/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2023 Cppcheck team.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*/
//---------------------------------------------------------------------------
#include "astutils.h"
#include "config.h"
#include "errortypes.h"
#include "findtoken.h"
#include "infer.h"
#include "library.h"
#include "mathlib.h"
#include "settings.h"
#include "symboldatabase.h"
#include "token.h"
#include "utils.h"
#include "valueflow.h"
#include "valueptr.h"
#include "vfvalue.h"
#include "checkclass.h"
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
const Token* findExpression(const nonneg int exprid,
const Token* start,
const Token* end,
const std::function& pred)
{
if (exprid == 0)
return nullptr;
if (!precedes(start, end))
return nullptr;
for (const Token* tok = start; tok != end; tok = tok->next()) {
if (tok->exprId() != exprid)
continue;
if (pred(tok))
return tok;
}
return nullptr;
}
static int findArgumentPosRecursive(const Token* tok, const Token* tokToFind, bool &found, nonneg int depth=0)
{
++depth;
if (!tok || depth >= 100)
return -1;
if (tok->str() == ",") {
int res = findArgumentPosRecursive(tok->astOperand1(), tokToFind, found, depth);
if (res == -1)
return -1;
if (found)
return res;
const int argn = res;
res = findArgumentPosRecursive(tok->astOperand2(), tokToFind, found, depth);
if (res == -1)
return -1;
return argn + res;
}
if (tokToFind == tok)
found = true;
return 1;
}
static int findArgumentPos(const Token* tok, const Token* tokToFind){
bool found = false;
const int argn = findArgumentPosRecursive(tok, tokToFind, found, 0);
if (found)
return argn - 1;
return -1;
}
static int getArgumentPos(const Token* ftok, const Token* tokToFind){
const Token* tok = ftok;
if (Token::Match(tok, "%name% (|{"))
tok = ftok->next();
if (!Token::Match(tok, "(|{|["))
return -1;
const Token* startTok = tok->astOperand2();
if (!startTok && tok->next() != tok->link())
startTok = tok->astOperand1();
return findArgumentPos(startTok, tokToFind);
}
std::vector astFlatten(const Token* tok, const char* op)
{
std::vector result;
astFlattenCopy(tok, op, std::back_inserter(result));
return result;
}
std::vector astFlatten(Token* tok, const char* op)
{
std::vector result;
astFlattenCopy(tok, op, std::back_inserter(result));
return result;
}
nonneg int astCount(const Token* tok, const char* op, int depth)
{
--depth;
if (!tok || depth < 0)
return 0;
if (tok->str() == op)
return astCount(tok->astOperand1(), op, depth) + astCount(tok->astOperand2(), op, depth);
return 1;
}
bool astHasToken(const Token* root, const Token * tok)
{
if (!root)
return false;
while (tok->astParent() && tok != root)
tok = tok->astParent();
return root == tok;
}
bool astHasVar(const Token * tok, nonneg int varid)
{
if (!tok)
return false;
if (tok->varId() == varid)
return true;
return astHasVar(tok->astOperand1(), varid) || astHasVar(tok->astOperand2(), varid);
}
bool astHasExpr(const Token* tok, nonneg int exprid)
{
if (!tok)
return false;
if (tok->exprId() == exprid)
return true;
return astHasExpr(tok->astOperand1(), exprid) || astHasExpr(tok->astOperand2(), exprid);
}
static bool astIsCharWithSign(const Token *tok, ValueType::Sign sign)
{
if (!tok)
return false;
const ValueType *valueType = tok->valueType();
if (!valueType)
return false;
return valueType->type == ValueType::Type::CHAR && valueType->pointer == 0U && valueType->sign == sign;
}
bool astIsSignedChar(const Token *tok)
{
return astIsCharWithSign(tok, ValueType::Sign::SIGNED);
}
bool astIsUnknownSignChar(const Token *tok)
{
return astIsCharWithSign(tok, ValueType::Sign::UNKNOWN_SIGN);
}
bool astIsGenericChar(const Token* tok)
{
return !astIsPointer(tok) && tok && tok->valueType() && (tok->valueType()->type == ValueType::Type::CHAR || tok->valueType()->type == ValueType::Type::WCHAR_T);
}
bool astIsPrimitive(const Token* tok)
{
const ValueType* vt = tok ? tok->valueType() : nullptr;
if (!vt)
return false;
return vt->isPrimitive();
}
bool astIsIntegral(const Token *tok, bool unknown)
{
const ValueType *vt = tok ? tok->valueType() : nullptr;
if (!vt)
return unknown;
return vt->isIntegral() && vt->pointer == 0U;
}
bool astIsUnsigned(const Token* tok)
{
return tok && tok->valueType() && tok->valueType()->sign == ValueType::UNSIGNED;
}
bool astIsFloat(const Token *tok, bool unknown)
{
const ValueType *vt = tok ? tok->valueType() : nullptr;
if (!vt)
return unknown;
return vt->type >= ValueType::Type::FLOAT && vt->pointer == 0U;
}
bool astIsBool(const Token *tok)
{
return tok && (tok->isBoolean() || (tok->valueType() && tok->valueType()->type == ValueType::Type::BOOL && !tok->valueType()->pointer));
}
bool astIsPointer(const Token *tok)
{
return tok && tok->valueType() && tok->valueType()->pointer;
}
bool astIsSmartPointer(const Token* tok)
{
return tok && tok->valueType() && tok->valueType()->smartPointerTypeToken;
}
bool astIsUniqueSmartPointer(const Token* tok)
{
if (!astIsSmartPointer(tok))
return false;
if (!tok->valueType()->smartPointer)
return false;
return tok->valueType()->smartPointer->unique;
}
bool astIsIterator(const Token *tok)
{
return tok && tok->valueType() && tok->valueType()->type == ValueType::Type::ITERATOR;
}
bool astIsContainer(const Token* tok) {
return getLibraryContainer(tok) != nullptr && !astIsIterator(tok);
}
bool astIsContainerView(const Token* tok)
{
const Library::Container* container = getLibraryContainer(tok);
return container && !astIsIterator(tok) && container->view;
}
bool astIsContainerOwned(const Token* tok) {
return astIsContainer(tok) && !astIsContainerView(tok);
}
bool astIsContainerString(const Token* tok)
{
if (!tok)
return false;
if (!tok->valueType())
return false;
const Library::Container* container = tok->valueType()->container;
if (!container)
return false;
return container->stdStringLike;
}
static const Token* getContainerFunction(const Token* tok)
{
if (!tok || !tok->valueType() || !tok->valueType()->container)
return nullptr;
const Token* parent = tok->astParent();
if (Token::Match(parent, ". %name% (") && astIsLHS(tok)) {
return parent->next();
}
return nullptr;
}
Library::Container::Action astContainerAction(const Token* tok, const Token** ftok)
{
const Token* ftok2 = getContainerFunction(tok);
if (ftok)
*ftok = ftok2;
if (!ftok2)
return Library::Container::Action::NO_ACTION;
return tok->valueType()->container->getAction(ftok2->str());
}
Library::Container::Yield astContainerYield(const Token* tok, const Token** ftok)
{
const Token* ftok2 = getContainerFunction(tok);
if (ftok)
*ftok = ftok2;
if (!ftok2)
return Library::Container::Yield::NO_YIELD;
return tok->valueType()->container->getYield(ftok2->str());
}
Library::Container::Yield astFunctionYield(const Token* tok, const Settings* settings, const Token** ftok)
{
if (!tok)
return Library::Container::Yield::NO_YIELD;
const auto* function = settings->library.getFunction(tok);
if (!function)
return Library::Container::Yield::NO_YIELD;
if (ftok)
*ftok = tok;
return function->containerYield;
}
bool astIsRangeBasedForDecl(const Token* tok)
{
return Token::simpleMatch(tok->astParent(), ":") && Token::simpleMatch(tok->astParent()->astParent(), "(");
}
std::string astCanonicalType(const Token *expr, bool pointedToType)
{
if (!expr)
return "";
std::pair decl = Token::typeDecl(expr, pointedToType);
if (decl.first && decl.second) {
std::string ret;
for (const Token *type = decl.first; Token::Match(type,"%name%|::") && type != decl.second; type = type->next()) {
if (!Token::Match(type, "const|static"))
ret += type->str();
}
return ret;
}
return "";
}
static bool match(const Token *tok, const std::string &rhs)
{
if (tok->str() == rhs)
return true;
if (!tok->varId() && tok->hasKnownIntValue() && std::to_string(tok->values().front().intvalue) == rhs)
return true;
return false;
}
const Token * astIsVariableComparison(const Token *tok, const std::string &comp, const std::string &rhs, const Token **vartok)
{
if (!tok)
return nullptr;
const Token *ret = nullptr;
if (tok->isComparisonOp()) {
if (tok->astOperand1() && match(tok->astOperand1(), rhs)) {
// Invert comparator
std::string s = tok->str();
if (s[0] == '>')
s[0] = '<';
else if (s[0] == '<')
s[0] = '>';
if (s == comp) {
ret = tok->astOperand2();
}
} else if (tok->str() == comp && tok->astOperand2() && match(tok->astOperand2(), rhs)) {
ret = tok->astOperand1();
}
} else if (comp == "!=" && rhs == "0") {
if (tok->str() == "!") {
ret = tok->astOperand1();
// handle (!(x==0)) as (x!=0)
astIsVariableComparison(ret, "==", "0", &ret);
} else
ret = tok;
} else if (comp == "==" && rhs == "0") {
if (tok->str() == "!") {
ret = tok->astOperand1();
// handle (!(x!=0)) as (x==0)
astIsVariableComparison(ret, "!=", "0", &ret);
}
}
while (ret && ret->str() == ".")
ret = ret->astOperand2();
if (ret && ret->str() == "=" && ret->astOperand1() && ret->astOperand1()->varId())
ret = ret->astOperand1();
else if (ret && ret->varId() == 0U)
ret = nullptr;
if (vartok)
*vartok = ret;
return ret;
}
bool isVariableDecl(const Token* tok)
{
if (!tok)
return false;
const Variable* var = tok->variable();
if (!var)
return false;
if (var->nameToken() == tok)
return true;
const Token * const varDeclEndToken = var->declEndToken();
return Token::Match(varDeclEndToken, "; %var%") && varDeclEndToken->next() == tok;
}
bool isStlStringType(const Token* tok)
{
return Token::Match(tok, "std :: string|wstring|u16string|u32string !!::") ||
(Token::simpleMatch(tok, "std :: basic_string <") && !Token::simpleMatch(tok->linkAt(3), "> ::"));
}
bool isTemporary(bool cpp, const Token* tok, const Library* library, bool unknown)
{
if (!tok)
return false;
if (Token::simpleMatch(tok, "."))
return (tok->originalName() != "->" && isTemporary(cpp, tok->astOperand1(), library)) ||
isTemporary(cpp, tok->astOperand2(), library);
if (Token::Match(tok, ",|::"))
return isTemporary(cpp, tok->astOperand2(), library);
if (tok->isCast() || (cpp && isCPPCast(tok)))
return isTemporary(cpp, tok->astOperand2(), library);
if (Token::Match(tok, ".|[|++|--|%name%|%assign%"))
return false;
if (tok->isUnaryOp("*"))
return false;
if (Token::Match(tok, "&|<<|>>") && isLikelyStream(cpp, tok->astOperand1()))
return false;
if (Token::simpleMatch(tok, "?")) {
const Token* branchTok = tok->astOperand2();
if (!branchTok->astOperand1() || !branchTok->astOperand1()->valueType())
return false;
if (!branchTok->astOperand2()->valueType())
return false;
return !branchTok->astOperand1()->valueType()->isTypeEqual(branchTok->astOperand2()->valueType());
}
if (Token::simpleMatch(tok, "(") && tok->astOperand1() &&
(tok->astOperand2() || Token::simpleMatch(tok->next(), ")"))) {
if (Token::simpleMatch(tok->astOperand1(), "typeid"))
return false;
if (tok->valueType()) {
return tok->valueType()->reference == Reference::None;
}
const Token* ftok = nullptr;
if (Token::simpleMatch(tok->previous(), ">") && tok->previous()->link())
ftok = tok->previous()->link()->previous();
else
ftok = tok->previous();
if (!ftok)
return false;
if (const Function * f = ftok->function())
return !Function::returnsReference(f, true);
if (ftok->type())
return true;
if (library) {
std::string returnType = library->returnValueType(ftok);
return !returnType.empty() && returnType.back() != '&';
}
return unknown;
}
if (tok->isCast())
return false;
// Currying a function is unknown in cppcheck
if (Token::simpleMatch(tok, "(") && Token::simpleMatch(tok->astOperand1(), "("))
return unknown;
if (Token::simpleMatch(tok, "{") && Token::simpleMatch(tok->astParent(), "return") && tok->astOperand1() &&
!tok->astOperand2())
return isTemporary(cpp, tok->astOperand1(), library);
return true;
}
static bool isFunctionCall(const Token* tok)
{
if (Token::Match(tok, "%name% ("))
return true;
if (Token::Match(tok, "%name% <") && Token::simpleMatch(tok->next()->link(), "> ("))
return true;
if (Token::Match(tok, "%name% ::"))
return isFunctionCall(tok->tokAt(2));
return false;
}
static bool hasToken(const Token * startTok, const Token * stopTok, const Token * tok)
{
for (const Token * tok2 = startTok; tok2 != stopTok; tok2 = tok2->next()) {
if (tok2 == tok)
return true;
}
return false;
}
template )>
static T* previousBeforeAstLeftmostLeafGeneric(T* tok)
{
if (!tok)
return nullptr;
T* leftmostLeaf = tok;
while (leftmostLeaf->astOperand1())
leftmostLeaf = leftmostLeaf->astOperand1();
return leftmostLeaf->previous();
}
const Token* previousBeforeAstLeftmostLeaf(const Token* tok)
{
return previousBeforeAstLeftmostLeafGeneric(tok);
}
Token* previousBeforeAstLeftmostLeaf(Token* tok)
{
return previousBeforeAstLeftmostLeafGeneric(tok);
}
template )>
static T* nextAfterAstRightmostLeafGeneric(T* tok)
{
T * rightmostLeaf = tok;
if (!rightmostLeaf || !rightmostLeaf->astOperand1())
return nullptr;
do {
if (T* lam = findLambdaEndToken(rightmostLeaf)) {
rightmostLeaf = lam;
break;
}
if (rightmostLeaf->astOperand2() && precedes(rightmostLeaf, rightmostLeaf->astOperand2()))
rightmostLeaf = rightmostLeaf->astOperand2();
else if (rightmostLeaf->astOperand1() && precedes(rightmostLeaf, rightmostLeaf->astOperand1()))
rightmostLeaf = rightmostLeaf->astOperand1();
else
break;
} while (rightmostLeaf->astOperand1() || rightmostLeaf->astOperand2());
while (Token::Match(rightmostLeaf->next(), "]|)") && !hasToken(rightmostLeaf->next()->link(), rightmostLeaf->next(), tok))
rightmostLeaf = rightmostLeaf->next();
if (Token::Match(rightmostLeaf, "{|(|[") && rightmostLeaf->link())
rightmostLeaf = rightmostLeaf->link();
return rightmostLeaf->next();
}
const Token* nextAfterAstRightmostLeaf(const Token* tok)
{
return nextAfterAstRightmostLeafGeneric(tok);
}
Token* nextAfterAstRightmostLeaf(Token* tok)
{
return nextAfterAstRightmostLeafGeneric(tok);
}
const Token* astParentSkipParens(const Token* tok)
{
return astParentSkipParens(const_cast(tok));
}
Token* astParentSkipParens(Token* tok)
{
if (!tok)
return nullptr;
Token * parent = tok->astParent();
if (!Token::simpleMatch(parent, "("))
return parent;
if (parent->link() != nextAfterAstRightmostLeaf(tok))
return parent;
if (Token::Match(parent->previous(), "%name% (") ||
(Token::simpleMatch(parent->previous(), "> (") && parent->previous()->link()))
return parent;
return astParentSkipParens(parent);
}
const Token* getParentMember(const Token * tok)
{
if (!tok)
return tok;
const Token * parent = tok->astParent();
if (!Token::simpleMatch(parent, "."))
