Implement AsmParser for ARM unwind directives.

This commit implements the AsmParser for fnstart, fnend,
cantunwind, personality, handlerdata, pad, setfp, save, and
vsave directives.

This commit fixes some minor issue in the ARMELFStreamer:

* The switch back to corresponding section after the .fnend
  directive.

* Emit the unwind opcode while processing .fnend directive
  if there is no .handlerdata directive.

* Emit the unwind opcode to .ARM.extab while processing
  .handlerdata even if .personality directive does not exist.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181603 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 254 insertions, 1 deletions

diff --git a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index 1dd2953b29..4d3bf34d48 100644
--- a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -49,6 +49,20 @@ class ARMAsmParser : public MCTargetAsmParser {
   MCAsmParser &Parser;
   const MCRegisterInfo *MRI;
 
+  // Unwind directives state
+  SMLoc FnStartLoc;
+  SMLoc CantUnwindLoc;
+  SMLoc PersonalityLoc;
+  SMLoc HandlerDataLoc;
+  int FPReg;
+  void resetUnwindDirectiveParserState() {
+    FnStartLoc = SMLoc();
+    CantUnwindLoc = SMLoc();
+    PersonalityLoc = SMLoc();
+    HandlerDataLoc = SMLoc();
+    FPReg = -1;
+  }
+
   // Map of register aliases registers via the .req directive.
   StringMap<unsigned> RegisterReqs;
 
@@ -113,6 +127,14 @@ class ARMAsmParser : public MCTargetAsmParser {
   bool parseDirectiveUnreq(SMLoc L);
   bool parseDirectiveArch(SMLoc L);
   bool parseDirectiveEabiAttr(SMLoc L);
+  bool parseDirectiveFnStart(SMLoc L);
+  bool parseDirectiveFnEnd(SMLoc L);
+  bool parseDirectiveCantUnwind(SMLoc L);
+  bool parseDirectivePersonality(SMLoc L);
+  bool parseDirectiveHandlerData(SMLoc L);
+  bool parseDirectiveSetFP(SMLoc L);
+  bool parseDirectivePad(SMLoc L);
+  bool parseDirectiveRegSave(SMLoc L, bool IsVector);
 
   StringRef splitMnemonic(StringRef Mnemonic, unsigned &PredicationCode,
                           bool &CarrySetting, unsigned &ProcessorIMod,
@@ -242,7 +264,7 @@ public:
   };
 
   ARMAsmParser(MCSubtargetInfo &_STI, MCAsmParser &_Parser)
-    : MCTargetAsmParser(), STI(_STI), Parser(_Parser) {
+    : MCTargetAsmParser(), STI(_STI), Parser(_Parser), FPReg(-1) {
     MCAsmParserExtension::Initialize(_Parser);
 
     // Cache the MCRegisterInfo.
@@ -7658,6 +7680,24 @@ bool ARMAsmParser::ParseDirective(AsmToken DirectiveID) {
     return parseDirectiveArch(DirectiveID.getLoc());
   else if (IDVal == ".eabi_attribute")
     return parseDirectiveEabiAttr(DirectiveID.getLoc());
+  else if (IDVal == ".fnstart")
+    return parseDirectiveFnStart(DirectiveID.getLoc());
+  else if (IDVal == ".fnend")
+    return parseDirectiveFnEnd(DirectiveID.getLoc());
+  else if (IDVal == ".cantunwind")
+    return parseDirectiveCantUnwind(DirectiveID.getLoc());
+  else if (IDVal == ".personality")
+    return parseDirectivePersonality(DirectiveID.getLoc());
+  else if (IDVal == ".handlerdata")
+    return parseDirectiveHandlerData(DirectiveID.getLoc());
+  else if (IDVal == ".setfp")
+    return parseDirectiveSetFP(DirectiveID.getLoc());
+  else if (IDVal == ".pad")
+    return parseDirectivePad(DirectiveID.getLoc());
+  else if (IDVal == ".save")
+    return parseDirectiveRegSave(DirectiveID.getLoc(), false);
+  else if (IDVal == ".vsave")
+    return parseDirectiveRegSave(DirectiveID.getLoc(), true);
   return true;
 }
 
@@ -7858,6 +7898,219 @@ bool ARMAsmParser::parseDirectiveEabiAttr(SMLoc L) {
   return true;
 }
 
