[PATCH] D13408: Skip NonNull sema checks in unevaluated contexts.

[Eric Fiselier via cfe-commits]

EricWF created this revision.
EricWF added reviewers: rsmith, majnemer.
EricWF added subscribers: cfe-commits, mclow.lists.

Currently when a function annotated with __attribute__((nonnull)) is called in an unevaluated context with a null argument a -Wnonnull warning is emitted. 
This warning seems like a false positive unless the call expression is potentially evaluated. 

Disclaimer: I have no idea what I'm doing.

http://reviews.llvm.org/D13408

Files:
  lib/Sema/SemaChecking.cpp
  test/Sema/non-null-warning.c

Index: test/Sema/non-null-warning.c
===================================================================
--- test/Sema/non-null-warning.c
+++ test/Sema/non-null-warning.c
@@ -39,4 +39,5 @@
 
 int main () {
   foo(0); // expected-warning {{null passed to a callee that requires a non-null argument}}
+  (void)sizeof(foo(0)); // expect no warning when in an unevaluated context.
 }
Index: lib/Sema/SemaChecking.cpp
===================================================================
--- lib/Sema/SemaChecking.cpp
+++ lib/Sema/SemaChecking.cpp
@@ -1348,7 +1348,8 @@
   }
 
   if (FDecl || Proto) {
-    CheckNonNullArguments(*this, FDecl, Proto, Args, Loc);
+    if (!isUnevaluatedContext())
+      CheckNonNullArguments(*this, FDecl, Proto, Args, Loc);
 
     // Type safety checking.
     if (FDecl) {


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