return tok;
if (astIsRHS(tok)) {
if (Token::simpleMatch(parent->astOperand1(), "."))
return parent->astOperand1()->astOperand2();
return parent->astOperand1();
}
const Token * gparent = parent->astParent();
if (!Token::simpleMatch(gparent, ".") || gparent->astOperand2() != parent)
return tok;
if (gparent->astOperand1())
return gparent->astOperand1();
return tok;
}
const Token* getParentLifetime(const Token* tok)
{
if (!tok)
return tok;
// Skipping checking for variable if its a pointer-to-member
if (!Token::simpleMatch(tok->previous(), ". *")) {
const Variable* var = tok->variable();
// TODO: Call getLifetimeVariable for deeper analysis
if (!var)
return tok;
if (var->isLocal() || var->isArgument())
return tok;
}
const Token* parent = getParentMember(tok);
if (parent != tok)
return getParentLifetime(parent);
return tok;
}
static std::vector getParentMembers(const Token* tok)
{
if (!tok)
return {};
if (!Token::simpleMatch(tok->astParent(), "."))
return {tok};
const Token* parent = tok->astParent();
while (Token::simpleMatch(parent->astParent(), "."))
parent = parent->astParent();
std::vector result;
for (const Token* tok2 : astFlatten(parent, ".")) {
if (Token::simpleMatch(tok2, "(") && Token::simpleMatch(tok2->astOperand1(), ".")) {
std::vector sub = getParentMembers(tok2->astOperand1());
result.insert(result.end(), sub.cbegin(), sub.cend());
}
result.push_back(tok2);
}
return result;
}
const Token* getParentLifetime(bool cpp, const Token* tok, const Library* library)
{
std::vector members = getParentMembers(tok);
if (members.size() < 2)
return tok;
// Find the first local variable or temporary
auto it = std::find_if(members.crbegin(), members.crend(), [&](const Token* tok2) {
const Variable* var = tok2->variable();
if (var)
return var->isLocal() || var->isArgument();
return isTemporary(cpp, tok2, library);
});
if (it == members.rend())
return tok;
// If any of the submembers are borrowed types then stop
if (std::any_of(it.base() - 1, members.cend() - 1, [&](const Token* tok2) {
if (astIsPointer(tok2) || astIsContainerView(tok2) || astIsIterator(tok2))
return true;
if (!astIsUniqueSmartPointer(tok2)) {
if (astIsSmartPointer(tok2))
return true;
const Token* dotTok = tok2->next();
if (!Token::simpleMatch(dotTok, ".")) {
const Token* endTok = nextAfterAstRightmostLeaf(tok2);
if (!endTok)
dotTok = tok2->next();
else if (Token::simpleMatch(endTok, "."))
dotTok = endTok;
else if (Token::simpleMatch(endTok->next(), "."))
dotTok = endTok->next();
}
// If we are dereferencing the member variable then treat it as borrowed
if (Token::simpleMatch(dotTok, ".") && dotTok->originalName() == "->")
return true;
}
const Variable* var = tok2->variable();
return var && var->isReference();
}))
return nullptr;
return *it;
}
static bool isInConstructorList(const Token* tok)
{
if (!tok)
return false;
if (!astIsRHS(tok))
return false;
const Token* parent = tok->astParent();
if (!Token::Match(parent, "{|("))
return false;
if (!Token::Match(parent->previous(), "%var% {|("))
return false;
if (!parent->astOperand1() || !parent->astOperand2())
return false;
do {
parent = parent->astParent();
} while (Token::simpleMatch(parent, ","));
return Token::simpleMatch(parent, ":") && !Token::simpleMatch(parent->astParent(), "?");
}
std::vector getParentValueTypes(const Token* tok, const Settings* settings, const Token** parent)
{
if (!tok)
return {};
if (!tok->astParent())
return {};
if (isInConstructorList(tok)) {
if (parent)
*parent = tok->astParent()->astOperand1();
if (tok->astParent()->astOperand1()->valueType())
return {*tok->astParent()->astOperand1()->valueType()};
return {};
}
const Token* ftok = nullptr;
if (Token::Match(tok->astParent(), "(|{|,")) {
int argn = -1;
ftok = getTokenArgumentFunction(tok, argn);
const Token* typeTok = nullptr;
if (ftok && argn >= 0) {
if (ftok->function()) {
std::vector result;
const Token* nameTok = nullptr;
for (const Variable* var : getArgumentVars(ftok, argn)) {
if (!var)
continue;
if (!var->valueType())
continue;
nameTok = var->nameToken();
result.push_back(*var->valueType());
}
if (result.size() == 1 && nameTok && parent) {
*parent = nameTok;
}
return result;
}
if (const Type* t = Token::typeOf(ftok, &typeTok)) {
if (astIsPointer(typeTok))
return {*typeTok->valueType()};
const Scope* scope = t->classScope;
// Check for aggregate constructors
if (scope && scope->numConstructors == 0 && t->derivedFrom.empty() &&
(t->isClassType() || t->isStructType()) && numberOfArguments(ftok) <= scope->varlist.size() &&
!scope->varlist.empty()) {
assert(argn < scope->varlist.size());
auto it = std::next(scope->varlist.cbegin(), argn);
if (it->valueType())
return {*it->valueType()};
}
}
}
}
if (settings && Token::Match(tok->astParent()->tokAt(-2), ". push_back|push_front|insert|push (") &&
astIsContainer(tok->astParent()->tokAt(-2)->astOperand1())) {
const Token* contTok = tok->astParent()->tokAt(-2)->astOperand1();
const ValueType* vtCont = contTok->valueType();
if (!vtCont->containerTypeToken)
return {};
ValueType vtParent = ValueType::parseDecl(vtCont->containerTypeToken, *settings);
return {std::move(vtParent)};
}
// The return type of a function is not the parent valuetype
if (Token::simpleMatch(tok->astParent(), "(") && ftok && !tok->astParent()->isCast() &&
ftok->tokType() != Token::eType)
return {};
if (Token::Match(tok->astParent(), "return|(|{|%assign%") && parent) {
*parent = tok->astParent();
}
if (tok->astParent()->valueType())
return {*tok->astParent()->valueType()};
return {};
}
bool astIsLHS(const Token* tok)
{
if (!tok)
return false;
const Token* parent = tok->astParent();
if (!parent)
return false;
if (!parent->astOperand1())
return false;
if (!parent->astOperand2())
return false;
return parent->astOperand1() == tok;
}
bool astIsRHS(const Token* tok)
{
if (!tok)
return false;
const Token* parent = tok->astParent();
if (!parent)
return false;
if (!parent->astOperand1())
return false;
if (!parent->astOperand2())
return false;
return parent->astOperand2() == tok;
}
template )>
static T* getCondTokImpl(T* tok)
{
if (!tok)
return nullptr;
if (Token::simpleMatch(tok, "("))
return getCondTok(tok->previous());
if (Token::simpleMatch(tok, "for") && Token::simpleMatch(tok->next()->astOperand2(), ";") &&
tok->next()->astOperand2()->astOperand2())
return tok->next()->astOperand2()->astOperand2()->astOperand1();
if (Token::simpleMatch(tok->next()->astOperand2(), ";"))
return tok->next()->astOperand2()->astOperand1();
return tok->next()->astOperand2();
}
template )>
static T* getCondTokFromEndImpl(T* endBlock)
{
if (!Token::simpleMatch(endBlock, "}"))
return nullptr;
T* startBlock = endBlock->link();
if (!Token::simpleMatch(startBlock, "{"))
return nullptr;
if (Token::simpleMatch(startBlock->previous(), ")"))
return getCondTok(startBlock->previous()->link());
if (Token::simpleMatch(startBlock->tokAt(-2), "} else {"))
return getCondTokFromEnd(startBlock->tokAt(-2));
return nullptr;
}
template )>
static T* getInitTokImpl(T* tok)
{
if (!tok)
return nullptr;
if (Token::Match(tok, "%name% ("))
return getInitTokImpl(tok->next());
if (tok->str() != "(")
return nullptr;
if (!Token::simpleMatch(tok->astOperand2(), ";"))
return nullptr;
if (Token::simpleMatch(tok->astOperand2()->astOperand1(), ";"))
return nullptr;
return tok->astOperand2()->astOperand1();
}
template )>
static T* getStepTokImpl(T* tok)
{
if (!tok)
return nullptr;
if (Token::Match(tok, "%name% ("))
return getStepTokImpl(tok->next());
if (tok->str() != "(")
return nullptr;
if (!Token::simpleMatch(tok->astOperand2(), ";"))
return nullptr;
if (!Token::simpleMatch(tok->astOperand2()->astOperand2(), ";"))
return nullptr;
return tok->astOperand2()->astOperand2()->astOperand2();
}
Token* getCondTok(Token* tok)
{
return getCondTokImpl(tok);
}
const Token* getCondTok(const Token* tok)
{
return getCondTokImpl(tok);
}
Token* getCondTokFromEnd(Token* endBlock)
{
return getCondTokFromEndImpl(endBlock);
}
const Token* getCondTokFromEnd(const Token* endBlock)
{
return getCondTokFromEndImpl(endBlock);
}
Token* getInitTok(Token* tok) {
return getInitTokImpl(tok);
}
const Token* getInitTok(const Token* tok) {
return getInitTokImpl(tok);
}
Token* getStepTok(Token* tok) {
return getStepTokImpl(tok);
}
const Token* getStepTok(const Token* tok) {
return getStepTokImpl(tok);
}
const Token *findNextTokenFromBreak(const Token *breakToken)
{
const Scope *scope = breakToken->scope();
while (scope) {
if (scope->isLoopScope() || scope->type == Scope::ScopeType::eSwitch) {
if (scope->type == Scope::ScopeType::eDo && Token::simpleMatch(scope->bodyEnd, "} while ("))
return scope->bodyEnd->linkAt(2)->next();
return scope->bodyEnd;
}
scope = scope->nestedIn;
}
return nullptr;
}
bool extractForLoopValues(const Token *forToken,
nonneg int &varid,
bool &knownInitValue,
MathLib::bigint &initValue,
bool &partialCond,
MathLib::bigint &stepValue,
MathLib::bigint &lastValue)
{
if (!Token::simpleMatch(forToken, "for (") || !Token::simpleMatch(forToken->next()->astOperand2(), ";"))
return false;
const Token *initExpr = forToken->next()->astOperand2()->astOperand1();
const Token *condExpr = forToken->next()->astOperand2()->astOperand2()->astOperand1();
const Token *incExpr = forToken->next()->astOperand2()->astOperand2()->astOperand2();
if (!initExpr || !initExpr->isBinaryOp() || initExpr->str() != "=" || !Token::Match(initExpr->astOperand1(), "%var%"))
return false;
std::vector minInitValue = getMinValue(ValueFlow::makeIntegralInferModel(), initExpr->astOperand2()->values());
if (minInitValue.empty()) {
const ValueFlow::Value* v = initExpr->astOperand2()->getMinValue(true);
if (v)
minInitValue.push_back(v->intvalue);
}
if (minInitValue.empty())
return false;
varid = initExpr->astOperand1()->varId();
knownInitValue = initExpr->astOperand2()->hasKnownIntValue();
initValue = minInitValue.front();
partialCond = Token::Match(condExpr, "%oror%|&&");
visitAstNodes(condExpr, [varid, &condExpr](const Token *tok) {
if (Token::Match(tok, "%oror%|&&"))
return ChildrenToVisit::op1_and_op2;
if (Token::Match(tok, "<|<=") && tok->isBinaryOp() && tok->astOperand1()->varId() == varid && tok->astOperand2()->hasKnownIntValue()) {
if (Token::Match(condExpr, "%oror%|&&") || tok->astOperand2()->getKnownIntValue() < condExpr->astOperand2()->getKnownIntValue())
condExpr = tok;
}
return ChildrenToVisit::none;
});
if (!Token::Match(condExpr, "<|<=") || !condExpr->isBinaryOp() || condExpr->astOperand1()->varId() != varid || !condExpr->astOperand2()->hasKnownIntValue())
return false;
if (!incExpr || !incExpr->isUnaryOp("++") || incExpr->astOperand1()->varId() != varid)
return false;
stepValue = 1;
if (condExpr->str() == "<")
lastValue = condExpr->astOperand2()->getKnownIntValue() - 1;
else
lastValue = condExpr->astOperand2()->getKnownIntValue();
return true;
}
static const Token * getVariableInitExpression(const Variable * var)
{
if (!var)
return nullptr;
const Token *varDeclEndToken = var->declEndToken();
if (!varDeclEndToken)
return nullptr;
if (Token::Match(varDeclEndToken, "; %varid% =", var->declarationId()))
return varDeclEndToken->tokAt(2)->astOperand2();
return varDeclEndToken->astOperand2();
}
const Token* isInLoopCondition(const Token* tok)
{
const Token* top = tok->astTop();
return top && Token::Match(top->previous(), "for|while (") ? top : nullptr;
}
/// If tok2 comes after tok1
bool precedes(const Token * tok1, const Token * tok2)
{
if (tok1 == tok2)
return false;
if (!tok1)
return false;
if (!tok2)
return true;
return tok1->index() < tok2->index();
}
/// If tok1 comes after tok2
bool succeeds(const Token* tok1, const Token* tok2)
{
if (tok1 == tok2)
return false;
if (!tok1)
return false;
if (!tok2)
return true;
return tok1->index() > tok2->index();
}
bool isAliasOf(const Token *tok, nonneg int varid, bool* inconclusive)
{
if (tok->varId() == varid)
return false;
// NOLINTNEXTLINE(readability-use-anyofallof) - TODO: fix this / also Cppcheck false negative
for (const ValueFlow::Value &val : tok->values()) {
if (!val.isLocalLifetimeValue())
continue;
if (val.tokvalue->varId() == varid) {
if (val.isInconclusive()) {
if (inconclusive)
*inconclusive = true;
else
continue;
}
return true;
}
}
return false;
}
bool isAliasOf(const Token* tok, const Token* expr, int* indirect, bool* inconclusive)
{
const ValueFlow::Value* value = nullptr;
const Token* r = nullptr;
if (indirect)
*indirect = 1;
for (const ReferenceToken& ref : followAllReferences(tok)) {
const bool pointer = astIsPointer(ref.token);
r = findAstNode(expr, [&](const Token* childTok) {
if (childTok->exprId() == 0)
return false;
if (ref.token != tok && expr->exprId() == childTok->exprId()) {
if (indirect)
*indirect = 0;
return true;
}
for (const ValueFlow::Value& val : ref.token->values()) {
if (val.isImpossible())
continue;
if (val.isLocalLifetimeValue() || (pointer && val.isSymbolicValue() && val.intvalue == 0)) {
if (findAstNode(val.tokvalue,
[&](const Token* aliasTok) {
return aliasTok != childTok && aliasTok->exprId() == childTok->exprId();
})) {
if (val.isInconclusive() && inconclusive != nullptr) {
value = &val;
} else {
return true;
}
}
}
}
return false;
});
if (r)
break;
}
if (!r && value && inconclusive)
*inconclusive = true;
return r || value;
}
static bool isAliased(const Token *startTok, const Token *endTok, nonneg int varid)
{
if (!precedes(startTok, endTok))
return false;
for (const Token *tok = startTok; tok != endTok; tok = tok->next()) {
if (Token::Match(tok, "= & %varid% ;", varid))
return true;
if (isAliasOf(tok, varid))
return true;
}
return false;
}
bool isAliased(const Variable *var)
{
if (!var)
return false;
if (!var->scope())
return false;
const Token *start = var->declEndToken();
if (!start)
return false;
return isAliased(start, var->scope()->bodyEnd, var->declarationId());
}
bool exprDependsOnThis(const Token* expr, bool onVar, nonneg int depth)
{
if (!expr)
return false;
if (expr->str() == "this")
return true;
if (depth >= 1000)
// Abort recursion to avoid stack overflow
return true;
++depth;
// calling nonstatic method?