+/// parseDirectiveFnStart
+///  ::= .fnstart
+bool ARMAsmParser::parseDirectiveFnStart(SMLoc L) {
+  if (FnStartLoc.isValid()) {
+    Error(L, ".fnstart starts before the end of previous one");
+    Error(FnStartLoc, "previous .fnstart starts here");
+    return true;
+  }
+
+  FnStartLoc = L;
+  getParser().getStreamer().EmitFnStart();
+  return false;
+}
+
+/// parseDirectiveFnEnd
+///  ::= .fnend
+bool ARMAsmParser::parseDirectiveFnEnd(SMLoc L) {
+  // Check the ordering of unwind directives
+  if (!FnStartLoc.isValid())
+    return Error(L, ".fnstart must precede .fnend directive");
+
+  // Reset the unwind directives parser state
+  resetUnwindDirectiveParserState();
+
+  getParser().getStreamer().EmitFnEnd();
+  return false;
+}
+
+/// parseDirectiveCantUnwind
+///  ::= .cantunwind
+bool ARMAsmParser::parseDirectiveCantUnwind(SMLoc L) {
+  // Check the ordering of unwind directives
+  CantUnwindLoc = L;
+  if (!FnStartLoc.isValid())
+    return Error(L, ".fnstart must precede .cantunwind directive");
+  if (HandlerDataLoc.isValid()) {
+    Error(L, ".cantunwind can't be used with .handlerdata directive");
+    Error(HandlerDataLoc, ".handlerdata was specified here");
+    return true;
+  }
+  if (PersonalityLoc.isValid()) {
+    Error(L, ".cantunwind can't be used with .personality directive");
+    Error(PersonalityLoc, ".personality was specified here");
+    return true;
+  }
+
+  getParser().getStreamer().EmitCantUnwind();
+  return false;
+}
+
+/// parseDirectivePersonality
+///  ::= .personality name
+bool ARMAsmParser::parseDirectivePersonality(SMLoc L) {
+  // Check the ordering of unwind directives
+  PersonalityLoc = L;
+  if (!FnStartLoc.isValid())
+    return Error(L, ".fnstart must precede .personality directive");
+  if (CantUnwindLoc.isValid()) {
+    Error(L, ".personality can't be used with .cantunwind directive");
+    Error(CantUnwindLoc, ".cantunwind was specified here");
+    return true;
+  }
+  if (HandlerDataLoc.isValid()) {
+    Error(L, ".personality must precede .handlerdata directive");
+    Error(HandlerDataLoc, ".handlerdata was specified here");
+    return true;
+  }
+
+  // Parse the name of the personality routine
+  if (Parser.getTok().isNot(AsmToken::Identifier)) {
+    Parser.eatToEndOfStatement();
+    return Error(L, "unexpected input in .personality directive.");
+  }
+  StringRef Name(Parser.getTok().getIdentifier());
+  Parser.Lex();
+
+  MCSymbol *PR = getParser().getContext().GetOrCreateSymbol(Name);
+  getParser().getStreamer().EmitPersonality(PR);
+  return false;
+}
+
+/// parseDirectiveHandlerData
+///  ::= .handlerdata
+bool ARMAsmParser::parseDirectiveHandlerData(SMLoc L) {
+  // Check the ordering of unwind directives
+  HandlerDataLoc = L;
+  if (!FnStartLoc.isValid())
+    return Error(L, ".fnstart must precede .personality directive");
+  if (CantUnwindLoc.isValid()) {
+    Error(L, ".handlerdata can't be used with .cantunwind directive");
+    Error(CantUnwindLoc, ".cantunwind was specified here");
+    return true;
+  }
+
+  getParser().getStreamer().EmitHandlerData();
+  return false;
+}
+
+/// parseDirectiveSetFP
+///  ::= .setfp fpreg, spreg [, offset]
+bool ARMAsmParser::parseDirectiveSetFP(SMLoc L) {
+  // Check the ordering of unwind directives
+  if (!FnStartLoc.isValid())
+    return Error(L, ".fnstart must precede .setfp directive");
+  if (HandlerDataLoc.isValid())
+    return Error(L, ".setfp must precede .handlerdata directive");
+
+  // Parse fpreg
+  SMLoc NewFPRegLoc = Parser.getTok().getLoc();
+  int NewFPReg = tryParseRegister();
+  if (NewFPReg == -1)
