Add support for warning on general null pointer expressions of boolean

type rather than just the literal 'false'. This begins fixing PR9612,
but the message is now wrong. WIP, the cleanup of the messaging is next.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@129204 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index 3212c36b9ab092634edbbaa37860a528d03b2ad8..905b555381aeba6fabbad4fe51a7784d8266230d 100644 (file)
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -1982,11 +1982,11 @@ bool Sema::CheckPointerConversion(Expr *From, QualType ToType,
 
   Kind = CK_BitCast;
 
-  if (CXXBoolLiteralExpr* LitBool
-                          = dyn_cast<CXXBoolLiteralExpr>(From->IgnoreParens()))
-    if (!IsCStyleOrFunctionalCast && LitBool->getValue() == false)
-      DiagRuntimeBehavior(LitBool->getExprLoc(), From,
-                          PDiag(diag::warn_init_pointer_from_false) << ToType);
+  if (!IsCStyleOrFunctionalCast &&
+      Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy) &&
+      From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull))
+    DiagRuntimeBehavior(From->getExprLoc(), From,
+                        PDiag(diag::warn_init_pointer_from_false) << ToType);
 
   if (const PointerType *FromPtrType = FromType->getAs<PointerType>())
     if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) {

diff --git a/test/SemaCXX/warn_false_to_pointer.cpp b/test/SemaCXX/warn_false_to_pointer.cpp
index 26b54f6e685b3588b5b0940fcfab64b5d5e7d6a2..20d4b3a52d4601318cc079e20e746be924fd523b 100644 (file)
--- a/test/SemaCXX/warn_false_to_pointer.cpp
+++ b/test/SemaCXX/warn_false_to_pointer.cpp
@@ -5,7 +5,14 @@ int* j = false; // expected-warning{{ initialization of pointer of type 'int *'
 void foo(int* i, int *j=(false)) // expected-warning{{ initialization of pointer of type 'int *' from literal 'false'}}
 {
   foo(false); // expected-warning{{ initialization of pointer of type 'int *' from literal 'false'}}
-  foo((int*)false);
+  foo((int*)false); // no-warning: explicit cast
+  foo(0); // no-warning: not a bool, even though its convertible to bool
+
+  foo(false == true); // expected-warning{{ initialization of pointer of type 'int *' from literal 'false'}}
+  foo((42 + 24) < 32); // expected-warning{{ initialization of pointer of type 'int *' from literal 'false'}}
+
+  const bool kFlag = false;
+  foo(kFlag); // expected-warning{{ initialization of pointer of type 'int *' from literal 'false'}}
 }
 
 char f(struct Undefined*);