Add a new warning to -Wliteral-conversion to catch cases where a string literal
is cast to a boolean. An exception has been made for string literals in
logical expressions to allow the common case of use in assert statements.
bool x;
x = "hi"; // Warn here
void foo(bool x);
foo("hi"); // Warn here
assert(0 && "error");
assert("error); // Warn here
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@140405 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 052ef3b..5de43bb 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -3237,9 +3237,17 @@
if (CC.isInvalid())
return;
- // Never diagnose implicit casts to bool.
- if (Target->isSpecificBuiltinType(BuiltinType::Bool))
- return;
+ // Diagnose implicit casts to bool.
+ if (Target->isSpecificBuiltinType(BuiltinType::Bool)) {
+ if (isa<StringLiteral>(E))
+ // Warn on string literal to bool. Checks for string literals in logical
+ // expressions, for instances, assert(0 && "error here"), is prevented
+ // by a check in AnalyzeImplicitConversions().
+ return DiagnoseImpCast(S, E, T, CC,
+ diag::warn_impcast_string_literal_to_bool);
+ else // Other casts to bool are not checked.
+ return;
+ }
// Strip vector types.
if (isa<VectorType>(Source)) {
@@ -3508,8 +3516,16 @@
// Now just recurse over the expression's children.
CC = E->getExprLoc();
- for (Stmt::child_range I = E->children(); I; ++I)
- AnalyzeImplicitConversions(S, cast<Expr>(*I), CC);
+ BinaryOperator *BO = dyn_cast<BinaryOperator>(E);
+ bool IsLogicalOperator = BO && BO->isLogicalOp();
+ for (Stmt::child_range I = E->children(); I; ++I) {
+ Expr *ChildExpr = cast<Expr>(*I);
+ if (IsLogicalOperator &&
+ isa<StringLiteral>(ChildExpr->IgnoreParenImpCasts()))
+ // Ignore checking string literals that are in logical operators.
+ continue;
+ AnalyzeImplicitConversions(S, ChildExpr, CC);
+ }
}
} // end anonymous namespace