843 lines
36 KiB
C++
843 lines
36 KiB
C++
#include "forwardanalyzer.h"
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#include "analyzer.h"
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#include "astutils.h"
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#include "settings.h"
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#include "symboldatabase.h"
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#include "token.h"
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#include "valueptr.h"
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#include "checknullpointer.h" // UninitValue => isPointerDeref
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#include <algorithm>
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#include <cstdio>
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#include <functional>
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#include <tuple>
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#include <utility>
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struct OnExit {
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std::function<void()> f;
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~OnExit() {
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f();
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}
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};
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struct ForwardTraversal {
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enum class Progress { Continue, Break, Skip };
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enum class Terminate { None, Bail, Escape, Modified, Inconclusive, Conditional };
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ForwardTraversal(const ValuePtr<Analyzer>& analyzer, const Settings* settings)
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: analyzer(analyzer), settings(settings), actions(Analyzer::Action::None), analyzeOnly(false), analyzeTerminate(false)
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{}
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ValuePtr<Analyzer> analyzer;
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const Settings* settings;
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Analyzer::Action actions;
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bool analyzeOnly;
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bool analyzeTerminate;
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Analyzer::Terminate terminate = Analyzer::Terminate::None;
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bool forked = false;
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std::vector<Token*> loopEnds = {};
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Progress Break(Analyzer::Terminate t = Analyzer::Terminate::None) {
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if ((!analyzeOnly || analyzeTerminate) && t != Analyzer::Terminate::None)
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terminate = t;
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return Progress::Break;
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}
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struct Branch {
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Branch(Token* tok = nullptr) : endBlock(tok) {}
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Token* endBlock = nullptr;
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Analyzer::Action action = Analyzer::Action::None;
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bool check = false;
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bool escape = false;
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bool escapeUnknown = false;
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bool isEscape() const {
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return escape || escapeUnknown;
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}
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bool isConclusiveEscape() const {
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return escape && !escapeUnknown;
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}
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bool isModified() const {
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return action.isModified() && !isConclusiveEscape();
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}
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bool isInconclusive() const {
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return action.isInconclusive() && !isConclusiveEscape();
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}
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bool isDead() const {
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return action.isModified() || action.isInconclusive() || isEscape();
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}
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};
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bool stopUpdates() {
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analyzeOnly = true;
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return actions.isModified();
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}
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std::pair<bool, bool> evalCond(const Token* tok, const Token* ctx = nullptr) const {
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if (!tok)
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return std::make_pair(false, false);
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std::vector<int> result = analyzer->evaluate(tok, ctx);
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// TODO: We should convert to bool
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bool checkThen = std::any_of(result.begin(), result.end(), [](int x) {
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return x != 0;
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});
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bool checkElse = std::any_of(result.begin(), result.end(), [](int x) {
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return x == 0;
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});
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return std::make_pair(checkThen, checkElse);
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}
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bool isConditionTrue(const Token* tok, const Token* ctx = nullptr) const {
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return evalCond(tok, ctx).first;
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}
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bool isConditionFalse(const Token* tok, const Token* ctx = nullptr) const {
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return evalCond(tok, ctx).second;
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}
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template<class T, REQUIRES("T must be a Token class", std::is_convertible<T*, const Token*> )>
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Progress traverseTok(T* tok, std::function<Progress(T*)> f, bool traverseUnknown, T** out = nullptr) {
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if (Token::Match(tok, "asm|goto|setjmp|longjmp"))
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return Break(Analyzer::Terminate::Bail);
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else if (Token::simpleMatch(tok, "continue")) {
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if (loopEnds.empty())
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return Break(Analyzer::Terminate::Escape);
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// If we are in a loop then jump to the end
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if (out)
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*out = loopEnds.back();
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} else if (Token::Match(tok, "return|throw") || isEscapeFunction(tok, &settings->library)) {