if (Token::Match(expr, "%name% (") && expr->function() && expr->function()->nestedIn && expr->function()->nestedIn->isClassOrStruct() && !expr->function()->isStatic()) {
// is it a method of this?
const Scope* fScope = expr->scope();
while (!fScope->functionOf && fScope->nestedIn)
fScope = fScope->nestedIn;
const Scope* classScope = fScope->functionOf;
if (classScope && classScope->function)
classScope = classScope->function->token->scope();
if (classScope && classScope->isClassOrStruct())
return contains(classScope->findAssociatedScopes(), expr->function()->nestedIn);
return false;
}
if (onVar && expr->variable()) {
const Variable* var = expr->variable();
return ((var->isPrivate() || var->isPublic() || var->isProtected()) && !var->isStatic());
}
if (Token::simpleMatch(expr, "."))
return exprDependsOnThis(expr->astOperand1(), onVar, depth);
return exprDependsOnThis(expr->astOperand1(), onVar, depth) || exprDependsOnThis(expr->astOperand2(), onVar, depth);
}
static bool hasUnknownVars(const Token* startTok)
{
bool result = false;
visitAstNodes(startTok, [&](const Token* tok) {
if (tok->varId() > 0 && !tok->variable()) {
result = true;
return ChildrenToVisit::done;
}
return ChildrenToVisit::op1_and_op2;
});
return result;
}
bool isStructuredBindingVariable(const Variable* var)
{
if (!var)
return false;
const Token* tok = var->nameToken();
while (tok && Token::Match(tok->astParent(), "[|,|:"))
tok = tok->astParent();
return tok && (tok->str() == "[" || Token::simpleMatch(tok->previous(), "] :")); // TODO: remove workaround when #11105 is fixed
}
/// This takes a token that refers to a variable and it will return the token
/// to the expression that the variable is assigned to. If its not valid to
/// make such substitution then it will return the original token.
static const Token * followVariableExpression(const Token * tok, bool cpp, const Token * end = nullptr)
{
if (!tok)
return tok;
// Skip following variables that is across multiple files
if (end && end->fileIndex() != tok->fileIndex())
return tok;
// Skip array access
if (Token::Match(tok, "%var% ["))
return tok;
// Skip pointer indirection
if (tok->astParent() && tok->isUnaryOp("*"))
return tok;
// Skip following variables if it is used in an assignment
if (Token::Match(tok->next(), "%assign%"))
return tok;
const Variable * var = tok->variable();
const Token * varTok = getVariableInitExpression(var);
if (!varTok)
return tok;
if (hasUnknownVars(varTok))
return tok;
if (var->isVolatile())
return tok;
if (!var->isLocal() && !var->isConst())
return tok;
if (var->isStatic() && !var->isConst())
return tok;
if (var->isArgument())
return tok;
if (isStructuredBindingVariable(var))
return tok;
// assigning a floating point value to an integer does not preserve the value
if (var->valueType() && var->valueType()->isIntegral() && varTok->valueType() && varTok->valueType()->isFloat())
return tok;
const Token * lastTok = precedes(tok, end) ? end : tok;
// If this is in a loop then check if variables are modified in the entire scope
const Token * endToken = (isInLoopCondition(tok) || isInLoopCondition(varTok) || var->scope() != tok->scope()) ? var->scope()->bodyEnd : lastTok;
if (!var->isConst() && (!precedes(varTok, endToken) || isVariableChanged(varTok, endToken, tok->varId(), false, nullptr, cpp)))
return tok;
if (precedes(varTok, endToken) && isAliased(varTok, endToken, tok->varId()))
return tok;
const Token* startToken = nextAfterAstRightmostLeaf(varTok);
if (!startToken)
startToken = varTok;
if (varTok->exprId() == 0) {
if (!varTok->isLiteral())
return tok;
} else if (!precedes(startToken, endToken)) {
return tok;
} else if (findExpressionChanged(varTok, startToken, endToken, nullptr, cpp)) {
return tok;
}
return varTok;
}
static void followVariableExpressionError(const Token *tok1, const Token *tok2, ErrorPath* errors)
{
if (!errors)
return;
if (!tok1)
return;
if (!tok2)
return;
ErrorPathItem item = std::make_pair(tok2, "'" + tok1->str() + "' is assigned value '" + tok2->expressionString() + "' here.");
if (std::find(errors->cbegin(), errors->cend(), item) != errors->cend())
return;
errors->push_back(std::move(item));
}
SmallVector followAllReferences(const Token* tok,
bool temporary,
bool inconclusive,
ErrorPath errors,
int depth)
{
struct ReferenceTokenLess {
bool operator()(const ReferenceToken& x, const ReferenceToken& y) const {
return x.token < y.token;
}
};
if (!tok)
return {};
if (depth < 0) {
SmallVector refs_result;
refs_result.push_back({tok, std::move(errors)});
return refs_result;
}
const Variable *var = tok->variable();
if (var && var->declarationId() == tok->varId()) {
if (var->nameToken() == tok || isStructuredBindingVariable(var)) {
SmallVector refs_result;
refs_result.push_back({tok, std::move(errors)});
return refs_result;
}
if (var->isReference() || var->isRValueReference()) {
const Token * const varDeclEndToken = var->declEndToken();
if (!varDeclEndToken) {
SmallVector refs_result;
refs_result.push_back({tok, std::move(errors)});
return refs_result;
}
if (var->isArgument()) {
errors.emplace_back(varDeclEndToken, "Passed to reference.");
SmallVector refs_result;
refs_result.push_back({tok, std::move(errors)});
return refs_result;
}
if (Token::simpleMatch(varDeclEndToken, "=")) {
if (astHasToken(varDeclEndToken, tok))
return {};
errors.emplace_back(varDeclEndToken, "Assigned to reference.");
const Token *vartok = varDeclEndToken->astOperand2();
if (vartok == tok || (!temporary && isTemporary(true, vartok, nullptr, true) &&
(var->isConst() || var->isRValueReference()))) {
SmallVector refs_result;
refs_result.push_back({tok, std::move(errors)});
return refs_result;
}
if (vartok)
return followAllReferences(vartok, temporary, inconclusive, std::move(errors), depth - 1);
}
}
} else if (Token::simpleMatch(tok, "?") && Token::simpleMatch(tok->astOperand2(), ":")) {
std::set result;
const Token* tok2 = tok->astOperand2();
auto refs = followAllReferences(tok2->astOperand1(), temporary, inconclusive, errors, depth - 1);
result.insert(refs.cbegin(), refs.cend());
refs = followAllReferences(tok2->astOperand2(), temporary, inconclusive, errors, depth - 1);
result.insert(refs.cbegin(), refs.cend());
if (!inconclusive && result.size() != 1) {
SmallVector refs_result;
refs_result.push_back({tok, std::move(errors)});
return refs_result;
}
if (!result.empty()) {
SmallVector refs_result;
refs_result.insert(refs_result.end(), result.cbegin(), result.cend());
return refs_result;
}
} else if (tok->previous() && tok->previous()->function() && Token::Match(tok->previous(), "%name% (")) {
const Function *f = tok->previous()->function();
if (!Function::returnsReference(f)) {
SmallVector refs_result;
refs_result.push_back({tok, std::move(errors)});
return refs_result;
}
std::set result;
std::vector returns = Function::findReturns(f);
for (const Token* returnTok : returns) {
if (returnTok == tok)
continue;
for (const ReferenceToken& rt :
followAllReferences(returnTok, temporary, inconclusive, errors, depth - returns.size())) {
const Variable* argvar = rt.token->variable();
if (!argvar) {
SmallVector refs_result;
refs_result.push_back({tok, std::move(errors)});
return refs_result;
}
if (argvar->isArgument() && (argvar->isReference() || argvar->isRValueReference())) {
const int n = getArgumentPos(argvar, f);
if (n < 0) {
SmallVector refs_result;
refs_result.push_back({tok, std::move(errors)});
return refs_result;
}
std::vector args = getArguments(tok->previous());
if (n >= args.size()) {
SmallVector refs_result;
refs_result.push_back({tok, std::move(errors)});
return refs_result;
}
const Token* argTok = args[n];
ErrorPath er = errors;
er.emplace_back(returnTok, "Return reference.");
er.emplace_back(tok->previous(), "Called function passing '" + argTok->expressionString() + "'.");
auto refs =
followAllReferences(argTok, temporary, inconclusive, std::move(er), depth - returns.size());
result.insert(refs.cbegin(), refs.cend());
if (!inconclusive && result.size() > 1) {
SmallVector refs_result;
refs_result.push_back({tok, std::move(errors)});
return refs_result;
}
}
}
}
if (!result.empty()) {
SmallVector refs_result;
refs_result.insert(refs_result.end(), result.cbegin(), result.cend());
return refs_result;
}
}
SmallVector refs_result;
refs_result.push_back({tok, std::move(errors)});
return refs_result;
}
const Token* followReferences(const Token* tok, ErrorPath* errors)
{
if (!tok)
return nullptr;
auto refs = followAllReferences(tok, true, false);
if (refs.size() == 1) {
if (errors)
*errors = std::move(refs.front().errors);
return refs.front().token;
}
return nullptr;
}
static bool isSameLifetime(const Token * const tok1, const Token * const tok2)
{
ValueFlow::Value v1 = ValueFlow::getLifetimeObjValue(tok1);
if (!v1.isLifetimeValue())
return false;
ValueFlow::Value v2 = ValueFlow::getLifetimeObjValue(tok2);
if (!v2.isLifetimeValue())
return false;
return v1.tokvalue == v2.tokvalue;
}
static bool compareKnownValue(const Token * const tok1, const Token * const tok2, const std::function &compare)
{
static const auto isKnownFn = std::mem_fn(&ValueFlow::Value::isKnown);
const auto v1 = std::find_if(tok1->values().cbegin(), tok1->values().cend(), isKnownFn);
if (v1 == tok1->values().end()) {
return false;
}
if (v1->isNonValue() || v1->isContainerSizeValue() || v1->isSymbolicValue())
return false;
const auto v2 = std::find_if(tok2->values().cbegin(), tok2->values().cend(), isKnownFn);
if (v2 == tok2->values().end()) {
return false;
}
if (v1->valueType != v2->valueType) {
return false;
}
const bool sameLifetime = isSameLifetime(tok1, tok2);
return compare(*v1, *v2, sameLifetime);
}
bool isEqualKnownValue(const Token * const tok1, const Token * const tok2)
{
return compareKnownValue(tok1, tok2, [&](const ValueFlow::Value& v1, const ValueFlow::Value& v2, bool sameLifetime) {
bool r = v1.equalValue(v2);
if (v1.isIteratorValue()) {
r &= sameLifetime;
}
return r;
});
}
static inline bool isDifferentKnownValues(const Token * const tok1, const Token * const tok2)
{
return compareKnownValue(tok1, tok2, [&](const ValueFlow::Value& v1, const ValueFlow::Value& v2, bool sameLifetime) {
bool r = v1.equalValue(v2);
if (v1.isIteratorValue()) {
r &= sameLifetime;
}
return !r;
});
}
static inline bool isSameConstantValue(bool macro, const Token* tok1, const Token* tok2)
{
if (tok1 == nullptr || tok2 == nullptr)
return false;
auto adjustForCast = [](const Token* tok) {
if (tok->astOperand2() && Token::Match(tok->previous(), "%type% (|{") && tok->previous()->isStandardType())
return tok->astOperand2();
return tok;
};
tok1 = adjustForCast(tok1);
if (!tok1->isNumber() && !tok1->enumerator())
return false;
tok2 = adjustForCast(tok2);
if (!tok2->isNumber() && !tok2->enumerator())
return false;
if (macro && (tok1->isExpandedMacro() || tok2->isExpandedMacro() || tok1->isTemplateArg() || tok2->isTemplateArg()))
return false;
const ValueType * v1 = tok1->valueType();
const ValueType * v2 = tok2->valueType();
if (!v1 || !v2 || v1->sign != v2->sign || v1->type != v2->type || v1->pointer != v2->pointer)
return false;
return isEqualKnownValue(tok1, tok2);
}
static bool isForLoopCondition(const Token * const tok)
{
if (!tok)
return false;
const Token *const parent = tok->astParent();
return Token::simpleMatch(parent, ";") && parent->astOperand1() == tok &&
Token::simpleMatch(parent->astParent(), ";") &&
Token::simpleMatch(parent->astParent()->astParent(), "(") &&
parent->astParent()->astParent()->astOperand1()->str() == "for";
}
static bool isForLoopIncrement(const Token* const tok)
{
if (!tok)
return false;
const Token *const parent = tok->astParent();
return Token::simpleMatch(parent, ";") && parent->astOperand2() == tok &&
Token::simpleMatch(parent->astParent(), ";") &&
Token::simpleMatch(parent->astParent()->astParent(), "(") &&
parent->astParent()->astParent()->astOperand1()->str() == "for";
}
bool isUsedAsBool(const Token* const tok, const Settings* settings)
{
if (!tok)
return false;
if (isForLoopIncrement(tok))
return false;
if (astIsBool(tok))
return true;
if (Token::Match(tok, "!|&&|%oror%|%comp%"))
return true;
const Token* parent = tok->astParent();
if (!parent)
return false;
if (Token::simpleMatch(parent, "["))
return false;
if (parent->isUnaryOp("*"))
return false;
if (Token::simpleMatch(parent, ".")) {
if (astIsRHS(tok))
return isUsedAsBool(parent, settings);
return false;
}
