diff options
author | Richard Trieu <rtrieu@google.com> | 2019-10-19 01:47:49 +0000 |
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committer | Richard Trieu <rtrieu@google.com> | 2019-10-19 01:47:49 +0000 |
commit | ae3e9c83d470f2f2c4fa84e66c0451abcbfb3598 (patch) | |
tree | e40f515caace6e493e49953ad72cd3ca630f14d4 /lib | |
parent | 56ddb2a69c92a417a93e8ccf3f8fe1ce047c78e3 (diff) |
Add -Wbitwise-conditional-parentheses to warn on mixing '|' and '&' with "?:"
Extend -Wparentheses to cover mixing bitwise-and and bitwise-or with the
conditional operator. There's two main cases seen with this:
unsigned bits1 = 0xf0 | cond ? 0x4 : 0x1;
unsigned bits2 = cond1 ? 0xf0 : 0x10 | cond2 ? 0x5 : 0x2;
// Intended order of evaluation:
unsigned bits1 = 0xf0 | (cond ? 0x4 : 0x1);
unsigned bits2 = (cond1 ? 0xf0 : 0x10) | (cond2 ? 0x5 : 0x2);
// Actual order of evaluation:
unsigned bits1 = (0xf0 | cond) ? 0x4 : 0x1;
unsigned bits2 = cond1 ? 0xf0 : ((0x10 | cond2) ? 0x5 : 0x2);
Differential Revision: https://reviews.llvm.org/D66043
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@375326 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
-rw-r--r-- | lib/Sema/SemaExpr.cpp | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp index 2734b4d076..e41cd5b665 100644 --- a/lib/Sema/SemaExpr.cpp +++ b/lib/Sema/SemaExpr.cpp @@ -7620,7 +7620,12 @@ static void SuggestParentheses(Sema &Self, SourceLocation Loc, static bool IsArithmeticOp(BinaryOperatorKind Opc) { return BinaryOperator::isAdditiveOp(Opc) || BinaryOperator::isMultiplicativeOp(Opc) || - BinaryOperator::isShiftOp(Opc); + BinaryOperator::isShiftOp(Opc) || Opc == BO_And || Opc == BO_Or; + // This only checks for bitwise-or and bitwise-and, but not bitwise-xor and + // not any of the logical operators. Bitwise-xor is commonly used as a + // logical-xor because there is no logical-xor operator. The logical + // operators, including uses of xor, have a high false positive rate for + // precedence warnings. } /// IsArithmeticBinaryExpr - Returns true if E is an arithmetic binary @@ -7710,7 +7715,11 @@ static void DiagnoseConditionalPrecedence(Sema &Self, // The condition is an arithmetic binary expression, with a right- // hand side that looks boolean, so warn. - Self.Diag(OpLoc, diag::warn_precedence_conditional) + unsigned DiagID = BinaryOperator::isBitwiseOp(CondOpcode) + ? diag::warn_precedence_bitwise_conditional + : diag::warn_precedence_conditional; + + Self.Diag(OpLoc, DiagID) << Condition->getSourceRange() << BinaryOperator::getOpcodeStr(CondOpcode); |