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traverseRecursive(tok->astOperand1(), f, traverseUnknown);
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traverseRecursive(tok->astOperand2(), f, traverseUnknown);
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return Break(Analyzer::Terminate::Escape);
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} else if (isUnevaluated(tok)) {
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if (out)
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*out = tok->link();
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return Progress::Skip;
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} else if (tok->astOperand1() && tok->astOperand2() && Token::Match(tok, "?|&&|%oror%")) {
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if (traverseConditional(tok, f, traverseUnknown) == Progress::Break)
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return Break();
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if (out)
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*out = nextAfterAstRightmostLeaf(tok);
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return Progress::Skip;
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// Skip lambdas
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} else if (T* lambdaEndToken = findLambdaEndToken(tok)) {
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if (checkScope(lambdaEndToken).isModified())
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return Break(Analyzer::Terminate::Bail);
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if (out)
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*out = lambdaEndToken->next();
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// Skip class scope
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} else if (tok->str() == "{" && tok->scope() && tok->scope()->isClassOrStruct()) {
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if (out)
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*out = tok->link();
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} else {
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if (f(tok) == Progress::Break)
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return Break();
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}
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return Progress::Continue;
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}
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template<class T, REQUIRES("T must be a Token class", std::is_convertible<T*, const Token*> )>
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Progress traverseRecursive(T* tok, std::function<Progress(T*)> f, bool traverseUnknown, unsigned int recursion=0) {
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if (!tok)
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return Progress::Continue;
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if (recursion > 10000)
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return Progress::Skip;
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T* firstOp = tok->astOperand1();
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T* secondOp = tok->astOperand2();
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// Evaluate:
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// 1. RHS of assignment before LHS
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// 2. Unary op before operand
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if (tok->isAssignmentOp() || !secondOp)
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std::swap(firstOp, secondOp);
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if (firstOp && traverseRecursive(firstOp, f, traverseUnknown, recursion+1) == Progress::Break)
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return Break();
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Progress p = tok->isAssignmentOp() ? Progress::Continue : traverseTok(tok, f, traverseUnknown);
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if (p == Progress::Break)
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return Break();
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if (p == Progress::Continue && secondOp && traverseRecursive(secondOp, f, traverseUnknown, recursion+1) == Progress::Break)
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return Break();
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if (tok->isAssignmentOp() && traverseTok(tok, f, traverseUnknown) == Progress::Break)
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return Break();
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return Progress::Continue;
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}
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template<class T, class F, REQUIRES("T must be a Token class", std::is_convertible<T*, const Token*> )>
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Progress traverseConditional(T* tok, F f, bool traverseUnknown) {
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if (Token::Match(tok, "?|&&|%oror%") && tok->astOperand1() && tok->astOperand2()) {
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T* condTok = tok->astOperand1();
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T* childTok = tok->astOperand2();
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bool checkThen, checkElse;
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std::tie(checkThen, checkElse) = evalCond(condTok);
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if (!checkThen && !checkElse) {
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if (!traverseUnknown && analyzer->stopOnCondition(condTok) && stopUpdates()) {
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return Progress::Continue;
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}
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checkThen = true;
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checkElse = true;
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}
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if (childTok->str() == ":") {
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if (checkThen && traverseRecursive(childTok->astOperand1(), f, traverseUnknown) == Progress::Break)
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return Break();
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if (checkElse && traverseRecursive(childTok->astOperand2(), f, traverseUnknown) == Progress::Break)
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return Break();
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} else {
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if (!checkThen && tok->str() == "&&")
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return Progress::Continue;
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if (!checkElse && tok->str() == "||")
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return Progress::Continue;
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if (traverseRecursive(childTok, f, traverseUnknown) == Progress::Break)
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return Break();
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}
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}
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return Progress::Continue;
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}
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Progress update(Token* tok) {
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Analyzer::Action action = analyzer->analyze(tok, Analyzer::Direction::Forward);
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actions |= action;
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if (!action.isNone() && !analyzeOnly) {
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analyzer->update(tok, action, Analyzer::Direction::Forward);
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// uninit value => skip further analysis
