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/AST/StmtPrinter.cpp b/AST/StmtPrinter.cpp
new file mode 100644
index 0000000..2c4b21e
--- /dev/null
+++ b/AST/StmtPrinter.cpp
@@ -0,0 +1,520 @@
+//===--- StmtPrinter.cpp - Printing implementation for Stmt ASTs ----------===//
+//
+//                     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 implements the Stmt::dump/Stmt::print methods.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/AST/StmtVisitor.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/ExprCXX.h"
+#include "clang/Lex/IdentifierTable.h"
+#include "llvm/Support/Compiler.h"
+#include <iostream>
+#include <iomanip>
+using namespace clang;
+
+//===----------------------------------------------------------------------===//
+// StmtPrinter Visitor
+//===----------------------------------------------------------------------===//
+
+namespace  {
+  class VISIBILITY_HIDDEN StmtPrinter : public StmtVisitor {
+    std::ostream &OS;
+    unsigned IndentLevel;
+  public:
+    StmtPrinter(std::ostream &os) : OS(os), IndentLevel(0) {}
+    
+    void PrintStmt(Stmt *S, int SubIndent = 1) {
+      IndentLevel += SubIndent;
+      if (S && isa<Expr>(S)) {
+        // If this is an expr used in a stmt context, indent and newline it.
+        Indent();
+        S->visit(*this);
+        OS << ";\n";
+      } else if (S) {
+        S->visit(*this);
+      } else {
+        Indent() << "<<<NULL STATEMENT>>>\n";
+      }
+      IndentLevel -= SubIndent;
+    }
+    
+    void PrintRawCompoundStmt(CompoundStmt *S);
+    void PrintRawDecl(Decl *D);
+    void PrintRawIfStmt(IfStmt *If);
+    
+    void PrintExpr(Expr *E) {
+      if (E)
+        E->visit(*this);
+      else
+        OS << "<null expr>";
+    }
+    
+    std::ostream &Indent(int Delta = 0) const {
+      for (int i = 0, e = IndentLevel+Delta; i < e; ++i)
+        OS << "  ";
+      return OS;
+    }
+    
+    virtual void VisitStmt(Stmt *Node);
+#define STMT(N, CLASS, PARENT) \
+    virtual void Visit##CLASS(CLASS *Node);
+#include "clang/AST/StmtNodes.def"
+  };
+}
+
+//===----------------------------------------------------------------------===//
+//  Stmt printing methods.
+//===----------------------------------------------------------------------===//
+
+void StmtPrinter::VisitStmt(Stmt *Node) {
+  Indent() << "<<unknown stmt type>>\n";
+}
+
+/// PrintRawCompoundStmt - Print a compound stmt without indenting the {, and
+/// with no newline after the }.
+void StmtPrinter::PrintRawCompoundStmt(CompoundStmt *Node) {
+  OS << "{\n";
+  for (CompoundStmt::body_iterator I = Node->body_begin(), E = Node->body_end();
+       I != E; ++I)
+    PrintStmt(*I);
+  
+  Indent() << "}";
+}
+
+void StmtPrinter::PrintRawDecl(Decl *D) {
+  // FIXME: Need to complete/beautify this... this code simply shows the
+  // nodes are where they need to be.
+  if (TypedefDecl *localType = dyn_cast<TypedefDecl>(D)) {
+    OS << "typedef " << localType->getUnderlyingType().getAsString();
+    OS << " " << localType->getName();
+  } else if (ValueDecl *VD = dyn_cast<ValueDecl>(D)) {
+    // Emit storage class for vardecls.
+    if (VarDecl *V = dyn_cast<VarDecl>(VD)) {
+      switch (V->getStorageClass()) {
+        default: assert(0 && "Unknown storage class!");
+        case VarDecl::None:     break;
+        case VarDecl::Extern:   OS << "extern "; break;
+        case VarDecl::Static:   OS << "static "; break; 
+        case VarDecl::Auto:     OS << "auto "; break;
+        case VarDecl::Register: OS << "register "; break;
+      }
+    }
+    
+    std::string Name = VD->getName();
+    VD->getType().getAsStringInternal(Name);
+    OS << Name;
+    
+    // If this is a vardecl with an initializer, emit it.
