[PATCH] D63369: [AST] Fixed extraneous warnings for binary conditional operator

[Nathan Huckleberry via Phabricator via cfe-commits]

Nathan-Huckleberry updated this revision to Diff 205117.
Nathan-Huckleberry added a comment.

- [AST] Cleanup of conditional operator unused warning detection


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D63369/new/

https://reviews.llvm.org/D63369

Files:
  clang/lib/AST/Expr.cpp
  clang/test/Sema/warn-binary-conditional-expression-unused.c


Index: clang/test/Sema/warn-binary-conditional-expression-unused.c
===================================================================
--- /dev/null
+++ clang/test/Sema/warn-binary-conditional-expression-unused.c
@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 -fsyntax-only -Wunused-value -verify %s
+int main() {
+    int a;
+    int b;
+    a ? : b; //expected-warning{{expression result unused}}
+    a ? a : b; //expected-warning{{expression result unused}}
+    a ? : ++b;
+    a ? a : ++b;
+    ++a ? : b; //expected-warning{{expression result unused}}
+    ++a ? a : b; //expected-warning{{expression result unused}}
+    ++a ? : ++b;
+    ++a ? a : ++b;
+    return 0;
+};
+
Index: clang/lib/AST/Expr.cpp
===================================================================
--- clang/lib/AST/Expr.cpp
+++ clang/lib/AST/Expr.cpp
@@ -2346,11 +2346,12 @@
     // be being used for control flow. Only warn if both the LHS and
     // RHS are warnings.
     const ConditionalOperator *Exp = cast<ConditionalOperator>(this);
-    if (!Exp->getRHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx))
-      return false;
-    if (!Exp->getLHS())
-      return true;
-    return Exp->getLHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
+    return Exp->getLHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx) &&
+        Exp->getRHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
+  }
+  case BinaryConditionalOperatorClass: {
+    auto *Exp = cast<BinaryConditionalOperator>(this);
+    return Exp->getFalseExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
   }
 
   case MemberExprClass:


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