/* * 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 "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; } else { 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); } template )> static void astFlattenRecursive(T* tok, std::vector& result, const char* op, nonneg int depth = 0) { ++depth; if (!tok || depth >= 100) return; if (tok->str() == op) { astFlattenRecursive(tok->astOperand1(), result, op, depth); astFlattenRecursive(tok->astOperand2(), result, op, depth); } else { result.push_back(tok); } } std::vector astFlatten(const Token* tok, const char* op) { std::vector result; astFlattenRecursive(tok, result, op); return result; } std::vector astFlatten(Token* tok, const char* op) { std::vector result; astFlattenRecursive(tok, result, op); 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); else 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); } 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); } 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() && MathLib::toString(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); } else if (ftok->type()) { return true; } else if (library) { std::string returnType = library->returnValueType(ftok); return !returnType.empty() && returnType.back() != '&'; } else { 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(); } else { 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 {}; } else if (Token::Match(tok->astParent(), "(|{|,")) { int argn = -1; const Token* 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; } else 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()) { 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, true); // TODO: set isCpp return {std::move(vtParent)}; } 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()); } else 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()); varid = initExpr->astOperand1()->varId(); knownInitValue = initExpr->astOperand2()->hasKnownIntValue(); initValue = minInitValue.empty() ? 0 : 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; 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, bool* inconclusive) { const bool pointer = astIsPointer(tok); const ValueFlow::Value* value = nullptr; const Token* r = findAstNode(expr, [&](const Token* childTok) { for (const ValueFlow::Value& val : tok->values()) { if (val.isImpossible()) continue; if (val.isLocalLifetimeValue() || (pointer && val.isSymbolicValue() && val.intvalue == 0)) { if (findAstNode(val.tokvalue, [&](const Token* aliasTok) { return aliasTok->exprId() == childTok->exprId(); })) { if (val.isInconclusive() && inconclusive != nullptr) { value = &val; } else { return true; } } } } return false; }); 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; } else 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 (isExpressionChanged(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; } }; SmallVector refs_result; if (!tok) return refs_result; if (depth < 0) { 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)) { refs_result.push_back({tok, std::move(errors)}); return refs_result; } else if (var->isReference() || var->isRValueReference()) { const Token * const varDeclEndToken = var->declEndToken(); if (!varDeclEndToken) { refs_result.push_back({tok, std::move(errors)}); return refs_result; } if (var->isArgument()) { errors.emplace_back(varDeclEndToken, "Passed to reference."); refs_result.push_back({tok, std::move(errors)}); return refs_result; } else if (Token::simpleMatch(varDeclEndToken, "=")) { if (astHasToken(varDeclEndToken, tok)) return refs_result; 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()))) { refs_result.push_back({tok, std::move(errors)}); return refs_result; } if (vartok) return followAllReferences(vartok, temporary, inconclusive, std::move(errors), depth - 1); } else { refs_result.push_back({tok, std::move(errors)}); return refs_result; } } } 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) { refs_result.push_back({tok, std::move(errors)}); return refs_result; } if (!result.empty()) { 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)) { 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) { 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) { refs_result.push_back({tok, std::move(errors)}); return refs_result; } std::vector args = getArguments(tok->previous()); if (n >= args.size()) { 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) { refs_result.push_back({tok, std::move(errors)}); return refs_result; } } } } if (!result.empty()) { refs_result.insert(refs_result.end(), result.cbegin(), result.cend()); return 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()) return false; tok2 = adjustForCast(tok2); if (!tok2->isNumber()) 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) { 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::Match(parent, "&&|!|%oror%")) return true; if (parent->isCast()) return isUsedAsBool(parent); if (parent->isUnaryOp("*")) return isUsedAsBool(parent); if (Token::Match(parent, "==|!=") && 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%")) { std::vector vtParents = getParentValueTypes(tok); 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(), "=")) { return isSameExpression(cpp, macro, tok1->astOperand1()->astOperand1(), tok2, library, pure, followVar, errors); } if (Token::simpleMatch(tok2, "!") && Token::simpleMatch(tok2->astOperand1(), "!") && !Token::simpleMatch(tok2->astParent(), "=")) { 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; if (isSameConstantValue(macro, tok1, tok2)) return true; // Follow variable if (followVar && !tok_str_eq && (tok1->varId() || tok2->varId())) { const Token * varTok1 = followVariableExpression(tok1, cpp, tok2); if ((varTok1->str() == tok2->str()) || isSameConstantValue(macro, varTok1, tok2)) { followVariableExpressionError(tok1, varTok1, errors); return isSameExpression(cpp, macro, varTok1, tok2, library, true, followVar, errors); } const Token * varTok2 = followVariableExpression(tok2, cpp, tok1); if ((tok1->str() == varTok2->str()) || isSameConstantValue(macro, tok1, varTok2)) { followVariableExpressionError(tok2, varTok2, errors); return isSameExpression(cpp, macro, tok1, 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 (isExpressionChanged(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); else 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 (isSizeOfEtc(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; } else 