Move parsing of identifiers in MS-style inline assembly into

the actual parser and support arbitrary id-expressions.

We're actually basically set up to do arbitrary expressions here
if we wanted to.

Assembly operands permit things like A::x to be written regardless
of language mode, which forces us to embellish the evaluation
context logic somewhat.  The logic here under template instantiation
is incorrect;  we need to preserve the fact that an expression was
unevaluated.  Of course, template instantiation in general is fishy
here because we have no way of delaying semantic analysis in the
MC parser.  It's all just fishy.

I've also fixed the serialization of MS asm statements.

This commit depends on an LLVM commit.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180976 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 47 insertions, 285 deletions

diff --git a/lib/Sema/SemaStmtAsm.cpp b/lib/Sema/SemaStmtAsm.cpp
index 14ee67bfc3..fce95bebd1 100644
--- a/lib/Sema/SemaStmtAsm.cpp
+++ b/lib/Sema/SemaStmtAsm.cpp
@@ -22,18 +22,6 @@
 #include "clang/Sema/ScopeInfo.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/BitVector.h"
-#include "llvm/ADT/SmallString.h"
-#include "llvm/MC/MCAsmInfo.h"
-#include "llvm/MC/MCContext.h"
-#include "llvm/MC/MCObjectFileInfo.h"
-#include "llvm/MC/MCParser/MCAsmParser.h"
-#include "llvm/MC/MCRegisterInfo.h"
-#include "llvm/MC/MCStreamer.h"
-#include "llvm/MC/MCSubtargetInfo.h"
-#include "llvm/MC/MCTargetAsmParser.h"
-#include "llvm/Support/SourceMgr.h"
-#include "llvm/Support/TargetRegistry.h"
-#include "llvm/Support/TargetSelect.h"
 using namespace clang;
 using namespace sema;
 
@@ -381,180 +369,60 @@ StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
   return Owned(NS);
 }
 
-// getSpelling - Get the spelling of the AsmTok token.
-static StringRef getSpelling(Sema &SemaRef, Token AsmTok) {
-  StringRef Asm;
-  SmallString<512> TokenBuf;
-  TokenBuf.resize(512);
-  bool StringInvalid = false;
-  Asm = SemaRef.PP.getSpelling(AsmTok, TokenBuf, &StringInvalid);
-  assert (!StringInvalid && "Expected valid string!");
-  return Asm;
-}
+ExprResult Sema::LookupInlineAsmIdentifier(CXXScopeSpec &SS,
+                                           SourceLocation TemplateKWLoc,
+                                           UnqualifiedId &Id,
+                                           InlineAsmIdentifierInfo &Info,
+                                           bool IsUnevaluatedContext) {
+  Info.clear();
 
-// Build the inline assembly string.  Returns true on error.
-static bool buildMSAsmString(Sema &SemaRef,
-                             SourceLocation AsmLoc,
-                             ArrayRef<Token> AsmToks,
-                             SmallVectorImpl<unsigned> &TokOffsets,
-                             std::string &AsmString) {
-  assert (!AsmToks.empty() && "Didn't expect an empty AsmToks!");
-
-  SmallString<512> Asm;
-  for (unsigned i = 0, e = AsmToks.size(); i < e; ++i) {
-    bool isNewAsm = ((i == 0) ||
-                     AsmToks[i].isAtStartOfLine() ||
-                     AsmToks[i].is(tok::kw_asm));
-    if (isNewAsm) {
-      if (i != 0)
-        Asm += "\n\t";
-
-      if (AsmToks[i].is(tok::kw_asm)) {
-        i++; // Skip __asm
-        if (i == e) {
-          SemaRef.Diag(AsmLoc, diag::err_asm_empty);
-          return true;
-        }
+  if (IsUnevaluatedContext)
+    PushExpressionEvaluationContext(UnevaluatedAbstract,
+                                    ReuseLambdaContextDecl);
 
-      }
-    }
+  ExprResult Result = ActOnIdExpression(getCurScope(), SS, TemplateKWLoc, Id,
+                                        /*trailing lparen*/ false,
+                                        /*is & operand*/ false);
 
-    if (i && AsmToks[i].hasLeadingSpace() && !isNewAsm)
-      Asm += ' ';
+  if (IsUnevaluatedContext)
+    PopExpressionEvaluationContext();
 
-    StringRef Spelling = getSpelling(SemaRef, AsmToks[i]);
-    Asm += Spelling;
-    TokOffsets.push_back(Asm.size());
-  }
-  AsmString = Asm.str();
-  return false;
-}
+  if (!Result.isUsable()) return Result;
 
