Fix a couple of bugs, add some new cool stuff.

1. Fix a todo in Parser::ParseTag, to recover better.  On code like
   that in test/Sema/decl-invalid.c it causes us to return a single
   error instead of multiple.
2. Fix an error in Sema::ParseDeclarator, where it would crash if the
   declarator didn't have an identifier.  Instead, diagnose the problem.
3. Start adding infrastructure to track the range of locations covered
   by a declspec or declarator.  This is mostly implemented for declspec,
   but could be improved, it is missing for declarator.

Thanks to Neil for pointing out this crash.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@40482 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Sema/Sema.h b/Sema/Sema.h
new file mode 100644
index 0000000..e1857b7
--- /dev/null
+++ b/Sema/Sema.h
@@ -0,0 +1,383 @@
+//===--- Sema.h - Semantic Analysis & AST Building --------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the Sema class, which performs semantic analysis and
+// builds ASTs.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_AST_SEMA_H
+#define LLVM_CLANG_AST_SEMA_H
+
+#include "clang/Parse/Action.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallVector.h"
+#include <vector>
+#include <string>
+
+namespace clang {
+  class ASTContext;
+  class Preprocessor;
+  class Decl;
+  class Expr;
+  class VarDecl;
+  class ParmVarDecl;
+  class TypedefDecl;
+  class FunctionDecl;
+  class QualType;
+  class LangOptions;
+  class DeclaratorChunk;
+  class Token;
+  class IntegerLiteral;
+  class ArrayType;
+  class LabelStmt;
+  class SwitchStmt;
+  
+/// Sema - This implements semantic analysis and AST building for C.
+class Sema : public Action {
+  Preprocessor &PP;
+  
+  ASTContext &Context;
+  
+  /// CurFunctionDecl - If inside of a function body, this contains a pointer to
+  /// the function decl for the function being parsed.
+  FunctionDecl *CurFunctionDecl;
+  
+  /// LastInGroupList - This vector is populated when there are multiple
+  /// declarators in a single decl group (e.g. "int A, B, C").  In this case,
+  /// all but the last decl will be entered into this.  This is used by the
+  /// ASTStreamer.
+  std::vector<Decl*> &LastInGroupList;
+  
+  /// LabelMap - This is a mapping from label identifiers to the LabelStmt for
+  /// it (which acts like the label decl in some ways).  Forward referenced
+  /// labels have a LabelStmt created for them with a null location & SubStmt.
+  llvm::DenseMap<IdentifierInfo*, LabelStmt*> LabelMap;
+  
+  llvm::SmallVector<SwitchStmt*, 8> SwitchStack;
+public:
+  Sema(Preprocessor &pp, ASTContext &ctxt, std::vector<Decl*> &prevInGroup);
+  
+  const LangOptions &getLangOptions() const;
+  
+  /// The primitive diagnostic helpers - always returns true, which simplifies 
+  /// error handling (i.e. less code).
+  bool Diag(SourceLocation Loc, unsigned DiagID);
+  bool Diag(SourceLocation Loc, unsigned DiagID, const std::string &Msg);
+  bool Diag(SourceLocation Loc, unsigned DiagID, const std::string &Msg1,
+            const std::string &Msg2);
+
+  /// More expressive diagnostic helpers for expressions (say that 6 times:-)
+  bool Diag(SourceLocation Loc, unsigned DiagID, SourceRange R1);
+  bool Diag(SourceLocation Loc, unsigned DiagID, 
+            SourceRange R1, SourceRange R2);
+  bool Diag(SourceLocation Loc, unsigned DiagID, const std::string &Msg,
+            SourceRange R1);
+  bool Diag(SourceLocation Loc, unsigned DiagID, const std::string &Msg,
+            SourceRange R1, SourceRange R2);
+  bool Diag(SourceLocation Loc, unsigned DiagID, const std::string &Msg1, 
+            const std::string &Msg2, SourceRange R1);
+  bool Diag(SourceLocation Loc, unsigned DiagID, 
+            const std::string &Msg1, const std::string &Msg2, 
+            SourceRange R1, SourceRange R2);
+
+  //===--------------------------------------------------------------------===//
+  // Type Analysis / Processing: SemaType.cpp.
+  //
+  QualType GetTypeForDeclarator(Declarator &D, Scope *S);
+  
+  virtual TypeResult ParseTypeName(Scope *S, Declarator &D);
+  
+  virtual TypeResult ParseParamDeclaratorType(Scope *S, Declarator &D);
+private:
+  //===--------------------------------------------------------------------===//
+  // Symbol table / Decl tracking callbacks: SemaDecl.cpp.