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) 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) 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"); else 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"); else 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; } else 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 )> T* getTokenArgumentFunctionImpl(T* tok, int& argn) { argn = -1; { T* parent = tok->astParent(); if (parent && parent->isUnaryOp("&")) 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, "[(,{]")) ; 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(); 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}; else 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 if (tok->astParent() && tok->astParent()->isUnaryOp("&")) 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) && tok->str().compare(0,8,"operator") != 0) 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 (arg->isArray() || (!arg->isPointer() && (!arg->valueType() || arg->valueType()->type == ValueType::UNKNOWN_TYPE))) return true; } if (!arg->isConst() && arg->isReference()) 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("&") && !tok2->astParent()->astOperand2() && 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(); } while ((Token::simpleMatch(tok2, ":") && Token::simpleMatch(tok2->astParent(), "?")) || (Token::simpleMatch(tok2->astParent(), ":") && Token::simpleMatch(tok2->astParent()->astParent(), "?"))) tok2 = tok2->astParent(); if (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 (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()) { if (!var->isLocal() || isVariableChanged(var, settings, cpp, depth - 1)) return true; } } const ValueType* vt = tok->variable() ? tok->variable()->valueType() : tok->valueType(); // If its already const then it cant be modified if (vt) { if (vt->isConst(indirect)) return false; } // Check addressof if (tok2->astParent() && tok2->astParent()->isUnaryOp("&") && isVariableChanged(tok2->astParent(), indirect + 1, settings, depth - 1)) { return true; } 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 = tok->tokAt(2); if (astIsContainer(tok) && 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::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); } else 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); } else if (contains({Library::Container::Yield::SIZE, Library::Container::Yield::EMPTY, Library::Container::Yield::END_ITERATOR}, yield)) { return false; } } if (settings && settings->library.isFunctionConst(ftok)) 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::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(); bool inconclusive = false; bool isChanged = isVariableChangedByFunctionCall(ptok, indirect, 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) 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 = 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->exprId() != exprid) { if (globalvar && !tok->isKeyword() && Token::Match(tok, "%name% (") && !(tok->function() && tok->function()->isAttributePure())) // TODO: Is global variable really changed by function call? return true; 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); if (!aliased) return false; if (isVariableChanged(tok, indirect + 1, 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); return isExpressionChanged(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()); } else if (!tok->previous()->isKeyword()) { return true; } } if (isVariableChanged(tok, indirect, settings, cpp)) return true; return false; } bool isThisChanged(const Token* start, const Token* end, int indirect, const Settings* settings, bool cpp) { if (!precedes(start, end)) return false; for (const Token* tok = start; tok != end; tok = tok->next()) { if (!exprDependsOnThis(tok)) continue; if (isThisChanged(tok, indirect, settings, cpp)) return true; } return false; } bool isExpressionChanged(const Token* expr, const Token* start, const Token* end, const Settings* settings, bool cpp, int depth) { if (depth < 0) return true; if (!precedes(start, end)) return false; const Token* result = findAstNode(expr, [&](const Token* tok) { if (exprDependsOnThis(tok) && isThisChanged(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) { for (const Token* tok2 = start; tok2 != end; tok2 = tok2->next()) { int indirect = 0; if (const ValueType* vt = tok->valueType()) { indirect = vt->pointer; if (vt->type == ValueType::ITERATOR) ++indirect; } if (isExpressionChangedAt(tok, tok2, indirect, global, settings, cpp, depth)) return true; } } return false; }); return result; } 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(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 T* findLambdaEndTokenGeneric(T* first) { if (!first || first->str() != "[") return nullptr; if (!Token::Match(first->link(), "] (|{")) return nullptr; if (first->astOperand1() != first->link()->next()) 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 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 (!args.empty() && indirect == 0 && !addressOf) 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; } ExprUsage getExprUsage(const Token* tok, int indirect, const Settings* settings) { if (indirect > 0 && tok->astParent()) { if (Token::Match(tok->astParent(), "%assign%") && astIsRHS(tok)) return ExprUsage::NotUsed; if (tok->astParent()->isConstOp()) return ExprUsage::NotUsed; if (tok->astParent()->isCast()) return ExprUsage::NotUsed; } if (indirect == 0) { if (Token::Match(tok->astParent(), "%cop%|%assign%|++|--") && !Token::simpleMatch(tok->astParent(), "=") && !tok->astParent()->isUnaryOp("&")) return ExprUsage::Used; if (Token::simpleMatch(tok->astParent(), "=") && astIsRHS(tok)) return ExprUsage::Used; // Function call or index if (((Token::simpleMatch(tok->astParent(), "(") && !tok->astParent()->isCast()) || (Token::simpleMatch(tok->astParent(), "[") && tok->valueType())) && (astIsLHS(tok) || Token::simpleMatch(tok->astParent(), "( )"))) 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; } else 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; } else if (lhsvar->isArgument() && lhsvar->isArray()) { globalData = true; return ChildrenToVisit::none; } else 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 isSizeOfEtc(const Token *tok) { return Token::Match(tok, "sizeof|typeof|offsetof|decltype|__typeof__ ("); }