[clang] [clang] Added warn-assignment-bool-context (PR #115234)

[Philipp Rados via cfe-commits]

================
@@ -687,6 +687,48 @@ void Sema::diagnoseZeroToNullptrConversion(CastKind Kind, const Expr *E) {
       << FixItHint::CreateReplacement(E->getSourceRange(), "nullptr");
 }
 
+void Sema::DiagnoseAssignmentBoolContext(Expr *E, QualType Ty) {
+  // Use copy to not alter original expression.
+  Expr *ECopy = E;
+
+  if (Ty->isBooleanType()) {
+    // `bool(x=0)` and if (x=0){} emit:
+    // - ImplicitCastExpr bool IntegralToBoolean
+    // -- ImplicitCastExpr int LValueToRValue
+    // --- Assignment ...
+    // But should still emit this warning (at least gcc does), even if bool-cast
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PhilippRados wrote:

> Not sure what the question is here, can you clarify?

Basically just asking if `ImplicitCastExpr` is the only valid expression that can be in between the outer cast and the assignment expression or if there is another implicit expression that would need to be matched here.

https://github.com/llvm/llvm-project/pull/115234