Couldn't build llvm with gcc on archlinux - c++

Question

I tried to build llvm and got an error message related to stdlib.
I searched the cause with error message but
I don't know c/c++ well, so I couldn't understand what happened or how to fix this.
Please tell me what this means and what happened in my environment.
1: What I did
I tried to build llvm with below.
git clone https://github.com/llvm/llvm-project -b release/12.x
cd llvm-project
mkdir build
cd build
cmake -G Ninja \
-DDEFAULT_SYSROOT=${HOME}/riscv_github/riscv64-unknown-elf \
-DCMAKE_BUILD_TYPE="Debug" \
-DLLVM_TARGETS_TO_BUILD="X86;AArch64;RISCV" \
-DLLVM_ENABLE_PROJECTS="clang;libcxx;libcxxabi" \
../llvm
ninja
And got an error message below.
[8/4685] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/ARMBuildAttrs.cpp.o
FAILED: lib/Support/CMakeFiles/LLVMSupport.dir/ARMBuildAttrs.cpp.o
/usr/bin/c++ -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/xxx/github.com/llvm-myriscvx120/build/lib/Support -I/home/xxx/github.com/llvm-myriscvx120/llvm/lib/Support -I/home/xxx/github.com/llvm-myriscvx120/build/include -I/home/xxx/github.com/llvm-myriscvx120/llvm/include -isystem /usr/bin/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wmisleading-indentation -fdiagnostics-color -g -std=c++14 -fno-exceptions -fno-rtti -MD -MT lib/Support/CMakeFiles/LLVMSupport.dir/ARMBuildAttrs.cpp.o -MF lib/Support/CMakeFiles/LLVMSupport.dir/ARMBuildAttrs.cpp.o.d -o lib/Support/CMakeFiles/LLVMSupport.dir/ARMBuildAttrs.cpp.o -c /home/xxx/github.com/llvm-myriscvx120/llvm/lib/Support/ARMBuildAttrs.cpp
In file included from /usr/include/c++/12.1.1/cstdlib:75,
from /usr/include/c++/12.1.1/bits/stl_algo.h:69,
from /usr/include/c++/12.1.1/algorithm:61,
from /home/xxx/github.com/llvm-myriscvx120/llvm/include/llvm/ADT/Hashing.h:51,
from /home/xxx/github.com/llvm-myriscvx120/llvm/include/llvm/ADT/ArrayRef.h:12,
from /home/xxx/github.com/llvm-myriscvx120/llvm/include/llvm/Support/ELFAttributes.h:12,
from /home/xxx/github.com/llvm-myriscvx120/llvm/include/llvm/Support/ARMBuildAttributes.h:21,
from /home/xxx/github.com/llvm-myriscvx120/llvm/lib/Support/ARMBuildAttrs.cpp:9:
/usr/include/stdlib.h:579:5: error: expected initializer before ‘__attr_dealloc_free’
579 | __attr_dealloc_free;
| ^~~~~~~~~~~~~~~~~~~
/usr/include/stdlib.h:583:14: error: expected initializer before ‘__attr_dealloc’
583 | __THROW __attr_dealloc (reallocarray, 1);
| ^~~~~~~~~~~~~~
/usr/include/stdlib.h:606:35: error: expected initializer before ‘__attribute_alloc_align__’
606 | __THROW __attribute_malloc__ __attribute_alloc_align__ ((1))
| ^~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/stdlib.h:812:6: error: expected initializer before ‘__attr_dealloc_free’
812 | __attr_dealloc_free __wur;
| ^~~~~~~~~~~~~~~~~~~
/usr/include/stdlib.h:961:3: error: expected initializer before ‘__fortified_attr_access’
961 | __fortified_attr_access (__write_only__, 1, 3)
| ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/stdlib.h:1016:30: error: expected initializer before ‘__fortified_attr_access’
1016 | __THROW __nonnull ((2)) __fortified_attr_access (__write_only__, 2, 3);
| ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/12.1.1/cstdlib:171:11: error: ‘wcstombs’ has not been declared in ‘::’
171 | using ::wcstombs;
| ^~~~~~~~
ninja: build stopped: subcommand failed.
It seemed to me that gcc is broken, so I tried to build llvm with gcc-11(g++-11) and gcc-10(g++-10), and got the same error.
After that, I checkout to the release/11.x branch and try to build with the same cmake options.
Then the build step started and it seems well.
So I tried another branches, release/13.x, release/14.x, release/15.x and they wouldn't work.
2: My Env
$ uname -a
Linux arch-x13 5.18.16-arch1-1 #1 SMP PREEMPT_DYNAMIC Wed, 03 Aug 2022 11:25:04 +000 x86_64 GNU/Linux
$ gcc --version
gcc (GCC) 12.1.1 20220730
Copyright (C) 2022 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ cmake --version
cmake version 3.23.3
CMake suite maintained and supported by Kitware (kitware.com/cmake).**strong text**
$ ninja --version
1.11.0
Edit:
I could build llvm of release/12.x branch at Ubuntu20.04 machine with gcc-9 and gcc-10, so I tagged archlinux to this question.
I also tried some version of c++ standard, 20, 17 and 14 using the option DCMAKE_CXX_STANDARD=, but it wouldn't help.

Answer 1

I could find the cause with the help of my colleague.
The reason is the -isystem /usr/bin/include option.
In my laptop, the path existed surely, but I don't remember what this is, and pacman and paru knew neither...