path: root/lib/Parse/ParseExprCXX.cpp

//===--- ParseExprCXX.cpp - C++ Expression Parsing ------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the Expression parsing implementation for C++.
//
//===----------------------------------------------------------------------===//

#include "clang/Parse/ParseDiagnostic.h"
#include "clang/Parse/Parser.h"
#include "clang/Parse/DeclSpec.h"
using namespace clang;

/// \brief Parse global scope or nested-name-specifier if present.
///
/// Parses a C++ global scope specifier ('::') or nested-name-specifier (which
/// may be preceded by '::'). Note that this routine will not parse ::new or
/// ::delete; it will just leave them in the token stream.
///
///       '::'[opt] nested-name-specifier
///       '::'
///
///       nested-name-specifier:
///         type-name '::'
///         namespace-name '::'
///         nested-name-specifier identifier '::'
///         nested-name-specifier 'template'[opt] simple-template-id '::'
///
///
/// \param SS the scope specifier that will be set to the parsed
/// nested-name-specifier (or empty)
///
/// \param ObjectType if this nested-name-specifier is being parsed following
/// the "." or "->" of a member access expression, this parameter provides the
/// type of the object whose members are being accessed.
///
/// \param EnteringContext whether we will be entering into the context of
/// the nested-name-specifier after parsing it.
///
/// \returns true if a scope specifier was parsed.
bool Parser::ParseOptionalCXXScopeSpecifier(CXXScopeSpec &SS,
                                            Action::TypeTy *ObjectType,
                                            bool EnteringContext) {
  assert(getLang().CPlusPlus &&
         "Call sites of this function should be guarded by checking for C++");

  if (Tok.is(tok::annot_cxxscope)) {
    SS.setScopeRep(Tok.getAnnotationValue());
    SS.setRange(Tok.getAnnotationRange());
    ConsumeToken();
    return true;
  }

  bool HasScopeSpecifier = false;

  if (Tok.is(tok::coloncolon)) {
    // ::new and ::delete aren't nested-name-specifiers.
    tok::TokenKind NextKind = NextToken().getKind();
    if (NextKind == tok::kw_new || NextKind == tok::kw_delete)
      return false;

    // '::' - Global scope qualifier.
    SourceLocation CCLoc = ConsumeToken();
    SS.setBeginLoc(CCLoc);
    SS.setScopeRep(Actions.ActOnCXXGlobalScopeSpecifier(CurScope, CCLoc));
    SS.setEndLoc(CCLoc);
    HasScopeSpecifier = true;
  }

  while (true) {
    if (HasScopeSpecifier) {
      // C++ [basic.lookup.classref]p5:
      //   If the qualified-id has the form
      //
      //       ::class-name-or-namespace-name::...
      //
      //   the class-name-or-namespace-name is looked up in global scope as a
      //   class-name or namespace-name.
      //
      // To implement this, we clear out the object type as soon as we've
      // seen a leading '::' or part of a nested-name-specifier.
      ObjectType = 0;
      
      if (Tok.is(tok::code_completion)) {
        // Code completion for a nested-name-specifier, where the code
        // code completion token follows the '::'.
        Actions.CodeCompleteQualifiedId(CurScope, SS, EnteringContext);
        ConsumeToken();
      }
    }

    // nested-name-specifier:
    //   nested-name-specifier 'template'[opt] simple-template-id '::'

    // Parse the optional 'template' keyword, then make sure we have
    // 'identifier <' after it.
    if (Tok.is(tok::kw_template)) {
      // If we don't have a scope specifier or an object type, this isn't a
      // nested-name-specifier, since they aren't allowed to start with
      // 'template'.
      if (!HasScopeSpecifier && !ObjectType)