[PATCH] D146897: [clang:diagnostics] Turning off warn_self_assignment_overloaded for user-defined compound assignments

[Xiang Li via Phabricator via cfe-commits]

python3kgae updated this revision to Diff 510976.
python3kgae added a comment.

skip warning on field for compound assignment when isImplicitCXXThis matches.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D146897/new/

https://reviews.llvm.org/D146897

Files:
  clang/lib/Sema/SemaExpr.cpp
  clang/test/SemaCXX/warn-self-assign-field-overloaded.cpp
  clang/test/SemaCXX/warn-self-assign-overloaded.cpp


Index: clang/test/SemaCXX/warn-self-assign-overloaded.cpp
===================================================================
--- clang/test/SemaCXX/warn-self-assign-overloaded.cpp
+++ clang/test/SemaCXX/warn-self-assign-overloaded.cpp
@@ -53,15 +53,15 @@
 
 #ifndef DUMMY
   a *= a;
-  a /= a; // expected-warning {{explicitly assigning}}
-  a %= a; // expected-warning {{explicitly assigning}}
+  a /= a;
+  a %= a;
   a += a;
-  a -= a; // expected-warning {{explicitly assigning}}
+  a -= a;
   a <<= a;
   a >>= a;
-  a &= a; // expected-warning {{explicitly assigning}}
-  a |= a; // expected-warning {{explicitly assigning}}
-  a ^= a; // expected-warning {{explicitly assigning}}
+  a &= a;
+  a |= a;
+  a ^= a;
 #endif
 }
 
Index: clang/test/SemaCXX/warn-self-assign-field-overloaded.cpp
===================================================================
--- clang/test/SemaCXX/warn-self-assign-field-overloaded.cpp
+++ clang/test/SemaCXX/warn-self-assign-field-overloaded.cpp
@@ -58,15 +58,49 @@
 
 #ifndef DUMMY
     a *= a;
-    a /= a; // expected-warning {{assigning field to itself}}
-    a %= a; // expected-warning {{assigning field to itself}}
+    a /= a;
+    a %= a;
     a += a;
-    a -= a; // expected-warning {{assigning field to itself}}
+    a -= a;
     a <<= a;
     a >>= a;
-    a &= a; // expected-warning {{assigning field to itself}}
-    a |= a; // expected-warning {{assigning field to itself}}
-    a ^= a; // expected-warning {{assigning field to itself}}
+    a &= a;
+    a |= a;
+    a ^= a;
+
+    this->a *= a;
+    this->a /= a; // expected-warning {{assigning field to itself}}
+    this->a %= a; // expected-warning {{assigning field to itself}}
+    this->a += a;
+    this->a -= a; // expected-warning {{assigning field to itself}}
+    this->a <<= a;
+    this->a >>= a;
+    this->a &= a; // expected-warning {{assigning field to itself}}
+    this->a |= a; // expected-warning {{assigning field to itself}}
+    this->a ^= a; // expected-warning {{assigning field to itself}}
+
+    a *= this->a;
+    a /= this->a; // expected-warning {{assigning field to itself}}
+    a %= this->a; // expected-warning {{assigning field to itself}}
+    a += this->a;
+    a -= this->a; // expected-warning {{assigning field to itself}}
+    a <<= this->a;
+    a >>= this->a;
+    a &= this->a; // expected-warning {{assigning field to itself}}
+    a |= this->a; // expected-warning {{assigning field to itself}}
+    a ^= this->a; // expected-warning {{assigning field to itself}}
+
+    this->a *= this->a;
+    this->a /= this->a;
+    this->a %= this->a;
+    this->a += this->a;
+    this->a -= this->a;
+    this->a <<= this->a;
+    this->a >>= this->a;
+    this->a &= this->a;
+    this->a |= this->a;
+    this->a ^= this->a;
+
 #endif
   }
 
Index: clang/lib/Sema/SemaExpr.cpp
===================================================================
--- clang/lib/Sema/SemaExpr.cpp
+++ clang/lib/Sema/SemaExpr.cpp
@@ -14099,7 +14099,7 @@
 }
 
 static void CheckIdentityFieldAssignment(Expr *LHSExpr, Expr *RHSExpr,
-                                         SourceLocation Loc,
+                                         bool IsCompound, SourceLocation Loc,
                                          Sema &Sema) {
   if (Sema.inTemplateInstantiation())
     return;
@@ -14116,6 +14116,10 @@
   if (ML && MR) {
     if (!(isa<CXXThisExpr>(ML->getBase()) && isa<CXXThisExpr>(MR->getBase())))
       return;
+    // For compound case, only warning on this->x -= x or x -= this->x.
+    if (IsCompound && ML->getBase()->isImplicitCXXThis() ==
+                          MR->getBase()->isImplicitCXXThis())
+      return;
     const ValueDecl *LHSDecl =
         cast<ValueDecl>(ML->getMemberDecl()->getCanonicalDecl());
     const ValueDecl *RHSDecl =
@@ -14127,7 +14131,7 @@
     if (const ReferenceType *RefTy = LHSDecl->getType()->getAs<ReferenceType>())
       if (RefTy->getPointeeType().isVolatileQualified())
         return;
-
+    
     Sema.Diag(Loc, diag::warn_identity_field_assign) << 0;
   }
 
@@ -14171,7 +14175,8 @@
   if (CompoundType.isNull()) {
     Expr *RHSCheck = RHS.get();
 
-    CheckIdentityFieldAssignment(LHSExpr, RHSCheck, Loc, *this);
+    CheckIdentityFieldAssignment(LHSExpr, RHSCheck, /*IsCompound*/ false, Loc,
+                                 *this);
 
     QualType LHSTy(LHSType);
     ConvTy = CheckSingleAssignmentConstraints(LHSTy, RHS);
@@ -15644,14 +15649,17 @@
                                        Expr *LHS, Expr *RHS) {
   switch (Opc) {
   case BO_Assign:
+    // Skip diagnose on compound assignment.
+    DiagnoseSelfAssignment(S, LHS, RHS, OpLoc, false);
+    [[fallthrough]];
   case BO_DivAssign:
   case BO_RemAssign:
   case BO_SubAssign:
   case BO_AndAssign:
   case BO_OrAssign:
   case BO_XorAssign:
-    DiagnoseSelfAssignment(S, LHS, RHS, OpLoc, false);
-    CheckIdentityFieldAssignment(LHS, RHS, OpLoc, S);
+    CheckIdentityFieldAssignment(LHS, RHS, /*IsCompound*/ (Opc != BO_Assign),
+                                 OpLoc, S);
     break;
   default:
     break;

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