if (Token::Match(parent, "&&|!|%oror%"))
return true;
if (parent->isCast())
return !Token::simpleMatch(parent->astOperand1(), "dynamic_cast") && isUsedAsBool(parent);
if (parent->isUnaryOp("*"))
return isUsedAsBool(parent);
if (Token::Match(parent, "==|!=") && (tok->astSibling()->isNumber() || tok->astSibling()->isKeyword()) && tok->astSibling()->hasKnownIntValue() &&
tok->astSibling()->values().front().intvalue == 0)
return true;
if (parent->str() == "(" && astIsRHS(tok) && Token::Match(parent->astOperand1(), "if|while"))
return true;
if (Token::simpleMatch(parent, "?") && astIsLHS(tok))
return true;
if (isForLoopCondition(tok))
return true;
if (!Token::Match(parent, "%cop%") && !(parent->str() == "(" && tok == parent->astOperand1())) {
if (parent->str() == "," && parent->isInitComma())
return false;
std::vector vtParents = getParentValueTypes(tok, settings);
return std::any_of(vtParents.cbegin(), vtParents.cend(), [&](const ValueType& vt) {
return vt.pointer == 0 && vt.type == ValueType::BOOL;
});
}
return false;
}
static bool astIsBoolLike(const Token* tok)
{
return astIsBool(tok) || isUsedAsBool(tok);
}
bool isSameExpression(bool cpp, bool macro, const Token *tok1, const Token *tok2, const Library& library, bool pure, bool followVar, ErrorPath* errors)
{
if (tok1 == nullptr && tok2 == nullptr)
return true;
if (tok1 == nullptr || tok2 == nullptr)
return false;
if (cpp) {
if (tok1->str() == "." && tok1->astOperand1() && tok1->astOperand1()->str() == "this")
tok1 = tok1->astOperand2();
if (tok2->str() == "." && tok2->astOperand1() && tok2->astOperand1()->str() == "this")
tok2 = tok2->astOperand2();
}
// Skip double not
if (Token::simpleMatch(tok1, "!") && Token::simpleMatch(tok1->astOperand1(), "!") && !Token::simpleMatch(tok1->astParent(), "=") && astIsBoolLike(tok2)) {
return isSameExpression(cpp, macro, tok1->astOperand1()->astOperand1(), tok2, library, pure, followVar, errors);
}
if (Token::simpleMatch(tok2, "!") && Token::simpleMatch(tok2->astOperand1(), "!") && !Token::simpleMatch(tok2->astParent(), "=") && astIsBoolLike(tok1)) {
return isSameExpression(cpp, macro, tok1, tok2->astOperand1()->astOperand1(), library, pure, followVar, errors);
}
const bool tok_str_eq = tok1->str() == tok2->str();
if (!tok_str_eq && isDifferentKnownValues(tok1, tok2))
return false;
const Token *followTok1 = tok1, *followTok2 = tok2;
while (Token::simpleMatch(followTok1, "::") && followTok1->astOperand2())
followTok1 = followTok1->astOperand2();
while (Token::simpleMatch(followTok2, "::") && followTok2->astOperand2())
followTok2 = followTok2->astOperand2();
if (isSameConstantValue(macro, followTok1, followTok2))
return true;
// Follow variable
if (followVar && !tok_str_eq && (followTok1->varId() || followTok2->varId() || followTok1->enumerator() || followTok2->enumerator())) {
const Token * varTok1 = followVariableExpression(followTok1, cpp, followTok2);
if ((varTok1->str() == followTok2->str()) || isSameConstantValue(macro, varTok1, followTok2)) {
followVariableExpressionError(followTok1, varTok1, errors);
return isSameExpression(cpp, macro, varTok1, followTok2, library, true, followVar, errors);
}
const Token * varTok2 = followVariableExpression(followTok2, cpp, followTok1);
if ((followTok1->str() == varTok2->str()) || isSameConstantValue(macro, followTok1, varTok2)) {
followVariableExpressionError(followTok2, varTok2, errors);
return isSameExpression(cpp, macro, followTok1, varTok2, library, true, followVar, errors);
}
if ((varTok1->str() == varTok2->str()) || isSameConstantValue(macro, varTok1, varTok2)) {
followVariableExpressionError(tok1, varTok1, errors);
followVariableExpressionError(tok2, varTok2, errors);
return isSameExpression(cpp, macro, varTok1, varTok2, library, true, followVar, errors);
}
}
// Follow references
if (!tok_str_eq) {
const Token* refTok1 = followReferences(tok1, errors);
const Token* refTok2 = followReferences(tok2, errors);
if (refTok1 != tok1 || refTok2 != tok2) {
if (refTok1 && !refTok1->varId() && refTok2 && !refTok2->varId()) { // complex reference expression
const Token *start = refTok1, *end = refTok2;
if (!precedes(start, end))
std::swap(start, end);
if (findExpressionChanged(start, start, end, nullptr, cpp))
return false;
}
return isSameExpression(cpp, macro, refTok1, refTok2, library, pure, followVar, errors);
}
}
if (tok1->varId() != tok2->varId() || !tok_str_eq || tok1->originalName() != tok2->originalName()) {
if ((Token::Match(tok1,"<|>") && Token::Match(tok2,"<|>")) ||
(Token::Match(tok1,"<=|>=") && Token::Match(tok2,"<=|>="))) {
return isSameExpression(cpp, macro, tok1->astOperand1(), tok2->astOperand2(), library, pure, followVar, errors) &&
isSameExpression(cpp, macro, tok1->astOperand2(), tok2->astOperand1(), library, pure, followVar, errors);
}
const Token* condTok = nullptr;
const Token* exprTok = nullptr;
if (Token::Match(tok1, "==|!=")) {
condTok = tok1;
exprTok = tok2;
} else if (Token::Match(tok2, "==|!=")) {
condTok = tok2;
exprTok = tok1;
}
if (condTok && condTok->astOperand1() && condTok->astOperand2() && !Token::Match(exprTok, "%comp%")) {
const Token* varTok1 = nullptr;
const Token* varTok2 = exprTok;
const ValueFlow::Value* value = nullptr;
if (condTok->astOperand1()->hasKnownIntValue()) {
value = &condTok->astOperand1()->values().front();
varTok1 = condTok->astOperand2();
} else if (condTok->astOperand2()->hasKnownIntValue()) {
value = &condTok->astOperand2()->values().front();
varTok1 = condTok->astOperand1();
}
const bool exprIsNot = Token::simpleMatch(exprTok, "!");
if (exprIsNot)
varTok2 = exprTok->astOperand1();
bool compare = false;
if (value) {
if (value->intvalue == 0 && exprIsNot && Token::simpleMatch(condTok, "==")) {
compare = true;
} else if (value->intvalue == 0 && !exprIsNot && Token::simpleMatch(condTok, "!=")) {
compare = true;
} else if (value->intvalue != 0 && exprIsNot && Token::simpleMatch(condTok, "!=")) {
compare = true;
} else if (value->intvalue != 0 && !exprIsNot && Token::simpleMatch(condTok, "==")) {
compare = true;
}
}
if (compare && astIsBoolLike(varTok1) && astIsBoolLike(varTok2))
return isSameExpression(cpp, macro, varTok1, varTok2, library, pure, followVar, errors);
}
return false;
}
auto flagsDiffer = [](const Token* tok1, const Token* tok2, bool macro) {
if (macro && (tok1->isExpandedMacro() || tok2->isExpandedMacro() || tok1->isTemplateArg() || tok2->isTemplateArg()))
return true;
if (tok1->isComplex() != tok2->isComplex())
return true;
if (tok1->isLong() != tok2->isLong())
return true;
if (tok1->isUnsigned() != tok2->isUnsigned())
return true;
if (tok1->isSigned() != tok2->isSigned())
return true;
return false;
};
if (flagsDiffer(tok1, tok2, macro))
return false;
if (pure && tok1->isName() && tok1->next()->str() == "(" && tok1->str() != "sizeof" && !(tok1->variable() && tok1 == tok1->variable()->nameToken())) {
if (!tok1->function()) {
if (Token::simpleMatch(tok1->previous(), ".")) {
const Token *lhs = tok1->previous();
while (Token::Match(lhs, "(|.|["))
lhs = lhs->astOperand1();
if (!lhs)
return false;
const bool lhsIsConst = (lhs->variable() && lhs->variable()->isConst()) ||
(lhs->valueType() && lhs->valueType()->constness > 0) ||
(Token::Match(lhs, "%var% . %name% (") && library.isFunctionConst(lhs->tokAt(2)));
if (!lhsIsConst)
return false;
} else {
const Token * ftok = tok1;
if (Token::simpleMatch(tok1->previous(), "::"))
ftok = tok1->previous();
if (!library.isFunctionConst(ftok) && !ftok->isAttributeConst() && !ftok->isAttributePure())
return false;
}
} else {
if (!tok1->function()->isConst() && !tok1->function()->isAttributeConst() &&
!tok1->function()->isAttributePure())
return false;
}
}
// templates/casts
if ((tok1->next() && tok1->next()->link() && Token::Match(tok1, "%name% <")) ||
(tok2->next() && tok2->next()->link() && Token::Match(tok2, "%name% <"))) {
// non-const template function that is not a dynamic_cast => return false
if (pure && Token::simpleMatch(tok1->next()->link(), "> (") &&
!(tok1->function() && tok1->function()->isConst()) &&
tok1->str() != "dynamic_cast")
return false;
// some template/cast stuff.. check that the template arguments are same
const Token *t1 = tok1->next();
const Token *t2 = tok2->next();
const Token *end1 = t1->link();
const Token *end2 = t2->link();
while (t1 && t2 && t1 != end1 && t2 != end2) {
if (t1->str() != t2->str() || flagsDiffer(t1, t2, macro))
return false;
t1 = t1->next();
t2 = t2->next();
}
if (t1 != end1 || t2 != end2)
return false;
}
if (tok1->tokType() == Token::eIncDecOp || tok1->isAssignmentOp())
return false;
// bailout when we see ({..})
if (tok1->str() == "{")
return false;
// cast => assert that the casts are equal
if (tok1->str() == "(" && tok1->previous() &&
!tok1->previous()->isName() &&
!(tok1->previous()->str() == ">" && tok1->previous()->link())) {
const Token *t1 = tok1->next();
const Token *t2 = tok2->next();
while (t1 && t2 &&
t1->str() == t2->str() &&
!flagsDiffer(t1, t2, macro) &&
(t1->isName() || t1->str() == "*")) {
t1 = t1->next();
t2 = t2->next();
}
if (!t1 || !t2 || t1->str() != ")" || t2->str() != ")")
return false;
}
bool noncommutativeEquals =
isSameExpression(cpp, macro, tok1->astOperand1(), tok2->astOperand1(), library, pure, followVar, errors);
noncommutativeEquals = noncommutativeEquals &&
isSameExpression(cpp, macro, tok1->astOperand2(), tok2->astOperand2(), library, pure, followVar, errors);
if (noncommutativeEquals)
return true;
// in c++, a+b might be different to b+a, depending on the type of a and b
if (cpp && tok1->str() == "+" && tok1->isBinaryOp()) {
const ValueType* vt1 = tok1->astOperand1()->valueType();
const ValueType* vt2 = tok1->astOperand2()->valueType();
if (!(vt1 && (vt1->type >= ValueType::VOID || vt1->pointer) && vt2 && (vt2->type >= ValueType::VOID || vt2->pointer)))
return false;
}
const bool commutative = tok1->isBinaryOp() && Token::Match(tok1, "%or%|%oror%|+|*|&|&&|^|==|!=");
bool commutativeEquals = commutative &&
isSameExpression(cpp, macro, tok1->astOperand2(), tok2->astOperand1(), library, pure, followVar, errors);
commutativeEquals = commutativeEquals &&
isSameExpression(cpp, macro, tok1->astOperand1(), tok2->astOperand2(), library, pure, followVar, errors);
return commutativeEquals;
}
static bool isZeroBoundCond(const Token * const cond)
{
if (cond == nullptr)
return false;
// Assume unsigned
// TODO: Handle reverse conditions
const bool isZero = cond->astOperand2()->getValue(0);
if (cond->str() == "==" || cond->str() == ">=")
return isZero;
if (cond->str() == "<=")
return true;
if (cond->str() == "<")
return !isZero;
if (cond->str() == ">")
return false;
return false;
}
bool isOppositeCond(bool isNot, bool cpp, const Token * const cond1, const Token * const cond2, const Library& library, bool pure, bool followVar, ErrorPath* errors)
{
if (!cond1 || !cond2)
return false;
if (isSameExpression(cpp, true, cond1, cond2, library, pure, followVar, errors))
return false;
if (!isNot && cond1->str() == "&&" && cond2->str() == "&&") {
for (const Token* tok1: {
cond1->astOperand1(), cond1->astOperand2()
}) {
for (const Token* tok2: {
cond2->astOperand1(), cond2->astOperand2()
}) {
if (isSameExpression(cpp, true, tok1, tok2, library, pure, followVar, errors)) {
if (isOppositeCond(isNot, cpp, tok1->astSibling(), tok2->astSibling(), library, pure, followVar, errors))
return true;
}
}
}
}
if (cond1->str() != cond2->str() && (cond1->str() == "||" || cond2->str() == "||")) {
const Token* orCond = nullptr;
const Token* otherCond = nullptr;
if (cond1->str() == "||") {
orCond = cond1;
otherCond = cond2;
}
if (cond2->str() == "||") {
orCond = cond2;
otherCond = cond1;
}
return isOppositeCond(isNot, cpp, orCond->astOperand1(), otherCond, library, pure, followVar, errors) &&
isOppositeCond(isNot, cpp, orCond->astOperand2(), otherCond, library, pure, followVar, errors);
}
if (cond1->str() == "!") {
if (cond2->str() == "!=") {
if (cond2->astOperand1() && cond2->astOperand1()->str() == "0")
return isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand2(), library, pure, followVar, errors);
if (cond2->astOperand2() && cond2->astOperand2()->str() == "0")
return isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand1(), library, pure, followVar, errors);
}
if (!isUsedAsBool(cond2))
return false;
return isSameExpression(cpp, true, cond1->astOperand1(), cond2, library, pure, followVar, errors);
}
if (cond2->str() == "!")
