зеркало из https://github.com/mozilla/gecko-dev.git
60 строки
2.6 KiB
C++
60 строки
2.6 KiB
C++
|
/* This Source Code Form is subject to the terms of the Mozilla Public
|
||
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
||
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
||
|
|
|
||
|
|
#include "NaNExprChecker.h"
|
||
|
|
#include "CustomMatchers.h"
|
||
|
|
|
||
|
|
void NaNExprChecker::registerMatcher(MatchFinder& AstMatcher) {
|
||
|
|
AstMatcher.addMatcher(
|
||
|
|
binaryOperator(
|
||
|
|
allOf(binaryEqualityOperator(),
|
||
|
|
hasLHS(hasIgnoringParenImpCasts(
|
||
|
|
declRefExpr(hasType(qualType((isFloat())))).bind("lhs"))),
|
||
|
|
hasRHS(hasIgnoringParenImpCasts(
|
||
|
|
declRefExpr(hasType(qualType((isFloat())))).bind("rhs"))),
|
||
|
|
unless(anyOf(isInSystemHeader(), isInWhitelistForNaNExpr()))))
|
||
|
|
.bind("node"),
|
||
|
|
this);
|
||
|
|
}
|
||
|
|
|
||
|
|
void NaNExprChecker::run(
|
||
|
|
const MatchFinder::MatchResult &Result) {
|
||
|
|
if (!Result.Context->getLangOpts().CPlusPlus) {
|
||
|
|
// mozilla::IsNaN is not usable in C, so there is no point in issuing these
|
||
|
|
// warnings.
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
DiagnosticsEngine &Diag = Result.Context->getDiagnostics();
|
||
|
|
unsigned ErrorID = Diag.getDiagnosticIDs()->getCustomDiagID(
|
||
|
|
DiagnosticIDs::Error, "comparing a floating point value to itself for "
|
||
|
|
"NaN checking can lead to incorrect results");
|
||
|
|
unsigned NoteID = Diag.getDiagnosticIDs()->getCustomDiagID(
|
||
|
|
DiagnosticIDs::Note, "consider using mozilla::IsNaN instead");
|
||
|
|
const BinaryOperator *Expression = Result.Nodes.getNodeAs<BinaryOperator>(
|
||
|
|
"node");
|
||
|
|
const DeclRefExpr *LHS = Result.Nodes.getNodeAs<DeclRefExpr>("lhs");
|
||
|
|
const DeclRefExpr *RHS = Result.Nodes.getNodeAs<DeclRefExpr>("rhs");
|
||
|
|
const ImplicitCastExpr *LHSExpr = dyn_cast<ImplicitCastExpr>(
|
||
|
|
Expression->getLHS());
|
||
|
|
const ImplicitCastExpr *RHSExpr = dyn_cast<ImplicitCastExpr>(
|
||
|
|
Expression->getRHS());
|
||
|
|
// The AST subtree that we are looking for will look like this:
|
||
|
|
// -BinaryOperator ==/!=
|
||
|
|
// |-ImplicitCastExpr LValueToRValue
|
||
|
|
// | |-DeclRefExpr
|
||
|
|
// |-ImplicitCastExpr LValueToRValue
|
||
|
|
// |-DeclRefExpr
|
||
|
|
// The check below ensures that we are dealing with the correct AST subtree
|
||
|
|
// shape, and
|
||
|
|
// also that both of the found DeclRefExpr's point to the same declaration.
|
||
|
|
if (LHS->getFoundDecl() == RHS->getFoundDecl() && LHSExpr && RHSExpr &&
|
||
|
|
std::distance(LHSExpr->child_begin(), LHSExpr->child_end()) == 1 &&
|
||
|
|
std::distance(RHSExpr->child_begin(), RHSExpr->child_end()) == 1 &&
|
||
|
|
*LHSExpr->child_begin() == LHS && *RHSExpr->child_begin() == RHS) {
|
||
|
|
Diag.Report(Expression->getLocStart(), ErrorID);
|
||
|
|
Diag.Report(Expression->getLocStart(), NoteID);
|
||
|
|
}
|
||
|
|
}
|