[ms-inline asm] Extend the MC AsmParser API to match MCInsts (but not emit).

This new API will be used by clang to parse ms-style inline asms.

One goal of this project is to use this style of inline asm for targets other
then x86.  Therefore, this API needs to be implemented for non-x86 targets at
some point in the future.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161624 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 32 insertions, 3 deletions

diff --git a/include/llvm/MC/MCTargetAsmParser.h b/include/llvm/MC/MCTargetAsmParser.h
index 4e3fd0d..929a204 100644
--- a/include/llvm/MC/MCTargetAsmParser.h
+++ b/include/llvm/MC/MCTargetAsmParser.h
@@ -79,6 +79,19 @@ public:
   /// \param DirectiveID - the identifier token of the directive.
   virtual bool ParseDirective(AsmToken DirectiveID) = 0;
 
+  /// MatchInstruction - Recognize a series of operands of a parsed instruction
+  /// as an actual MCInst.  This returns false on success and returns true on
+  /// failure to match.
+  ///
+  /// On failure, the target parser is responsible for emitting a diagnostic
+  /// explaining the match failure.
+  virtual bool
+  MatchInstruction(SMLoc IDLoc,
+                   SmallVectorImpl<MCParsedAsmOperand*> &Operands,
+                   SmallVectorImpl<MCInst> &MCInsts) {
+    return true;
+  }
+
   /// MatchAndEmitInstruction - Recognize a series of operands of a parsed
   /// instruction as an actual MCInst and emit it to the specified MCStreamer.
   /// This returns false on success and returns true on failure to match.
diff --git a/lib/Target/X86/AsmParser/X86AsmParser.cpp b/lib/Target/X86/AsmParser/X86AsmParser.cpp
index 95e83ec..fbbaa95 100644
--- a/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -65,6 +65,10 @@ private:
                                SmallVectorImpl<MCParsedAsmOperand*> &Operands,
                                MCStreamer &Out);
 
+  bool MatchInstruction(SMLoc IDLoc,
+                        SmallVectorImpl<MCParsedAsmOperand*> &Operands,
+                        SmallVectorImpl<MCInst> &MCInsts);
+
   /// isSrcOp - Returns true if operand is either (%rsi) or %ds:%(rsi)
   /// in 64bit mode or (%esi) or %es:(%esi) in 32bit mode.
   bool isSrcOp(X86Operand &Op);
@@ -1508,6 +1512,18 @@ bool X86AsmParser::
 MatchAndEmitInstruction(SMLoc IDLoc,
                         SmallVectorImpl<MCParsedAsmOperand*> &Operands,
                         MCStreamer &Out) {
+  SmallVector<MCInst, 2> Insts;
+  bool Error = MatchInstruction(IDLoc, Operands, Insts);
+  if (!Error)
+    for (unsigned i = 0, e = Insts.size(); i != e; ++i)
+      Out.EmitInstruction(Insts[i]);
+  return Error;
+}
+
+bool X86AsmParser::
+MatchInstruction(SMLoc IDLoc,
+                 SmallVectorImpl<MCParsedAsmOperand*> &Operands,
+                 SmallVectorImpl<MCInst> &MCInsts) {
   assert(!Operands.empty() && "Unexpect empty operand list!");
   X86Operand *Op = static_cast<X86Operand*>(Operands[0]);
   assert(Op->isToken() && "Leading operand should always be a mnemonic!");
@@ -1523,7 +1539,7 @@ MatchAndEmitInstruction(SMLoc IDLoc,
     MCInst Inst;
     Inst.setOpcode(X86::WAIT);
     Inst.setLoc(IDLoc);
-    Out.EmitInstruction(Inst);
+    MCInsts.push_back(Inst);
 
     const char *Repl =
       StringSwitch<const char*>(Op->getToken())
@@ -1557,7 +1573,7 @@ MatchAndEmitInstruction(SMLoc IDLoc,
       ;
 
     Inst.setLoc(IDLoc);
-    Out.EmitInstruction(Inst);
+    MCInsts.push_back(Inst);
     return false;
   case Match_MissingFeature:
     Error(IDLoc, "instruction requires a CPU feature not currently enabled");
@@ -1615,7 +1631,7 @@ MatchAndEmitInstruction(SMLoc IDLoc,
     (Match3 == Match_Success) + (Match4 == Match_Success);
   if (NumSuccessfulMatches == 1) {
     Inst.setLoc(IDLoc);
-    Out.EmitInstruction(Inst);
+    MCInsts.push_back(Inst);
     return false;
   }