return isOppositeCond(isNot, cpp, cond2, cond1, library, pure, followVar, errors);
if (!isNot) {
if (cond1->str() == "==" && cond2->str() == "==") {
if (isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand1(), library, pure, followVar, errors))
return isDifferentKnownValues(cond1->astOperand2(), cond2->astOperand2());
if (isSameExpression(cpp, true, cond1->astOperand2(), cond2->astOperand2(), library, pure, followVar, errors))
return isDifferentKnownValues(cond1->astOperand1(), cond2->astOperand1());
}
// TODO: Handle reverse conditions
if (Library::isContainerYield(cond1, Library::Container::Yield::EMPTY, "empty") &&
Library::isContainerYield(cond2->astOperand1(), Library::Container::Yield::SIZE, "size") &&
isSameExpression(cpp,
true,
cond1->astOperand1()->astOperand1(),
cond2->astOperand1()->astOperand1()->astOperand1(),
library,
pure,
followVar,
errors)) {
return !isZeroBoundCond(cond2);
}
if (Library::isContainerYield(cond2, Library::Container::Yield::EMPTY, "empty") &&
Library::isContainerYield(cond1->astOperand1(), Library::Container::Yield::SIZE, "size") &&
isSameExpression(cpp,
true,
cond2->astOperand1()->astOperand1(),
cond1->astOperand1()->astOperand1()->astOperand1(),
library,
pure,
followVar,
errors)) {
return !isZeroBoundCond(cond1);
}
}
if (!cond1->isComparisonOp() || !cond2->isComparisonOp())
return false;
const std::string &comp1 = cond1->str();
// condition found .. get comparator
std::string comp2;
if (isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand1(), library, pure, followVar, errors) &&
isSameExpression(cpp, true, cond1->astOperand2(), cond2->astOperand2(), library, pure, followVar, errors)) {
comp2 = cond2->str();
} else if (isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand2(), library, pure, followVar, errors) &&
isSameExpression(cpp, true, cond1->astOperand2(), cond2->astOperand1(), library, pure, followVar, errors)) {
comp2 = cond2->str();
if (comp2[0] == '>')
comp2[0] = '<';
else if (comp2[0] == '<')
comp2[0] = '>';
}
if (!isNot && comp2.empty()) {
const Token *expr1 = nullptr, *value1 = nullptr, *expr2 = nullptr, *value2 = nullptr;
std::string op1 = cond1->str(), op2 = cond2->str();
if (cond1->astOperand2()->hasKnownIntValue()) {
expr1 = cond1->astOperand1();
value1 = cond1->astOperand2();
} else if (cond1->astOperand1()->hasKnownIntValue()) {
expr1 = cond1->astOperand2();
value1 = cond1->astOperand1();
if (op1[0] == '>')
op1[0] = '<';
else if (op1[0] == '<')
op1[0] = '>';
}
if (cond2->astOperand2()->hasKnownIntValue()) {
expr2 = cond2->astOperand1();
value2 = cond2->astOperand2();
} else if (cond2->astOperand1()->hasKnownIntValue()) {
expr2 = cond2->astOperand2();
value2 = cond2->astOperand1();
if (op2[0] == '>')
op2[0] = '<';
else if (op2[0] == '<')
op2[0] = '>';
}
if (!expr1 || !value1 || !expr2 || !value2) {
return false;
}
if (!isSameExpression(cpp, true, expr1, expr2, library, pure, followVar, errors))
return false;
const ValueFlow::Value &rhsValue1 = value1->values().front();
const ValueFlow::Value &rhsValue2 = value2->values().front();
if (op1 == "<" || op1 == "<=")
return (op2 == "==" || op2 == ">" || op2 == ">=") && (rhsValue1.intvalue < rhsValue2.intvalue);
if (op1 == ">=" || op1 == ">")
return (op2 == "==" || op2 == "<" || op2 == "<=") && (rhsValue1.intvalue > rhsValue2.intvalue);
return false;
}
// is condition opposite?
return ((comp1 == "==" && comp2 == "!=") ||
(comp1 == "!=" && comp2 == "==") ||
(comp1 == "<" && comp2 == ">=") ||
(comp1 == "<=" && comp2 == ">") ||
(comp1 == ">" && comp2 == "<=") ||
(comp1 == ">=" && comp2 == "<") ||
(!isNot && ((comp1 == "<" && comp2 == ">") ||
(comp1 == ">" && comp2 == "<") ||
(comp1 == "==" && (comp2 == "!=" || comp2 == ">" || comp2 == "<")) ||
((comp1 == "!=" || comp1 == ">" || comp1 == "<") && comp2 == "==")
)));
}
bool isOppositeExpression(bool cpp, const Token * const tok1, const Token * const tok2, const Library& library, bool pure, bool followVar, ErrorPath* errors)
{
if (!tok1 || !tok2)
return false;
if (isOppositeCond(true, cpp, tok1, tok2, library, pure, followVar, errors))
return true;
if (tok1->isUnaryOp("-") && !(tok2->astParent() && tok2->astParent()->tokType() == Token::eBitOp))
return isSameExpression(cpp, true, tok1->astOperand1(), tok2, library, pure, followVar, errors);
if (tok2->isUnaryOp("-") && !(tok2->astParent() && tok2->astParent()->tokType() == Token::eBitOp))
return isSameExpression(cpp, true, tok2->astOperand1(), tok1, library, pure, followVar, errors);
return false;
}
static bool functionModifiesArguments(const Function* f)
{
return std::any_of(f->argumentList.cbegin(), f->argumentList.cend(), [](const Variable& var) {
if (var.isReference() || var.isPointer())
return !var.isConst();
return true;
});
}
bool isConstFunctionCall(const Token* ftok, const Library& library)
{
if (isUnevaluated(ftok))
return true;
if (!Token::Match(ftok, "%name% ("))
return false;
if (const Function* f = ftok->function()) {
if (f->isAttributePure() || f->isAttributeConst())
return true;
// Any modified arguments
if (functionModifiesArguments(f))
return false;
if (Function::returnsVoid(f))
return false;
// Member function call
if (Token::simpleMatch(ftok->previous(), ".") || exprDependsOnThis(ftok->next())) {
if (f->isConst())
return true;
// Check for const overloaded function that just return the const version
if (!Function::returnsConst(f)) {
std::vector fs = f->getOverloadedFunctions();
if (std::any_of(fs.cbegin(), fs.cend(), [&](const Function* g) {
if (f == g)
return false;
if (f->argumentList.size() != g->argumentList.size())
return false;
if (functionModifiesArguments(g))
return false;
if (g->isConst() && Function::returnsConst(g))
return true;
return false;
}))
return true;
}
return false;
}
if (f->argumentList.empty())
return f->isConstexpr();
} else if (Token::Match(ftok->previous(), ". %name% (") && ftok->previous()->originalName() != "->" &&
astIsSmartPointer(ftok->previous()->astOperand1())) {
return Token::Match(ftok, "get|get_deleter ( )");
} else if (Token::Match(ftok->previous(), ". %name% (") && astIsContainer(ftok->previous()->astOperand1())) {
const Library::Container* container = ftok->previous()->astOperand1()->valueType()->container;
if (!container)
return false;
if (container->getYield(ftok->str()) != Library::Container::Yield::NO_YIELD)
return true;
if (container->getAction(ftok->str()) == Library::Container::Action::FIND_CONST)
return true;
return false;
} else if (const Library::Function* lf = library.getFunction(ftok)) {
if (lf->ispure)
return true;
if (lf->containerYield != Library::Container::Yield::NO_YIELD)
return true;
if (lf->containerAction == Library::Container::Action::FIND_CONST)
return true;
return false;
} else {
const bool memberFunction = Token::Match(ftok->previous(), ". %name% (");
bool constMember = !memberFunction;
if (Token::Match(ftok->tokAt(-2), "%var% . %name% (")) {
const Variable* var = ftok->tokAt(-2)->variable();
if (var)
constMember = var->isConst();
}
// TODO: Only check const on lvalues
std::vector args = getArguments(ftok);
if (args.empty())
return false;
return constMember && std::all_of(args.cbegin(), args.cend(), [](const Token* tok) {
const Variable* var = tok->variable();
if (var)
return var->isConst();
return false;
});
}
return true;
}
bool isConstExpression(const Token *tok, const Library& library, bool cpp)
{
if (!tok)
return true;
if (tok->variable() && tok->variable()->isVolatile())
return false;
if (tok->isName() && tok->next()->str() == "(") {
if (!isConstFunctionCall(tok, library))
return false;
}
if (tok->tokType() == Token::eIncDecOp)
return false;
if (tok->isAssignmentOp())
return false;
if (isLikelyStreamRead(cpp, tok))
return false;
// bailout when we see ({..})
if (tok->str() == "{")
return false;
return isConstExpression(tok->astOperand1(), library, cpp) && isConstExpression(tok->astOperand2(), library, cpp);
}
bool isWithoutSideEffects(bool cpp, const Token* tok, bool checkArrayAccess, bool checkReference)
{
if (!cpp)
return true;
while (tok && tok->astOperand2() && tok->astOperand2()->str() != "(")
tok = tok->astOperand2();
if (tok && tok->varId()) {
const Variable* var = tok->variable();
return var && ((!var->isClass() && (checkReference || !var->isReference())) || var->isPointer() || (checkArrayAccess ? var->isStlType() && !var->isStlType(CheckClass::stl_containers_not_const) : var->isStlType()));
}
return true;
}
bool isUniqueExpression(const Token* tok)
{
if (!tok)
return true;
if (tok->function()) {
const Function * fun = tok->function();
const Scope * scope = fun->nestedIn;
if (!scope)
return true;
const std::string returnType = fun->retType ? fun->retType->name() : fun->retDef->stringifyList(fun->tokenDef);
if (!std::all_of(scope->functionList.begin(), scope->functionList.end(), [&](const Function& f) {
if (f.type != Function::eFunction)
return true;
const std::string freturnType = f.retType ? f.retType->name() : f.retDef->stringifyList(f.returnDefEnd());
return f.argumentList.size() != fun->argumentList.size() || returnType != freturnType || f.name() == fun->name();
}))
return false;
} else if (tok->variable()) {
const Variable * var = tok->variable();
const Scope * scope = var->scope();
if (!scope)
return true;
const Type * varType = var->type();
// Iterate over the variables in scope and the parameters of the function if possible
const Function * fun = scope->function;
auto pred = [=](const Variable& v) {
if (varType)
return v.type() && v.type()->name() == varType->name() && v.name() != var->name();
return v.isFloatingType() == var->isFloatingType() &&
v.isEnumType() == var->isEnumType() &&
v.isClass() == var->isClass() &&
v.isArray() == var->isArray() &&
v.isPointer() == var->isPointer() &&
v.name() != var->name();
};
if (std::any_of(scope->varlist.cbegin(), scope->varlist.cend(), pred))
return false;
if (fun) {
if (std::any_of(fun->argumentList.cbegin(), fun->argumentList.cend(), pred))
return false;
}
} else if (!isUniqueExpression(tok->astOperand1())) {
return false;
}
return isUniqueExpression(tok->astOperand2());
}
static bool isEscaped(const Token* tok, bool functionsScope, const Library* library)
{
if (library && library->isnoreturn(tok))
return true;
if (functionsScope)
return Token::simpleMatch(tok, "throw");
return Token::Match(tok, "return|throw");
}
static bool isEscapedOrJump(const Token* tok, bool functionsScope, const Library* library)
{
if (library && library->isnoreturn(tok))
return true;
if (functionsScope)
return Token::simpleMatch(tok, "throw");
return Token::Match(tok, "return|goto|throw|continue|break");
}
bool isEscapeFunction(const Token* ftok, const Library* library)
{
if (!Token::Match(ftok, "%name% ("))
return false;
const Function* function = ftok->function();
if (function) {
if (function->isEscapeFunction())
return true;
if (function->isAttributeNoreturn())
return true;
} else if (library) {
if (library->isnoreturn(ftok))
return true;
}
return false;
}
static bool hasNoreturnFunction(const Token* tok, const Library* library, const Token** unknownFunc)
{
if (!tok)
return false;
const Token* ftok = tok->str() == "(" ? tok->previous() : nullptr;
while (Token::simpleMatch(ftok, "("))
ftok = ftok->astOperand1();
if (ftok) {
const Function * function = ftok->function();
if (function) {
if (function->isEscapeFunction())
return true;
if (function->isAttributeNoreturn())
return true;
} else if (library && library->isnoreturn(ftok)) {
return true;
} else if (Token::Match(ftok, "exit|abort")) {
return true;
}
if (unknownFunc && !function && library && library->functions.count(library->getFunctionName(ftok)) == 0)
*unknownFunc = ftok;
return false;
}
if (tok->isConstOp()) {
return hasNoreturnFunction(tok->astOperand1(), library, unknownFunc) || hasNoreturnFunction(tok->astOperand2(), library, unknownFunc);
}
return false;
}
bool isReturnScope(const Token* const endToken, const Library* library, const Token** unknownFunc, bool functionScope)
{
if (!endToken || endToken->str() != "}")
return false;
const Token *prev = endToken->previous();
while (prev && Token::simpleMatch(prev->previous(), "; ;"))
prev = prev->previous();
if (prev && Token::simpleMatch(prev->previous(), "} ;"))
prev = prev->previous();
if (Token::simpleMatch(prev, "}")) {
if (Token::simpleMatch(prev->link()->tokAt(-2), "} else {"))
return isReturnScope(prev, library, unknownFunc, functionScope) &&
isReturnScope(prev->link()->tokAt(-2), library, unknownFunc, functionScope);
// TODO: Check all cases
if (!functionScope && Token::simpleMatch(prev->link()->previous(), ") {") &&
Token::simpleMatch(prev->link()->linkAt(-1)->previous(), "switch (") &&
!Token::findsimplematch(prev->link(), "break", prev)) {
return isReturnScope(prev, library, unknownFunc, functionScope);
}
if (isEscaped(prev->link()->astTop(), functionScope, library))
return true;
if (Token::Match(prev->link()->previous(), "[;{}] {"))
return isReturnScope(prev, library, unknownFunc, functionScope);
} else if (Token::simpleMatch(prev, ";")) {
if (prev->tokAt(-2) && hasNoreturnFunction(prev->tokAt(-2)->astTop(), library, unknownFunc))
return true;
// Unknown symbol
if (Token::Match(prev->tokAt(-2), ";|}|{ %name% ;") && prev->previous()->isIncompleteVar()) {
if (unknownFunc)
*unknownFunc = prev->previous();
return false;
}
if (Token::simpleMatch(prev->previous(), ") ;") && prev->previous()->link() &&
isEscaped(prev->previous()->link()->astTop(), functionScope, library))
return true;
if (isEscaped(prev->previous()->astTop(), functionScope, library))
return true;
// return/goto statement
prev = prev->previous();
while (prev && !Token::Match(prev, ";|{|}") && !isEscapedOrJump(prev, functionScope, library))
prev = prev->previous();
return prev && prev->isName();
}
return false;
}
bool isWithinScope(const Token* tok, const Variable* var, Scope::ScopeType type)
{
if (!tok || !var)
return false;
const Scope* scope = tok->scope();
while (scope && scope != var->scope()) {
if (scope->type == type)
return true;
scope = scope->nestedIn;
}
return false;
}
bool isVariableChangedByFunctionCall(const Token *tok, int indirect, nonneg int varid, const Settings *settings, bool *inconclusive)
{
if (!tok)
return false;
if (tok->varId() == varid)
return isVariableChangedByFunctionCall(tok, indirect, settings, inconclusive);
return isVariableChangedByFunctionCall(tok->astOperand1(), indirect, varid, settings, inconclusive) ||
isVariableChangedByFunctionCall(tok->astOperand2(), indirect, varid, settings, inconclusive);
}
bool isScopeBracket(const Token* tok)
{
if (!Token::Match(tok, "{|}"))
return false;
if (!tok->scope())
return false;
if (tok->str() == "{")
return tok->scope()->bodyStart == tok;
if (tok->str() == "}")
return tok->scope()->bodyEnd == tok;
return false;
}
template )>
static T* getTokenArgumentFunctionImpl(T* tok, int& argn)
{
argn = -1;
{
T* parent = tok->astParent();
if (parent && (parent->isUnaryOp("&") || parent->isIncDecOp()))
parent = parent->astParent();
while (parent && parent->isCast())
parent = parent->astParent();
if (Token::Match(parent, "[+-]") && parent->valueType() && parent->valueType()->pointer)
parent = parent->astParent();
// passing variable to subfunction?