+    return Error(NewFPRegLoc, "frame pointer register expected");
+
+  // Consume comma
+  if (!Parser.getTok().is(AsmToken::Comma))
+    return Error(Parser.getTok().getLoc(), "comma expected");
+  Parser.Lex(); // skip comma
+
+  // Parse spreg
+  SMLoc NewSPRegLoc = Parser.getTok().getLoc();
+  int NewSPReg = tryParseRegister();
+  if (NewSPReg == -1)
+    return Error(NewSPRegLoc, "stack pointer register expected");
+
+  if (NewSPReg != ARM::SP && NewSPReg != FPReg)
+    return Error(NewSPRegLoc,
+                 "register should be either $sp or the latest fp register");
+
+  // Update the frame pointer register
+  FPReg = NewFPReg;
+
+  // Parse offset
+  int64_t Offset = 0;
+  if (Parser.getTok().is(AsmToken::Comma)) {
+    Parser.Lex(); // skip comma
+
+    if (Parser.getTok().isNot(AsmToken::Hash) &&
+        Parser.getTok().isNot(AsmToken::Dollar)) {
+      return Error(Parser.getTok().getLoc(), "'#' expected");
+    }
+    Parser.Lex(); // skip hash token.
+
+    const MCExpr *OffsetExpr;
+    SMLoc ExLoc = Parser.getTok().getLoc();
+    SMLoc EndLoc;
+    if (getParser().parseExpression(OffsetExpr, EndLoc))
+      return Error(ExLoc, "malformed setfp offset");
+    const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(OffsetExpr);
+    if (!CE)
+      return Error(ExLoc, "setfp offset must be an immediate");
+
+    Offset = CE->getValue();
+  }
+
+  getParser().getStreamer().EmitSetFP(static_cast<unsigned>(NewFPReg),
+                                      static_cast<unsigned>(NewSPReg),
+                                      Offset);
+  return false;
+}
+
+/// parseDirective
+///  ::= .pad offset
+bool ARMAsmParser::parseDirectivePad(SMLoc L) {
+  // Check the ordering of unwind directives
+  if (!FnStartLoc.isValid())
+    return Error(L, ".fnstart must precede .pad directive");
+  if (HandlerDataLoc.isValid())
+    return Error(L, ".pad must precede .handlerdata directive");
+
+  // Parse the offset
+  if (Parser.getTok().isNot(AsmToken::Hash) &&
+      Parser.getTok().isNot(AsmToken::Dollar)) {
+    return Error(Parser.getTok().getLoc(), "'#' expected");
+  }
+  Parser.Lex(); // skip hash token.
+
+  const MCExpr *OffsetExpr;
+  SMLoc ExLoc = Parser.getTok().getLoc();
+  SMLoc EndLoc;
+  if (getParser().parseExpression(OffsetExpr, EndLoc))
+    return Error(ExLoc, "malformed pad offset");
+  const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(OffsetExpr);
+  if (!CE)
+    return Error(ExLoc, "pad offset must be an immediate");
+
+  getParser().getStreamer().EmitPad(CE->getValue());
+  return false;
+}
+
+/// parseDirectiveRegSave
+///  ::= .save  { registers }
+///  ::= .vsave { registers }
+bool ARMAsmParser::parseDirectiveRegSave(SMLoc L, bool IsVector) {
+  // Check the ordering of unwind directives
+  if (!FnStartLoc.isValid())
+    return Error(L, ".fnstart must precede .save or .vsave directives");
+  if (HandlerDataLoc.isValid())
+    return Error(L, ".save or .vsave must precede .handlerdata directive");
+
+  // Parse the register list
+  SmallVector<MCParsedAsmOperand*, 1> Operands;
+  if (parseRegisterList(Operands))
+    return true;
+  ARMOperand *Op = (ARMOperand*)Operands[0];
+  if (!IsVector && !Op->isRegList())
+    return Error(L, ".save expects GPR registers");
+  if (IsVector && !Op->isDPRRegList())
+    return Error(L, ".vsave expects DPR registers");
+
+  getParser().getStreamer().EmitRegSave(Op->getRegList(), IsVector);
+  return false;
+}
+
 /// Force static initialization.
 extern "C" void LLVMInitializeARMAsmParser() {
   RegisterMCAsmParser<ARMAsmParser> X(TheARMTarget);