[PATCH] D85716: [AST][RecoveryExpr] Fix a bogus unused diagnostic when the type is preserved.

[Haojian Wu via Phabricator via cfe-commits]

hokein updated this revision to Diff 284742.
hokein added a comment.

address review comment:
a dependent-kind cast expr should not be warned about the unused result.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D85716/new/

https://reviews.llvm.org/D85716

Files:
  clang/lib/AST/Expr.cpp
  clang/test/SemaCXX/recovery-expr-type.cpp


Index: clang/test/SemaCXX/recovery-expr-type.cpp
===================================================================
--- clang/test/SemaCXX/recovery-expr-type.cpp
+++ clang/test/SemaCXX/recovery-expr-type.cpp
@@ -75,3 +75,17 @@
   template<typename...Ts> U<Ts...>& f(); // expected-error {{pack expansion used as argument for non-pack parameter of alias template}}
   double &s1 = f(); // expected-error {{no matching function}}
 }
+
+namespace test6 {
+struct Base {
+private:
+  ~Base();
+};
+struct Derived : Base { // expected-note {{default constructor of}}
+};
+
+void func() {
+  // verify that no -Wunused-value diagnostic.
+  (Derived(Derived())); // expected-error {{call to implicitly-deleted default constructor}}
+}
+}
Index: clang/lib/AST/Expr.cpp
===================================================================
--- clang/lib/AST/Expr.cpp
+++ clang/lib/AST/Expr.cpp
@@ -2658,6 +2658,8 @@
     // Otherwise, the result of the cast is unused.
     if (CE->getCastKind() == CK_ConstructorConversion)
       return CE->getSubExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
+    if (CE->getCastKind() == CK_Dependent)
+      return false;
 
     WarnE = this;
     if (const CXXFunctionalCastExpr *CXXCE =


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