-namespace {
-
-class MCAsmParserSemaCallbackImpl : public llvm::MCAsmParserSemaCallback {
-  Sema &SemaRef;
-  SourceLocation AsmLoc;
-  ArrayRef<Token> AsmToks;
-  ArrayRef<unsigned> TokOffsets;
-
-public:
-  MCAsmParserSemaCallbackImpl(Sema &Ref, SourceLocation Loc,
-                              ArrayRef<Token> Toks,
-                              ArrayRef<unsigned> Offsets)
-    : SemaRef(Ref), AsmLoc(Loc), AsmToks(Toks), TokOffsets(Offsets) { }
-  ~MCAsmParserSemaCallbackImpl() {}
-
-  void *LookupInlineAsmIdentifier(StringRef &LineBuf,
-                                  InlineAsmIdentifierInfo &Info) {
-    SourceLocation Loc = SourceLocation::getFromPtrEncoding(LineBuf.data());
-    NamedDecl *OpDecl = SemaRef.LookupInlineAsmIdentifier(LineBuf, Loc, Info);
-    Info.OpDecl = static_cast<void *>(OpDecl);
-    return static_cast<void *>(OpDecl);
-  }
+  Result = CheckPlaceholderExpr(Result.take());
+  if (!Result.isUsable()) return Result;
 
-  bool LookupInlineAsmField(StringRef Base, StringRef Member,
-                            unsigned &Offset) {
-    return SemaRef.LookupInlineAsmField(Base, Member, Offset, AsmLoc);
-  }
+  QualType T = Result.get()->getType();
 
-  static void MSAsmDiagHandlerCallback(const llvm::SMDiagnostic &D,
-                                       void *Context) {
-    ((MCAsmParserSemaCallbackImpl*)Context)->MSAsmDiagHandler(D);
+  // For now, reject dependent types.
+  if (T->isDependentType()) {
+    Diag(Id.getLocStart(), diag::err_asm_incomplete_type) << T;
+    return ExprError();
   }
-  void MSAsmDiagHandler(const llvm::SMDiagnostic &D) {
-    // Compute an offset into the inline asm buffer.
-    // FIXME: This isn't right if .macro is involved (but hopefully, no
-    // real-world code does that).
-    const llvm::SourceMgr &LSM = *D.getSourceMgr();
-    const llvm::MemoryBuffer *LBuf =
-    LSM.getMemoryBuffer(LSM.FindBufferContainingLoc(D.getLoc()));
-    unsigned Offset = D.getLoc().getPointer()  - LBuf->getBufferStart();
-
-    // Figure out which token that offset points into.
-    const unsigned *OffsetPtr =
-        std::lower_bound(TokOffsets.begin(), TokOffsets.end(), Offset);
-    unsigned TokIndex = OffsetPtr - TokOffsets.begin();
-
-    // If we come up with an answer which seems sane, use it; otherwise,
-    // just point at the __asm keyword.
-    // FIXME: Assert the answer is sane once we handle .macro correctly.
-    SourceLocation Loc = AsmLoc;
-    if (TokIndex < AsmToks.size()) {
-      const Token *Tok = &AsmToks[TokIndex];
-      Loc = Tok->getLocation();
-      Loc = Loc.getLocWithOffset(Offset - (*OffsetPtr - Tok->getLength()));
-    }
-    SemaRef.Diag(Loc, diag::err_inline_ms_asm_parsing) << D.getMessage();
-  }
-};
 
-}
-
-// FIXME: Temporary hack until the frontend parser is hooked up to parse 
-// variables.
-static bool isIdentifierChar(char c) {
-  return isalnum(c) || c == '_' || c == '$' || c == '.' || c == '@';
-}
-
-static void lexIdentifier(const char *&CurPtr) {
-  while (isIdentifierChar(*CurPtr))
-    ++CurPtr;
-}
-
-static StringRef parseIdentifier(StringRef Identifier) {
-  const char *StartPtr = Identifier.data(), *EndPtr, *CurPtr;
-  EndPtr = StartPtr + Identifier.size();
-  CurPtr = StartPtr;
-  while(CurPtr <= EndPtr) {
-    if (isIdentifierChar(*CurPtr))
-      lexIdentifier(CurPtr);
-    else if (CurPtr[0] == ':' && CurPtr[1] == ':')
-      CurPtr += 2;
-    else
-      break;
+  // Any sort of function type is fine.
+  if (T->isFunctionType()) {
+    return Result;
   }
-  return StringRef(StartPtr, CurPtr - StartPtr);
-}
 
