[Bug libstdc++/97758] New: bits/std_function.h: error: unknown type name 'type_info' when using -fno-exceptions -fno-rtti

["romain.geissler at amadeus dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97758

            Bug ID: 97758
           Summary: bits/std_function.h: error: unknown type name
                    'type_info' when using -fno-exceptions -fno-rtti
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: romain.geissler at amadeus dot com
  Target Milestone: ---

Hi,

I am using the trunk from today (8th november, git revision
b642fca1c31b2e2175e0860daf32b4ee0d918085).

When trying to build clang with it I end up with this error (on Linux x86_64):

FAILED: lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/ParallelCG.cpp.o 
/workdir/build/final-system/llvm-build/./bin/clang++  -DGTEST_HAS_RTTI=0
-D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS
-D__STDC_LIMIT_MACROS -Ilib/CodeGen -I/workdir/src/llvm-12.0.0/llvm/lib/CodeGen
-Iinclude -I/workdir/src/llvm-12.0.0/llvm/include -isystem
/workdir/build/final-system/llvm-temporary-static-dependencies/install/include
-O2
-I/workdir/build/final-system/llvm-temporary-static-dependencies/install/include
-I/workdir/build/final-system/llvm-temporary-static-dependencies/install/include/ncursesw
-fPIC -fvisibility-inlines-hidden -Werror=date-time
-Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter
-Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic
-Wno-long-long -Wimplicit-fallthrough -Wcovered-switch-default
-Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor
-Wsuggest-override -Wstring-conversion -fdiagnostics-color -ffunction-sections
-fdata-sections
-fprofile-instr-generate="/workdir/build/final-system/llvm-build/tools/clang/stage2-instrumented-bins/profiles/%4m.profraw"
-flto -O3 -DNDEBUG    -fno-exceptions -fno-rtti -std=c++14 -MD -MT
lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/ParallelCG.cpp.o -MF
lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/ParallelCG.cpp.o.d -o
lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/ParallelCG.cpp.o -c
/workdir/src/llvm-12.0.0/llvm/lib/CodeGen/ParallelCG.cpp
In file included from
/workdir/src/llvm-12.0.0/llvm/lib/CodeGen/ParallelCG.cpp:13:
In file included from
/workdir/src/llvm-12.0.0/llvm/include/llvm/CodeGen/ParallelCG.h:17:
In file included from
/opt/1A/toolchain/x86_64-v21.0.10/lib64/gcc/x86_64-1a-linux-gnu/11.0.0/../../../../include/c++/11.0.0/functional:59:
/opt/1A/toolchain/x86_64-v21.0.10/lib64/gcc/x86_64-1a-linux-gnu/11.0.0/../../../../include/c++/11.0.0/bits/std_function.h:190:31:
error: unknown type name 'type_info'
              __dest._M_access<const type_info*>() = nullptr;
                                     ^
1 error generated.

Note that apparently these llvm files are compiled with -fno-exceptions
-fno-rtti, so it seems triggered by the recent changes around std::function
without rtti support.

Cheers,
Romain