if (Token::Match(parent, "[*[(,{.]") || Token::Match(parent, "%oror%|&&"))
;
else if (Token::simpleMatch(parent, ":")) {
while (Token::Match(parent, "[?:]"))
parent = parent->astParent();
while (Token::simpleMatch(parent, ","))
parent = parent->astParent();
if (!parent || parent->str() != "(")
return nullptr;
} else
return nullptr;
}
T* argtok = tok;
while (argtok && argtok->astParent() && (!Token::Match(argtok->astParent(), ",|(|{") || argtok->astParent()->isCast())) {
argtok = argtok->astParent();
}
if (!argtok)
return nullptr;
if (Token::simpleMatch(argtok, ","))
argtok = argtok->astOperand1();
tok = argtok;
while (Token::Match(tok->astParent(), ",|(|{")) {
tok = tok->astParent();
if (Token::Match(tok, "(|{"))
break;
}
argn = getArgumentPos(tok, argtok);
if (argn == -1)
return nullptr;
if (!Token::Match(tok, "{|("))
return nullptr;
if (tok->astOperand2())
tok = tok->astOperand1();
while (tok && (tok->isUnaryOp("*") || tok->str() == "["))
tok = tok->astOperand1();
if (Token::Match(tok, ". * %name%")) // bailout for pointer to member
return tok->tokAt(2);
while (Token::simpleMatch(tok, "."))
tok = tok->astOperand2();
while (Token::simpleMatch(tok, "::")) {
// If there is only a op1 and not op2, then this is a global scope
if (!tok->astOperand2() && tok->astOperand1()) {
tok = tok->astOperand1();
break;
}
tok = tok->astOperand2();
if (Token::simpleMatch(tok, "<") && tok->link())
tok = tok->astOperand1();
}
if (tok && tok->link() && tok->str() == ">")
tok = tok->link()->previous();
if (!Token::Match(tok, "%name%|(|{"))
return nullptr;
// Skip labels
if (Token::Match(tok, "%name% :"))
return nullptr;
return tok;
}
const Token* getTokenArgumentFunction(const Token* tok, int& argn) {
return getTokenArgumentFunctionImpl(tok, argn);
}
Token* getTokenArgumentFunction(Token* tok, int& argn) {
return getTokenArgumentFunctionImpl(tok, argn);
}
std::vector getArgumentVars(const Token* tok, int argnr)
{
std::vector result;
if (!tok)
return result;
if (tok->function()) {
const Variable* argvar = tok->function()->getArgumentVar(argnr);
if (argvar)
return {argvar};
return result;
}
if (tok->variable() || Token::simpleMatch(tok, "{") || Token::Match(tok->previous(), "%type% (|{")) {
const Type* type = Token::typeOf(tok);
if (!type)
return result;
const Scope* typeScope = type->classScope;
if (!typeScope)
return result;
const bool tokIsBrace = Token::simpleMatch(tok, "{");
// Aggregate constructor
if (tokIsBrace && typeScope->numConstructors == 0 && argnr < typeScope->varlist.size()) {
auto it = std::next(typeScope->varlist.cbegin(), argnr);
return {&*it};
}
const int argCount = numberOfArguments(tok);
const bool constructor = tokIsBrace || (tok->variable() && tok->variable()->nameToken() == tok);
for (const Function &function : typeScope->functionList) {
if (function.argCount() < argCount)
continue;
if (constructor && !function.isConstructor())
continue;
if (!constructor && !Token::simpleMatch(function.token, "operator()"))
continue;
const Variable* argvar = function.getArgumentVar(argnr);
if (argvar)
result.push_back(argvar);
}
}
return result;
}
static bool isCPPCastKeyword(const Token* tok)
{
if (!tok)
return false;
return endsWith(tok->str(), "_cast");
}
static bool isTrivialConstructor(const Token* tok)
{
const Token* typeTok = nullptr;
const Type* t = Token::typeOf(tok, &typeTok);
if (t)
return false;
if (typeTok->valueType() && typeTok->valueType()->isPrimitive())
return true;
return false;
}
static bool isArray(const Token* tok)
{
if (!tok)
return false;
if (tok->variable())
return tok->variable()->isArray();
if (Token::simpleMatch(tok, "."))
return isArray(tok->astOperand2());
return false;
}
bool isVariableChangedByFunctionCall(const Token *tok, int indirect, const Settings *settings, bool *inconclusive)
{
if (!tok)
return false;
if (Token::simpleMatch(tok, ","))
return false;
const Token * const tok1 = tok;
// address of variable
const bool addressOf = tok->astParent() && tok->astParent()->isUnaryOp("&");
if (addressOf)
indirect++;
const bool deref = tok->astParent() && tok->astParent()->isUnaryOp("*");
if (deref && indirect > 0)
indirect--;
int argnr;
tok = getTokenArgumentFunction(tok, argnr);
if (!tok)
return false; // not a function => variable not changed
if (Token::simpleMatch(tok, "{") && isTrivialConstructor(tok))
return false;
if (tok->isKeyword() && !isCPPCastKeyword(tok) && !startsWith(tok->str(),"operator"))
return false;
// A functional cast won't modify the variable
if (Token::Match(tok, "%type% (|{") && tok->tokType() == Token::eType && astIsPrimitive(tok->next()))
return false;
const Token * parenTok = tok->next();
if (Token::simpleMatch(parenTok, "<") && parenTok->link())
parenTok = parenTok->link()->next();
const bool possiblyPassedByReference = (parenTok->next() == tok1 || Token::Match(tok1->previous(), ", %name% [,)}]"));
if (!tok->function() && !tok->variable() && tok->isName()) {
if (settings) {
// Check if direction (in, out, inout) is specified in the library configuration and use that
const Library::ArgumentChecks::Direction argDirection = settings->library.getArgDirection(tok, 1 + argnr);
if (argDirection == Library::ArgumentChecks::Direction::DIR_IN)
return false;
const bool requireNonNull = settings->library.isnullargbad(tok, 1 + argnr);
if (argDirection == Library::ArgumentChecks::Direction::DIR_OUT ||
argDirection == Library::ArgumentChecks::Direction::DIR_INOUT) {
if (indirect == 0 && isArray(tok1))
return true;
const bool requireInit = settings->library.isuninitargbad(tok, 1 + argnr);
// Assume that if the variable must be initialized then the indirection is 1
if (indirect > 0 && requireInit && requireNonNull)
return true;
}
if (Token::simpleMatch(tok->tokAt(-2), "std :: tie"))
return true;
// if the library says 0 is invalid
// => it is assumed that parameter is an in parameter (TODO: this is a bad heuristic)
if (indirect == 0 && requireNonNull)
return false;
}
// possible pass-by-reference => inconclusive
if (possiblyPassedByReference) {
if (inconclusive != nullptr)
*inconclusive = true;
return false;
}
// Safe guess: Assume that parameter is changed by function call
return true;
}
std::vector args = getArgumentVars(tok, argnr);
bool conclusive = false;
for (const Variable *arg:args) {
if (!arg)
continue;
conclusive = true;
if (indirect > 0) {
if (arg->isPointer() && !(arg->valueType() && arg->valueType()->isConst(indirect)))
return true;
if (indirect > 1 && addressOf && arg->isPointer() && (!arg->valueType() || !arg->valueType()->isConst(indirect-1)))
return true;
if (arg->isArray() || (!arg->isPointer() && (!arg->valueType() || arg->valueType()->type == ValueType::UNKNOWN_TYPE)))
return true;
}
if (!arg->isConst() && arg->isReference())
return true;
}
if (addressOf && tok1->astParent()->isUnaryOp("&")) {
const Token* castToken = tok1->astParent();
while (castToken->astParent()->isCast())
castToken = castToken->astParent();
if (Token::Match(castToken->astParent(), ",|(") &&
castToken->valueType() &&
castToken->valueType()->isIntegral() &&
castToken->valueType()->pointer == 0)
return true;
}
if (!conclusive && inconclusive) {
*inconclusive = true;
}
return false;
}
bool isVariableChanged(const Token *tok, int indirect, const Settings *settings, bool cpp, int depth)
{
if (!tok)
return false;
if (indirect == 0 && isConstVarExpression(tok))
return false;
const Token *tok2 = tok;
int derefs = 0;
while (Token::simpleMatch(tok2->astParent(), "*") ||
(Token::simpleMatch(tok2->astParent(), ".") && !Token::simpleMatch(tok2->astParent()->astParent(), "(")) ||
(tok2->astParent() && tok2->astParent()->isUnaryOp("&") && Token::simpleMatch(tok2->astParent()->astParent(), ".") && tok2->astParent()->astParent()->originalName()=="->") ||
(Token::simpleMatch(tok2->astParent(), "[") && tok2 == tok2->astParent()->astOperand1())) {
if (tok2->astParent() && (tok2->astParent()->isUnaryOp("*") || (astIsLHS(tok2) && tok2->astParent()->originalName() == "->")))
derefs++;
if (derefs > indirect)
break;
if (tok2->astParent() && tok2->astParent()->isUnaryOp("&") && Token::simpleMatch(tok2->astParent()->astParent(), ".") && tok2->astParent()->astParent()->originalName()=="->")
tok2 = tok2->astParent();
tok2 = tok2->astParent();
}
if (tok2->astParent() && tok2->astParent()->isUnaryOp("&")) {
const Token* parent = tok2->astParent();
while (parent->astParent() && parent->astParent()->isCast())
parent = parent->astParent();
if (parent->astParent() && parent->astParent()->isUnaryOp("*"))
tok2 = parent->astParent();
}
while ((Token::simpleMatch(tok2, ":") && Token::simpleMatch(tok2->astParent(), "?")) ||
(Token::simpleMatch(tok2->astParent(), ":") && Token::simpleMatch(tok2->astParent()->astParent(), "?")))
tok2 = tok2->astParent();
if (indirect == 0 && tok2->astParent() && tok2->astParent()->tokType() == Token::eIncDecOp)
return true;
auto skipRedundantPtrOp = [](const Token* tok, const Token* parent) {
const Token* gparent = parent ? parent->astParent() : nullptr;
while (parent && gparent && ((parent->isUnaryOp("*") && gparent->isUnaryOp("&")) || (parent->isUnaryOp("&") && gparent->isUnaryOp("*")))) {
tok = gparent;
parent = gparent->astParent();
if (parent)
gparent = parent->astParent();
}
return tok;
};
tok2 = skipRedundantPtrOp(tok2, tok2->astParent());
if (tok2->astParent() && tok2->astParent()->isAssignmentOp()) {
if ((indirect == 0 || tok2 != tok) && tok2 == tok2->astParent()->astOperand1())
return true;
// Check if assigning to a non-const lvalue
const Variable * var = getLHSVariable(tok2->astParent());
if (var && var->isReference() && !var->isConst() &&
((var->nameToken() && var->nameToken()->next() == tok2->astParent()) || var->isPointer())) {
if (!var->isLocal() || isVariableChanged(var, settings, cpp, depth - 1))
return true;
}
}
const ValueType* vt = tok->variable() ? tok->variable()->valueType() : tok->valueType();
// Check addressof
if (tok2->astParent() && tok2->astParent()->isUnaryOp("&")) {
if (isVariableChanged(tok2->astParent(), indirect + 1, settings, cpp, depth - 1))
return true;
} else {
// If its already const then it cant be modified
if (vt && vt->isConst(indirect))
return false;
}
if (cpp && Token::Match(tok2->astParent(), ">>|&") && astIsRHS(tok2) && isLikelyStreamRead(cpp, tok2->astParent()))
return true;
if (isLikelyStream(cpp, tok2))
return true;
// Member function call
if (Token::Match(tok2->astParent(), ". %name%") && isFunctionCall(tok2->astParent()->next()) &&
tok2->astParent()->astOperand1() == tok2) {
// Member function cannot change what `this` points to
if (indirect == 0 && astIsPointer(tok))
return false;
const Token *ftok = tok2->astParent()->astOperand2();
if (astIsContainer(tok2->astParent()->astOperand1()) && vt && vt->container) {
const Library::Container* c = vt->container;
const Library::Container::Action action = c->getAction(ftok->str());
if (contains({Library::Container::Action::INSERT,
Library::Container::Action::ERASE,
Library::Container::Action::CHANGE,
Library::Container::Action::CHANGE_CONTENT,
Library::Container::Action::CHANGE_INTERNAL,
Library::Container::Action::CLEAR,
Library::Container::Action::FIND,
Library::Container::Action::PUSH,
Library::Container::Action::POP,
Library::Container::Action::RESIZE},
action))
return true;
const Library::Container::Yield yield = c->getYield(ftok->str());
// If accessing element check if the element is changed
if (contains({Library::Container::Yield::ITEM, Library::Container::Yield::AT_INDEX}, yield))
return isVariableChanged(ftok->next(), indirect, settings, cpp, depth - 1);
if (contains({Library::Container::Yield::BUFFER,
Library::Container::Yield::BUFFER_NT,
Library::Container::Yield::START_ITERATOR,
Library::Container::Yield::ITERATOR},
yield)) {
return isVariableChanged(ftok->next(), indirect + 1, settings, cpp, depth - 1);
}
if (contains({Library::Container::Yield::SIZE,
Library::Container::Yield::EMPTY,
Library::Container::Yield::END_ITERATOR},
yield)) {
return false;
}
}
if ((settings && settings->library.isFunctionConst(ftok)) || (astIsSmartPointer(tok) && ftok->str() == "get")) // TODO: replace with action/yield?
