[RISCV] Add ELFObjectFileBase::getRISCVFeatures let llvm-objdump could get RISCV target feature

llvm-objdump could get C feature by ELF::EF_RISCV_RVC e_flag,
so then we don't have to add -mattr=+c on the command line.

Differential Revision: https://reviews.llvm.org/D42629

llvm-svn: 324058

1 files changed, 13 insertions, 0 deletions

diff --git a/llvm/lib/Object/ELFObjectFile.cpp b/llvm/lib/Object/ELFObjectFile.cpp
index 3c1bdf5a1de..e806c8f28b1 100644
--- a/llvm/lib/Object/ELFObjectFile.cpp
+++ b/llvm/lib/Object/ELFObjectFile.cpp
@@ -238,12 +238,25 @@ SubtargetFeatures ELFObjectFileBase::getARMFeatures() const {
   return Features;
 }
 
+SubtargetFeatures ELFObjectFileBase::getRISCVFeatures() const {
+  SubtargetFeatures Features;
+  unsigned PlatformFlags = getPlatformFlags();
+
+  if (PlatformFlags & ELF::EF_RISCV_RVC) {
+    Features.AddFeature("c");
+  }
+
+  return Features;
+}
+
 SubtargetFeatures ELFObjectFileBase::getFeatures() const {
   switch (getEMachine()) {
   case ELF::EM_MIPS:
     return getMIPSFeatures();
   case ELF::EM_ARM:
     return getARMFeatures();
+  case ELF::EM_RISCV:
+    return getRISCVFeatures();
   default:
     return SubtargetFeatures();
   }