+  //
+  virtual DeclTy *isTypeName(const IdentifierInfo &II, Scope *S) const;
+  virtual DeclTy *ParseDeclarator(Scope *S, Declarator &D, ExprTy *Init,
+                                  DeclTy *LastInGroup);
+  virtual DeclTy *FinalizeDeclaratorGroup(Scope *S, DeclTy *Group);
+
+  virtual DeclTy *ParseStartOfFunctionDef(Scope *S, Declarator &D);
+  virtual DeclTy *ParseFunctionDefBody(DeclTy *Decl, StmtTy *Body);
+  virtual void PopScope(SourceLocation Loc, Scope *S);
+
+  /// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with
+  /// no declarator (e.g. "struct foo;") is parsed.
+  virtual DeclTy *ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS);  
+  
+  virtual DeclTy *ParseTag(Scope *S, unsigned TagType, TagKind TK,
+                           SourceLocation KWLoc, IdentifierInfo *Name,
+                           SourceLocation NameLoc, AttributeList *Attr);
+  virtual DeclTy *ParseField(Scope *S, DeclTy *TagDecl,SourceLocation DeclStart,
+                             Declarator &D, ExprTy *BitfieldWidth);
+  virtual void ParseRecordBody(SourceLocation RecLoc, DeclTy *TagDecl,
+                               DeclTy **Fields, unsigned NumFields);
+  virtual DeclTy *ParseEnumConstant(Scope *S, DeclTy *EnumDecl,
+                                    DeclTy *LastEnumConstant,
+                                    SourceLocation IdLoc, IdentifierInfo *Id,
+                                    SourceLocation EqualLoc, ExprTy *Val);
+  virtual void ParseEnumBody(SourceLocation EnumLoc, DeclTy *EnumDecl,
+                             DeclTy **Elements, unsigned NumElements);
+private:
+  /// Subroutines of ParseDeclarator()...
+  TypedefDecl *ParseTypedefDecl(Scope *S, Declarator &D, Decl *LastDeclarator);
+  TypedefDecl *MergeTypeDefDecl(TypedefDecl *New, Decl *Old);
+  FunctionDecl *MergeFunctionDecl(FunctionDecl *New, Decl *Old);
+  VarDecl *MergeVarDecl(VarDecl *New, Decl *Old);
+  /// AddTopLevelDecl - called after the decl has been fully processed.
+  /// Allows for bookkeeping and post-processing of each declaration.
+  void AddTopLevelDecl(Decl *current, Decl *last);
+
+  /// More parsing and symbol table subroutines...
+  ParmVarDecl *ParseParamDeclarator(DeclaratorChunk &FI, unsigned ArgNo,
+                                    Scope *FnBodyScope);
+  Decl *LookupScopedDecl(IdentifierInfo *II, unsigned NSI, SourceLocation IdLoc,
+                         Scope *S);  
+  Decl *LazilyCreateBuiltin(IdentifierInfo *II, unsigned ID, Scope *S);
+  Decl *ImplicitlyDefineFunction(SourceLocation Loc, IdentifierInfo &II,
+                                 Scope *S);
+  // Decl attributes - this routine is the top level dispatcher. 
+  void HandleDeclAttributes(Decl *New, AttributeList *declspec_prefix,
+                            AttributeList *declarator_postfix);
+  void HandleDeclAttribute(Decl *New, AttributeList *rawAttr);
+                                
+  // HandleVectorTypeAttribute - this attribute is only applicable to 
+  // integral and float scalars, although arrays, pointers, and function
+  // return values are allowed in conjunction with this construct. Aggregates
+  // with this attribute are invalid, even if they are of the same size as a
+  // corresponding scalar.
+  // The raw attribute should contain precisely 1 argument, the vector size 
+  // for the variable, measured in bytes. If curType and rawAttr are well
+  // formed, this routine will return a new vector type.
+  QualType HandleVectorTypeAttribute(QualType curType, AttributeList *rawAttr);
+  QualType HandleOCUVectorTypeAttribute(QualType curType, AttributeList *rawAttr);
+  
+  //===--------------------------------------------------------------------===//
+  // Statement Parsing Callbacks: SemaStmt.cpp.
