// should result in a warning, since these always evaluate to a constant.
// Array comparisons have similar warnings
def warn_comparison_always : Warning<
- "%select{self-|array }0comparison always evaluates to %select{a constant|%2}1">,
+ "%select{self-|array }0comparison always evaluates to "
+ "%select{a constant|true|false|'std::strong_ordering::equal'}1">,
InGroup<TautologicalCompare>;
def warn_comparison_bitwise_always : Warning<
"bitwise comparison always evaluates to %select{false|true}0">,
// result.
ValueDecl *DL = getCompareDecl(LHSStripped);
ValueDecl *DR = getCompareDecl(RHSStripped);
+
+ // Used for indexing into %select in warn_comparison_always
+ enum {
+ AlwaysConstant,
+ AlwaysTrue,
+ AlwaysFalse,
+ AlwaysEqual, // std::strong_ordering::equal from operator<=>
+ };
if (DL && DR && declaresSameEntity(DL, DR)) {
- StringRef Result;
+ unsigned Result;
switch (Opc) {
case BO_EQ: case BO_LE: case BO_GE:
- Result = "true";
+ Result = AlwaysTrue;
break;
case BO_NE: case BO_LT: case BO_GT:
- Result = "false";
+ Result = AlwaysFalse;
break;
case BO_Cmp:
- Result = "'std::strong_ordering::equal'";
+ Result = AlwaysEqual;
break;
default:
+ Result = AlwaysConstant;
break;
}
S.DiagRuntimeBehavior(Loc, nullptr,
S.PDiag(diag::warn_comparison_always)
- << 0 /*self-comparison*/ << !Result.empty()
+ << 0 /*self-comparison*/
<< Result);
} else if (DL && DR &&
DL->getType()->isArrayType() && DR->getType()->isArrayType() &&
!DL->isWeak() && !DR->isWeak()) {
// What is it always going to evaluate to?
- StringRef Result;
+ unsigned Result;
switch(Opc) {
case BO_EQ: // e.g. array1 == array2
- Result = "false";
+ Result = AlwaysFalse;
break;
case BO_NE: // e.g. array1 != array2
- Result = "true";
+ Result = AlwaysTrue;
break;
default: // e.g. array1 <= array2
// The best we can say is 'a constant'
+ Result = AlwaysConstant;
break;
}
S.DiagRuntimeBehavior(Loc, nullptr,
S.PDiag(diag::warn_comparison_always)
<< 1 /*array comparison*/
- << !Result.empty() << Result);
+ << Result);
}
if (isa<CastExpr>(LHSStripped))