Successfully identified regression in *gcc* in CI configuration tcwg_bmk_gnu_eabi_stm32/gnu_eabi-master-arm_eabi-coremark-Os. So far, this commit has regressed CI configurations: - tcwg_bmk_gnu_eabi_stm32/gnu_eabi-master-arm_eabi-coremark-Os
Culprit: <cut> commit 784de5292c34e287c848b382b431599b818ea76e Author: Jakub Jelinek jakub@redhat.com Date: Fri Apr 16 09:34:26 2021 +0200
c++: Fix up C++23 [] <...> requires primary -> type {} parsing [PR99850]
The requires clause parsing has code to suggest users wrapping non-primary expressions in (), so if it e.g. parses a primary expression and sees it is followed by ++, --, ., ( or -> among other things it will try to reparse it as assignment expression or what and if that works suggests wrapping it inside of parens. When it is requires-clause that is after <typename T> etc. it already has an exception from that as ( can occur in valid C++20 expression there - starting the parameters of the lambda. In C++23 another case can occur, as the parameters with the ()s can be omitted, requires C can be followed immediately by -> which starts a trailing return type. Even in that case, we don't want to parse that as C->...
2021-04-16 Jakub Jelinek jakub@redhat.com
PR c++/99850 * parser.c (cp_parser_constraint_requires_parens) <case CPP_DEREF>: If lambda_p, return pce_ok instead of pce_maybe_postfix.
* g++.dg/cpp23/lambda-specifiers2.C: New test. </cut>
Results regressed to (for first_bad == 784de5292c34e287c848b382b431599b818ea76e) # reset_artifacts: -10 # build_abe binutils: -9 # build_abe stage1 -- --set gcc_override_configure=--disable-libsanitizer --set gcc_override_configure=--disable-multilib --set gcc_override_configure=--with-cpu=cortex-m4 --set gcc_override_configure=--with-mode=thumb --set gcc_override_configure=--with-float=hard: -8 # build_abe newlib: -6 # build_abe stage2 -- --set gcc_override_configure=--disable-libsanitizer --set gcc_override_configure=--disable-multilib --set gcc_override_configure=--with-cpu=cortex-m4 --set gcc_override_configure=--with-mode=thumb --set gcc_override_configure=--with-float=hard: -5 # true: 0 # benchmark -Os_mthumb -- artifacts/build-784de5292c34e287c848b382b431599b818ea76e/results_id: 1
from (for last_good == 20eb7a1891cfd7fa85295a236cebe0322d041edd) # reset_artifacts: -10 # build_abe binutils: -9 # build_abe stage1 -- --set gcc_override_configure=--disable-libsanitizer --set gcc_override_configure=--disable-multilib --set gcc_override_configure=--with-cpu=cortex-m4 --set gcc_override_configure=--with-mode=thumb --set gcc_override_configure=--with-float=hard: -8 # build_abe newlib: -6 # build_abe stage2 -- --set gcc_override_configure=--disable-libsanitizer --set gcc_override_configure=--disable-multilib --set gcc_override_configure=--with-cpu=cortex-m4 --set gcc_override_configure=--with-mode=thumb --set gcc_override_configure=--with-float=hard: -5 # true: 0 # benchmark -Os_mthumb -- artifacts/build-baseline/results_id: 1
Artifacts of last_good build: https://ci.linaro.org/job/tcwg_bmk_ci_gnu_eabi-bisect-tcwg_bmk_stm32-gnu_eab... Results ID of last_good: stm32_STM32L476RGTx/tcwg_bmk_gnu_eabi_stm32/baseline-gnu_eabi-master-arm_eabi-coremark-Os/2215 Artifacts of first_bad build: https://ci.linaro.org/job/tcwg_bmk_ci_gnu_eabi-bisect-tcwg_bmk_stm32-gnu_eab... Results ID of first_bad: stm32_STM32L476RGTx/tcwg_bmk_gnu_eabi_stm32/bisect-gnu_eabi-master-arm_eabi-coremark-Os/2252 Build top page/logs: https://ci.linaro.org/job/tcwg_bmk_ci_gnu_eabi-bisect-tcwg_bmk_stm32-gnu_eab...
