r213267 - Handle __assume in the VoidExprEvaluator

[Hal Finkel]

Author: hfinkel
Date: Thu Jul 17 09:49:58 2014
New Revision: 213267

URL: http://llvm.org/viewvc/llvm-project?rev=213267&view=rev
Log:
Handle __assume in the VoidExprEvaluator

This is a follow-up to an IRC conversation with Richard last night; __assume
does not evaluate its argument, and so the argument should not contribute to
whether (__assume(e), constant) can be used where a constant is required.

Modified:
    cfe/trunk/lib/AST/ExprConstant.cpp
    cfe/trunk/test/Sema/builtin-assume.c

Modified: cfe/trunk/lib/AST/ExprConstant.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=213267&r1=213266&r2=213267&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)
+++ cfe/trunk/lib/AST/ExprConstant.cpp Thu Jul 17 09:49:58 2014
@@ -7955,6 +7955,16 @@ public:
       return true;
     }
   }
+
+  bool VisitCallExpr(const CallExpr *E) {
+    switch (E->getBuiltinCallee()) {
+    default:
+      return ExprEvaluatorBaseTy::VisitCallExpr(E);
+    case Builtin::BI__assume:
+      // The argument is not evaluated!
+      return true;
+    }
+  }
 };
 } // end anonymous namespace
 

Modified: cfe/trunk/test/Sema/builtin-assume.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/builtin-assume.c?rev=213267&r1=213266&r2=213267&view=diff
==============================================================================
--- cfe/trunk/test/Sema/builtin-assume.c (original)
+++ cfe/trunk/test/Sema/builtin-assume.c Thu Jul 17 09:49:58 2014
@@ -3,6 +3,9 @@
 int foo(int *a, int i) {
   __assume(i != 4);
   __assume(++i > 2); //expected-warning {{the argument to __assume has side effects that will be discarded}}
+
+  int test = sizeof(struct{char qq[(__assume(i != 5), 7)];});
+
   return a[i];
 }