+public:
+  virtual StmtResult ParseExprStmt(ExprTy *Expr);
+  
+  virtual StmtResult ParseNullStmt(SourceLocation SemiLoc);
+  virtual StmtResult ParseCompoundStmt(SourceLocation L, SourceLocation R,
+                                       StmtTy **Elts, unsigned NumElts);
+  virtual StmtResult ParseDeclStmt(DeclTy *Decl);
+  virtual StmtResult ParseCaseStmt(SourceLocation CaseLoc, ExprTy *LHSVal,
+                                   SourceLocation DotDotDotLoc, ExprTy *RHSVal,
+                                   SourceLocation ColonLoc, StmtTy *SubStmt);
+  virtual StmtResult ParseDefaultStmt(SourceLocation DefaultLoc,
+                                      SourceLocation ColonLoc, StmtTy *SubStmt,
+                                      Scope *CurScope);
+  virtual StmtResult ParseLabelStmt(SourceLocation IdentLoc, IdentifierInfo *II,
+                                    SourceLocation ColonLoc, StmtTy *SubStmt);
+  virtual StmtResult ParseIfStmt(SourceLocation IfLoc, ExprTy *CondVal,
+                                 StmtTy *ThenVal, SourceLocation ElseLoc,
+                                 StmtTy *ElseVal);
+  virtual StmtResult StartSwitchStmt(ExprTy *Cond);
+  virtual StmtResult FinishSwitchStmt(SourceLocation SwitchLoc, StmtTy *Switch, 
+                                      ExprTy *Body);
+  virtual StmtResult ParseWhileStmt(SourceLocation WhileLoc, ExprTy *Cond,
+                                    StmtTy *Body);
+  virtual StmtResult ParseDoStmt(SourceLocation DoLoc, StmtTy *Body,
+                                 SourceLocation WhileLoc, ExprTy *Cond);
+  
+  virtual StmtResult ParseForStmt(SourceLocation ForLoc, 
+                                  SourceLocation LParenLoc, 
+                                  StmtTy *First, ExprTy *Second, ExprTy *Third,
+                                  SourceLocation RParenLoc, StmtTy *Body);
+  virtual StmtResult ParseGotoStmt(SourceLocation GotoLoc,
+                                   SourceLocation LabelLoc,
+                                   IdentifierInfo *LabelII);
+  virtual StmtResult ParseIndirectGotoStmt(SourceLocation GotoLoc,
+                                           SourceLocation StarLoc,
+                                           ExprTy *DestExp);
+  virtual StmtResult ParseContinueStmt(SourceLocation ContinueLoc,
+                                       Scope *CurScope);
+  virtual StmtResult ParseBreakStmt(SourceLocation GotoLoc, Scope *CurScope);
+  
+  virtual StmtResult ParseReturnStmt(SourceLocation ReturnLoc,
+                                     ExprTy *RetValExp);
+  
+  //===--------------------------------------------------------------------===//
+  // Expression Parsing Callbacks: SemaExpr.cpp.
+
+  // Primary Expressions.
+  virtual ExprResult ParseIdentifierExpr(Scope *S, SourceLocation Loc,
+                                         IdentifierInfo &II,
+                                         bool HasTrailingLParen);
+  virtual ExprResult ParsePreDefinedExpr(SourceLocation Loc,
+                                            tok::TokenKind Kind);
+  virtual ExprResult ParseNumericConstant(const Token &);
+  virtual ExprResult ParseCharacterConstant(const Token &);
+  virtual ExprResult ParseParenExpr(SourceLocation L, SourceLocation R,
+                                    ExprTy *Val);
+
+  /// ParseStringLiteral - The specified tokens were lexed as pasted string
+  /// fragments (e.g. "foo" "bar" L"baz").
+  virtual ExprResult ParseStringLiteral(const Token *Toks, unsigned NumToks);
+    
+  // Binary/Unary Operators.  'Tok' is the token for the operator.
+  virtual ExprResult ParseUnaryOp(SourceLocation OpLoc, tok::TokenKind Op,
+                                  ExprTy *Input);
+  virtual ExprResult 
+    ParseSizeOfAlignOfTypeExpr(SourceLocation OpLoc, bool isSizeof, 
+                               SourceLocation LParenLoc, TypeTy *Ty,
+                               SourceLocation RParenLoc);
+  
+  virtual ExprResult ParsePostfixUnaryOp(SourceLocation OpLoc, 
+                                         tok::TokenKind Kind, ExprTy *Input);
+  
+  virtual ExprResult ParseArraySubscriptExpr(ExprTy *Base, SourceLocation LLoc,
+                                             ExprTy *Idx, SourceLocation RLoc);
+  virtual ExprResult ParseMemberReferenceExpr(ExprTy *Base,SourceLocation OpLoc,
+                                              tok::TokenKind OpKind,
+                                              SourceLocation MemberLoc,
+                                              IdentifierInfo &Member);
+  
+  /// ParseCallExpr - Handle a call to Fn with the specified array of arguments.
