[PPC64LE] Add a CALL_ELF macro to indicate use of the ELFv2 ABI.

Additional clarification from Uli for the background on _CALL_ELF:
"Historically GCC has provided various _CALL_... predefines depending on the
ABI currently being compiled for. (_CALL_SYSV,_CALL_AIXDESC, _CALL_DARWIN )
When we needed a new define for the current ABI, we decided on using _CALL_ELF
since the official name of the ABI is the OpenPower ElfV2 ABI, with the
current Linux ABI retro-actively being renamed the ELFv1 ABI
and so we decided on using _CALL_ELF to identify the Linux (+BSD etc.) ELF ABI,
with _CALL_ELF=1 for the v1 ABI and _CALL_ELF=2 for the v2 ABI.
(Note that this matches the gcc compiler switch -mabi=elfv1 vs. -mabi=elfv2)."

In code, a (_CALL_ELF==2) check will indicate when the ELFv2 ABI is
to be used.   This is the desired default for the PPC64 LE target.

llvm-svn: 204627

1 files changed, 1 insertions, 0 deletions

diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index 0e1292d48d5..d22599dec61 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -939,6 +939,7 @@ void PPCTargetInfo::getTargetDefines(const LangOptions &Opts,
   // Target properties.
   if (getTriple().getArch() == llvm::Triple::ppc64le) {
     Builder.defineMacro("_LITTLE_ENDIAN");
+    Builder.defineMacro("_CALL_ELF","2");
   } else {
     if (getTriple().getOS() != llvm::Triple::NetBSD &&
         getTriple().getOS() != llvm::Triple::OpenBSD)