[llvm-mc] Add -M to replace -riscv-no-aliases and -riscv-arch-reg-names

In objdump, many targets support `-M no-aliases`.  Instead of having a
`-*-no-aliases` for each target when LLVM adds the support, it makes more sense
to introduce objdump style `-M`.

-riscv-arch-reg-names is removed. -riscv-no-aliases has too many uses and thus is retained for now.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D103004

llvm/include/llvm/MC/MCInstPrinter.h

@@ -54,6 +54,9 @@ protected:
   /// True if we are printing marked up assembly.
   bool UseMarkup = false;
 
+  /// True if we prefer aliases (e.g. nop) to raw mnemonics.
+  bool PrintAliases = true;
+
   /// True if we are printing immediates as hex.
   bool PrintImmHex = false;
 

llvm/lib/Target/RISCV/MCTargetDesc/RISCVInstPrinter.cpp

@@ -39,11 +39,11 @@ static cl::opt<bool>
               cl::desc("Disable the emission of assembler pseudo instructions"),
               cl::init(false), cl::Hidden);
 
-static cl::opt<bool>
-    ArchRegNames("riscv-arch-reg-names",
-                 cl::desc("Print architectural register names rather than the "
-                          "ABI names (such as x2 instead of sp)"),
-                 cl::init(false), cl::Hidden);
+// Print architectural register names rather than the ABI names (such as x2
+// instead of sp).
+// TODO: Make RISCVInstPrinter::getRegisterName non-static so that this can a
+// member.
+static bool ArchRegNames;
 
 // The command-line flags above are used by llvm-mc and llc. They can be used by
 // `llvm-objdump`, but we override their values here to handle options passed to
@@ -52,7 +52,7 @@ static cl::opt<bool>
 // this way.
 bool RISCVInstPrinter::applyTargetSpecificCLOption(StringRef Opt) {
   if (Opt == "no-aliases") {
-    NoAliases = true;
+    PrintAliases = false;
     return true;
   }
   if (Opt == "numeric") {
@@ -69,11 +69,11 @@ void RISCVInstPrinter::printInst(const MCInst *MI, uint64_t Address,
   bool Res = false;
   const MCInst *NewMI = MI;
   MCInst UncompressedMI;
-  if (!NoAliases)
+  if (PrintAliases && !NoAliases)
     Res = uncompressInst(UncompressedMI, *MI, MRI, STI);
   if (Res)
     NewMI = const_cast<MCInst *>(&UncompressedMI);
-  if (NoAliases || !printAliasInstr(NewMI, Address, STI, O))
+  if (!PrintAliases || NoAliases || !printAliasInstr(NewMI, Address, STI, O))
     printInstruction(NewMI, Address, STI, O);
   printAnnotation(O, Annot);
 }

llvm/test/MC/RISCV/numeric-reg-names-d.s

@@ -1,4 +1,4 @@
-# RUN: llvm-mc -triple riscv32 -mattr=+f,+d < %s -riscv-arch-reg-names \
+# RUN: llvm-mc -triple riscv32 -mattr=+f,+d -M numeric < %s \
 # RUN:     | FileCheck -check-prefix=CHECK-NUMERIC %s
 # RUN: llvm-mc -filetype=obj -triple riscv32 -mattr=+f,+d < %s \
 # RUN:     | llvm-objdump --mattr=+f,+d -d -M numeric - \

llvm/test/MC/RISCV/numeric-reg-names-f.s

@@ -1,4 +1,4 @@
-# RUN: llvm-mc -triple riscv32 -mattr=+f < %s -riscv-arch-reg-names \
+# RUN: llvm-mc -triple riscv32 -mattr=+f -M numeric < %s \
 # RUN:     | FileCheck -check-prefix=CHECK-NUMERIC %s
 # RUN: llvm-mc -filetype=obj -triple riscv32 -mattr=+f < %s \
 # RUN:     | llvm-objdump --mattr=+f -d -M numeric - \

llvm/test/MC/RISCV/numeric-reg-names.s

@@ -1,4 +1,4 @@
-# RUN: llvm-mc -triple riscv32 < %s -riscv-arch-reg-names \
+# RUN: llvm-mc -triple riscv32 -M numeric %s \
 # RUN:     | FileCheck -check-prefix=CHECK-NUMERIC %s
 # RUN: llvm-mc -filetype=obj -triple riscv32 < %s \
 # RUN:     | llvm-objdump -d -M numeric - \

llvm/test/MC/RISCV/rvi-aliases-valid.s

@@ -1,8 +1,8 @@
-# RUN: llvm-mc %s -triple=riscv32 -riscv-no-aliases \
+# RUN: llvm-mc %s -triple=riscv32 -M no-aliases \
 # RUN:     | FileCheck -check-prefixes=CHECK-S-NOALIAS,CHECK-S-OBJ-NOALIAS %s
 # RUN: llvm-mc %s -triple=riscv32 \
 # RUN:     | FileCheck -check-prefixes=CHECK-S,CHECK-S-OBJ %s
-# RUN: llvm-mc %s -triple=riscv64 -riscv-no-aliases\
+# RUN: llvm-mc %s -triple=riscv64 -M no-aliases \
 # RUN:     | FileCheck -check-prefixes=CHECK-S-NOALIAS,CHECK-S-OBJ-NOALIAS %s
 # RUN: llvm-mc %s -triple=riscv64 \
 # RUN:     | FileCheck -check-prefixes=CHECK-S,CHECK-S-OBJ %s

llvm/test/tools/llvm-mc/disassembler-options.test

@@ -0,0 +1,3 @@
+# RUN: not llvm-mc -M invalid /dev/null 2>&1 | FileCheck %s
+
+# CHECK: error: invalid disassembler option 'invalid'

llvm/tools/llvm-mc/llvm-mc.cpp

@@ -46,6 +46,9 @@ static mc::RegisterMCTargetOptionsFlags MOF;
 static cl::opt<std::string>
 InputFilename(cl::Positional, cl::desc("<input file>"), cl::init("-"));
 
+static cl::list<std::string>
+    DisassemblerOptions("M", cl::desc("Disassembler options"));
+
 static cl::opt<std::string> OutputFilename("o", cl::desc("Output filename"),
                                            cl::value_desc("filename"),
                                            cl::init("-"));
@@ -496,6 +499,12 @@ int main(int argc, char **argv) {
       return 1;
     }
 
+    for (StringRef Opt : DisassemblerOptions)
+      if (!IP->applyTargetSpecificCLOption(Opt)) {
+        WithColor::error() << "invalid disassembler option '" << Opt << "'\n";
+        return 1;
+      }
+
     // Set the display preference for hex vs. decimal immediates.
     IP->setPrintImmHex(PrintImmHex);