+  /// This provides the location of the left/right parens and a list of comma
+  /// locations.
+  virtual ExprResult ParseCallExpr(ExprTy *Fn, SourceLocation LParenLoc,
+                                   ExprTy **Args, unsigned NumArgs,
+                                   SourceLocation *CommaLocs,
+                                   SourceLocation RParenLoc);
+  
+  virtual ExprResult ParseCastExpr(SourceLocation LParenLoc, TypeTy *Ty,
+                                   SourceLocation RParenLoc, ExprTy *Op);
+                                   
+  virtual ExprResult ParseCompoundLiteral(SourceLocation LParenLoc, TypeTy *Ty,
+                                          SourceLocation RParenLoc, ExprTy *Op);
+  
+  virtual ExprResult ParseInitList(SourceLocation LParenLoc, 
+                                   ExprTy **InitList, unsigned NumInit,
+                                   SourceLocation RParenLoc);
+                                   
+  virtual ExprResult ParseBinOp(SourceLocation TokLoc, tok::TokenKind Kind,
+                                ExprTy *LHS,ExprTy *RHS);
+  
+  /// ParseConditionalOp - Parse a ?: operation.  Note that 'LHS' may be null
+  /// in the case of a the GNU conditional expr extension.
+  virtual ExprResult ParseConditionalOp(SourceLocation QuestionLoc, 
+                                        SourceLocation ColonLoc,
+                                        ExprTy *Cond, ExprTy *LHS, ExprTy *RHS);
+
+  /// ParseAddrLabel - Parse the GNU address of label extension: "&&foo".
+  virtual ExprResult ParseAddrLabel(SourceLocation OpLoc, SourceLocation LabLoc,
+                                    IdentifierInfo *LabelII);
+  
+  virtual ExprResult ParseStmtExpr(SourceLocation LPLoc, StmtTy *SubStmt,
+                                   SourceLocation RPLoc); // "({..})"
+  
+  /// ParseCXXCasts - Parse {dynamic,static,reinterpret,const}_cast's.
+  virtual ExprResult ParseCXXCasts(SourceLocation OpLoc, tok::TokenKind Kind,
+                                   SourceLocation LAngleBracketLoc, TypeTy *Ty,
+                                   SourceLocation RAngleBracketLoc,
+                                   SourceLocation LParenLoc, ExprTy *E,
+                                   SourceLocation RParenLoc);
+
+  /// ParseCXXBoolLiteral - Parse {true,false} literals.
+  virtual ExprResult ParseCXXBoolLiteral(SourceLocation OpLoc,
+                                         tok::TokenKind Kind);
+private:
+  // UsualUnaryConversions - promotes integers (C99 6.3.1.1p2) and converts
+  // functions and arrays to their respective pointers (C99 6.3.2.1). 
+  void UsualUnaryConversions(Expr *&expr); 
+  
+  // DefaultFunctionArrayConversion - converts functions and arrays
+  // to their respective pointers (C99 6.3.2.1). 
+  void DefaultFunctionArrayConversion(Expr *&expr);
+  
+  // UsualArithmeticConversions - performs the UsualUnaryConversions on it's
+  // operands and then handles various conversions that are common to binary
+  // operators (C99 6.3.1.8). If both operands aren't arithmetic, this
+  // routine returns the first non-arithmetic type found. The client is 
+  // responsible for emitting appropriate error diagnostics.
+  void UsualArithmeticConversions(Expr *&lExpr, Expr *&rExpr);
+                                     
+  enum AssignmentCheckResult {
+    Compatible,
+    Incompatible,
+    PointerFromInt, 
+    IntFromPointer,
+    IncompatiblePointer,
+    CompatiblePointerDiscardsQualifiers
+  };
+  // CheckAssignmentConstraints - Perform type checking for assignment, 
+  // argument passing, variable initialization, and function return values. 
+  // This routine is only used by the following two methods. C99 6.5.16.