+    if (VarDecl *V = dyn_cast<VarDecl>(VD)) {
+      if (V->getInit()) {
+        OS << " = ";
+        PrintExpr(V->getInit());
+      }
+    }
+  } else {
+    // FIXME: "struct x;"
+    assert(0 && "Unexpected decl");
+  }
+}
+
+
+void StmtPrinter::VisitNullStmt(NullStmt *Node) {
+  Indent() << ";\n";
+}
+
+void StmtPrinter::VisitDeclStmt(DeclStmt *Node) {
+  for (Decl *D = Node->getDecl(); D; D = D->getNextDeclarator()) {
+    Indent();
+    PrintRawDecl(D);
+    OS << ";\n";
+  }
+}
+
+void StmtPrinter::VisitCompoundStmt(CompoundStmt *Node) {
+  Indent();
+  PrintRawCompoundStmt(Node);
+  OS << "\n";
+}
+
+void StmtPrinter::VisitCaseStmt(CaseStmt *Node) {
+  Indent(-1) << "case ";
+  PrintExpr(Node->getLHS());
+  if (Node->getRHS()) {
+    OS << " ... ";
+    PrintExpr(Node->getRHS());
+  }
+  OS << ":\n";
+  
+  PrintStmt(Node->getSubStmt(), 0);
+}
+
+void StmtPrinter::VisitDefaultStmt(DefaultStmt *Node) {
+  Indent(-1) << "default:\n";
+  PrintStmt(Node->getSubStmt(), 0);
+}
+
+void StmtPrinter::VisitLabelStmt(LabelStmt *Node) {
+  Indent(-1) << Node->getName() << ":\n";
+  PrintStmt(Node->getSubStmt(), 0);
+}
+
+void StmtPrinter::PrintRawIfStmt(IfStmt *If) {
+  OS << "if ";
+  PrintExpr(If->getCond());
+  
+  if (CompoundStmt *CS = dyn_cast<CompoundStmt>(If->getThen())) {
+    OS << ' ';
+    PrintRawCompoundStmt(CS);
+    OS << (If->getElse() ? ' ' : '\n');
+  } else {
+    OS << '\n';
+    PrintStmt(If->getThen());
+    if (If->getElse()) Indent();
+  }
+  
+  if (Stmt *Else = If->getElse()) {
+    OS << "else";
+    
+    if (CompoundStmt *CS = dyn_cast<CompoundStmt>(Else)) {
+      OS << ' ';
+      PrintRawCompoundStmt(CS);
+      OS << '\n';
+    } else if (IfStmt *ElseIf = dyn_cast<IfStmt>(Else)) {
+      OS << ' ';
+      PrintRawIfStmt(ElseIf);
+    } else {
+      OS << '\n';
+      PrintStmt(If->getElse());
+    }
+  }
+}
+
+void StmtPrinter::VisitIfStmt(IfStmt *If) {
+  Indent();
+  PrintRawIfStmt(If);
+}
+
+void StmtPrinter::VisitSwitchStmt(SwitchStmt *Node) {
+  Indent() << "switch (";
+  PrintExpr(Node->getCond());
+  OS << ")";
+  
+  // Pretty print compoundstmt bodies (very common).
+  if (CompoundStmt *CS = dyn_cast<CompoundStmt>(Node->getBody())) {
+    OS << " ";
+    PrintRawCompoundStmt(CS);
+    OS << "\n";
+  } else {
+    OS << "\n";
+    PrintStmt(Node->getBody());
+  }
+}
+
+void StmtPrinter::VisitSwitchCase(SwitchCase*) {
+  assert(0 && "SwitchCase is an abstract class");
+}
+
+void StmtPrinter::VisitWhileStmt(WhileStmt *Node) {
+  Indent() << "while (";
+  PrintExpr(Node->getCond());
+  OS << ")\n";
+  PrintStmt(Node->getBody());
+}
+
+void StmtPrinter::VisitDoStmt(DoStmt *Node) {
+  Indent() << "do\n";
+  PrintStmt(Node->getBody());
+  Indent() << "while ";
+  PrintExpr(Node->getCond());
+  OS << ";\n";
+}
+
+void StmtPrinter::VisitForStmt(ForStmt *Node) {
+  Indent() << "for (";
+  if (Node->getInit()) {
+    if (DeclStmt *DS = dyn_cast<DeclStmt>(Node->getInit()))
+      PrintRawDecl(DS->getDecl());
+    else
+      PrintExpr(cast<Expr>(Node->getInit()));
+  }
+  OS << "; ";
+  if (Node->getCond())
+    PrintExpr(Node->getCond());
+  OS << "; ";
+  if (Node->getInc())
+    PrintExpr(Node->getInc());
+  OS << ")\n";
+  PrintStmt(Node->getBody());
+}
+
+void StmtPrinter::VisitGotoStmt(GotoStmt *Node) {
+  Indent() << "goto " << Node->getLabel()->getName() << ";\n";
+}
+
+void StmtPrinter::VisitIndirectGotoStmt(IndirectGotoStmt *Node) {
+  Indent() << "goto *";
+  PrintExpr(Node->getTarget());
+  OS << ";\n";
+}
+
+void StmtPrinter::VisitContinueStmt(ContinueStmt *Node) {
+  Indent() << "continue;\n";
+}
+
+void StmtPrinter::VisitBreakStmt(BreakStmt *Node) {
+  Indent() << "break;\n";
+}
+
+
+void StmtPrinter::VisitReturnStmt(ReturnStmt *Node) {
+  Indent() << "return";
+  if (Node->getRetValue()) {
+    OS << " ";
+    PrintExpr(Node->getRetValue());
+  }
+  OS << ";\n";
+}
+
+//===----------------------------------------------------------------------===//
+//  Expr printing methods.
