Don't try keeping a 'LeadingEmptyMacroLoc' in NullStmt. This fails

in the face of buffering C++/ObjC method bodies.

llvm-svn: 138972

clang/include/clang/AST/Stmt.h

@@ -406,25 +406,25 @@ public:
 class NullStmt : public Stmt {
   SourceLocation SemiLoc;
 
-  /// \brief If the null statement was preceded by an empty macro this is
-  /// its instantiation source location, e.g:
+  /// \brief True if the null statement was preceded by an empty macro, e.g:
   /// @code
   ///   #define CALL(x)
   ///   CALL(0);
   /// @endcode
-  SourceLocation LeadingEmptyMacro;
+  bool HasLeadingEmptyMacro;
 public:
-  NullStmt(SourceLocation L, SourceLocation LeadingEmptyMacro =SourceLocation())
-    : Stmt(NullStmtClass), SemiLoc(L), LeadingEmptyMacro(LeadingEmptyMacro) {}
+  NullStmt(SourceLocation L, bool hasLeadingEmptyMacro = false)
+    : Stmt(NullStmtClass), SemiLoc(L),
+      HasLeadingEmptyMacro(hasLeadingEmptyMacro) {}
 
   /// \brief Build an empty null statement.
-  explicit NullStmt(EmptyShell Empty) : Stmt(NullStmtClass, Empty) { }
+  explicit NullStmt(EmptyShell Empty) : Stmt(NullStmtClass, Empty),
+      HasLeadingEmptyMacro(false) { }
 
   SourceLocation getSemiLoc() const { return SemiLoc; }
   void setSemiLoc(SourceLocation L) { SemiLoc = L; }
 
-  bool hasLeadingEmptyMacro() const { return LeadingEmptyMacro.isValid(); }
-  SourceLocation getLeadingEmptyMacroLoc() const { return LeadingEmptyMacro; }
+  bool hasLeadingEmptyMacro() const { return HasLeadingEmptyMacro; }
 
   SourceRange getSourceRange() const { return SourceRange(SemiLoc); }
 

clang/include/clang/Lex/Preprocessor.h

@@ -227,10 +227,6 @@ class Preprocessor : public llvm::RefCountedBase<Preprocessor> {
   /// previous macro value.
   llvm::DenseMap<IdentifierInfo*, std::vector<MacroInfo*> > PragmaPushMacroInfo;
 
-  /// \brief Expansion source location for the last macro that expanded
-  /// to no tokens.
-  SourceLocation LastEmptyMacroExpansionLoc;
-
   // Various statistics we track for performance analysis.
   unsigned NumDirectives, NumIncluded, NumDefined, NumUndefined, NumPragma;
   unsigned NumIf, NumElse, NumEndif;
@@ -399,12 +395,6 @@ public:
   macro_iterator macro_begin(bool IncludeExternalMacros = true) const;
   macro_iterator macro_end(bool IncludeExternalMacros = true) const;
 
-  /// \brief Expansion source location for the last macro that expanded
-  /// to no tokens.
-  SourceLocation getLastEmptyMacroExpansionLoc() const {
-    return LastEmptyMacroExpansionLoc;
-  }
-
   const std::string &getPredefines() const { return Predefines; }
   /// setPredefines - Set the predefines for this Preprocessor.  These
   /// predefines are automatically injected when parsing the main file.

clang/include/clang/Sema/Sema.h

@@ -2022,7 +2022,7 @@ public:
   StmtResult ActOnExprStmt(FullExprArg Expr);
 
   StmtResult ActOnNullStmt(SourceLocation SemiLoc,
-                        SourceLocation LeadingEmptyMacroLoc = SourceLocation());
+                           bool HasLeadingEmptyMacro = false);
   StmtResult ActOnCompoundStmt(SourceLocation L, SourceLocation R,
                                        MultiStmtArg Elts,
                                        bool isStmtExpr);

clang/lib/Lex/PPMacroExpansion.cpp

@@ -257,7 +257,6 @@ bool Preprocessor::HandleMacroExpandedIdentifier(Token &Identifier,
       if (HadLeadingSpace) Identifier.setFlag(Token::LeadingSpace);
     }
     Identifier.setFlag(Token::LeadingEmptyMacro);
-    LastEmptyMacroExpansionLoc = ExpandLoc;
     ++NumFastMacroExpanded;
     return false;
 

clang/lib/Parse/ParseStmt.cpp

@@ -224,10 +224,8 @@ Retry:
   case tok::l_brace:                // C99 6.8.2: compound-statement
     return ParseCompoundStatement(attrs);
   case tok::semi: {                 // C99 6.8.3p3: expression[opt] ';'
-    SourceLocation LeadingEmptyMacroLoc;
-    if (Tok.hasLeadingEmptyMacro())
-      LeadingEmptyMacroLoc = PP.getLastEmptyMacroExpansionLoc();
-    return Actions.ActOnNullStmt(ConsumeToken(), LeadingEmptyMacroLoc);
+    bool HasLeadingEmptyMacro = Tok.hasLeadingEmptyMacro();
+    return Actions.ActOnNullStmt(ConsumeToken(), HasLeadingEmptyMacro);
   }
 
   case tok::kw_if:                  // C99 6.8.4.1: if-statement

clang/lib/Sema/SemaStmt.cpp

@@ -47,8 +47,8 @@ StmtResult Sema::ActOnExprStmt(FullExprArg expr) {
 
 
 StmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc,
-                               SourceLocation LeadingEmptyMacroLoc) {
-  return Owned(new (Context) NullStmt(SemiLoc, LeadingEmptyMacroLoc));
+                               bool HasLeadingEmptyMacro) {
+  return Owned(new (Context) NullStmt(SemiLoc, HasLeadingEmptyMacro));
 }
 
 StmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg, SourceLocation StartLoc,

clang/lib/Serialization/ASTReaderStmt.cpp

@@ -109,7 +109,7 @@ void ASTStmtReader::VisitStmt(Stmt *S) {
 void ASTStmtReader::VisitNullStmt(NullStmt *S) {
   VisitStmt(S);
   S->setSemiLoc(ReadSourceLocation(Record, Idx));
-  S->LeadingEmptyMacro = ReadSourceLocation(Record, Idx);
+  S->HasLeadingEmptyMacro = Record[Idx++];
 }
 
 void ASTStmtReader::VisitCompoundStmt(CompoundStmt *S) {

clang/lib/Serialization/ASTWriterStmt.cpp

@@ -59,7 +59,7 @@ void ASTStmtWriter::VisitStmt(Stmt *S) {
 void ASTStmtWriter::VisitNullStmt(NullStmt *S) {
   VisitStmt(S);
   Writer.AddSourceLocation(S->getSemiLoc(), Record);
-  Writer.AddSourceLocation(S->LeadingEmptyMacro, Record);
+  Record.push_back(S->HasLeadingEmptyMacro);
   Code = serialization::STMT_NULL;
 }