return false;
const Function * fun = ftok->function();
if (!fun)
return true;
return !fun->isConst();
}
// Member pointer
if (Token::Match(tok2->astParent(), ". * ( & %name% ::")) {
const Token* ftok = tok2->astParent()->linkAt(2)->previous();
// TODO: Check for pointer to member variable
if (!ftok->function() || !ftok->function()->isConst())
return true;
}
if (Token::Match(tok2->astParent(), ". * %name%")) // bailout
return true;
if (Token::simpleMatch(tok2, "[") && astIsContainer(tok) && vt && vt->container && vt->container->stdAssociativeLike)
return true;
const Token *ftok = tok2;
while (ftok && (!Token::Match(ftok, "[({]") || ftok->isCast()))
ftok = ftok->astParent();
if (ftok && Token::Match(ftok->link(), ")|} !!{")) {
const Token * ptok = tok2;
while (Token::Match(ptok->astParent(), ".|::|["))
ptok = ptok->astParent();
int pindirect = indirect;
if (indirect == 0 && astIsLHS(tok2) && Token::Match(ptok, ". %var%") && astIsPointer(ptok->next()))
pindirect = 1;
bool inconclusive = false;
bool isChanged = isVariableChangedByFunctionCall(ptok, pindirect, settings, &inconclusive);
isChanged |= inconclusive;
if (isChanged)
return true;
}
const Token *parent = tok2->astParent();
while (Token::Match(parent, ".|::"))
parent = parent->astParent();
if (parent && parent->tokType() == Token::eIncDecOp && (indirect == 0 || tok2 != tok))
return true;
// structured binding, nonconst reference variable in lhs
if (Token::Match(tok2->astParent(), ":|=") && tok2 == tok2->astParent()->astOperand2() && Token::simpleMatch(tok2->astParent()->previous(), "]")) {
const Token *typeStart = tok2->astParent()->previous()->link()->previous();
if (Token::simpleMatch(typeStart, "&"))
typeStart = typeStart->previous();
if (typeStart && Token::Match(typeStart->previous(), "[;{}(] auto &| [")) {
for (const Token *vartok = typeStart->tokAt(2); vartok != tok2; vartok = vartok->next()) {
if (vartok->varId()) {
const Variable* refvar = vartok->variable();
if (!refvar || (!refvar->isConst() && refvar->isReference()))
return true;
}
}
}
}
if (Token::simpleMatch(tok2->astParent(), ":") && tok2->astParent()->astParent() && Token::simpleMatch(tok2->astParent()->astParent()->previous(), "for (")) {
// TODO: Check if container is empty or not
if (astIsLHS(tok2))
return true;
const Token * varTok = tok2->astParent()->previous();
if (!varTok)
return false;
const Variable * loopVar = varTok->variable();
if (!loopVar)
return false;
if (!loopVar->isConst() && loopVar->isReference() && isVariableChanged(loopVar, settings, cpp, depth - 1))
return true;
return false;
}
if (indirect > 0) {
// check for `*(ptr + 1) = new_value` case
parent = tok2->astParent();
while (parent && ((parent->isArithmeticalOp() && parent->isBinaryOp()) || parent->isIncDecOp())) {
parent = parent->astParent();
}
if (Token::simpleMatch(parent, "*")) {
if (parent->astParent() && parent->astParent()->isAssignmentOp() &&
(parent->astParent()->astOperand1() == parent)) {
return true;
}
}
}
return false;
}
bool isVariableChanged(const Token *start, const Token *end, const nonneg int exprid, bool globalvar, const Settings *settings, bool cpp, int depth)
{
return findVariableChanged(start, end, 0, exprid, globalvar, settings, cpp, depth) != nullptr;
}
bool isVariableChanged(const Token *start, const Token *end, int indirect, const nonneg int exprid, bool globalvar, const Settings *settings, bool cpp, int depth)
{
return findVariableChanged(start, end, indirect, exprid, globalvar, settings, cpp, depth) != nullptr;
}
const Token* findExpression(const Token* start, const nonneg int exprid)
{
const Function* f = Scope::nestedInFunction(start->scope());
if (!f)
return nullptr;
const Scope* scope = f->functionScope;
if (!scope)
return nullptr;
for (const Token *tok = scope->bodyStart; tok != scope->bodyEnd; tok = tok->next()) {
if (tok->exprId() != exprid)
continue;
return tok;
}
return nullptr;
}
// Thread-unsafe memoization
template()())>
static std::function memoize(F f)
{
bool init = false;
R result{};
return [=]() mutable -> R {
if (init)
return result;
result = f();
init = true;
return result;
};
}
template()()), const Token*> )>
static bool isExpressionChangedAt(const F& getExprTok,
const Token* tok,
int indirect,
const nonneg int exprid,
bool globalvar,
const Settings* settings,
bool cpp,
int depth)
{
if (depth < 0)
return true;
if (tok->isLiteral() || tok->isKeyword() || tok->isStandardType() || Token::Match(tok, ",|;|:"))
return false;
if (tok->exprId() != exprid) {
if (globalvar && Token::Match(tok, "%name% (") && !(tok->function() && tok->function()->isAttributePure()))
// TODO: Is global variable really changed by function call?
return true;
int i = 1;
bool aliased = false;
// If we can't find the expression then assume it is an alias
auto expr = getExprTok();
if (!expr)
aliased = true;
if (!aliased)
aliased = isAliasOf(tok, expr, &i);
if (!aliased)
return false;
if (isVariableChanged(tok, indirect + i, settings, cpp, depth))
return true;
// TODO: Try to traverse the lambda function
if (Token::Match(tok, "%var% ("))
return true;
return false;
}
return (isVariableChanged(tok, indirect, settings, cpp, depth));
}
bool isExpressionChangedAt(const Token* expr,
const Token* tok,
int indirect,
bool globalvar,
const Settings* settings,
bool cpp,
int depth)
{
return isExpressionChangedAt([&] {
return expr;
}, tok, indirect, expr->exprId(), globalvar, settings, cpp, depth);
}
Token* findVariableChanged(Token *start, const Token *end, int indirect, const nonneg int exprid, bool globalvar, const Settings *settings, bool cpp, int depth)
{
if (!precedes(start, end))
return nullptr;
if (depth < 0)
return start;
auto getExprTok = memoize([&] {
return findExpression(start, exprid);
});
for (Token *tok = start; tok != end; tok = tok->next()) {
if (isExpressionChangedAt(getExprTok, tok, indirect, exprid, globalvar, settings, cpp, depth))
return tok;
}
return nullptr;
}
const Token* findVariableChanged(const Token *start, const Token *end, int indirect, const nonneg int exprid, bool globalvar, const Settings *settings, bool cpp, int depth)
{
return findVariableChanged(const_cast(start), end, indirect, exprid, globalvar, settings, cpp, depth);
}
bool isVariableChanged(const Variable * var, const Settings *settings, bool cpp, int depth)
{
if (!var)
return false;
if (!var->scope())
return false;
const Token * start = var->declEndToken();
if (!start)
return false;
if (Token::Match(start, "; %varid% =", var->declarationId()))
start = start->tokAt(2);
if (Token::simpleMatch(start, "=")) {
const Token* next = nextAfterAstRightmostLeafGeneric(start);
if (next)
start = next;
}
return findExpressionChanged(var->nameToken(), start->next(), var->scope()->bodyEnd, settings, cpp, depth);
}
bool isVariablesChanged(const Token* start,
const Token* end,
int indirect,
const std::vector &vars,
const Settings* settings,
bool cpp)
{
std::set varids;
std::transform(vars.cbegin(), vars.cend(), std::inserter(varids, varids.begin()), [](const Variable* var) {
return var->declarationId();
});
const bool globalvar = std::any_of(vars.cbegin(), vars.cend(), [](const Variable* var) {
return var->isGlobal();
});
for (const Token* tok = start; tok != end; tok = tok->next()) {
if (tok->varId() == 0 || varids.count(tok->varId()) == 0) {
if (globalvar && Token::Match(tok, "%name% ("))
// TODO: Is global variable really changed by function call?
return true;
continue;
}
if (isVariableChanged(tok, indirect, settings, cpp))
return true;
}
return false;
}
bool isThisChanged(const Token* tok, int indirect, const Settings* settings, bool cpp)
{
if ((Token::Match(tok->previous(), "%name% (") && !Token::simpleMatch(tok->astOperand1(), ".")) ||
Token::Match(tok->tokAt(-3), "this . %name% (")) {
if (tok->previous()->function()) {
return (!tok->previous()->function()->isConst() && !tok->previous()->function()->isStatic());
}
if (!tok->previous()->isKeyword()) {
return true;
}
}
if (isVariableChanged(tok, indirect, settings, cpp))
return true;
return false;
}
const Token* findThisChanged(const Token* start, const Token* end, int indirect, const Settings* settings, bool cpp)
{
if (!precedes(start, end))
return nullptr;
for (const Token* tok = start; tok != end; tok = tok->next()) {
if (!exprDependsOnThis(tok))
continue;
if (isThisChanged(tok, indirect, settings, cpp))
return tok;
}
return nullptr;
}
template
static const Token* findExpressionChangedImpl(const Token* expr,
const Token* start,
const Token* end,
const Settings* settings,
bool cpp,
int depth,
Find find)
{
if (depth < 0)
return start;
if (!precedes(start, end))
return nullptr;
const Token* result = nullptr;
findAstNode(expr, [&](const Token* tok) {
if (exprDependsOnThis(tok)) {
result = findThisChanged(start, end, false, settings, cpp);
return true;
}
bool global = false;
if (tok->variable()) {
if (tok->variable()->isConst())
return false;
global = !tok->variable()->isLocal() && !tok->variable()->isArgument() &&
!(tok->variable()->isMember() && !tok->variable()->isStatic());
} else if (tok->isIncompleteVar() && !tok->isIncompleteConstant()) {
global = true;
}
if (tok->exprId() > 0) {
const Token* modifedTok = find(start, end, [&](const Token* tok2) {
int indirect = 0;
if (const ValueType* vt = tok->valueType()) {
indirect = vt->pointer;
if (vt->type == ValueType::ITERATOR)
++indirect;
}
for (int i = 0; i <= indirect; ++i)
if (isExpressionChangedAt(tok, tok2, i, global, settings, cpp, depth))
return true;
return false;
});
if (modifedTok) {
result = modifedTok;
return true;
}
}
return false;
});
return result;
}
namespace {
struct ExpressionChangedSimpleFind {
template
const Token* operator()(const Token* start, const Token* end, F f) const
{
return findToken(start, end, f);
}
};
struct ExpressionChangedSkipDeadCode {
const Library* library;
const std::function(const Token* tok)>* evaluate;
ExpressionChangedSkipDeadCode(const Library* library,
const std::function(const Token* tok)>& evaluate)
: library(library), evaluate(&evaluate)
{}
template
const Token* operator()(const Token* start, const Token* end, F f) const
{
return findTokenSkipDeadCode(library, start, end, f, *evaluate);
}
};
}
const Token* findExpressionChanged(const Token* expr,
const Token* start,
const Token* end,
const Settings* settings,
bool cpp,
int depth)
{
return findExpressionChangedImpl(expr, start, end, settings, cpp, depth, ExpressionChangedSimpleFind{});
}
const Token* findExpressionChangedSkipDeadCode(const Token* expr,
const Token* start,
const Token* end,
const Settings* settings,
bool cpp,
const std::function(const Token* tok)>& evaluate,
int depth)
{
return findExpressionChangedImpl(
expr, start, end, settings, cpp, depth, ExpressionChangedSkipDeadCode{&settings->library, evaluate});
}
const Token* getArgumentStart(const Token* ftok)
{
const Token* tok = ftok;
if (Token::Match(tok, "%name% (|{"))
tok = ftok->next();
if (!Token::Match(tok, "(|{|["))
return nullptr;
const Token* startTok = tok->astOperand2();
if (!startTok && tok->next() != tok->link())
startTok = tok->astOperand1();
return startTok;
}
int numberOfArguments(const Token* ftok) {
return astCount(getArgumentStart(ftok), ",");
}
int numberOfArgumentsWithoutAst(const Token* start)
{
int arguments = 0;
const Token* openBracket = start->next();
while (Token::simpleMatch(openBracket, ")"))
openBracket = openBracket->next();
if (openBracket && openBracket->str()=="(" && openBracket->next() && openBracket->next()->str()!=")") {
const Token* argument=openBracket->next();
while (argument) {
++arguments;
argument = argument->nextArgument();
}
}
return arguments;
}
std::vector getArguments(const Token* ftok) {
return astFlatten(getArgumentStart(ftok), ",");
}
int getArgumentPos(const Variable* var, const Function* f)
{
auto arg_it = std::find_if(f->argumentList.cbegin(), f->argumentList.cend(), [&](const Variable& v) {
return v.nameToken() == var->nameToken();
});
if (arg_it == f->argumentList.end())
return -1;
return std::distance(f->argumentList.cbegin(), arg_it);
}
const Token* getIteratorExpression(const Token* tok)
{
if (!tok)
return nullptr;
if (tok->isUnaryOp("*"))
return nullptr;
if (!tok->isName()) {
const Token* iter1 = getIteratorExpression(tok->astOperand1());
if (iter1)
return iter1;
if (tok->str() == "(")
return nullptr;
const Token* iter2 = getIteratorExpression(tok->astOperand2());
if (iter2)
return iter2;
} else if (Token::Match(tok, "begin|cbegin|rbegin|crbegin|end|cend|rend|crend (")) {
if (Token::Match(tok->previous(), ". %name% ( ) !!."))
return tok->previous()->astOperand1();
if (!Token::simpleMatch(tok->previous(), ".") && Token::Match(tok, "%name% ( !!)") &&
!Token::simpleMatch(tok->linkAt(1), ") ."))