+//===----------------------------------------------------------------------===//
+
+void StmtPrinter::VisitExpr(Expr *Node) {
+  OS << "<<unknown expr type>>";
+}
+
+void StmtPrinter::VisitDeclRefExpr(DeclRefExpr *Node) {
+  OS << Node->getDecl()->getName();
+}
+
+void StmtPrinter::VisitPreDefinedExpr(PreDefinedExpr *Node) {
+  switch (Node->getIdentType()) {
+    default:
+      assert(0 && "unknown case");
+    case PreDefinedExpr::Func:
+      OS << "__func__";
+      break;
+    case PreDefinedExpr::Function:
+      OS << "__FUNCTION__";
+      break;
+    case PreDefinedExpr::PrettyFunction:
+      OS << "__PRETTY_FUNCTION__";
+      break;
+  }
+}
+
+void StmtPrinter::VisitCharacterLiteral(CharacterLiteral *Node) {
+  // FIXME should print an L for wchar_t constants
+  unsigned value = Node->getValue();
+  switch (value) {
+  case '\\':
+    OS << "'\\\\'";
+    break;
+  case '\'':
+    OS << "'\\''";
+    break;
+  case '\a':
+    // TODO: K&R: the meaning of '\\a' is different in traditional C
+    OS << "'\\a'";
+    break;
+  case '\b':
+    OS << "'\\b'";
+    break;
+  // Nonstandard escape sequence.
+  /*case '\e':
+    OS << "'\\e'";
+    break;*/
+  case '\f':
+    OS << "'\\f'";
+    break;
+  case '\n':
+    OS << "'\\n'";
+    break;
+  case '\r':
+    OS << "'\\r'";
+    break;
+  case '\t':
+    OS << "'\\t'";
+    break;
+  case '\v':
+    OS << "'\\v'";
+    break;
+  default:
+    if (isprint(value) && value < 256) {
+      OS << "'" << (char)value << "'";
+    } else if (value < 256) {
+      OS << "'\\x" << std::hex << value << std::dec << "'";
+    } else {
+      // FIXME what to really do here?
+      OS << value;
+    }
+  }
+}
+
+void StmtPrinter::VisitIntegerLiteral(IntegerLiteral *Node) {
+  bool isSigned = Node->getType()->isSignedIntegerType();
+  OS << Node->getValue().toString(10, isSigned);
+  
+  // Emit suffixes.  Integer literals are always a builtin integer type.
+  switch (cast<BuiltinType>(Node->getType().getCanonicalType())->getKind()) {
+  default: assert(0 && "Unexpected type for integer literal!");
+  case BuiltinType::Int:       break; // no suffix.
+  case BuiltinType::UInt:      OS << 'U'; break;
+  case BuiltinType::Long:      OS << 'L'; break;
+  case BuiltinType::ULong:     OS << "UL"; break;
+  case BuiltinType::LongLong:  OS << "LL"; break;
+  case BuiltinType::ULongLong: OS << "ULL"; break;
+  }
+}
+void StmtPrinter::VisitFloatingLiteral(FloatingLiteral *Node) {
+  // FIXME: print value.
+  OS << "~1.0~";
+}
+void StmtPrinter::VisitStringLiteral(StringLiteral *Str) {
+  if (Str->isWide()) OS << 'L';
+  OS << '"';
+  
+  // FIXME: this doesn't print wstrings right.
+  for (unsigned i = 0, e = Str->getByteLength(); i != e; ++i) {
+    switch (Str->getStrData()[i]) {
+    default: OS << Str->getStrData()[i]; break;
+    // Handle some common ones to make dumps prettier.
