Apologies for the late review... On Tue, Apr 16, 2013 at 7:12 PM, Richard Trieu <[email protected]> wrote: > Author: rtrieu > Date: Tue Apr 16 21:12:45 2013 > New Revision: 179662 > > URL: http://llvm.org/viewvc/llvm-project?rev=179662&view=rev > Log: > Add warning group -Woverloaded-shift-op-parentheses to -Wparentheses. This > will fire on code such as: > > cout << x == 0; > > which the compiler will intrepret as > > (cout << x) == 0; > > This warning comes with two fixits attached to notes, one for parentheses to > silence the warning, and another to evaluate the comparison first. > > Modified: > cfe/trunk/include/clang/Basic/DiagnosticGroups.td > cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td > cfe/trunk/lib/Sema/SemaExpr.cpp > cfe/trunk/test/Sema/parentheses.cpp > > Modified: cfe/trunk/include/clang/Basic/DiagnosticGroups.td > URL: > http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticGroups.td?rev=179662&r1=179661&r2=179662&view=diff > ============================================================================== > --- cfe/trunk/include/clang/Basic/DiagnosticGroups.td (original) > +++ cfe/trunk/include/clang/Basic/DiagnosticGroups.td Tue Apr 16 21:12:45 2013 > @@ -122,6 +122,7 @@ def GlobalConstructors : DiagGroup<"glob > def BitwiseOpParentheses: DiagGroup<"bitwise-op-parentheses">; > def LogicalOpParentheses: DiagGroup<"logical-op-parentheses">; > def ShiftOpParentheses: DiagGroup<"shift-op-parentheses">; > +def OverloadedShiftOpParentheses: > DiagGroup<"overloaded-shift-op-parentheses">;
Do we really need a separate flag for this? Seems like it would be fine to include the new warning in -Wshift-op-parentheses. > def DanglingElse: DiagGroup<"dangling-else">; > def DanglingField : DiagGroup<"dangling-field">; > def DistributedObjectModifiers : DiagGroup<"distributed-object-modifiers">; > @@ -352,6 +353,7 @@ def Parentheses : DiagGroup<"parentheses > [LogicalOpParentheses, > BitwiseOpParentheses, > ShiftOpParentheses, > + OverloadedShiftOpParentheses, > ParenthesesOnEquality, > DanglingElse]>; > > > Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td > URL: > http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=179662&r1=179661&r2=179662&view=diff > ============================================================================== > --- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original) > +++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Tue Apr 16 21:12:45 > 2013 > @@ -4041,6 +4041,13 @@ def warn_bitwise_and_in_bitwise_or : War > def warn_logical_and_in_logical_or : Warning< > "'&&' within '||'">, InGroup<LogicalOpParentheses>; > > +def warn_overloaded_shift_in_comparison :Warning< > + "overloaded operator %select{>>|<<}0 has lower precedence than " Pretty sure this should say "overloaded operator ... has *higher* precedence than". > + "comparison operator">, > + InGroup<OverloadedShiftOpParentheses>; > +def note_evaluate_comparison_first :Note< > + "place parentheses around comparison expression to evaluate it first">; > + > def warn_addition_in_bitshift : Warning< > "operator '%0' has lower precedence than '%1'; " > "'%1' will be evaluated first">, InGroup<ShiftOpParentheses>; > > Modified: cfe/trunk/lib/Sema/SemaExpr.cpp > URL: > http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=179662&r1=179661&r2=179662&view=diff > ============================================================================== > --- cfe/trunk/lib/Sema/SemaExpr.cpp (original) > +++ cfe/trunk/lib/Sema/SemaExpr.cpp Tue Apr 16 21:12:45 2013 > @@ -8877,6 +8877,33 @@ static void DiagnoseAdditionInShift(Sema > } > } > > +static void DiagnoseShiftCompare(Sema &S, SourceLocation OpLoc, > + Expr *LHSExpr, Expr *RHSExpr) { > + CXXOperatorCallExpr *OCE = dyn_cast<CXXOperatorCallExpr>(LHSExpr); > + if (!OCE) > + return; > + > + FunctionDecl *FD = OCE->getDirectCallee(); > + if (!FD || !FD->isOverloadedOperator()) > + return; > + > + OverloadedOperatorKind Kind = FD->getOverloadedOperator(); > + if (Kind != OO_LessLess && Kind != OO_GreaterGreater) > + return; > + > + S.Diag(OpLoc, diag::warn_overloaded_shift_in_comparison) > + << LHSExpr->getSourceRange() << RHSExpr->getSourceRange() > + << (Kind == OO_LessLess); > + SuggestParentheses(S, OpLoc, > + S.PDiag(diag::note_evaluate_comparison_first), > + SourceRange(OCE->getArg(1)->getLocStart(), > + RHSExpr->getLocEnd())); > + SuggestParentheses(S, OCE->getOperatorLoc(), > + S.PDiag(diag::note_precedence_silence) > + << (Kind == OO_LessLess ? "<<" : ">>"), > + OCE->getSourceRange()); > +} > + > /// DiagnoseBinOpPrecedence - Emit warnings for expressions with tricky > /// precedence. > static void DiagnoseBinOpPrecedence(Sema &Self, BinaryOperatorKind Opc, > @@ -8905,6 +8932,11 @@ static void DiagnoseBinOpPrecedence(Sema > DiagnoseAdditionInShift(Self, OpLoc, LHSExpr, Shift); > DiagnoseAdditionInShift(Self, OpLoc, RHSExpr, Shift); > } > + > + // Warn on overloaded shift operators and comparisons, such as: > + // cout << 5 == 4; > + if (BinaryOperator::isComparisonOp(Opc)) > + DiagnoseShiftCompare(Self, OpLoc, LHSExpr, RHSExpr); > } > > // Binary Operators. 'Tok' is the token for the operator. > > Modified: cfe/trunk/test/Sema/parentheses.cpp > URL: > http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/parentheses.cpp?rev=179662&r1=179661&r2=179662&view=diff > ============================================================================== > --- cfe/trunk/test/Sema/parentheses.cpp (original) > +++ cfe/trunk/test/Sema/parentheses.cpp Tue Apr 16 21:12:45 2013 > @@ -29,6 +29,12 @@ void f(Stream& s, bool b) { > (void)(s << b ? "foo" : "bar"); // expected-warning {{operator '?:' has > lower precedence than '<<'}} \ > // expected-note {{place parentheses > around the '?:' expression to evaluate it first}} \ > // expected-note {{place parentheses > around the '<<' expression to silence this warning}} > + (void)(s << 5 == 1); // expected-warning {{overloaded operator << has > lower precedence than comparison operator}} \ > + // expected-note {{place parentheses around the '<<' > expression to silence this warning}} \ > + // expected-note {{place parentheses around > comparison expression to evaluate it first}} > + (void)(s >> 5 == 1); // expected-warning {{overloaded operator >> has > lower precedence than comparison operator}} \ > + // expected-note {{place parentheses around the '>>' > expression to silence this warning}} \ > + // expected-note {{place parentheses around > comparison expression to evaluate it first}} > } > > struct S { > > > _______________________________________________ > cfe-commits mailing list > [email protected] > http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
