[PowerPC] Drop stdlib paths in freestanding tests

[lichray]

Summary

When targeting FreeBSD on a Linux host with a copy
of system libc++, Clang prepends /usr/include/c++/v1
to the search paths even with -ffreestanding, and
fails to compile a program with a
single #include <xmmintrin.h>

Dropping the path with -nostdlibinc.

[MaskRay]

GCC -ffreestanding doesn't change libstdc++ search paths. Clang's behavior matches GCC.

To drop /usr/include/c++/v1, you need -nostdinc++. If you want to drop /usr/include etc, you need to specify --sysroot=

[lichray]

• Adapt tests instead

[nemanjai]

Seems fine to me but maybe give @MaskRay a couple of days to see if this adequately addresses his comment.

[MaskRay]

LGTM (in a trip, slow to reply)

clang/test/CodeGen/ppc-xmmintrin.c

 // NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py
 // REQUIRES: powerpc-registered-target
 
 // RUN: %clang -S -emit-llvm -target powerpc64-unknown-linux-gnu -mcpu=pwr8 -ffreestanding -DNO_WARN_X86_INTRINSICS %s \
 // RUN: -ffp-contract=off -fno-discard-value-names -mllvm -disable-llvm-optzns -o - | llvm-cxxfilt -n | FileCheck %s --check-prefixes=CHECK,CHECK-BE
 // RUN: %clang -x c++ -fsyntax-only -target powerpc64-unknown-linux-gnu -mcpu=pwr8 -ffreestanding -DNO_WARN_X86_INTRINSICS %s \
 // RUN:   -fno-discard-value-names -mllvm -disable-llvm-optzns
 // RUN: %clang -S -emit-llvm -target powerpc64le-unknown-linux-gnu -mcpu=pwr8 -ffreestanding -DNO_WARN_X86_INTRINSICS %s \
 // RUN: -ffp-contract=off -fno-discard-value-names -mllvm -disable-llvm-optzns -o - | llvm-cxxfilt -n | FileCheck %s --check-prefixes=CHECK,CHECK-LE
 // RUN: %clang -x c++ -fsyntax-only -target powerpc64le-unknown-linux-gnu -mcpu=pwr8 -ffreestanding -DNO_WARN_X86_INTRINSICS %s \
 // RUN:   -fno-discard-value-names -mllvm -disable-llvm-optzns
 
-// RUN: %clang -S -emit-llvm -target powerpc64-unknown-freebsd13.0 -mcpu=pwr8 -ffreestanding -DNO_WARN_X86_INTRINSICS %s \
+// RUN: %clang -S -emit-llvm -target powerpc64-unknown-freebsd13.0 -mcpu=pwr8 -ffreestanding -nostdlibinc -DNO_WARN_X86_INTRINSICS %s \
 // RUN:   -fno-discard-value-names -mllvm -disable-llvm-optzns -o - | llvm-cxxfilt -n | FileCheck %s --check-prefixes=CHECK,CHECK-BE
-// RUN: %clang -x c++ -fsyntax-only -target powerpc64-unknown-freebsd13.0 -mcpu=pwr8 -ffreestanding -DNO_WARN_X86_INTRINSICS %s \
+// RUN: %clang -x c++ -fsyntax-only -target powerpc64-unknown-freebsd13.0 -mcpu=pwr8 -ffreestanding -nostdlibinc -DNO_WARN_X86_INTRINSICS %s \
 // RUN:   -fno-discard-value-names -mllvm -disable-llvm-optzns
-// RUN: %clang -S -emit-llvm -target powerpc64le-unknown-freebsd13.0 -mcpu=pwr8 -ffreestanding -DNO_WARN_X86_INTRINSICS %s \
+// RUN: %clang -S -emit-llvm -target powerpc64le-unknown-freebsd13.0 -mcpu=pwr8 -ffreestanding -nostdlibinc -DNO_WARN_X86_INTRINSICS %s \
 // RUN:   -fno-discard-value-names -mllvm -disable-llvm-optzns -o - | llvm-cxxfilt -n | FileCheck %s --check-prefixes=CHECK,CHECK-LE
-// RUN: %clang -x c++ -fsyntax-only -target powerpc64le-unknown-freebsd13.0 -mcpu=pwr8 -ffreestanding -DNO_WARN_X86_INTRINSICS %s \
+// RUN: %clang -x c++ -fsyntax-only -target powerpc64le-unknown-freebsd13.0 -mcpu=pwr8 -ffreestanding -nostdlibinc -DNO_WARN_X86_INTRINSICS %s \
 // RUN:   -fno-discard-value-names -mllvm -disable-llvm-optzns
 
 #include <xmmintrin.h>
 
 __m128 res, m1, m2;
 __m64 res64, ms[2];
 float fs[4];
 int i, i2;