
# Reproduce the baseline build (build all pre-requisites)
./jenkins-scripts/tcwg_gnu-build.sh @@ artifacts/manifests/build-baseline.sh
# Save baseline build state (which is then restored in artifacts/test.sh)
mkdir -p ./bisect
rsync -a --del --delete-excluded --exclude /bisect/ --exclude /artifacts/
--exclude /gcc/ ./ ./bisect/baseline/
cd gcc
# Reproduce first_bad build
git checkout --detach caf81d3b57501b1f58dcd9b1ef9d7b4bc76f4ab1
../artifacts/test.sh
# Reproduce last_good build
git checkout --detach d7e56b084d0b230ae5ee280f569d679fa0f09f4d
../artifacts/test.sh
cd ..
</cut>
History of pending regressions and results:
https://git.linaro.org/toolchain/ci/base-artifacts.git/log/?h=linaro-local/ci/tcwg_gnu_cross_build/master-arm
Artifacts:
https://ci.linaro.org/job/tcwg_gnu_cross_build-bisect-master-arm/1/artifact/artifacts/
Build log:
https://ci.linaro.org/job/tcwg_gnu_cross_build-bisect-master-arm/1/consoleText
Full commit (up to 1000 lines):
<cut>
commit caf81d3b57501b1f58dcd9b1ef9d7b4bc76f4ab1
Author: Sebastian Huber <sebastian.hu...@embedded-brains.de>
Date: Tue Aug 17 09:53:43 2021 +0200
Use __builtin_trap() for abort() if inhibit_libc
abort() is used in gcc_assert() and gcc_unreachable() which is used by
target
libraries such as libgcov.a. This patch changes the abort() definition
under
certain conditions. If inhibit_libc is defined and abort is not already
defined, then abort() is defined to __builtin_trap().
The inhibit_libc define is usually defined if GCC is built for targets
running
in embedded systems which may optionally use a C standard library. If
inhibit_libc is defined, then there may be still a full featured abort()
available. abort() is a heavy weight function which depends on signals and
file streams. For statically linked applications, this means that a
dependency
on gcc_assert() pulls in the support for signals and file streams. This
could
prevent using gcov to test low end targets for example. Using
__builtin_trap()
avoids these dependencies if the target implements a "trap" instruction.
The
application or operating system could use a trap handler to react to failed
GCC
runtime checks which caused a trap.
gcc/
* tsystem.h (abort): Define abort() if inhibit_libc is defined and
it
is not already defined.
---
gcc/tsystem.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/gcc/tsystem.h b/gcc/tsystem.h
index e1e6a96a4f4..5c72c69ff3e 100644
--- a/gcc/tsystem.h
+++ b/gcc/tsystem.h
@@ -59,7 +59,7 @@ extern int atexit (void (*)(void));
#endif
#ifndef abort
-extern void abort (void) __attribute__ ((__noreturn__));
+#define abort() __builtin_trap ()
#endif
#ifndef strlen
</cut>
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