Re: [PATCH v2 0/1] MR1219: ntdll: Fix building on Mojave / Xcode 11.3.1.

[Stefan Dösinger (＠stefan)]

bshanks was wondering about some details. While the fix seems sensible, it shouldn't be necessary according to him.

I had a closer look, and indeed Xcode 11.3.1 is not the problem. The command line tools for Xcode 11.3.1 are. Having them installed, even without pointing xcode-select, DEVELOPER_DIR or SDKROOT to them does some magic, for good (32 bit programs compile) and bad (the bug fixed here).

Some possibly relevant info:

```
grey:ntdll stefan$ xcode-select -p
/Applications/Xcode.app/Contents/Developer
grey:ntdll stefan$ sudo xcode-select -p
/Applications/Xcode.app/Contents/Developer
grey:ntdll stefan$ echo $DEVELOPER_DIR

grey:ntdll stefan$ echo $SDKROOT
```

(Homebrew choked on a difference between xcode-select -p and sudo xcode-select -p once. I have no idea how that can happen, since xcode-select -s is system wide. Oh well)

wine configure command line:
`~/src/wine/configure --enable-win64 --without-x LDFLAGS="-L/Users/stefan/src/MoltenVK/Package/Latest/MoltenVK/dylib/macOS"`

And the exact build failure:
```
gcc -m64 -c -o dlls/ntdll/unix/signal_x86_64.o /Users/stefan/src/wine/dlls/ntdll/unix/signal_x86_64.c -Idlls/ntdll \
  -I/Users/stefan/src/wine/dlls/ntdll -Iinclude -I/Users/stefan/src/wine/include -D__WINESRC__ \
  -DWINE_NO_LONG_TYPES -D_NTSYSTEM_ -D_ACRTIMP= -DWINBASEAPI= -D_MSVCR_VER=0 -DWINE_UNIX_LIB -Wall \
  -pipe -fcf-protection=none -fno-stack-protector -fno-strict-aliasing -Wdeclaration-after-statement \
  -Wempty-body -Wignored-qualifiers -Winit-self -Wno-pragma-pack -Wstrict-prototypes -Wtype-limits \
  -Wvla -Wwrite-strings -Wpointer-arith -gdwarf-4 -fPIC -fasynchronous-unwind-tables -g -O2 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=0
In file included from /Users/stefan/src/wine/dlls/ntdll/unix/signal_x86_64.c:83:
/Users/stefan/src/wine/dlls/ntdll/unix/dwarf.h:913:45: warning: taking the absolute value of unsigned type 'ULONG_PTR'
      (aka 'unsigned long') has no effect [-Wabsolute-value]
        case DW_OP_abs:         stack[sp] = labs(stack[sp]); break;
                                            ^
/Users/stefan/src/wine/dlls/ntdll/unix/dwarf.h:913:45: note: remove the call to 'labs' since unsigned values cannot be negative
        case DW_OP_abs:         stack[sp] = labs(stack[sp]); break;
                                            ^~~~
/Users/stefan/src/wine/dlls/ntdll/unix/signal_x86_64.c:282:38: error: use of undeclared identifier '_STRUCT_MCONTEXT64_FULL'
    if (context->uc_mcsize == sizeof(_STRUCT_MCONTEXT64_FULL) ||
                                     ^
/Users/stefan/src/wine/dlls/ntdll/unix/signal_x86_64.c:283:38: error: use of undeclared identifier '_STRUCT_MCONTEXT_AVX64_FULL'
        context->uc_mcsize == sizeof(_STRUCT_MCONTEXT_AVX64_FULL) ||
                                     ^
/Users/stefan/src/wine/dlls/ntdll/unix/signal_x86_64.c:286:63: error: expected expression
        return (XMM_SAVE_AREA32 *)&((_STRUCT_MCONTEXT64_FULL *)context->uc_mcontext)->__fs.__fpu_fcw;
                                                              ^
/Users/stefan/src/wine/dlls/ntdll/unix/signal_x86_64.c:286:38: error: use of undeclared identifier '_STRUCT_MCONTEXT64_FULL'
        return (XMM_SAVE_AREA32 *)&((_STRUCT_MCONTEXT64_FULL *)context->uc_mcontext)->__fs.__fpu_fcw;
```