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

[Nathan Huckleberry via Phabricator via cfe-commits]

Nathan-Huckleberry updated this revision to Diff 205470.
Nathan-Huckleberry added a comment.

- [analyzer] Fix clang-tidy crash on GCCAsmStmt


Repository:
  rG LLVM Github Monorepo

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

https://reviews.llvm.org/D63369

Files:
  clang-tools-extra/test/clang-tidy/asm-goto.cpp
  clang/lib/AST/Expr.cpp
  clang/lib/StaticAnalyzer/Core/CoreEngine.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/StaticAnalyzer/Core/CoreEngine.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Core/CoreEngine.cpp
+++ clang/lib/StaticAnalyzer/Core/CoreEngine.cpp
@@ -396,6 +396,9 @@
       case Stmt::WhileStmtClass:
         HandleBranch(cast<WhileStmt>(Term)->getCond(), Term, B, Pred);
         return;
+
+      case Stmt::GCCAsmStmtClass:
+        return;
     }
   }
 
Index: clang/lib/AST/Expr.cpp
===================================================================
--- clang/lib/AST/Expr.cpp
+++ clang/lib/AST/Expr.cpp
@@ -2345,12 +2345,13 @@
     // If only one of the LHS or RHS is a warning, the operator might
     // 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);
+    const auto *Exp = cast<ConditionalOperator>(this);
+    return Exp->getLHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx) &&
+           Exp->getRHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
+  }
+  case BinaryConditionalOperatorClass: {
+    const auto *Exp = cast<BinaryConditionalOperator>(this);
+    return Exp->getFalseExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
   }
 
   case MemberExprClass:
Index: clang-tools-extra/test/clang-tidy/asm-goto.cpp
===================================================================
--- /dev/null
+++ clang-tools-extra/test/clang-tidy/asm-goto.cpp
@@ -0,0 +1,29 @@
+// REQUIRES: static-analyzer
+// RUN: clang-tidy %s -checks='bugprone-use-after-move' -- | FileCheck %s
+#include <string>
+#include <utility>
+int main() {
+    struct S {
+      std::string str;
+      int i;
+    };
+
+    S s = { "Hello, world!\n", 42 };
+    S s_other = std::move(s);
+    asm goto( "xor %0, %0\n je %l[label1]\n jl %l[label2]" : /* no outputs */ : /* inputs */ : /* clobbers */ : label1, label2 /* any labels used */ );
+    return 0;
+
+    label1:
+    // CHECK: warning: 's' used after it was moved [bugprone-use-after-move]
+    s.str = "ABC";
+    s.i = 99;
+    return 2;
+
+    label2:
+    // There should be a warning here, but UseAfterMoveCheck only reports one
+    // warning per std::move
+    s.str = "DEF";
+    s.i = 100;
+    return 0;
+}
+


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