Merging r261669:
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r261669 | aaronballman | 2016-02-23 10:55:15 -0800 (Tue, 23 Feb 2016) | 1 line
Amends r252104 to evaluate the controlling expression in an unevaluated context. This eliminates false-positive diagnostics about null pointer dereferences (etc) in the controlling expression.
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llvm-svn: 261684
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index ebf7981..5a2eb60 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -1365,10 +1365,13 @@
// Decay and strip qualifiers for the controlling expression type, and handle
// placeholder type replacement. See committee discussion from WG14 DR423.
- ExprResult R = DefaultFunctionArrayLvalueConversion(ControllingExpr);
- if (R.isInvalid())
- return ExprError();
- ControllingExpr = R.get();
+ {
+ EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated);
+ ExprResult R = DefaultFunctionArrayLvalueConversion(ControllingExpr);
+ if (R.isInvalid())
+ return ExprError();
+ ControllingExpr = R.get();
+ }
// The controlling expression is an unevaluated operand, so side effects are
// likely unintended.
diff --git a/clang/test/Sema/generic-selection.c b/clang/test/Sema/generic-selection.c
index 0563ec0..5c02005 100644
--- a/clang/test/Sema/generic-selection.c
+++ b/clang/test/Sema/generic-selection.c
@@ -31,4 +31,8 @@
const int i = 12;
int a9[_Generic(i, int: 1, default: 2) == 1 ? 1 : -1];
+
+ // This is expected to not trigger any diagnostics because the controlling
+ // expression is not evaluated.
+ (void)_Generic(*(int *)0, int: 1);
}
