diff options
| -rw-r--r-- | lib/AST/Expr.cpp | 15 | ||||
| -rw-r--r-- | test/SemaCXX/overloaded-operator.cpp | 4 | ||||
| -rw-r--r-- | test/SemaCXX/warn-unused-comparison.cpp | 14 | ||||
| -rw-r--r-- | test/SemaTemplate/overload-uneval.cpp | 2 |
4 files changed, 24 insertions, 11 deletions
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp index 5e795be56d..41fa850184 100644 --- a/lib/AST/Expr.cpp +++ b/lib/AST/Expr.cpp @@ -1524,8 +1524,21 @@ bool Expr::isUnusedResultAWarning(SourceLocation &Loc, SourceRange &R1, R2 = cast<ArraySubscriptExpr>(this)->getRHS()->getSourceRange(); return true; + case CXXOperatorCallExprClass: { + // We warn about operator== and operator!= even when user-defined operator + // overloads as there is no reasonable way to define these such that they + // have non-trivial, desirable side-effects. See the -Wunused-comparison + // warning: these operators are commonly typo'ed, and so warning on them + // provides additional value as well. If this list is updated, + // DiagnoseUnusedComparison should be as well. + const CXXOperatorCallExpr *Op = cast<CXXOperatorCallExpr>(this); + if (Op->getOperator() == OO_EqualEqual || + Op->getOperator() == OO_ExclaimEqual) + return true; + + // Fallthrough for generic call handling. + } case CallExprClass: - case CXXOperatorCallExprClass: case CXXMemberCallExprClass: { // If this is a direct call, get the callee. const CallExpr *CE = cast<CallExpr>(this); diff --git a/test/SemaCXX/overloaded-operator.cpp b/test/SemaCXX/overloaded-operator.cpp index 462d0234f3..36d95599ff 100644 --- a/test/SemaCXX/overloaded-operator.cpp +++ b/test/SemaCXX/overloaded-operator.cpp @@ -36,7 +36,7 @@ A make_A(); bool operator==(A&, Z&); // expected-note 3{{candidate function}} void h(A a, const A ac, Z z) { - make_A() == z; + make_A() == z; // expected-warning{{equality comparison result unused}} a == z; // expected-error{{use of overloaded operator '==' is ambiguous}} ac == z; // expected-error{{invalid operands to binary expression ('const A' and 'Z')}} } @@ -45,7 +45,7 @@ struct B { bool operator==(const B&) const; void test(Z z) { - make_A() == z; + make_A() == z; // expected-warning{{equality comparison result unused}} } }; diff --git a/test/SemaCXX/warn-unused-comparison.cpp b/test/SemaCXX/warn-unused-comparison.cpp index 79a644cefc..f790c669ff 100644 --- a/test/SemaCXX/warn-unused-comparison.cpp +++ b/test/SemaCXX/warn-unused-comparison.cpp @@ -19,13 +19,13 @@ void test() { p == p; // expected-warning {{equality comparison result unused}} \ // expected-note {{use '=' to turn this equality comparison into an assignment}} \ // expected-warning {{self-comparison always evaluates to true}} - a == a; // FIXME: missing-warning {{equality comparison result unused}} \ - // FIXME: missing-note {{use '=' to turn this equality comparison into an assignment}} - a == b; // FIXME: missing-warning {{equality comparison result unused}} \ - // FIXME: missing-note {{use '=' to turn this equality comparison into an assignment}} - a != b; // FIXME: missing-warning {{inequality comparison result unused}} \ - // FIXME: missing-note {{use '|=' to turn this inequality comparison into an or-assignment}} - A() == b; // FIXME: missing-warning {{equality comparison result unused}} + a == a; // expected-warning {{equality comparison result unused}} \ + // expected-note {{use '=' to turn this equality comparison into an assignment}} + a == b; // expected-warning {{equality comparison result unused}} \ + // expected-note {{use '=' to turn this equality comparison into an assignment}} + a != b; // expected-warning {{inequality comparison result unused}} \ + // expected-note {{use '|=' to turn this inequality comparison into an or-assignment}} + A() == b; // expected-warning {{equality comparison result unused}} if (42) x == 7; // expected-warning {{equality comparison result unused}} \ // expected-note {{use '=' to turn this equality comparison into an assignment}} else if (42) x == 7; // expected-warning {{equality comparison result unused}} \ diff --git a/test/SemaTemplate/overload-uneval.cpp b/test/SemaTemplate/overload-uneval.cpp index 632d1cd521..8d8a2f42cf 100644 --- a/test/SemaTemplate/overload-uneval.cpp +++ b/test/SemaTemplate/overload-uneval.cpp @@ -1,4 +1,4 @@ -// RUN: %clang_cc1 -fsyntax-only -verify %s +// RUN: %clang_cc1 -fsyntax-only -verify -Wno-unused %s // Tests that overload resolution is treated as an unevaluated context. // PR5541 |