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auto v = std::find_if(tok->values().begin(), tok->values().end(), std::mem_fn(&ValueFlow::Value::isUninitValue));
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if (v != tok->values().end()) {
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if (tok->valueType() && tok->valueType()->pointer > 0) {
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bool unknown = false;
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if (CheckNullPointer::isPointerDeRef(tok, unknown, settings))
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return Break(Analyzer::Terminate::Modified);
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}
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if (Token::Match(tok->astParent(), "[,(]") && !isSizeOfEtc(tok->astParent()->previous()))
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return Break(Analyzer::Terminate::Modified);
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}
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}
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if (action.isInconclusive() && !analyzer->lowerToInconclusive())
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return Break(Analyzer::Terminate::Inconclusive);
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if (action.isInvalid())
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return Break(Analyzer::Terminate::Modified);
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if (action.isWrite() && !action.isRead())
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// Analysis of this write will continue separately
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return Break(Analyzer::Terminate::Modified);
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return Progress::Continue;
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}
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Progress updateTok(Token* tok, Token** out = nullptr) {
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std::function<Progress(Token*)> f = [this](Token* tok2) {
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return update(tok2);
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};
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return traverseTok(tok, f, false, out);
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}
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Progress updateRecursive(Token* tok) {
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forked = false;
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std::function<Progress(Token*)> f = [this](Token* tok2) {
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return update(tok2);
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};
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return traverseRecursive(tok, f, false);
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}
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template<class T>
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T* findRange(T* start, const Token* end, std::function<bool(Analyzer::Action)> pred) {
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for (T* tok = start; tok && tok != end; tok = tok->next()) {
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Analyzer::Action action = analyzer->analyze(tok, Analyzer::Direction::Forward);
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if (pred(action))
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return tok;
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}
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return nullptr;
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}
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Analyzer::Action analyzeRecursive(const Token* start) {
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Analyzer::Action result = Analyzer::Action::None;
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std::function<Progress(const Token*)> f = [&](const Token* tok) {
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result = analyzer->analyze(tok, Analyzer::Direction::Forward);
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if (result.isModified() || result.isInconclusive())
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return Break();
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return Progress::Continue;
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};
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traverseRecursive(start, f, true);
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return result;
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}
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Analyzer::Action analyzeRange(const Token* start, const Token* end) {
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Analyzer::Action result = Analyzer::Action::None;
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for (const Token* tok = start; tok && tok != end; tok = tok->next()) {
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Analyzer::Action action = analyzer->analyze(tok, Analyzer::Direction::Forward);
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if (action.isModified() || action.isInconclusive())
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return action;
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result |= action;
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}
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return result;
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}
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ForwardTraversal fork(bool analyze = false) const {
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ForwardTraversal ft = *this;
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if (analyze) {
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ft.analyzeOnly = true;
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ft.analyzeTerminate = true;
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}
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ft.actions = Analyzer::Action::None;
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ft.forked = true;
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return ft;
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}
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std::vector<ForwardTraversal> tryForkScope(Token* endBlock, bool isModified = false) {
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if (analyzer->updateScope(endBlock, isModified)) {
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ForwardTraversal ft = fork();
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return {ft};
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}
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return std::vector<ForwardTraversal> {};
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}
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std::vector<ForwardTraversal> tryForkUpdateScope(Token* endBlock, bool isModified = false) {
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std::vector<ForwardTraversal> result = tryForkScope(endBlock, isModified);
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for (ForwardTraversal& ft : result)
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ft.updateScope(endBlock);
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return result;
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}
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static bool hasGoto(const Token* endBlock) {
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return Token::findsimplematch(endBlock->link(), "goto", endBlock);
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}
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bool hasInnerReturnScope(const Token* start, const Token* end) const {
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for (const Token* tok=start; tok != end; tok = tok->previous()) {
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if (Token::simpleMatch(tok, "}")) {
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const Token* ftok = nullptr;