+  AssignmentCheckResult CheckAssignmentConstraints(QualType lhs, QualType rhs);
+  
+  // CheckSingleAssignmentConstraints - Currently used by ParseCallExpr,
+  // CheckAssignmentOperands, and ParseReturnStmt. Prior to type checking, 
+  // this routine performs the default function/array converions.
+  AssignmentCheckResult CheckSingleAssignmentConstraints(QualType lhs, 
+                                                         Expr *&rExpr);
+  // CheckCompoundAssignmentConstraints - Type check without performing any 
+  // conversions. For compound assignments, the "Check...Operands" methods 
+  // perform the necessary conversions. 
+  AssignmentCheckResult CheckCompoundAssignmentConstraints(QualType lhs, 
+                                                           QualType rhs);
+  
+  // Helper function for CheckAssignmentConstraints (C99 6.5.16.1p1)
+  AssignmentCheckResult CheckPointerTypesForAssignment(QualType lhsType, 
+                                                       QualType rhsType);
+  
+  /// the following "Check" methods will return a valid/converted QualType
+  /// or a null QualType (indicating an error diagnostic was issued).
+    
+  /// type checking binary operators (subroutines of ParseBinOp).
+  inline void InvalidOperands(SourceLocation l, Expr *&lex, Expr *&rex);
+  inline QualType CheckVectorOperands(SourceLocation l, Expr *&lex, Expr *&rex);
+  inline QualType CheckMultiplyDivideOperands( // C99 6.5.5
+    Expr *&lex, Expr *&rex, SourceLocation OpLoc); 
+  inline QualType CheckRemainderOperands( // C99 6.5.5
+    Expr *&lex, Expr *&rex, SourceLocation OpLoc); 
+  inline QualType CheckAdditionOperands( // C99 6.5.6
+    Expr *&lex, Expr *&rex, SourceLocation OpLoc);
+  inline QualType CheckSubtractionOperands( // C99 6.5.6
+    Expr *&lex, Expr *&rex, SourceLocation OpLoc);
+  inline QualType CheckShiftOperands( // C99 6.5.7
+    Expr *&lex, Expr *&rex, SourceLocation OpLoc);
+  inline QualType CheckRelationalOperands( // C99 6.5.8
+    Expr *&lex, Expr *&rex, SourceLocation OpLoc);
+  inline QualType CheckEqualityOperands( // C99 6.5.9
+    Expr *&lex, Expr *&rex, SourceLocation OpLoc); 
+  inline QualType CheckBitwiseOperands( // C99 6.5.[10...12]
+    Expr *&lex, Expr *&rex, SourceLocation OpLoc); 
+  inline QualType CheckLogicalOperands( // C99 6.5.[13,14]
+    Expr *&lex, Expr *&rex, SourceLocation OpLoc);
+  // CheckAssignmentOperands is used for both simple and compound assignment.
+  // For simple assignment, pass both expressions and a null converted type.
+  // For compound assignment, pass both expressions and the converted type.
+  inline QualType CheckAssignmentOperands( // C99 6.5.16.[1,2]
+    Expr *lex, Expr *rex, SourceLocation OpLoc, QualType convertedType);
+  inline QualType CheckCommaOperands( // C99 6.5.17
+    Expr *&lex, Expr *&rex, SourceLocation OpLoc);
+  inline QualType CheckConditionalOperands( // C99 6.5.15
+    Expr *&cond, Expr *&lhs, Expr *&rhs, SourceLocation questionLoc);
+  
+  /// type checking unary operators (subroutines of ParseUnaryOp).
+  /// C99 6.5.3.1, 6.5.3.2, 6.5.3.4
+  QualType CheckIncrementDecrementOperand(Expr *op, SourceLocation OpLoc);   
+  QualType CheckAddressOfOperand(Expr *op, SourceLocation OpLoc);
+  QualType CheckIndirectionOperand(Expr *op, SourceLocation OpLoc);
+  QualType CheckSizeOfAlignOfOperand(QualType type, SourceLocation loc, 
+                                     bool isSizeof);
+    
+  /// C99: 6.7.5p3: Used by ParseDeclarator/ParseField to make sure we have
+  /// a constant expression of type int with a value greater than zero.  If the
+  /// array has an incomplete type or a valid constant size, return false,
+  /// otherwise emit a diagnostic and return true.
+  bool VerifyConstantArrayType(const ArrayType *ary, SourceLocation loc); 
+};
+
+
+}  // end namespace clang
+
+#endif