Configuration details:
Reproduce builds: <cut> mkdir investigate-gcc-784de5292c34e287c848b382b431599b818ea76e cd investigate-gcc-784de5292c34e287c848b382b431599b818ea76e
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_bmk_ci_gnu_eabi-bisect-tcwg_bmk_stm32-gnu_eab... --fail curl -o artifacts/manifests/build-parameters.sh https://ci.linaro.org/job/tcwg_bmk_ci_gnu_eabi-bisect-tcwg_bmk_stm32-gnu_eab... --fail curl -o artifacts/test.sh https://ci.linaro.org/job/tcwg_bmk_ci_gnu_eabi-bisect-tcwg_bmk_stm32-gnu_eab... --fail chmod +x artifacts/test.sh
# Reproduce the baseline build (build all pre-requisites) ./jenkins-scripts/tcwg_bmk-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 784de5292c34e287c848b382b431599b818ea76e ../artifacts/test.sh
# Reproduce last_good build git checkout --detach 20eb7a1891cfd7fa85295a236cebe0322d041edd ../artifacts/test.sh
cd .. </cut>
History of pending regressions and results: https://git.linaro.org/toolchain/ci/base-artifacts.git/log/?h=linaro-local/c...
Artifacts: https://ci.linaro.org/job/tcwg_bmk_ci_gnu_eabi-bisect-tcwg_bmk_stm32-gnu_eab... Build log: https://ci.linaro.org/job/tcwg_bmk_ci_gnu_eabi-bisect-tcwg_bmk_stm32-gnu_eab...
Full commit (up to 1000 lines): <cut> commit 784de5292c34e287c848b382b431599b818ea76e Author: Jakub Jelinek jakub@redhat.com Date: Fri Apr 16 09:34:26 2021 +0200
c++: Fix up C++23 [] <...> requires primary -> type {} parsing [PR99850]
The requires clause parsing has code to suggest users wrapping non-primary expressions in (), so if it e.g. parses a primary expression and sees it is followed by ++, --, ., ( or -> among other things it will try to reparse it as assignment expression or what and if that works suggests wrapping it inside of parens. When it is requires-clause that is after <typename T> etc. it already has an exception from that as ( can occur in valid C++20 expression there - starting the parameters of the lambda. In C++23 another case can occur, as the parameters with the ()s can be omitted, requires C can be followed immediately by -> which starts a trailing return type. Even in that case, we don't want to parse that as C->...
2021-04-16 Jakub Jelinek jakub@redhat.com
PR c++/99850 * parser.c (cp_parser_constraint_requires_parens) <case CPP_DEREF>: If lambda_p, return pce_ok instead of pce_maybe_postfix.
* g++.dg/cpp23/lambda-specifiers2.C: New test. --- gcc/cp/parser.c | 13 +++++++++++++ gcc/testsuite/g++.dg/cpp23/lambda-specifiers2.C | 7 +++++++ 2 files changed, 20 insertions(+)
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c index 940751b5f05..dfc9b8251a7 100644 --- a/gcc/cp/parser.c +++ b/gcc/cp/parser.c @@ -28530,7 +28530,20 @@ cp_parser_constraint_requires_parens (cp_parser *parser, bool lambda_p) case CPP_PLUS_PLUS: case CPP_MINUS_MINUS: case CPP_DOT: + /* Unenclosed postfix operator. */ + return pce_maybe_postfix; + case CPP_DEREF: + /* A primary constraint that precedes the lambda-declarator of a + lambda expression is followed by trailing return type. + + []<typename T> requires C -> void {} + + Don't try to re-parse this as a postfix expression in + C++23 and later. In C++20 ( needs to come in between but we + allow it to be omitted with pedwarn. */ + if (lambda_p) + return pce_ok; /* Unenclosed postfix operator. */ return pce_maybe_postfix; } diff --git a/gcc/testsuite/g++.dg/cpp23/lambda-specifiers2.C b/gcc/testsuite/g++.dg/cpp23/lambda-specifiers2.C new file mode 100644 index 00000000000..0cc69bebc64 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp23/lambda-specifiers2.C @@ -0,0 +1,7 @@ +// PR c++/99850 +// P1102R2 - Down with ()! +// { dg-do compile { target c++23 } } + +auto l = []<auto> requires true -> void {}; +template <typename...> concept C = true; +auto m = []<typename... Ts> requires (C<Ts> && ...) -> void {}; </cut>