Add the exception for strings in logical and expressions to -Wstring-conversion

for C code.

llvm-svn: 222327

2 files changed, 26 insertions, 2 deletions

diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index aa6bf1760d3..91ba91e4f53 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -6613,10 +6613,17 @@ void AnalyzeImplicitConversions(Sema &S, Expr *OrigE, SourceLocation CC) {
       continue;
     AnalyzeImplicitConversions(S, ChildExpr, CC);
   }
+
   if (BO && BO->isLogicalOp()) {
-    ::CheckBoolLikeConversion(S, BO->getLHS(), BO->getLHS()->getExprLoc());
-    ::CheckBoolLikeConversion(S, BO->getRHS(), BO->getRHS()->getExprLoc());
+    Expr *SubExpr = BO->getLHS()->IgnoreParenImpCasts();
+    if (!IsLogicalAndOperator || !isa<StringLiteral>(SubExpr))
+      ::CheckBoolLikeConversion(S, SubExpr, SubExpr->getExprLoc());
+
+    SubExpr = BO->getRHS()->IgnoreParenImpCasts();
+    if (!IsLogicalAndOperator || !isa<StringLiteral>(SubExpr))
+      ::CheckBoolLikeConversion(S, SubExpr, SubExpr->getExprLoc());
   }
+
   if (const UnaryOperator *U = dyn_cast<UnaryOperator>(E))
     if (U->getOpcode() == UO_LNot)
       ::CheckBoolLikeConversion(S, U->getSubExpr(), CC);
diff --git a/clang/test/Sema/warn-string-conversion.c b/clang/test/Sema/warn-string-conversion.c
new file mode 100644
index 00000000000..708dd543e40
--- /dev/null
+++ b/clang/test/Sema/warn-string-conversion.c
@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -verify -fsyntax-only -Wstring-conversion %s
+
+#define assert(EXPR) (void)(EXPR);
+
+// Expection for common assert form.
+void test1() {
+  assert(0 && "foo");
+  assert("foo" && 0);
+  assert(0 || "foo"); // expected-warning {{string literal}}
+}
+
+void test2() {
+  if ("hi") {}           // expected-warning {{string literal}}
+  while ("hello") {}     // expected-warning {{string literal}}
+  for (;"howdy";) {}     // expected-warning {{string literal}}
+  do { } while ("hey");  // expected-warning {{string literal}}
+}