-NamedDecl *Sema::LookupInlineAsmIdentifier(StringRef &LineBuf, SourceLocation Loc,
-                                           InlineAsmIdentifierInfo &Info) {
-  Info.clear();
-  // FIXME: Temporary hack until the frontend parser is hooked up to parse 
-  // variables.
-  LineBuf = parseIdentifier(LineBuf);
-  LookupResult Result(*this, &Context.Idents.get(LineBuf), Loc,
-                      Sema::LookupOrdinaryName);
-
-  if (!LookupName(Result, getCurScope())) {
-    // If we don't find anything, return null; the AsmParser will assume
-    // it is a label of some sort.
-    return 0;
+  // Otherwise, it needs to be a complete type.
+  if (RequireCompleteExprType(Result.get(), diag::err_asm_incomplete_type)) {
+    return ExprError();
   }
 
-  if (!Result.isSingleResult()) {
-    // FIXME: Diagnose result.
-    return 0;
+  // Compute the type size (and array length if applicable?).
+  Info.Type = Info.Size = Context.getTypeSizeInChars(T).getQuantity();
+  if (T->isArrayType()) {
+    const ArrayType *ATy = Context.getAsArrayType(T);
+    Info.Type = Context.getTypeSizeInChars(ATy->getElementType()).getQuantity();
+    Info.Length = Info.Size / Info.Type;
   }
 
-  NamedDecl *FoundDecl = Result.getFoundDecl();
-  if (isa<FunctionDecl>(FoundDecl))
-    return FoundDecl;
-  if (VarDecl *Var = dyn_cast<VarDecl>(FoundDecl)) {
-    QualType Ty = Var->getType();
-    Info.Type = Info.Size = Context.getTypeSizeInChars(Ty).getQuantity();
-    if (Ty->isArrayType()) {
-      const ArrayType *ATy = Context.getAsArrayType(Ty);
-      Info.Type = Context.getTypeSizeInChars(ATy->getElementType()).getQuantity();
-      Info.Length = Info.Size / Info.Type;
-    }
+  // We can work with the expression as long as it's not an r-value.
+  if (!Result.get()->isRValue())
     Info.IsVarDecl = true;
-    return FoundDecl;
-  }
 
-  // FIXME: Handle other kinds of results? (FieldDecl, etc.)
-  // FIXME: Diagnose if we find something we can't handle, like a typedef.
-  return 0;
+  return Result;
 }
 
 bool Sema::LookupInlineAsmField(StringRef Base, StringRef Member,
@@ -601,124 +469,18 @@ bool Sema::LookupInlineAsmField(StringRef Base, StringRef Member,
 }
 
