llvm dev - May 2021 - Building LLVM on Mac

Hi.
> I am trying to build the framework on MacBook but getting errors while
compilation; e.g., some are
> 
>
/Users/abidmalik/Programming/MLIR_target/llvm-project/libcxx/include/wchar.h:137:77:
error: use of undeclared identifier 'wcschr'
> wchar_t* __libcpp_wcschr(const wchar_t* __s, wchar_t __c) {return
(wchar_t*)wcschr(__s, __c);}
>                                                                            
^
>
/Users/abidmalik/Programming/MLIR_target/llvm-project/libcxx/include/wchar.h:144:87:
error: use of undeclared identifier 'wcspbrk'
> wchar_t* __libcpp_wcspbrk(const wchar_t* __s1, const wchar_t* __s2) {return
(wchar_t*)wcspbrk(__s1, __s2);}
I'm building Clang/LLVM on a daily basis on Mac and I get these types of
errors when I upgrade/update Xcode. Then I remove the build directory and build
everything from scratch.

>  -DCMAKE_C_FLAGS="-isysroot
/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk"
-DCMAKE_CXX_FLAGS="-isysroot
/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk
I do not use option -isysroot. Do these directories exist? I think you do not
have to set it.

Boris

> >  -DCMAKE_C_FLAGS="-isysroot
/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk"
-DCMAKE_CXX_FLAGS="-isysroot
/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk
>
> I do not use option -isysroot. Do these directories exist? I think you do
not have to set it.
The right way to do this is to set -DCMAKE_OSX_SYSROOT - not to pass
isysroot directly.

-- Tobias