[llvm-objdump] Implement -Mreg-names-raw/-std options.

The --disassembler-options, or -M, are used to customize
the disassembler and affect its output.

The two implemented options allow selecting register names on ARM:
* With -Mreg-names-raw, the disassembler uses rNN for all registers.
* With -Mreg-names-std it prints sp, lr and pc for r13, r14 and r15,
  which is the default behavior of llvm-objdump.

Differential Revision: https://reviews.llvm.org/D57680

llvm-svn: 354870

1 files changed, 13 insertions, 1 deletions

diff --git a/llvm/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp b/llvm/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
index ee909f46af2..ec5fd16cd7d 100644
--- a/llvm/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
+++ b/llvm/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
@@ -72,8 +72,20 @@ ARMInstPrinter::ARMInstPrinter(const MCAsmInfo &MAI, const MCInstrInfo &MII,
                                const MCRegisterInfo &MRI)
     : MCInstPrinter(MAI, MII, MRI) {}
 
+bool ARMInstPrinter::applyTargetSpecificCLOption(StringRef Opt) {
+  if (Opt == "reg-names-std") {
+    DefaultAltIdx = ARM::NoRegAltName;
+    return true;
+  }
+  if (Opt == "reg-names-raw") {
+    DefaultAltIdx = ARM::RegNamesRaw;
+    return true;
+  }
+  return false;
+}
+
 void ARMInstPrinter::printRegName(raw_ostream &OS, unsigned RegNo) const {
-  OS << markup("<reg:") << getRegisterName(RegNo) << markup(">");
+  OS << markup("<reg:") << getRegisterName(RegNo, DefaultAltIdx) << markup(">");
 }
 
 void ARMInstPrinter::printInst(const MCInst *MI, raw_ostream &O,