+    case '\\': OS << "\\\\"; break;
+    case '"': OS << "\\\""; break;
+    case '\n': OS << "\\n"; break;
+    case '\t': OS << "\\t"; break;
+    case '\a': OS << "\\a"; break;
+    case '\b': OS << "\\b"; break;
+    }
+  }
+  OS << '"';
+}
+void StmtPrinter::VisitParenExpr(ParenExpr *Node) {
+  OS << "(";
+  PrintExpr(Node->getSubExpr());
+  OS << ")";
+}
+void StmtPrinter::VisitUnaryOperator(UnaryOperator *Node) {
+  if (!Node->isPostfix())
+    OS << UnaryOperator::getOpcodeStr(Node->getOpcode());
+  PrintExpr(Node->getSubExpr());
+  
+  if (Node->isPostfix())
+    OS << UnaryOperator::getOpcodeStr(Node->getOpcode());
+
+}
+void StmtPrinter::VisitSizeOfAlignOfTypeExpr(SizeOfAlignOfTypeExpr *Node) {
+  OS << (Node->isSizeOf() ? "sizeof(" : "__alignof(");
+  OS << Node->getArgumentType().getAsString() << ")";
+}
+void StmtPrinter::VisitArraySubscriptExpr(ArraySubscriptExpr *Node) {
+  PrintExpr(Node->getBase());
+  OS << "[";
+  PrintExpr(Node->getIdx());
+  OS << "]";
+}
+
+void StmtPrinter::VisitCallExpr(CallExpr *Call) {
+  PrintExpr(Call->getCallee());
+  OS << "(";
+  for (unsigned i = 0, e = Call->getNumArgs(); i != e; ++i) {
+    if (i) OS << ", ";
+    PrintExpr(Call->getArg(i));
+  }
+  OS << ")";
+}
+void StmtPrinter::VisitMemberExpr(MemberExpr *Node) {
+  PrintExpr(Node->getBase());
+  OS << (Node->isArrow() ? "->" : ".");
+  
+  FieldDecl *Field = Node->getMemberDecl();
+  assert(Field && "MemberExpr should alway reference a field!");
+  OS << Field->getName();
+}
+void StmtPrinter::VisitCastExpr(CastExpr *Node) {
+  OS << "(" << Node->getType().getAsString() << ")";
+  PrintExpr(Node->getSubExpr());
+}
+void StmtPrinter::VisitCompoundLiteralExpr(CompoundLiteralExpr *Node) {
+  OS << "(" << Node->getType().getAsString() << ")";
+  PrintExpr(Node->getInitializer());
+}
+void StmtPrinter::VisitImplicitCastExpr(ImplicitCastExpr *Node) {
+  // No need to print anything, simply forward to the sub expression.
+  PrintExpr(Node->getSubExpr());
+}
+void StmtPrinter::VisitBinaryOperator(BinaryOperator *Node) {
+  PrintExpr(Node->getLHS());
+  OS << " " << BinaryOperator::getOpcodeStr(Node->getOpcode()) << " ";
+  PrintExpr(Node->getRHS());
+}
+void StmtPrinter::VisitConditionalOperator(ConditionalOperator *Node) {
+  PrintExpr(Node->getCond());
+  OS << " ? ";
+  PrintExpr(Node->getLHS());
+  OS << " : ";
+  PrintExpr(Node->getRHS());
+}
+
+// GNU extensions.
+
+void StmtPrinter::VisitAddrLabel(AddrLabel *Node) {
+  OS << "&&" << Node->getLabel()->getName();
+}
+
+void StmtPrinter::VisitStmtExpr(StmtExpr *E) {
+  OS << "(";
+  PrintRawCompoundStmt(E->getSubStmt());
+  OS << ")";
+}
+
+
+// C++
+
+void StmtPrinter::VisitCXXCastExpr(CXXCastExpr *Node) {
+  switch (Node->getOpcode()) {
+    default:
+      assert(0 && "Not a C++ cast expression");
+      abort();
+    case CXXCastExpr::ConstCast:       OS << "const_cast<";       break;
+    case CXXCastExpr::DynamicCast:     OS << "dynamic_cast<";     break;
+    case CXXCastExpr::ReinterpretCast: OS << "reinterpret_cast<"; break;
+    case CXXCastExpr::StaticCast:      OS << "static_cast<";      break;
+  }
+  
+  OS << Node->getDestType().getAsString() << ">(";
+  PrintExpr(Node->getSubExpr());
+  OS << ")";
+}
+
+void StmtPrinter::VisitCXXBoolLiteralExpr(CXXBoolLiteralExpr *Node) {
+  OS << (Node->getValue() ? "true" : "false");
+}
+
+
+//===----------------------------------------------------------------------===//
+// Stmt method implementations
+//===----------------------------------------------------------------------===//
+
+void Stmt::dump() const {
+  // FIXME: eliminate use of <iostream>
+  print(std::cerr);
+}
+
+void Stmt::print(std::ostream &OS) const {
+  if (this == 0) {
+    OS << "<NULL>";
+    return;
+  }
+
+  StmtPrinter P(OS);
+  const_cast<Stmt*>(this)->visit(P);
+}