return QualType();
}
+/// SuggestParentheses - Emit a diagnostic together with a fixit hint that wraps
+/// ParenRange in parentheses.
+static void SuggestParentheses(Sema &Self, SourceLocation Loc,
+ const PartialDiagnostic &PD,
+ const PartialDiagnostic &FirstNote,
+ SourceRange FirstParenRange,
+ const PartialDiagnostic &SecondNote,
+ SourceRange SecondParenRange) {
+ Self.Diag(Loc, PD);
+
+ if (!FirstNote.getDiagID())
+ return;
+
+ SourceLocation EndLoc = Self.PP.getLocForEndOfToken(FirstParenRange.getEnd());
+ if (!FirstParenRange.getEnd().isFileID() || EndLoc.isInvalid()) {
+ // We can't display the parentheses, so just return.
+ return;
+ }
+
+ Self.Diag(Loc, FirstNote)
+ << FixItHint::CreateInsertion(FirstParenRange.getBegin(), "(")
+ << FixItHint::CreateInsertion(EndLoc, ")");
+
+ if (!SecondNote.getDiagID())
+ return;
+
+ EndLoc = Self.PP.getLocForEndOfToken(SecondParenRange.getEnd());
+ if (!SecondParenRange.getEnd().isFileID() || EndLoc.isInvalid()) {
+ // We can't display the parentheses, so just dig the
+ // warning/error and return.
+ Self.Diag(Loc, SecondNote);
+ return;
+ }
+
+ Self.Diag(Loc, SecondNote)
+ << FixItHint::CreateInsertion(SecondParenRange.getBegin(), "(")
+ << FixItHint::CreateInsertion(EndLoc, ")");
+}
+
+static bool IsArithmeticOp(BinaryOperatorKind Opc) {
+ return Opc >= BO_Mul && Opc <= BO_Shr;
+}
+
+static bool IsLogicOp(BinaryOperatorKind Opc) {
+ return (Opc >= BO_LT && Opc <= BO_NE) || (Opc >= BO_LAnd && Opc <= BO_LOr);
+}
+
+/// DiagnoseConditionalPrecedence - Emit a warning when a conditional operator
+/// and binary operator are mixed in a way that suggests the programmer assumed
+/// the conditional operator has higher precedence, for example:
+/// "int x = a + someBinaryCondition ? 1 : 2".
+static void DiagnoseConditionalPrecedence(Sema &Self,
+ SourceLocation OpLoc,
+ Expr *cond,
+ Expr *lhs,
+ Expr *rhs) {
+ while (ImplicitCastExpr *C = dyn_cast<ImplicitCastExpr>(cond))
+ cond = C->getSubExpr();
+
+ if (BinaryOperator *OP = dyn_cast<BinaryOperator>(cond)) {
+ if (!IsArithmeticOp(OP->getOpcode()))
+ return;
+
+ // Drill down on the RHS of the condition.
+ Expr *CondRHS = OP->getRHS();
+ while (ImplicitCastExpr *C = dyn_cast<ImplicitCastExpr>(CondRHS))
+ CondRHS = C->getSubExpr();
+ while (ParenExpr *P = dyn_cast<ParenExpr>(CondRHS))
+ CondRHS = P->getSubExpr();
+
+ bool CondRHSLooksBoolean = false;
+ if (CondRHS->getType()->isBooleanType())
+ CondRHSLooksBoolean = true;
+ else if (BinaryOperator *CondRHSOP = dyn_cast<BinaryOperator>(CondRHS))
+ CondRHSLooksBoolean = IsLogicOp(CondRHSOP->getOpcode());
+ else if (UnaryOperator *CondRHSOP = dyn_cast<UnaryOperator>(CondRHS))
+ CondRHSLooksBoolean = CondRHSOP->getOpcode() == UO_LNot;
+
+ if (CondRHSLooksBoolean) {
+ // The condition is an arithmetic binary expression, with a right-
+ // hand side that looks boolean, so warn.
+
+ PartialDiagnostic Warn = Self.PDiag(diag::warn_precedence_conditional)
+ << OP->getSourceRange()
+ << BinaryOperator::getOpcodeStr(OP->getOpcode());
+
+ PartialDiagnostic FirstNote =
+ Self.PDiag(diag::note_precedence_conditional_silence)
+ << BinaryOperator::getOpcodeStr(OP->getOpcode());
+
+ SourceRange FirstParenRange(OP->getLHS()->getLocStart(),
+ OP->getRHS()->getLocEnd());
+
+ PartialDiagnostic SecondNote =
+ Self.PDiag(diag::note_precedence_conditional_first);
+ SourceRange SecondParenRange(OP->getRHS()->getLocStart(),
+ rhs->getLocEnd());
+
+ SuggestParentheses(Self, OpLoc, Warn, FirstNote, FirstParenRange,
+ SecondNote, SecondParenRange);
+ }
+ }
+}
+
/// ActOnConditionalOp - Parse a ?: operation. Note that 'LHS' may be null
/// in the case of a the GNU conditional expr extension.
ExprResult Sema::ActOnConditionalOp(SourceLocation QuestionLoc,
RHS.isInvalid())
return ExprError();
+ DiagnoseConditionalPrecedence(*this, QuestionLoc, Cond.get(), LHS.get(),
+ RHS.get());
+
if (!commonExpr)
return Owned(new (Context) ConditionalOperator(Cond.take(), QuestionLoc,
LHS.take(), ColonLoc,
CompResultTy, OpLoc));
}
-/// SuggestParentheses - Emit a diagnostic together with a fixit hint that wraps
-/// ParenRange in parentheses.
-static void SuggestParentheses(Sema &Self, SourceLocation Loc,
- const PartialDiagnostic &PD,
- const PartialDiagnostic &FirstNote,
- SourceRange FirstParenRange,
- const PartialDiagnostic &SecondNote,
- SourceRange SecondParenRange) {
- Self.Diag(Loc, PD);
-
- if (!FirstNote.getDiagID())
- return;
-
- SourceLocation EndLoc = Self.PP.getLocForEndOfToken(FirstParenRange.getEnd());
- if (!FirstParenRange.getEnd().isFileID() || EndLoc.isInvalid()) {
- // We can't display the parentheses, so just return.
- return;
- }
-
- Self.Diag(Loc, FirstNote)
- << FixItHint::CreateInsertion(FirstParenRange.getBegin(), "(")
- << FixItHint::CreateInsertion(EndLoc, ")");
-
- if (!SecondNote.getDiagID())
- return;
-
- EndLoc = Self.PP.getLocForEndOfToken(SecondParenRange.getEnd());
- if (!SecondParenRange.getEnd().isFileID() || EndLoc.isInvalid()) {
- // We can't display the parentheses, so just dig the
- // warning/error and return.
- Self.Diag(Loc, SecondNote);
- return;
- }
-
- Self.Diag(Loc, SecondNote)
- << FixItHint::CreateInsertion(SecondParenRange.getBegin(), "(")
- << FixItHint::CreateInsertion(EndLoc, ")");
-}
-
/// DiagnoseBitwisePrecedence - Emit a warning when bitwise and comparison
/// operators are mixed in a way that suggests that the programmer forgot that
/// comparison operators have higher precedence. The most typical example of