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/*
This file is part of the clazy static checker.
Copyright (C) 2015 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com
Author: Sérgio Martins <sergio.martins@kdab.com>
Copyright (C) 2015 Sergio Martins <smartins@kde.org>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
#include "implicitcasts.h"
#include "ClazyContext.h"
#include "Utils.h"
#include "HierarchyUtils.h"
#include "checkmanager.h"
#include "StringUtils.h"
#include <clang/AST/AST.h>
#include <clang/Lex/Lexer.h>
using namespace clang;
using namespace std;
ImplicitCasts::ImplicitCasts(const std::string &name, ClazyContext *context)
: CheckBase(name, context)
{
m_filesToIgnore = { "qobject_impl.h", "qdebug.h", "hb-", "qdbusintegrator.cpp",
"harfbuzz-", "qunicodetools.cpp" };
}
static bool isInterestingFunction(FunctionDecl *func)
{
if (!func)
return false;
// The interesting function calls for the pointertoBool check are those having bool and also pointer arguments,
// which might get mixed
bool hasBoolArgument = false;
bool hasPointerArgument = false;
for (auto param : Utils::functionParameters(func)) {
const Type *t = param->getType().getTypePtrOrNull();
hasBoolArgument |= (t && t->isBooleanType());
hasPointerArgument |= (t && t->isPointerType());
if (hasBoolArgument && hasPointerArgument)
return true;
}
return false;
}
// Checks for pointer->bool implicit casts
template <typename T>
static bool iterateCallExpr(T* callExpr, CheckBase *check)
{
if (!callExpr)
return false;
bool result = false;
int i = 0;
for (auto arg : callExpr->arguments()) {
++i;
auto implicitCast = dyn_cast<ImplicitCastExpr>(arg);
if (!implicitCast || implicitCast->getCastKind() != clang::CK_PointerToBoolean)
continue;
check->emitWarning(implicitCast->getLocStart(), "Implicit pointer to bool cast (argument " + std::to_string(i) + ')');
result = true;
}
return result;
}
// Checks for bool->int implicit casts
template <typename T>
static bool iterateCallExpr2(T* callExpr, CheckBase *check, ParentMap *parentMap)
{
if (!callExpr)
return false;
bool result = false;
int i = 0;
for (auto arg : callExpr->arguments()) {
++i;
auto implicitCast = dyn_cast<ImplicitCastExpr>(arg);
if (!implicitCast || implicitCast->getCastKind() != clang::CK_IntegralCast)
continue;
if (implicitCast->getType().getTypePtrOrNull()->isBooleanType())
continue;
Expr *expr = implicitCast->getSubExpr();
QualType qt = expr->getType();
if (!qt.getTypePtrOrNull()->isBooleanType()) // Filter out some bool to const bool
continue;
if (HierarchyUtils::getFirstChildOfType<CXXFunctionalCastExpr>(implicitCast))
continue;
if (HierarchyUtils::getFirstChildOfType<CStyleCastExpr>(implicitCast))
continue;
if (Utils::isInsideOperatorCall(parentMap, implicitCast, {"QTextStream", "QAtomicInt", "QBasicAtomicInt"}))
continue;
if (Utils::insideCTORCall(parentMap, implicitCast, {"QAtomicInt", "QBasicAtomicInt"}))
continue;
check->emitWarning(implicitCast->getLocStart(), "Implicit bool to int cast (argument " + std::to_string(i) + ')');
result = true;
}
return result;
}
void ImplicitCasts::VisitStmt(clang::Stmt *stmt)
{
// Lets check only in function calls. Otherwise there are too many false positives, it's common
// to implicit cast to bool when checking pointers for validity, like if (ptr)
CallExpr *callExpr = dyn_cast<CallExpr>(stmt);
auto ctorExpr = dyn_cast<CXXConstructExpr>(stmt);
if (!callExpr && !ctorExpr)
return;
if (isa<CXXOperatorCallExpr>(stmt))
return;
if (isMacroToIgnore(stmt->getLocStart()))
return;
if (shouldIgnoreFile(stmt->getLocStart()))
return;
FunctionDecl *func = callExpr ? callExpr->getDirectCallee()
: ctorExpr->getConstructor();
if (isInterestingFunction(func)) {
// Check pointer->bool implicit casts
iterateCallExpr<CallExpr>(callExpr, this);
iterateCallExpr<CXXConstructExpr>(ctorExpr, this);
} else if (isBoolToInt(func)) {
// Check bool->int implicit casts
iterateCallExpr2<CallExpr>(callExpr, this, m_context->parentMap);
iterateCallExpr2<CXXConstructExpr>(ctorExpr, this, m_context->parentMap);
}
}
bool ImplicitCasts::isBoolToInt(FunctionDecl *func) const
{
if (!func || !isOptionSet("bool-to-int"))
return false;
if (func->getLanguageLinkage() != CXXLanguageLinkage || func->isVariadic())
return false; // Disabled for now, too many false-positives when interacting with C code
static const vector<string> functions = {"QString::arg"};
return !clazy_std::contains(functions, func->getQualifiedNameAsString());
}
bool ImplicitCasts::isMacroToIgnore(SourceLocation loc) const
{
static const vector<string> macros = {"QVERIFY", "Q_UNLIKELY", "Q_LIKELY"};
auto macro = Lexer::getImmediateMacroName(loc, sm(), lo());
return clazy_std::contains(macros, macro);
}
std::vector<string> ImplicitCasts::supportedOptions() const
{
static const vector<string> options = { "bool-to-int" };
return options;
}
REGISTER_CHECK("implicit-casts", ImplicitCasts, CheckLevel2)
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