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bool r = isReturnScope(tok, &settings->library, &ftok);
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if (r)
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return true;
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}
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}
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return false;
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}
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bool isEscapeScope(const Token* endBlock, bool& unknown) {
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const Token* ftok = nullptr;
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bool r = isReturnScope(endBlock, &settings->library, &ftok);
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if (!r && ftok)
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unknown = true;
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return r;
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}
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enum class Status {
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None,
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Escaped,
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Modified,
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Inconclusive,
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};
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Analyzer::Action analyzeScope(const Token* endBlock) {
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return analyzeRange(endBlock->link(), endBlock);
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}
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Analyzer::Action checkScope(Token* endBlock) {
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Analyzer::Action a = analyzeScope(endBlock);
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tryForkUpdateScope(endBlock, a.isModified());
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return a;
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}
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Analyzer::Action checkScope(const Token* endBlock) {
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Analyzer::Action a = analyzeScope(endBlock);
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return a;
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}
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bool checkBranch(Branch& branch) {
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Analyzer::Action a = analyzeScope(branch.endBlock);
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branch.action = a;
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std::vector<ForwardTraversal> ft1 = tryForkUpdateScope(branch.endBlock, a.isModified());
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bool bail = hasGoto(branch.endBlock);
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if (!a.isModified() && !bail) {
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if (ft1.empty()) {
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// Traverse into the branch to see if there is a conditional escape
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if (!branch.escape && hasInnerReturnScope(branch.endBlock->previous(), branch.endBlock->link())) {
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ForwardTraversal ft2 = fork(true);
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ft2.updateScope(branch.endBlock);
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if (ft2.terminate == Analyzer::Terminate::Escape) {
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branch.escape = true;
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branch.escapeUnknown = false;
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}
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}
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} else {
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if (ft1.front().terminate == Analyzer::Terminate::Escape) {
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branch.escape = true;
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branch.escapeUnknown = false;
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}
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}
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}
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return bail;
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}
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bool reentersLoop(Token* endBlock, const Token* condTok, const Token* stepTok) {
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if (!condTok)
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return true;
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if (Token::simpleMatch(condTok, ":"))
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return true;
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bool changed = false;
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if (stepTok) {
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std::pair<const Token*, const Token*> exprToks = stepTok->findExpressionStartEndTokens();
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if (exprToks.first != nullptr && exprToks.second != nullptr)
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changed |= isExpressionChanged(condTok, exprToks.first, exprToks.second->next(), settings, true);
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}
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changed |= isExpressionChanged(condTok, endBlock->link(), endBlock, settings, true);
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// Check for mutation in the condition
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changed |= nullptr !=
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findAstNode(condTok, [&](const Token* tok) {
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return isVariableChanged(tok, 0, settings, true);
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});
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if (!changed)
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return true;
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ForwardTraversal ft = fork(true);
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ft.analyzer->assume(condTok, false, Analyzer::Assume::Absolute);
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ft.updateScope(endBlock);
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return ft.isConditionTrue(condTok);
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}
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Progress updateInnerLoop(Token* endBlock, Token* stepTok, Token* condTok) {
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loopEnds.push_back(endBlock);
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OnExit oe{[&] {
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loopEnds.pop_back();
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}};
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if (endBlock && updateScope(endBlock) == Progress::Break)
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return Break();
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if (stepTok && updateRecursive(stepTok) == Progress::Break)
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return Break();
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if (condTok && updateRecursive(condTok) == Progress::Break)
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return Break();
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return Progress::Continue;
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}
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Progress updateLoop(const Token* endToken,
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Token* endBlock,
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Token* condTok,
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Token* initTok = nullptr,
