[OpenMP][NVPTX] Use appropriate _CALL_ELF macro when offloading

[gtbercea]

Summary

When offloading to a device and using the powerpc64le version of the auxiliary triple, the _CALL_ELF macro is not set correctly to 2 resulting in the attempt to include a header that does not exist. This patch fixes this problem.

[Hahnfeld]

LGTM. Can you add a comment to InitializePredefinedAuxMacros explaining that the macro is used in gnu/stubs.h and add a check to the test?

[gtbercea]

Add test.

[tra]

Reverted in rL341115 & rL341118.

lib/Frontend/InitPreprocessor.cpp

 
 /// Initialize macros based on AuxTargetInfo.
 static void InitializePredefinedAuxMacros(const TargetInfo &AuxTI,
                                           const LangOptions &LangOpts,
                                           MacroBuilder &Builder) {
   auto AuxTriple = AuxTI.getTriple();
 
   // Define basic target macros needed by at least bits/wordsize.h and
-  // bits/mathinline.h
+  // bits/mathinline.h.
+  // On PowerPC, explicitely set _CALL_ELF macro needed for gnu/stubs.h.
   switch (AuxTriple.getArch()) {
   case llvm::Triple::x86_64:
     Builder.defineMacro("__x86_64__");
     break;
   case llvm::Triple::ppc64:
+    Builder.defineMacro("__powerpc64__");
+    Builder.defineMacro("_CALL_ELF", "1");
+    break;
   case llvm::Triple::ppc64le:
     Builder.defineMacro("__powerpc64__");
+    Builder.defineMacro("_CALL_ELF", "2");
     break;
   default:
     break;
   }
 
   // libc++ needs to find out the object file format and threading API.
   if (AuxTriple.getOS() == llvm::Triple::Linux) {
     Builder.defineMacro("__ELF__");

test/Preprocessor/aux-triple.c

 // Ensure that Clang sets some very basic target defines based on -aux-triple.
 
 // RUN: %clang_cc1 -E -dM -ffreestanding < /dev/null \
 // RUN:     -triple nvptx64-none-none \
 // RUN:   | FileCheck -match-full-lines -check-prefixes NVPTX64,NONE %s
 // RUN: %clang_cc1 -x c++ -E -dM -ffreestanding < /dev/null \
 // RUN:     -triple nvptx64-none-none \
 // RUN:   | FileCheck -match-full-lines -check-prefixes NVPTX64,NONE %s
 // RUN: %clang_cc1 -x cuda -E -dM -ffreestanding < /dev/null \
 // RUN:     -triple nvptx64-none-none \
 // RUN:   | FileCheck -match-full-lines -check-prefixes NVPTX64,NONE %s
 
 // CUDA:
 // RUN: %clang_cc1 -x cuda -E -dM -ffreestanding < /dev/null \
 // RUN:     -triple nvptx64-none-none -aux-triple powerpc64le-unknown-linux-gnu \
 // RUN:   | FileCheck -match-full-lines %s \
-// RUN:     -check-prefixes NVPTX64,PPC64,LINUX,LINUX-CPP
+// RUN:     -check-prefixes NVPTX64,PPC64LE,LINUX,LINUX-CPP
 // RUN: %clang_cc1 -x cuda -E -dM -ffreestanding < /dev/null \
 // RUN:     -triple nvptx64-none-none -aux-triple x86_64-unknown-linux-gnu \
 // RUN:   | FileCheck -match-full-lines %s \
 // RUN:     -check-prefixes NVPTX64,X86_64,LINUX,LINUX-CPP
 
 // OpenMP:
 // RUN: %clang_cc1 -E -dM -ffreestanding < /dev/null \
 // RUN:     -fopenmp -fopenmp-is-device -triple nvptx64-none-none \
 // RUN:     -aux-triple powerpc64le-unknown-linux-gnu \
-// RUN:   | FileCheck -match-full-lines -check-prefixes NVPTX64,PPC64,LINUX %s
+// RUN:   | FileCheck -match-full-lines -check-prefixes NVPTX64,PPC64LE,LINUX %s
 // RUN: %clang_cc1 -E -dM -ffreestanding < /dev/null \
 // RUN:     -fopenmp -fopenmp-is-device -triple nvptx64-none-none \
 // RUN:     -aux-triple x86_64-unknown-linux-gnu \
 // RUN:   | FileCheck -match-full-lines -check-prefixes NVPTX64,X86_64,LINUX %s
 // RUN: %clang_cc1 -x c++ -E -dM -ffreestanding < /dev/null \
 // RUN:     -fopenmp -fopenmp-is-device -triple nvptx64-none-none \
 // RUN:     -aux-triple powerpc64le-unknown-linux-gnu \
 // RUN:   | FileCheck -match-full-lines %s \
-// RUN:     -check-prefixes NVPTX64,PPC64,LINUX,LINUX-CPP
+// RUN:     -check-prefixes NVPTX64,PPC64LE,LINUX,LINUX-CPP
 // RUN: %clang_cc1 -x c++ -E -dM -ffreestanding < /dev/null \
 // RUN:     -fopenmp -fopenmp-is-device -triple nvptx64-none-none \
 // RUN:     -aux-triple x86_64-unknown-linux-gnu \
 // RUN:   | FileCheck -match-full-lines %s \
 // RUN:     -check-prefixes NVPTX64,X86_64,LINUX,LINUX-CPP
 
+// PPC64LE:#define _CALL_ELF 2
+
 // NONE-NOT:#define _GNU_SOURCE
 // LINUX-CPP:#define _GNU_SOURCE 1
 
 // NVPTX64:#define _LP64 1
 
 // NONE-NOT:#define __ELF__
 // LINUX:#define __ELF__ 1
 
 // NVPTX64:#define __LP64__ 1
 // NVPTX64:#define __NVPTX__ 1
 // NVPTX64:#define __PTX__ 1
 
 // NONE-NOT:#define __linux__
 // LINUX:#define __linux__ 1
 
 // NONE-NOT:#define __powerpc64__
-// PPC64:#define __powerpc64__ 1
+// PPC64LE:#define __powerpc64__ 1
 
 // NONE-NOT:#define __x86_64__
 // X86_64:#define __x86_64__ 1