Add Sema::isNullPointerConstant which extwarns if necessary. Use it in Sema::CheckConditionalOperands.

llvm-svn: 60319

2 files changed, 25 insertions, 3 deletions

diff --git a/clang/lib/Sema/Sema.h b/clang/lib/Sema/Sema.h
index 7b69de5cc24..17af72ad9d8 100644
--- a/clang/lib/Sema/Sema.h
+++ b/clang/lib/Sema/Sema.h
@@ -1350,7 +1350,9 @@ public:
   /// VerifyIntegerConstantExpression - verifies that an expression is an ICE,
   /// and reports the appropriate diagnostics. Returns false on success.
   /// Can optionally return the value of the expression.
-  bool VerifyIntegerConstantExpression(const Expr* E, llvm::APSInt *Result = 0);
+  bool VerifyIntegerConstantExpression(const Expr*E, llvm::APSInt *Result = 0);
+
+  bool isNullPointerConstant(const Expr *E);
 
   //===--------------------------------------------------------------------===//
   // Extra semantic analysis beyond the C type system
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 0c17c75fceb..fa4b71b5bd7 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -1582,13 +1582,13 @@ inline QualType Sema::CheckConditionalOperands( // C99 6.5.15
   // the type of the other operand."
   if ((lexT->isPointerType() || lexT->isBlockPointerType() ||
        Context.isObjCObjectPointerType(lexT)) &&
-      rex->isNullPointerConstant(Context)) {
+      isNullPointerConstant(rex)) {
     ImpCastExprToType(rex, lexT); // promote the null to a pointer.
     return lexT;
   }
   if ((rexT->isPointerType() || rexT->isBlockPointerType() ||
        Context.isObjCObjectPointerType(rexT)) &&
-      lex->isNullPointerConstant(Context)) {
+      isNullPointerConstant(lex)) {
     ImpCastExprToType(lex, rexT); // promote the null to a pointer.
     return rexT;
   }
@@ -3706,3 +3706,23 @@ bool Sema::VerifyIntegerConstantExpression(const Expr* E, llvm::APSInt *Result)
     *Result = EvalResult.Val.getInt();
   return false;
 }
+
+bool Sema::isNullPointerConstant(const Expr *E)
+{
+  Expr::EvalResult EvalResult;
+  
+  if (!E->isNullPointerConstant(EvalResult, Context))
+    return false;
+  
+  if (EvalResult.Diag) {
+    Diag(E->getExprLoc(), diag::ext_null_pointer_expr_not_ice) << 
+      E->getSourceRange();
+
+    // Print the reason it's not a constant.
+    if (Diags.getDiagnosticLevel(diag::ext_null_pointer_expr_not_ice) != 
+        Diagnostic::Ignored)
+      Diag(EvalResult.DiagLoc, EvalResult.Diag);
+  }
+
+  return true;
+}