Bug #:

Submitted by:
Reviewed by:
Implement some FIXME's that stand in the way of fully typechecking "for"
statements. This involved:

- Adding a DeclStmt AST node (with statement visitor). The DeclStmt
printer is preliminary.
- Added a ParseDeclStmt action, called from Parser::ParseForStatement()
and Parser::ParseStatementOrDeclaration(). DID NOT add to
Parser::ParseIdentifierStatement()...probably could have, however didn't
really understand the context of this rule (will speak with Chris).
- Removed ParseExprStmt (and it's clients)...it was vestigial.

llvm-svn: 39518

clang/AST/StmtPrinter.cpp

@@ -109,6 +109,18 @@ void StmtPrinter::VisitNullStmt(NullStmt *Node) {
   Indent() << ";\n";
 }
 
+void StmtPrinter::VisitDeclStmt(DeclStmt *Node) {
+  // FIXME: Need to complete/beautify this...this code simply shows the
+  // nodes are where they need to be.
+  if (BlockVarDecl *localVar = dyn_cast<BlockVarDecl>(Node->getDecl())) {
+    Indent() << localVar->getType().getAsString();
+    OS << " " << localVar->getName() << ";\n";
+  } else if (TypedefDecl *localType = dyn_cast<TypedefDecl>(Node->getDecl())) {
+    Indent() << "typedef " << localType->getUnderlyingType().getAsString();
+    OS << " " << localType->getName() << ";\n";
+  }
+}
+
 void StmtPrinter::VisitCompoundStmt(CompoundStmt *Node) {
   Indent();
   PrintRawCompoundStmt(Node);

clang/Parse/ParseStmt.cpp

@@ -86,9 +86,7 @@ Parser::StmtResult Parser::ParseStatementOrDeclaration(bool OnlyStatement) {
   default:
     if (!OnlyStatement && isDeclarationSpecifier()) {
       // TODO: warn/disable if declaration is in the middle of a block and !C99.
-      ParseDeclaration(Declarator::BlockContext);
-      // FIXME: Make a DeclStmt node!
-      return 0;
+      return Actions.ParseDeclStmt(ParseDeclaration(Declarator::BlockContext));
     } else if (Tok.getKind() == tok::r_brace) {
       Diag(Tok, diag::err_expected_statement);
       return true;
@@ -102,7 +100,7 @@ Parser::StmtResult Parser::ParseStatementOrDeclaration(bool OnlyStatement) {
         SkipUntil(tok::semi);
         return true;
       } else {
-        return Actions.ParseExprStmt(Res.Val);
+        return Res.Val;
       }
     }
     
@@ -250,7 +248,7 @@ Parser::StmtResult Parser::ParseIdentifierStatement(bool OnlyStatement) {
     return true;
   } else {
     ConsumeToken();
-    return Actions.ParseExprStmt(Res.Val);
+    return Res.Val;
   }
 }
 
@@ -586,19 +584,12 @@ Parser::StmtResult Parser::ParseForStatement() {
     // Parse declaration, which eats the ';'.
     if (!getLang().C99)   // Use of C99-style for loops in C90 mode?
       Diag(Tok, diag::ext_c99_variable_decl_in_for_loop);
-    ParseDeclaration(Declarator::ForContext);
-    // FIXME: Turn declaration into a stmt ast node.
-    FirstPart = 0;
+    DeclTy *aBlockVarDecl = ParseDeclaration(Declarator::ForContext);
+    StmtResult stmtResult = Actions.ParseDeclStmt(aBlockVarDecl);
+    FirstPart = stmtResult.isInvalid ? 0 : stmtResult.Val;
   } else {
     Value = ParseExpression();
 
-    // Turn the expression into a stmt.
-    if (!Value.isInvalid) {
-      StmtResult R = Actions.ParseExprStmt(Value.Val);
-      if (!R.isInvalid)
-        FirstPart = R.Val;
-    }
-
     if (Tok.getKind() == tok::semi) {
       ConsumeToken();
     } else {

clang/Sema/Sema.h

@@ -143,9 +143,7 @@ public:
   virtual StmtResult ParseNullStmt(SourceLocation SemiLoc);
   virtual StmtResult ParseCompoundStmt(SourceLocation L, SourceLocation R,
                                        StmtTy **Elts, unsigned NumElts);
-  virtual StmtResult ParseExprStmt(ExprTy *Expr) {
-    return Expr; // Exprs are Stmts.
-  }
+  virtual StmtResult ParseDeclStmt(DeclTy *Decl);
   virtual StmtResult ParseCaseStmt(SourceLocation CaseLoc, ExprTy *LHSVal,
                                    SourceLocation DotDotDotLoc, ExprTy *RHSVal,
                                    SourceLocation ColonLoc, StmtTy *SubStmt);

clang/Sema/SemaStmt.cpp

@@ -25,6 +25,9 @@ Sema::StmtResult Sema::ParseNullStmt(SourceLocation SemiLoc) {
   return new NullStmt(SemiLoc);
 }
 
+Sema::StmtResult Sema::ParseDeclStmt(DeclTy *decl) {
+  return decl ? new DeclStmt(static_cast<Decl *>(decl)) : 0;
+}
 
 Action::StmtResult 
 Sema::ParseCompoundStmt(SourceLocation L, SourceLocation R,

clang/include/clang/AST/Stmt.h

@@ -21,6 +21,7 @@
 namespace llvm {
 namespace clang {
   class Expr;
+  class Decl;
   class IdentifierInfo;
   class StmtVisitor;
   
@@ -62,6 +63,25 @@ public:
   static bool classof(const Stmt *) { return true; }
 };
 
+/// DeclStmt - Adaptor class for mixing declarations with statements and
+/// expressions. For example, CompoundStmt mixes statements, expressions
+/// and declarations (variables, types). Another example is ForStmt, where 
+/// the first statement can be an expression or a declaration.
+///
+class DeclStmt : public Stmt {
+  Decl *BlockVarOrTypedefDecl;
+public:
+  DeclStmt(Decl *D) : Stmt(DeclStmtClass), BlockVarOrTypedefDecl(D) {}
+  
+  Decl *getDecl() const { return BlockVarOrTypedefDecl; }
+  
+  virtual void visit(StmtVisitor &Visitor);
+  static bool classof(const Stmt *T) { 
+    return T->getStmtClass() == DeclStmtClass; 
+  }
+  static bool classof(const DeclStmt *) { return true; }
+};
+
 /// NullStmt - This is the null statement ";": C99 6.8.3p3.
 ///
 class NullStmt : public Stmt {

clang/include/clang/AST/StmtNodes.def

@@ -38,7 +38,8 @@ STMT(12, IndirectGotoStmt, Stmt)
 STMT(13, ContinueStmt    , Stmt)
 STMT(14, BreakStmt       , Stmt)
 STMT(15, ReturnStmt      , Stmt)
-LAST_STMT(15)
+STMT(16, DeclStmt        , Stmt)
+LAST_STMT(16)
 
 FIRST_EXPR(32)
 // Expressions.

clang/include/clang/Parse/Action.h

@@ -180,7 +180,7 @@ public:
                                        StmtTy **Elts, unsigned NumElts) {
     return 0;
   }
-  virtual StmtResult ParseExprStmt(ExprTy *Expr) {
+  virtual StmtResult ParseDeclStmt(DeclTy *Decl) {
     return 0;
   }