 StmtResult Sema::ActOnMSAsmStmt(SourceLocation AsmLoc, SourceLocation LBraceLoc,
-                                ArrayRef<Token> AsmToks,SourceLocation EndLoc) {
-  SmallVector<IdentifierInfo*, 4> Names;
-  SmallVector<StringRef, 4> ConstraintRefs;
-  SmallVector<Expr*, 4> Exprs;
-  SmallVector<StringRef, 4> ClobberRefs;
-
-  llvm::Triple TheTriple = Context.getTargetInfo().getTriple();
-  llvm::Triple::ArchType ArchTy = TheTriple.getArch();
-  bool UnsupportedArch = ArchTy != llvm::Triple::x86 &&
-    ArchTy != llvm::Triple::x86_64;
-  if (UnsupportedArch)
-    Diag(AsmLoc, diag::err_msasm_unsupported_arch) << TheTriple.getArchName();
-    
-  // Empty asm statements don't need to instantiate the AsmParser, etc.
-  if (UnsupportedArch || AsmToks.empty()) {
-    StringRef EmptyAsmStr;
-    MSAsmStmt *NS =
-      new (Context) MSAsmStmt(Context, AsmLoc, LBraceLoc, /*IsSimple*/ true,
-                              /*IsVolatile*/ true, AsmToks, /*NumOutputs*/ 0,
-                              /*NumInputs*/ 0, Names, ConstraintRefs, Exprs,
-                              EmptyAsmStr, ClobberRefs, EndLoc);
-    return Owned(NS);
-  }
-
-  std::string AsmString;
-  SmallVector<unsigned, 8> TokOffsets;
-  if (buildMSAsmString(*this, AsmLoc, AsmToks, TokOffsets, AsmString))
-    return StmtError();
-
-  // Get the target specific parser.
-  std::string Error;
-  const std::string &TT = TheTriple.getTriple();
-  const llvm::Target *TheTarget(llvm::TargetRegistry::lookupTarget(TT, Error));
-
-  OwningPtr<llvm::MCAsmInfo> MAI(TheTarget->createMCAsmInfo(TT));
-  OwningPtr<llvm::MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TT));
-  OwningPtr<llvm::MCObjectFileInfo> MOFI(new llvm::MCObjectFileInfo());
-  OwningPtr<llvm::MCSubtargetInfo>
-    STI(TheTarget->createMCSubtargetInfo(TT, "", ""));
-
-  llvm::SourceMgr SrcMgr;
-  llvm::MCContext Ctx(*MAI, *MRI, MOFI.get(), &SrcMgr);
-  llvm::MemoryBuffer *Buffer =
-    llvm::MemoryBuffer::getMemBuffer(AsmString, "<MS inline asm>");
-
-  // Tell SrcMgr about this buffer, which is what the parser will pick up.
-  SrcMgr.AddNewSourceBuffer(Buffer, llvm::SMLoc());
-
-  OwningPtr<llvm::MCStreamer> Str(createNullStreamer(Ctx));
-  OwningPtr<llvm::MCAsmParser>
-    Parser(createMCAsmParser(SrcMgr, Ctx, *Str.get(), *MAI));
-  OwningPtr<llvm::MCTargetAsmParser>
-    TargetParser(TheTarget->createMCAsmParser(*STI, *Parser));
-
-  // Get the instruction descriptor.
-  const llvm::MCInstrInfo *MII = TheTarget->createMCInstrInfo(); 
-  llvm::MCInstPrinter *IP =
-    TheTarget->createMCInstPrinter(1, *MAI, *MII, *MRI, *STI);
-
-  // Change to the Intel dialect.
-  Parser->setAssemblerDialect(1);
-  Parser->setTargetParser(*TargetParser.get());
-  Parser->setParsingInlineAsm(true);
-  TargetParser->setParsingInlineAsm(true);
-
-  MCAsmParserSemaCallbackImpl MCAPSI(*this, AsmLoc, AsmToks, TokOffsets);
-  TargetParser->setSemaCallback(&MCAPSI);
-  SrcMgr.setDiagHandler(MCAsmParserSemaCallbackImpl::MSAsmDiagHandlerCallback,
-                        &MCAPSI);
-
-  unsigned NumOutputs;
-  unsigned NumInputs;
-  std::string AsmStringIR;
-  SmallVector<std::pair<void *, bool>, 4> OpDecls;
-  SmallVector<std::string, 4> Constraints;
-  SmallVector<std::string, 4> Clobbers;
-  if (Parser->parseMSInlineAsm(AsmLoc.getPtrEncoding(), AsmStringIR,
-                               NumOutputs, NumInputs, OpDecls, Constraints,
-                               Clobbers, MII, IP, MCAPSI))
-    return StmtError();
-
-  // Build the vector of clobber StringRefs.
-  unsigned NumClobbers = Clobbers.size();
-  ClobberRefs.resize(NumClobbers);
-  for (unsigned i = 0; i != NumClobbers; ++i)
-    ClobberRefs[i] = StringRef(Clobbers[i]);
-
-  // Recast the void pointers and build the vector of constraint StringRefs.
-  unsigned NumExprs = NumOutputs + NumInputs;
-  Names.resize(NumExprs);
-  ConstraintRefs.resize(NumExprs);
-  Exprs.resize(NumExprs);
-  for (unsigned i = 0, e = NumExprs; i != e; ++i) {
-    NamedDecl *OpDecl = static_cast<NamedDecl *>(OpDecls[i].first);
-    if (!OpDecl)
-      return StmtError();
-
-    DeclarationNameInfo NameInfo(OpDecl->getDeclName(), AsmLoc);
-    ExprResult OpExpr = BuildDeclarationNameExpr(CXXScopeSpec(), NameInfo,
-                                                 OpDecl);
-    if (OpExpr.isInvalid())
-      return StmtError();
-
-    // Need address of variable.
-    if (OpDecls[i].second)
-      OpExpr = BuildUnaryOp(getCurScope(), AsmLoc, clang::UO_AddrOf,
-                            OpExpr.take());
-
-    Names[i] = OpDecl->getIdentifier();
-    ConstraintRefs[i] = StringRef(Constraints[i]);
-    Exprs[i] = OpExpr.take();
-  }
-
-  bool IsSimple = NumExprs > 0;
+                                ArrayRef<Token> AsmToks,
+                                StringRef AsmString,
+                                unsigned NumOutputs, unsigned NumInputs,
+                                ArrayRef<StringRef> Constraints,
+                                ArrayRef<StringRef> Clobbers,
+                                ArrayRef<Expr*> Exprs,
+                                SourceLocation EndLoc) {
+  bool IsSimple = (NumOutputs != 0 || NumInputs != 0);
   MSAsmStmt *NS =
     new (Context) MSAsmStmt(Context, AsmLoc, LBraceLoc, IsSimple,
                             /*IsVolatile*/ true, AsmToks, NumOutputs, NumInputs,
-                            Names, ConstraintRefs, Exprs, AsmStringIR,
-                            ClobberRefs, EndLoc);
+                            Constraints, Exprs, AsmString,
+                            Clobbers, EndLoc);
   return Owned(NS);
 }