[Bug c++/81429] New: maybe_unused attribute triggers syntax error when used on first argument to a constructor
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81429 Bug ID: 81429 Summary: maybe_unused attribute triggers syntax error when used on first argument to a constructor Product: gcc Version: 7.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: jeff.benshetler at stackpath dot com Target Milestone: --- Created attachment 41746 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=41746&action=edit Preprocessed file that triggers the bug. maybe_unused attribute triggers syntax error when used on first argument to a constructor Systm Type: Linux bnx1-lab1-dfw0.stackpath.systems 3.10.0-514.10.2.el7.x86_64 #1 SMP Fri Mar 3 00:04:05 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux Options given when GCC was configured/built: tar xzf gcc-7.1.0.tar.gz cd gcc-7.1.0 ./contrib/download_prerequisites cd .. mkdir objdir-7.1.0 cd objdir-7.1.0 ../gcc-7.1.0/configure --prefix=/opt/gcc-7.1.0 --enable-languages=c,c++ --disable-multilib make -j60 sudo make install Complete command line that triggers the bug: g++ -Wall -Wextra -save-temps -c maybe_unused.cpp Compiler Output maybe_unused.cpp:3:9: error: expected unqualified-id before ‘[’ token Foo([[maybe_unused]] int x) // fails ^ maybe_unused.cpp:3:9: error: expected ‘)’ before ‘[’ token This bug occurs with gcc-6.3.0, gcc-6.4.0, gcc-7.1.0. clang-3.9 is fine with the code.
[Bug c++/81429] maybe_unused attribute triggers syntax error when used on first argument to a constructor
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81429 --- Comment #1 from Jeff Benshetler --- Created attachment 41747 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=41747&action=edit Source test case that triggers the bug; corresponds to .ii file Added in an abundance of caution. No header files are used. The first constructor has [[maybe_used]] on the first constructor parameter and it triggers the bug. The second constructor uses [[maybe_unused]] on the second constructor parameter and it is fine.
[Bug c++/82496] New: Optimization breaks duration_cast
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82496 Bug ID: 82496 Summary: Optimization breaks duration_cast Product: gcc Version: 6.4.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: jeff.benshetler at stackpath dot com Target Milestone: --- Created attachment 42331 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=42331&action=edit Compiler output duration_cast always returns zero when using any level of optimization. duration_cast works properly when compiled without optimization GCC Version: g++ (GCC) 6.3.0 System Type: Darwin Jeffs-MacBook-Pro.local 16.7.0 Darwin Kernel Version 16.7.0: Thu Jun 15 17:36:27 PDT 2017; root:xnu-3789.70.16~2/RELEASE_X86_64 x86_64 Options when GCC was configured/built: /Users/jbenshetler/build/gcc/objdir/../gcc-6.3.0/configure --prefix=/opt/gcc-6.3.0 --enable-languages=c,c++,fortran --disable-multilib Exact command line passed to gcc triggering the bug: g++ -O1 -o duration_cast_error -v -save-temps duration_cast_error.cpp 2> duration_cast_error.log
[Bug c++/82496] Optimization breaks duration_cast
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82496 Jeff Benshetler changed: What|Removed |Added CC||jeff.benshetler at stackpath dot c ||om --- Comment #1 from Jeff Benshetler --- Created attachment 42332 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=42332&action=edit Preprocessed file that triggers the bug. When compiled without optimization and run, running the executable produces the following correct output: deltaT=2.00275 When compiled with any level of optimization (-O1 or greater), running the executable produces the following erroneous output: deltaT=0
[Bug c++/82496] Optimization breaks duration_cast
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82496 --- Comment #2 from Jeff Benshetler --- I confirmed that the identical problem exists on Linux for both gcc-6.4.0 and gcc-7.2.0.
[Bug libstdc++/82496] Optimization breaks duration_cast
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82496 --- Comment #4 from Jeff Benshetler --- My apologies. Adding -Wall shows: warning: no return statement in function returning non-void [-Wreturn-type]
