Add Expr::getIntegerConstantExprValue helper method

 - For getting an APSInt from a known integer constant Expr.
 - TODO: Many users of Expr::isIntegerConstantExpr in codegen should
   probably be using this instead...


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@53974 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 0 deletions

diff --git a/include/clang/AST/Expr.h b/include/clang/AST/Expr.h
index 692a0ea85f..5569bb6c73 100644
--- a/include/clang/AST/Expr.h
+++ b/include/clang/AST/Expr.h
@@ -95,6 +95,16 @@ public:
   
   bool isNullPointerConstant(ASTContext &Ctx) const;
 
+  /// getIntegerConstantExprValue() - Return the value of an integer
+  /// constant expression. The expression must be a valid integer
+  /// constant expression as determined by isIntegerConstantExpr.
+  llvm::APSInt getIntegerConstantExprValue(ASTContext &Ctx) const {
+    llvm::APSInt X(32);
+    bool success = isIntegerConstantExpr(X, Ctx);
+    assert(success && "Illegal argument to getIntegerConstantExpr");
+    return X;
+  }
+
   /// isIntegerConstantExpr - Return true if this expression is a valid integer
   /// constant expression, and, if so, return its value in Result.  If not a
   /// valid i-c-e, return false and fill in Loc (if specified) with the location