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Token* stepTok = nullptr,
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bool exit = false) {
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if (initTok && updateRecursive(initTok) == Progress::Break)
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return Break();
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const bool isDoWhile = precedes(endBlock, condTok);
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bool checkThen = true;
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bool checkElse = false;
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if (condTok && !Token::simpleMatch(condTok, ":"))
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std::tie(checkThen, checkElse) = evalCond(condTok, isDoWhile ? endBlock->previous() : nullptr);
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if (checkElse && exit)
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return Progress::Continue;
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Analyzer::Action bodyAnalysis = analyzeScope(endBlock);
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Analyzer::Action allAnalysis = bodyAnalysis;
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Analyzer::Action condAnalysis;
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if (condTok) {
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condAnalysis = analyzeRecursive(condTok);
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allAnalysis |= condAnalysis;
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}
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if (stepTok)
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allAnalysis |= analyzeRecursive(stepTok);
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actions |= allAnalysis;
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// do while(false) is not really a loop
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if (checkElse && isDoWhile &&
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(condTok->hasKnownIntValue() || (!bodyAnalysis.isModified() && condAnalysis.isRead()))) {
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if (updateRange(endBlock->link(), endBlock) == Progress::Break)
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return Break();
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return updateRecursive(condTok);
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}
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if (allAnalysis.isInconclusive()) {
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if (!analyzer->lowerToInconclusive())
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return Break(Analyzer::Terminate::Bail);
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} else if (allAnalysis.isModified() || (exit && allAnalysis.isIdempotent())) {
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if (!analyzer->lowerToPossible())
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return Break(Analyzer::Terminate::Bail);
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}
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if (condTok && !Token::simpleMatch(condTok, ":")) {
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if (!isDoWhile || (!bodyAnalysis.isModified() && !bodyAnalysis.isIdempotent()))
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if (updateRecursive(condTok) == Progress::Break)
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return Break();
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}
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if (!checkThen && !checkElse && !isDoWhile && analyzer->stopOnCondition(condTok) && stopUpdates())
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return Break(Analyzer::Terminate::Conditional);
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// condition is false, we don't enter the loop
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if (checkElse)
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return Progress::Continue;
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if (checkThen || isDoWhile) {
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// Since we are re-entering the loop then assume the condition is true to update the state
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if (exit)
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analyzer->assume(condTok, true, Analyzer::Assume::Quiet | Analyzer::Assume::Absolute);
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if (updateInnerLoop(endBlock, stepTok, condTok) == Progress::Break)
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return Break();
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// If loop re-enters then it could be modified again
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if (allAnalysis.isModified() && reentersLoop(endBlock, condTok, stepTok))
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return Break(Analyzer::Terminate::Bail);
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if (allAnalysis.isIncremental())
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return Break(Analyzer::Terminate::Bail);
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} else if (allAnalysis.isModified()) {
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std::vector<ForwardTraversal> ftv = tryForkScope(endBlock, allAnalysis.isModified());
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bool forkContinue = true;
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for (ForwardTraversal& ft : ftv) {
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if (condTok)
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ft.analyzer->assume(condTok, false, Analyzer::Assume::Quiet);
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if (ft.updateInnerLoop(endBlock, stepTok, condTok) == Progress::Break)
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forkContinue = false;
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}
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if (allAnalysis.isModified() || !forkContinue) {
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// TODO: Don't bail on missing condition
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if (!condTok)
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return Break(Analyzer::Terminate::Bail);
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if (analyzer->isConditional() && stopUpdates())
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return Break(Analyzer::Terminate::Conditional);
|
|
analyzer->assume(condTok, false);
|
|
}
|
|
if (forkContinue) {
|
|
for (ForwardTraversal& ft : ftv) {
|
|
if (!ft.actions.isIncremental())
|
|
ft.updateRange(endBlock, endToken);
|
|
}
|
|
}
|
|
if (allAnalysis.isIncremental())
|
|
return Break(Analyzer::Terminate::Bail);
|
|
} else {
|
|
if (updateInnerLoop(endBlock, stepTok, condTok) == Progress::Break)
|
|
return Progress::Break;
|
|
if (allAnalysis.isIncremental())
|
|
return Break(Analyzer::Terminate::Bail);
|
|
}
|
|
return Progress::Continue;
|
|
}
|
|
|
|
Progress updateLoopExit(const Token* endToken,
|
|
Token* endBlock,
|
|
Token* condTok,
|
|
Token* initTok = nullptr,
|
|
Token* stepTok = nullptr) {
|
|
return updateLoop(endToken, endBlock, condTok, initTok, stepTok, true);
|
|
}
|
|
|
|
Progress updateScope(Token* endBlock) {
|
|
if (forked)
|
|
analyzer->forkScope(endBlock);
|
|
return updateRange(endBlock->link(), endBlock);
|
|
}
|
|
|
|
Progress updateRange(Token* start, const Token* end, int depth = 20) {
|
|
forked = false;
|
|
if (depth < 0)
|
|
return Break(Analyzer::Terminate::Bail);
|
|
std::size_t i = 0;
|
|
for (Token* tok = start; precedes(tok, end); tok = tok->next()) {
|
|
Token* next = nullptr;
|
|
if (tok->index() <= i)
|
|
throw InternalError(tok, "Cyclic forward analysis.");
|
|
i = tok->index();
|
|
|
|
if (tok->link()) {
|
|
// Skip casts..
|
|
if (tok->str() == "(" && !tok->astOperand2() && tok->isCast()) {
|
|
tok = tok->link();
|
|
continue;
|
|
}
|
|
// Skip template arguments..
