Implement .cfi_escape. Patch by Brian Anderson!

llvm-svn: 147352

3 files changed, 40 insertions, 0 deletions

diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index 46ab65ffeb4..38c78cd6f11 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -987,6 +987,10 @@ void FrameEmitterImpl::EmitCFIInstruction(MCStreamer &Streamer,
     Streamer.EmitULEB128IntValue(Reg);
     return;
   }
+  case MCCFIInstruction::Escape:
+    if (VerboseAsm) Streamer.AddComment("Escape bytes");
+    Streamer.EmitBytes(Instr.getValues(), 0);
+    return;
   }
   llvm_unreachable("Unhandled case in switch");
 }
diff --git a/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp
index aac020d17e8..2ccea786c79 100644
--- a/llvm/lib/MC/MCParser/AsmParser.cpp
+++ b/llvm/lib/MC/MCParser/AsmParser.cpp
@@ -301,6 +301,8 @@ public:
       &GenericAsmParser::ParseDirectiveCFIRestoreState>(".cfi_restore_state");
     AddDirectiveHandler<
       &GenericAsmParser::ParseDirectiveCFISameValue>(".cfi_same_value");
+    AddDirectiveHandler<
+      &GenericAsmParser::ParseDirectiveCFIEscape>(".cfi_escape");
 
     // Macro directives.
     AddDirectiveHandler<&GenericAsmParser::ParseDirectiveMacrosOnOff>(
@@ -334,6 +336,7 @@ public:
   bool ParseDirectiveCFIRememberState(StringRef, SMLoc DirectiveLoc);
   bool ParseDirectiveCFIRestoreState(StringRef, SMLoc DirectiveLoc);
   bool ParseDirectiveCFISameValue(StringRef, SMLoc DirectiveLoc);
+  bool ParseDirectiveCFIEscape(StringRef, SMLoc DirectiveLoc);
 
   bool ParseDirectiveMacrosOnOff(StringRef, SMLoc DirectiveLoc);
   bool ParseDirectiveMacro(StringRef, SMLoc DirectiveLoc);
@@ -2812,6 +2815,30 @@ bool GenericAsmParser::ParseDirectiveCFISameValue(StringRef IDVal,
   return false;
 }
 
+/// ParseDirectiveCFIEscape
+/// ::= .cfi_escape expression[,...]
+bool GenericAsmParser::ParseDirectiveCFIEscape(StringRef IDVal,
+					       SMLoc DirectiveLoc) {
+  std::string Values;
+  int64_t CurrValue;
+  if (getParser().ParseAbsoluteExpression(CurrValue))
+    return true;
+
+  Values.push_back((uint8_t)CurrValue);
+
+  while (getLexer().is(AsmToken::Comma)) {
+    Lex();
+
+    if (getParser().ParseAbsoluteExpression(CurrValue))
+      return true;
+
+    Values.push_back((uint8_t)CurrValue);
+  }
+
+  getStreamer().EmitCFIEscape(Values);
+  return false;
+}
+
 /// ParseDirectiveMacrosOnOff
 /// ::= .macros_on
 /// ::= .macros_off
diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index 74c3e39e3b9..23d8c1cd9a4 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -408,6 +408,15 @@ void MCStreamer::EmitCFISameValue(int64_t Register) {
   CurFrame->Instructions.push_back(Instruction);
 }
 
+void MCStreamer::EmitCFIEscape(StringRef Values) {
+  EnsureValidFrame();
+  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
+  MCSymbol *Label = getContext().CreateTempSymbol();
+  EmitLabel(Label);
+  MCCFIInstruction Instruction(MCCFIInstruction::Escape, Label, Values);
+  CurFrame->Instructions.push_back(Instruction);
+}
+
 void MCStreamer::setCurrentW64UnwindInfo(MCWin64EHUnwindInfo *Frame) {
   W64UnwindInfos.push_back(Frame);
   CurrentW64UnwindInfo = W64UnwindInfos.back();