[EABI] Add LLVM support for -meabi flag

"GCC requires the freestanding environment provide memcpy, memmove, memset
and memcmp": https://gcc.gnu.org/onlinedocs/gcc-5.2.0/gcc/Standards.html

Hence in GNUEABI targets LLVM should not convert 'memops' to their equivalent
'__aeabi_memops'. This convertion violates GCC contract.

The -meabi flag controls whether or not LLVM will modify 'memops' in GNUEABI
targets.

Without -meabi: use the triple default EABI.
With -meabi=default: use the triple default EABI.
With -meabi=gnu: use 'memops'.
With -meabi=4 or -meabi=5: use '__aeabi_memops'.
With -meabi set to an unknown value: same as -meabi=default.

Patch by Vinicius Tinti.

llvm-svn: 252462

1 files changed, 5 insertions, 0 deletions

diff --git a/llvm/lib/Target/ARM/ARMSubtarget.h b/llvm/lib/Target/ARM/ARMSubtarget.h
index 66b56d10faa..530aa63fff4 100644
--- a/llvm/lib/Target/ARM/ARMSubtarget.h
+++ b/llvm/lib/Target/ARM/ARMSubtarget.h
@@ -380,6 +380,11 @@ public:
             TargetTriple.getEnvironment() == Triple::EABIHF) &&
            !isTargetDarwin() && !isTargetWindows();
   }
+  bool isTargetGNUAEABI() const {
+    return (TargetTriple.getEnvironment() == Triple::GNUEABI ||
+            TargetTriple.getEnvironment() == Triple::GNUEABIHF) &&
+           !isTargetDarwin() && !isTargetWindows();
+  }
 
   // ARM Targets that support EHABI exception handling standard
   // Darwin uses SjLj. Other targets might need more checks.