return tok->next()->astOperand2();
}
return nullptr;
}
bool isIteratorPair(const std::vector& args)
{
if (args.size() != 2)
return false;
if (astIsPointer(args[0]) && astIsPointer(args[1]))
return true;
// Check if iterator is from same container
const Token* tok1 = nullptr;
const Token* tok2 = nullptr;
if (astIsIterator(args[0]) && astIsIterator(args[1])) {
tok1 = ValueFlow::getLifetimeObjValue(args[0]).tokvalue;
tok2 = ValueFlow::getLifetimeObjValue(args[1]).tokvalue;
if (!tok1 || !tok2)
return true;
} else {
tok1 = getIteratorExpression(args[0]);
tok2 = getIteratorExpression(args[1]);
}
if (tok1 && tok2)
return tok1->exprId() == tok2->exprId();
return tok1 || tok2;
}
const Token *findLambdaStartToken(const Token *last)
{
if (!last || last->str() != "}")
return nullptr;
const Token* tok = last->link();
if (Token::simpleMatch(tok->astParent(), "("))
tok = tok->astParent();
if (Token::simpleMatch(tok->astParent(), "["))
return tok->astParent();
return nullptr;
}
template
static T* findLambdaEndTokenGeneric(T* first)
{
auto maybeLambda = [](T* tok) -> bool {
while (Token::Match(tok, "*|%name%|::|>")) {
if (tok->link())
tok = tok->link()->previous();
else {
if (tok->str() == ">")
return true;
if (tok->str() == "new")
return false;
tok = tok->previous();
}
}
return true;
};
if (!first || first->str() != "[")
return nullptr;
if (!maybeLambda(first->previous()))
return nullptr;
if (!Token::Match(first->link(), "] (|{|<"))
return nullptr;
const Token* roundOrCurly = first->link()->next();
if (roundOrCurly->link() && roundOrCurly->str() == "<")
roundOrCurly = roundOrCurly->link()->next();
if (first->astOperand1() != roundOrCurly)
return nullptr;
T * tok = first;
if (tok->astOperand1() && tok->astOperand1()->str() == "(")
tok = tok->astOperand1();
if (tok->astOperand1() && tok->astOperand1()->str() == "{")
return tok->astOperand1()->link();
return nullptr;
}
const Token* findLambdaEndToken(const Token* first)
{
return findLambdaEndTokenGeneric(first);
}
Token* findLambdaEndToken(Token* first)
{
return findLambdaEndTokenGeneric(first);
}
bool isLikelyStream(bool cpp, const Token *stream)
{
if (!cpp)
return false;
if (!stream)
return false;
if (!Token::Match(stream->astParent(), "&|<<|>>") || !stream->astParent()->isBinaryOp())
return false;
if (stream->astParent()->astOperand1() != stream)
return false;
return !astIsIntegral(stream, false);
}
bool isLikelyStreamRead(bool cpp, const Token *op)
{
if (!cpp)
return false;
if (!Token::Match(op, "&|>>") || !op->isBinaryOp())
return false;
if (!Token::Match(op->astOperand2(), "%name%|.|*|[") && op->str() != op->astOperand2()->str())
return false;
const Token *parent = op;
while (parent->astParent() && parent->astParent()->str() == op->str())
parent = parent->astParent();
if (parent->astParent() && !Token::Match(parent->astParent(), "%oror%|&&|(|,|.|!|;|return"))
return false;
if (op->str() == "&" && parent->astParent())
return false;
if (!parent->astOperand1() || !parent->astOperand2())
return false;
return (!parent->astOperand1()->valueType() || !parent->astOperand1()->valueType()->isIntegral());
}
bool isCPPCast(const Token* tok)
{
return tok && Token::simpleMatch(tok->previous(), "> (") && tok->astOperand2() && tok->astOperand1() && isCPPCastKeyword(tok->astOperand1());
}
bool isConstVarExpression(const Token *tok, std::function skipPredicate)
{
if (!tok)
return false;
if (tok->str() == "?" && tok->astOperand2() && tok->astOperand2()->str() == ":") // ternary operator
return isConstVarExpression(tok->astOperand2()->astOperand1()) && isConstVarExpression(tok->astOperand2()->astOperand2()); // left and right of ":"
if (skipPredicate && skipPredicate(tok))
return false;
if (Token::simpleMatch(tok->previous(), "sizeof ("))
return true;
if (Token::Match(tok->previous(), "%name% (")) {
if (Token::simpleMatch(tok->astOperand1(), ".") && !isConstVarExpression(tok->astOperand1(), skipPredicate))
return false;
std::vector args = getArguments(tok);
if (args.empty() && tok->previous()->function() && tok->previous()->function()->isConstexpr())
return true;
return !args.empty() && std::all_of(args.cbegin(), args.cend(), [&](const Token* t) {
return isConstVarExpression(t, skipPredicate);
});
}
if (isCPPCast(tok)) {
return isConstVarExpression(tok->astOperand2(), skipPredicate);
}
if (Token::Match(tok, "( %type%"))
return isConstVarExpression(tok->astOperand1(), skipPredicate);
if (tok->str() == "::" && tok->hasKnownValue())
return isConstVarExpression(tok->astOperand2(), skipPredicate);
if (Token::Match(tok, "%cop%|[|.")) {
if (tok->astOperand1() && !isConstVarExpression(tok->astOperand1(), skipPredicate))
return false;
if (tok->astOperand2() && !isConstVarExpression(tok->astOperand2(), skipPredicate))
return false;
return true;
}
if (Token::Match(tok, "%bool%|%num%|%str%|%char%|nullptr|NULL"))
return true;
if (tok->isEnumerator())
return true;
if (tok->variable())
return tok->variable()->isConst() && tok->variable()->nameToken() && tok->variable()->nameToken()->hasKnownValue();
return false;
}
static ExprUsage getFunctionUsage(const Token* tok, int indirect, const Settings* settings)
{
const bool addressOf = tok->astParent() && tok->astParent()->isUnaryOp("&");
int argnr;
const Token* ftok = getTokenArgumentFunction(tok, argnr);
if (!ftok)
return ExprUsage::None;
if (ftok->function()) {
std::vector args = getArgumentVars(ftok, argnr);
for (const Variable* arg : args) {
if (!arg)
continue;
if (arg->isReference())
return ExprUsage::PassedByReference;
if (arg->isPointer() && indirect == 1)
return ExprUsage::PassedByReference;
}
if (!args.empty() && indirect == 0 && !addressOf)
return ExprUsage::Used;
} else if (ftok->isControlFlowKeyword()) {
return ExprUsage::Used;
} else if (ftok->str() == "{") {
return indirect == 0 ? ExprUsage::Used : ExprUsage::Inconclusive;
} else if (ftok->variable() && ftok == ftok->variable()->nameToken()) { // variable init/constructor call
if (ftok->variable()->type() && ftok->variable()->type()->needInitialization == Type::NeedInitialization::True)
return ExprUsage::Used;
if (ftok->variable()->isStlType() || (ftok->variable()->valueType() && ftok->variable()->valueType()->container)) // STL types or containers don't initialize external variables
return ExprUsage::Used;
} else {
const bool isnullbad = settings->library.isnullargbad(ftok, argnr + 1);
if (indirect == 0 && astIsPointer(tok) && !addressOf && isnullbad)
return ExprUsage::Used;
bool hasIndirect = false;
const bool isuninitbad = settings->library.isuninitargbad(ftok, argnr + 1, indirect, &hasIndirect);
if (isuninitbad && (!addressOf || isnullbad))
return ExprUsage::Used;
}
return ExprUsage::Inconclusive;
}
bool isLeafDot(const Token* tok)
{
if (!tok)
return false;
const Token * parent = tok->astParent();
if (!Token::simpleMatch(parent, "."))
return false;
if (parent->astOperand2() == tok && !Token::simpleMatch(parent->astParent(), "."))
return true;
return isLeafDot(parent);
}
ExprUsage getExprUsage(const Token* tok, int indirect, const Settings* settings, bool cpp)
{
const Token* parent = tok->astParent();
if (indirect > 0 && parent) {
while (Token::simpleMatch(parent, "[") && parent->astParent())
parent = parent->astParent();
if (Token::Match(parent, "%assign%") && (astIsRHS(tok) || astIsLHS(parent->astOperand1())))
return ExprUsage::NotUsed;
if (Token::Match(parent, "++|--"))
return ExprUsage::NotUsed;
if (parent->isConstOp())
return ExprUsage::NotUsed;
if (parent->isCast())
return ExprUsage::NotUsed;
if (Token::simpleMatch(parent, ":") && Token::simpleMatch(parent->astParent(), "?"))
return getExprUsage(parent->astParent(), indirect, settings, cpp);
}
if (indirect == 0) {
if (Token::Match(parent, "%cop%|%assign%|++|--") && parent->str() != "=" &&
!parent->isUnaryOp("&") &&
!(astIsRHS(tok) && isLikelyStreamRead(cpp, parent)))
return ExprUsage::Used;
if (isLeafDot(tok)) {
const Token* op = parent->astParent();
while (Token::simpleMatch(op, "."))
op = op->astParent();
if (Token::Match(op, "%assign%|++|--")) {
if (op->str() == "=") {
if (precedes(tok, op))
return ExprUsage::NotUsed;
} else
return ExprUsage::Used;
}
}
if (Token::simpleMatch(parent, "=") && astIsRHS(tok)) {
const Token* const lhs = parent->astOperand1();
if (lhs && lhs->variable() && lhs->variable()->isReference() && lhs == lhs->variable()->nameToken())
return ExprUsage::NotUsed;
return ExprUsage::Used;
}
// Function call or index
if (((Token::simpleMatch(parent, "(") && !parent->isCast()) || (Token::simpleMatch(parent, "[") && tok->valueType())) &&
(astIsLHS(tok) || Token::simpleMatch(parent, "( )")))
return ExprUsage::Used;
}
return getFunctionUsage(tok, indirect, settings);
}
static void getLHSVariablesRecursive(std::vector& vars, const Token* tok)
{
if (!tok)
return;
if (vars.empty() && Token::Match(tok, "*|&|&&|[")) {
getLHSVariablesRecursive(vars, tok->astOperand1());
if (!vars.empty() || Token::simpleMatch(tok, "["))
return;
getLHSVariablesRecursive(vars, tok->astOperand2());
} else if (Token::Match(tok->previous(), "this . %var%")) {
getLHSVariablesRecursive(vars, tok->next());
} else if (Token::simpleMatch(tok, ".")) {
getLHSVariablesRecursive(vars, tok->astOperand1());
getLHSVariablesRecursive(vars, tok->astOperand2());
} else if (Token::simpleMatch(tok, "::")) {
getLHSVariablesRecursive(vars, tok->astOperand2());
} else if (tok->variable()) {
vars.push_back(tok->variable());
}
}
std::vector getLHSVariables(const Token* tok)
{
std::vector result;
if (!Token::Match(tok, "%assign%|(|{"))
return result;
if (!tok->astOperand1())
return result;
if (tok->astOperand1()->varId() > 0 && tok->astOperand1()->variable())
return {tok->astOperand1()->variable()};
getLHSVariablesRecursive(result, tok->astOperand1());
return result;
}
static const Token* getLHSVariableRecursive(const Token* tok)
{
if (!tok)
return nullptr;
if (Token::Match(tok, "*|&|&&|[")) {
const Token* vartok = getLHSVariableRecursive(tok->astOperand1());
if ((vartok && vartok->variable()) || Token::simpleMatch(tok, "["))
return vartok;
return getLHSVariableRecursive(tok->astOperand2());
}
if (Token::Match(tok->previous(), "this . %var%"))
return tok->next();
return tok;
}
const Variable *getLHSVariable(const Token *tok)
{
if (!tok || !tok->isAssignmentOp())
return nullptr;
if (!tok->astOperand1())
return nullptr;
if (tok->astOperand1()->varId() > 0 && tok->astOperand1()->variable())
return tok->astOperand1()->variable();
const Token* vartok = getLHSVariableRecursive(tok->astOperand1());
if (!vartok)
return nullptr;
return vartok->variable();
}
const Token* getLHSVariableToken(const Token* tok)
{
if (!Token::Match(tok, "%assign%"))
return nullptr;
if (!tok->astOperand1())
return nullptr;
if (tok->astOperand1()->varId() > 0)
return tok->astOperand1();
const Token* vartok = getLHSVariableRecursive(tok->astOperand1());
if (vartok && vartok->variable() && vartok->variable()->nameToken() == vartok)
return vartok;
return tok->astOperand1();
}
const Token* findAllocFuncCallToken(const Token *expr, const Library &library)
{
if (!expr)
return nullptr;
if (Token::Match(expr, "[+-]")) {
const Token *tok1 = findAllocFuncCallToken(expr->astOperand1(), library);
return tok1 ? tok1 : findAllocFuncCallToken(expr->astOperand2(), library);
}
if (expr->isCast())
return findAllocFuncCallToken(expr->astOperand2() ? expr->astOperand2() : expr->astOperand1(), library);
if (Token::Match(expr->previous(), "%name% (") && library.getAllocFuncInfo(expr->astOperand1()))
return expr->astOperand1();
return (Token::simpleMatch(expr, "new") && expr->astOperand1()) ? expr : nullptr;
}
bool isNullOperand(const Token *expr)
{
if (!expr)
return false;
if (Token::Match(expr, "static_cast|const_cast|dynamic_cast|reinterpret_cast <"))
expr = expr->astParent();
else if (!expr->isCast())
return Token::Match(expr, "NULL|nullptr");
if (expr->valueType() && expr->valueType()->pointer == 0)
return false;
const Token *castOp = expr->astOperand2() ? expr->astOperand2() : expr->astOperand1();
return Token::Match(castOp, "NULL|nullptr") || (MathLib::isInt(castOp->str()) && MathLib::isNullValue(castOp->str()));
}
bool isGlobalData(const Token *expr, bool cpp)
{
// function call that returns reference => assume global data
if (expr && expr->str() == "(" && expr->valueType() && expr->valueType()->reference != Reference::None) {
if (expr->isBinaryOp())
return true;
if (expr->astOperand1() && precedes(expr->astOperand1(), expr))
return true;
}
bool globalData = false;
bool var = false;
visitAstNodes(expr,
[expr, cpp, &globalData, &var](const Token *tok) {
if (tok->varId())
var = true;
if (tok->varId() && !tok->variable()) {
// Bailout, this is probably global
globalData = true;
return ChildrenToVisit::none;
}
if (tok->originalName() == "->") {
// TODO check if pointer points at local data
globalData = true;
return ChildrenToVisit::none;
}
if (Token::Match(tok, "[*[]") && tok->astOperand1() && tok->astOperand1()->variable()) {
// TODO check if pointer points at local data
const Variable *lhsvar = tok->astOperand1()->variable();
const ValueType *lhstype = tok->astOperand1()->valueType();
if (lhsvar->isPointer()) {
globalData = true;
return ChildrenToVisit::none;
}
if (lhsvar->isArgument() && lhsvar->isArray()) {
globalData = true;
return ChildrenToVisit::none;
}
if (lhsvar->isArgument() && (!lhstype || (lhstype->type <= ValueType::Type::VOID && !lhstype->container))) {
globalData = true;
return ChildrenToVisit::none;
}
}
if (tok->varId() == 0 && tok->isName() && tok->previous()->str() != ".") {
globalData = true;
return ChildrenToVisit::none;
}
if (tok->variable()) {
// TODO : Check references
if (tok->variable()->isReference() && tok != tok->variable()->nameToken()) {
globalData = true;
return ChildrenToVisit::none;
}
if (tok->variable()->isExtern()) {
globalData = true;
return ChildrenToVisit::none;
}
if (tok->previous()->str() != "." && !tok->variable()->isLocal() && !tok->variable()->isArgument()) {
globalData = true;
return ChildrenToVisit::none;
}
if (tok->variable()->isArgument() && tok->variable()->isPointer() && tok != expr) {
globalData = true;
return ChildrenToVisit::none;
}
if (tok->variable()->isPointerArray()) {
globalData = true;
return ChildrenToVisit::none;
}
}
// Unknown argument type => it might be some reference type..
if (cpp && tok->str() == "." && tok->astOperand1() && tok->astOperand1()->variable() && !tok->astOperand1()->valueType()) {
globalData = true;
return ChildrenToVisit::none;
}
if (Token::Match(tok, ".|["))
return ChildrenToVisit::op1;
return ChildrenToVisit::op1_and_op2;
});
return globalData || !var;
}
bool isUnevaluated(const Token *tok)
{
return Token::Match(tok, "alignof|_Alignof|_alignof|__alignof|__alignof__|decltype|offsetof|sizeof|typeid|typeof|__typeof__ (");
}