|
|
if (tok->str() == "<") {
|
|
tok = tok->link();
|
|
continue;
|
|
}
|
|
}
|
|
|
|
// Evaluate RHS of assignment before LHS
|
|
if (Token* assignTok = assignExpr(tok)) {
|
|
if (updateRecursive(assignTok) == Progress::Break)
|
|
return Break();
|
|
tok = nextAfterAstRightmostLeaf(assignTok);
|
|
if (!tok)
|
|
return Break();
|
|
} else if (tok->str() == "break") {
|
|
const Token *scopeEndToken = findNextTokenFromBreak(tok);
|
|
if (!scopeEndToken)
|
|
return Break();
|
|
tok = skipTo(tok, scopeEndToken, end);
|
|
if (!analyzer->lowerToPossible())
|
|
return Break(Analyzer::Terminate::Bail);
|
|
// TODO: Don't break, instead move to the outer scope
|
|
if (!tok)
|
|
return Break();
|
|
} else if (Token::Match(tok, "%name% :") || tok->str() == "case") {
|
|
if (!analyzer->lowerToPossible())
|
|
return Break(Analyzer::Terminate::Bail);
|
|
} else if (tok->link() && tok->str() == "}") {
|
|
const Scope* scope = tok->scope();
|
|
if (!scope)
|
|
return Break();
|
|
if (Token::Match(tok->link()->previous(), ")|else {")) {
|
|
const Token* tok2 = tok->link()->previous();
|
|
const bool inElse = Token::simpleMatch(tok2, "else {");
|
|
const bool inLoop = inElse ? false : Token::Match(tok2->link()->previous(), "while|for (");
|
|
Token* condTok = getCondTokFromEnd(tok);
|
|
if (!condTok)
|
|
return Break();
|
|
if (!condTok->hasKnownIntValue() || inLoop) {
|
|
if (!analyzer->lowerToPossible())
|
|
return Break(Analyzer::Terminate::Bail);
|
|
} else if (condTok->values().front().intvalue == inElse) {
|
|
return Break();
|
|
}
|
|
// Handle for loop
|
|
Token* stepTok = getStepTokFromEnd(tok);
|
|
bool checkThen, checkElse;
|
|
std::tie(checkThen, checkElse) = evalCond(condTok);
|
|
if (stepTok && !checkElse) {
|
|
if (updateRecursive(stepTok) == Progress::Break)
|
|
return Break();
|
|
if (updateRecursive(condTok) == Progress::Break)
|
|
return Break();
|
|
}
|
|
analyzer->assume(condTok, !inElse, Analyzer::Assume::Quiet);
|
|
if (Token::simpleMatch(tok, "} else {"))
|
|
tok = tok->linkAt(2);
|
|
} else if (scope->type == Scope::eTry) {
|
|
if (!analyzer->lowerToPossible())
|
|
return Break(Analyzer::Terminate::Bail);
|
|
} else if (scope->type == Scope::eLambda) {
|
|
return Break();
|
|
} else if (scope->type == Scope::eDo && Token::simpleMatch(tok, "} while (")) {
|
|
if (updateLoopExit(end, tok, tok->tokAt(2)->astOperand2()) == Progress::Break)
|
|
return Break();
|
|
tok = tok->linkAt(2);
|
|
} else if (Token::simpleMatch(tok->next(), "else {")) {
|
|
tok = tok->linkAt(2);
|
|
}
|
|
} else if (tok->isControlFlowKeyword() && Token::Match(tok, "if|while|for (") && Token::simpleMatch(tok->next()->link(), ") {")) {
|
|
Token* endCond = tok->next()->link();
|
|
Token* endBlock = endCond->next()->link();
|
|
Token* condTok = getCondTok(tok);
|
|
Token* initTok = getInitTok(tok);
|
|
if (initTok && updateRecursive(initTok) == Progress::Break)
|
|
return Break();
|
|
if (Token::Match(tok, "for|while (")) {
|
|
// For-range loop
|
|
if (Token::simpleMatch(condTok, ":")) {
|
|
Token* conTok = condTok->astOperand2();
|
|
if (conTok && updateRecursive(conTok) == Progress::Break)
|
|
return Break();
|
|
bool isEmpty = false;
|
|
std::vector<int> result = analyzer->evaluate(Analyzer::Evaluate::ContainerEmpty, conTok);
|
|
if (result.empty())
|
|
analyzer->assume(conTok, false, Analyzer::Assume::ContainerEmpty);
|
|
else
|
|
isEmpty = result.front() != 0;
|
|
if (!isEmpty && updateLoop(end, endBlock, condTok) == Progress::Break)
|
|
return Break();
|
|
