1 files changed, 92 insertions, 4 deletions

diff --git a/include/clang/AST/StmtCXX.h b/include/clang/AST/StmtCXX.h
index 42dcf2b..a948722 100644
--- a/include/clang/AST/StmtCXX.h
+++ b/include/clang/AST/StmtCXX.h
@@ -15,6 +15,7 @@
 #define LLVM_CLANG_AST_STMTCXX_H
 
 #include "clang/AST/Stmt.h"
+#include "llvm/Support/Compiler.h"
 
 namespace clang {
 
@@ -37,7 +38,7 @@ public:
   CXXCatchStmt(EmptyShell Empty)
   : Stmt(CXXCatchStmtClass), ExceptionDecl(0), HandlerBlock(0) {}
 
-  SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const LLVM_READONLY {
     return SourceRange(CatchLoc, HandlerBlock->getLocEnd());
   }
 
@@ -83,7 +84,7 @@ public:
   static CXXTryStmt *Create(ASTContext &C, EmptyShell Empty,
                             unsigned numHandlers);
 
-  SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const LLVM_READONLY {
     return SourceRange(getTryLoc(), getEndLoc());
   }
 
@@ -148,7 +149,9 @@ public:
 
 
   DeclStmt *getRangeStmt() { return cast<DeclStmt>(SubExprs[RANGE]); }
-  DeclStmt *getBeginEndStmt() { return cast_or_null<DeclStmt>(SubExprs[BEGINEND]); }
+  DeclStmt *getBeginEndStmt() {
+    return cast_or_null<DeclStmt>(SubExprs[BEGINEND]);
+  }
   Expr *getCond() { return cast_or_null<Expr>(SubExprs[COND]); }
   Expr *getInc() { return cast_or_null<Expr>(SubExprs[INC]); }
   DeclStmt *getLoopVarStmt() { return cast<DeclStmt>(SubExprs[LOOPVAR]); }
@@ -187,7 +190,7 @@ public:
   SourceLocation getRParenLoc() const { return RParenLoc; }
   void setRParenLoc(SourceLocation Loc) { RParenLoc = Loc; }
 
-  SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const LLVM_READONLY {
     return SourceRange(ForLoc, SubExprs[BODY]->getLocEnd());
   }
   static bool classof(const Stmt *T) {
@@ -201,6 +204,91 @@ public:
   }
 };
 
+/// \brief Representation of a Microsoft __if_exists or __if_not_exists
+/// statement with a dependent name.
+///
+/// The __if_exists statement can be used to include a sequence of statements
+/// in the program only when a particular dependent name does not exist. For
+/// example:
+///
+/// \code
+/// template<typename T>
+/// void call_foo(T &t) {
+///   __if_exists (T::foo) {
+///     t.foo(); // okay: only called when T::foo exists.
+///   }
+/// }
+/// \endcode
+///
+/// Similarly, the __if_not_exists statement can be used to include the
+/// statements when a particular name does not exist.
+///
+/// Note that this statement only captures __if_exists and __if_not_exists
+/// statements whose name is dependent. All non-dependent cases are handled
+/// directly in the parser, so that they don't introduce a new scope. Clang
+/// introduces scopes in the dependent case to keep names inside the compound
+/// statement from leaking out into the surround statements, which would
+/// compromise the template instantiation model. This behavior differs from
+/// Visual C++ (which never introduces a scope), but is a fairly reasonable
+/// approximation of the VC++ behavior.
+class MSDependentExistsStmt : public Stmt {
+  SourceLocation KeywordLoc;
+  bool IsIfExists;
+  NestedNameSpecifierLoc QualifierLoc;
+  DeclarationNameInfo NameInfo;
+  Stmt *SubStmt;
+
+  friend class ASTReader;
+  friend class ASTStmtReader;
+
+public:
+  MSDependentExistsStmt(SourceLocation KeywordLoc, bool IsIfExists,
+                        NestedNameSpecifierLoc QualifierLoc,
+                        DeclarationNameInfo NameInfo,
+                        CompoundStmt *SubStmt)
+  : Stmt(MSDependentExistsStmtClass),
+    KeywordLoc(KeywordLoc), IsIfExists(IsIfExists),
+    QualifierLoc(QualifierLoc), NameInfo(NameInfo),
+    SubStmt(reinterpret_cast<Stmt *>(SubStmt)) { }
+
+  /// \brief Retrieve the location of the __if_exists or __if_not_exists
+  /// keyword.
+  SourceLocation getKeywordLoc() const { return KeywordLoc; }
+
+  /// \brief Determine whether this is an __if_exists statement.
+  bool isIfExists() const { return IsIfExists; }
+
+  /// \brief Determine whether this is an __if_exists statement.
+  bool isIfNotExists() const { return !IsIfExists; }
+
+  /// \brief Retrieve the nested-name-specifier that qualifies this name, if
+  /// any.
+  NestedNameSpecifierLoc getQualifierLoc() const { return QualifierLoc; }
+
+  /// \brief Retrieve the name of the entity we're testing for, along with
+  /// location information
+  DeclarationNameInfo getNameInfo() const { return NameInfo; }
+
+  /// \brief Retrieve the compound statement that will be included in the
+  /// program only if the existence of the symbol matches the initial keyword.
+  CompoundStmt *getSubStmt() const {
+    return reinterpret_cast<CompoundStmt *>(SubStmt);
+  }
+
+  SourceRange getSourceRange() const LLVM_READONLY {
+    return SourceRange(KeywordLoc, SubStmt->getLocEnd());
+  }
+
+  child_range children() {
+    return child_range(&SubStmt, &SubStmt+1);
+  }
+
+  static bool classof(const Stmt *T) {
+    return T->getStmtClass() == MSDependentExistsStmtClass;
+  }
+
+  static bool classof(MSDependentExistsStmt *) { return true; }
+};
 
 }  // end namespace clang