diff options
| author | Chris Lattner <sabre@nondot.org> | 2010-07-13 19:41:32 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2010-07-13 19:41:32 +0000 |
| commit | 90a8f27f144233b53cac0c88a1595f7f05105b7e (patch) | |
| tree | a3ef6406b2b4ac33704047c7ae3a8188a7200640 /lib/Sema/SemaExpr.cpp | |
| parent | 3d4b482b5f2cacc7686f65bb231ad666a5adad4a (diff) | |
Add a warning to catch a bug recently caught by code review, like this:
t2.c:2:12: warning: use of logical && with constant operand; switch to bitwise &
or remove constant [-Wlogical-bitwise-confusion]
return x && 4;
^ ~
wording improvement suggestions are welcome.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@108260 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Sema/SemaExpr.cpp')
| -rw-r--r-- | lib/Sema/SemaExpr.cpp | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp index 5d53ddeb98..cb3518ae83 100644 --- a/lib/Sema/SemaExpr.cpp +++ b/lib/Sema/SemaExpr.cpp @@ -5735,7 +5735,21 @@ inline QualType Sema::CheckBitwiseOperands( } inline QualType Sema::CheckLogicalOperands( // C99 6.5.[13,14] - Expr *&lex, Expr *&rex, SourceLocation Loc) { + Expr *&lex, Expr *&rex, SourceLocation Loc, unsigned Opc) { + + // Diagnose cases where the user write a logical and/or but probably meant a + // bitwise one. We do this when the LHS is a non-bool integer and the RHS + // is a constant. + if (lex->getType()->isIntegerType() && !lex->getType()->isBooleanType() && + rex->getType()->isIntegerType() && rex->isEvaluatable(Context) && + !Loc.isMacroID()) + Diag(Loc, diag::warn_logical_instead_of_bitwise) + << rex->getSourceRange() + << (Opc == BinaryOperator::LAnd ? "&&" : "||") + << (Opc == BinaryOperator::LAnd ? "&" : "|"); + + + if (!Context.getLangOptions().CPlusPlus) { UsualUnaryConversions(lex); UsualUnaryConversions(rex); @@ -6363,7 +6377,7 @@ Action::OwningExprResult Sema::CreateBuiltinBinOp(SourceLocation OpLoc, break; case BinaryOperator::LAnd: case BinaryOperator::LOr: - ResultTy = CheckLogicalOperands(lhs, rhs, OpLoc); + ResultTy = CheckLogicalOperands(lhs, rhs, OpLoc, Opc); break; case BinaryOperator::MulAssign: case BinaryOperator::DivAssign: |