} else {
|
|
Token* stepTok = getStepTok(tok);
|
|
if (updateLoop(end, endBlock, condTok, initTok, stepTok) == Progress::Break)
|
|
return Break();
|
|
}
|
|
tok = endBlock;
|
|
} else {
|
|
// Traverse condition
|
|
if (updateRecursive(condTok) == Progress::Break)
|
|
return Break();
|
|
Branch thenBranch{endBlock};
|
|
Branch elseBranch{endBlock->tokAt(2) ? endBlock->linkAt(2) : nullptr};
|
|
// Check if condition is true or false
|
|
std::tie(thenBranch.check, elseBranch.check) = evalCond(condTok);
|
|
if (!thenBranch.check && !elseBranch.check && analyzer->stopOnCondition(condTok) && stopUpdates())
|
|
return Break(Analyzer::Terminate::Conditional);
|
|
bool hasElse = Token::simpleMatch(endBlock, "} else {");
|
|
bool bail = false;
|
|
|
|
// Traverse then block
|
|
thenBranch.escape = isEscapeScope(endBlock, thenBranch.escapeUnknown);
|
|
if (thenBranch.check) {
|
|
if (updateRange(endCond->next(), endBlock, depth - 1) == Progress::Break)
|
|
return Break();
|
|
} else if (!elseBranch.check) {
|
|
if (checkBranch(thenBranch))
|
|
bail = true;
|
|
}
|
|
// Traverse else block
|
|
if (hasElse) {
|
|
elseBranch.escape = isEscapeScope(endBlock->linkAt(2), elseBranch.escapeUnknown);
|
|
if (elseBranch.check) {
|
|
Progress result = updateRange(endBlock->tokAt(2), endBlock->linkAt(2), depth - 1);
|
|
if (result == Progress::Break)
|
|
return Break();
|
|
} else if (!thenBranch.check) {
|
|
if (checkBranch(elseBranch))
|
|
bail = true;
|
|
}
|
|
tok = endBlock->linkAt(2);
|
|
} else {
|
|
tok = endBlock;
|
|
}
|
|
actions |= (thenBranch.action | elseBranch.action);
|
|
if (bail)
|
|
return Break(Analyzer::Terminate::Bail);
|
|
if (thenBranch.isDead() && elseBranch.isDead()) {
|
|
if (thenBranch.isModified() && elseBranch.isModified())
|
|
return Break(Analyzer::Terminate::Modified);
|
|
if (thenBranch.isConclusiveEscape() && elseBranch.isConclusiveEscape())
|
|
return Break(Analyzer::Terminate::Escape);
|
|
return Break(Analyzer::Terminate::Bail);
|
|
}
|
|
// Conditional return
|
|
if (thenBranch.isEscape() && !hasElse) {
|
|
if (!thenBranch.isConclusiveEscape()) {
|
|
if (!analyzer->lowerToInconclusive())
|
|
return Break(Analyzer::Terminate::Bail);
|
|
} else if (thenBranch.check) {
|
|
return Break();
|
|
} else {
|
|
if (analyzer->isConditional() && stopUpdates())
|
|
return Break(Analyzer::Terminate::Conditional);
|
|
analyzer->assume(condTok, false);
|
|
}
|
|
}
|
|
if (thenBranch.isInconclusive() || elseBranch.isInconclusive()) {
|
|
if (!analyzer->lowerToInconclusive())
|
|
return Break(Analyzer::Terminate::Bail);
|
|
} else if (thenBranch.isModified() || elseBranch.isModified()) {
|
|
if (!hasElse && analyzer->isConditional() && stopUpdates())
|
|
return Break(Analyzer::Terminate::Conditional);
|
|
if (!analyzer->lowerToPossible())
|
|
return Break(Analyzer::Terminate::Bail);
|
|
analyzer->assume(condTok, elseBranch.isModified());
|
|
}
|
|
}
|
|
} else if (Token::simpleMatch(tok, "try {")) {
|
|
Token* endBlock = tok->next()->link();
|
|
ForwardTraversal tryTraversal = fork();
|
|
tryTraversal.updateRange(tok->next(), endBlock, depth - 1);
|
|
bool bail = tryTraversal.actions.isModified();
|
|
if (bail)
|
|
analyzer->lowerToPossible();
|
|
|
|
while (Token::simpleMatch(endBlock, "} catch (")) {
|
|
Token* endCatch = endBlock->linkAt(2);
|
|
if (!Token::simpleMatch(endCatch, ") {"))
|
|
return Break();
|
|
endBlock = endCatch->linkAt(1);
|
|
ForwardTraversal ft = fork();
|
|
ft.updateRange(endBlock->link(), endBlock, depth - 1);
|
|
bail |= ft.terminate != Analyzer::Terminate::None || ft.actions.isModified();
|
|
}
|
|
if (bail)
|
|
return Break();
|
|
tok = endBlock;
|
|
} else if (Token::simpleMatch(tok, "do {")) {
|
|
Token* endBlock = tok->next()->link();
|
|
Token* condTok = Token::simpleMatch(endBlock, "} while (") ? endBlock->tokAt(2)->astOperand2() : nullptr;
|
|
if (updateLoop(end, endBlock, condTok) == Progress::Break)
|
|
return Break();
|
|
if (condTok)
|
|
tok = endBlock->linkAt(2)->next();
|
|
else
|
|
tok = endBlock;
|
|
} else if (Token::Match(tok, "assert|ASSERT (")) {
|
|
const Token* condTok = tok->next()->astOperand2();
|
|
bool checkThen, checkElse;
|
|
std::tie(checkThen, checkElse) = evalCond(condTok);
|
|
if (checkElse)
|
|
return Break();
|
|
if (!checkThen)
|
|
analyzer->assume(condTok, true, Analyzer::Assume::Quiet | Analyzer::Assume::Absolute);
|
|
} else if (Token::simpleMatch(tok, "switch (")) {
|
|
if (updateRecursive(tok->next()->astOperand2()) == Progress::Break)
|
|
return Break();
|
|
return Break();
|
|
} else {
|
|
if (updateTok(tok, &next) == Progress::Break)
|
|
return Break();
|
|
if (next) {
|
|
if (precedes(next, end))
|
|
tok = next->previous();
|
|
else
|
|
return Break();
|
|
}
|
|
}
|
|
// Prevent infinite recursion
|
|
if (tok->next() == start)
|
|
break;
|
|
}
|
|
return Progress::Continue;
|
|
}
|
|
|
|
static bool isUnevaluated(const Token* tok) {
|
|
if (Token::Match(tok->previous(), "sizeof|decltype ("))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
static Token* assignExpr(Token* tok) {
|
|
while (tok->astParent() && astIsLHS(tok)) {
|
|
if (tok->astParent()->isAssignmentOp())
|
|
return tok->astParent();
|
|
tok = tok->astParent();
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
static Token* skipTo(Token* tok, const Token* dest, const Token* end = nullptr) {
|
|
if (end && dest->index() > end->index())
|
|
return nullptr;
|
|
int i = dest->index() - tok->index();
|
|
if (i > 0)
|
|
return tok->tokAt(dest->index() - tok->index());
|
|
return nullptr;
|
|
}
|
|
|
|
static bool isConditional(const Token* tok) {
|
|
const Token* parent = tok->astParent();
|
|
while (parent && !Token::Match(parent, "%oror%|&&|:")) {
|
|
tok = parent;
|
|
parent = parent->astParent();
|
|
}
|
|
return parent && (parent->str() == ":" || parent->astOperand2() == tok);
|
|
}
|
|
|
|
static Token* getInitTok(Token* tok) {
|
|
if (!tok)
|
|
return nullptr;
|
|
if (Token::Match(tok, "%name% ("))
|
|
return getInitTok(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();
|
|
}
|
|
|
|
static Token* getStepTok(Token* tok) {
|
|
if (!tok)
|
|
return nullptr;
|
|
if (Token::Match(tok, "%name% ("))
|
|
return getStepTok(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();
|
|
}
|
|
|
|
static Token* getStepTokFromEnd(Token* tok) {
|
|
if (!Token::simpleMatch(tok, "}"))
|
|
return nullptr;
|
|
Token* end = tok->link()->previous();
|
|
if (!Token::simpleMatch(end, ")"))
|
|
return nullptr;
|
|
return getStepTok(end->link());
|
|
}
|
|
|
|
};
|
|
|
|
Analyzer::Result valueFlowGenericForward(Token* start, const Token* end, const ValuePtr<Analyzer>& a, const Settings* settings)
|
|
{
|
|
ForwardTraversal ft{a, settings};
|
|
ft.updateRange(start, end);
|
|
return {ft.actions, ft.terminate};
|
|
}
|
|
|
|
Analyzer::Result valueFlowGenericForward(Token* start, const ValuePtr<Analyzer>& a, const Settings* settings)
|
|
{
|
|
ForwardTraversal ft{a, settings};
|
|
ft.updateRecursive(start);
|
|
return {ft.actions, ft.terminate};
|
|
}
|