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Fix 13750: false negative: knownConditionTrueFalse/identicalConditionAfterEarlyExit #7430

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Merged
chrchr-github merged 4 commits into from
Apr 12, 2025
Merged

Fix 13750: false negative: knownConditionTrueFalse/identicalConditionAfterEarlyExit #7430

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c57eb4d
Fix 13750: false negative: knownConditionTrueFalse/identicalCondition…
pfultz2 Apr 4, 2025
d6bdc13
Format
pfultz2 Apr 4, 2025
6a2a196
Make constructor explicit
pfultz2 Apr 5, 2025
205be49
Fix tidy
pfultz2 Apr 12, 2025
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65 changes: 49 additions & 16 deletions lib/forwardanalyzer.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -202,7 +202,8 @@ namespace {

template<class T, class F, REQUIRES("T must be a Token class", std::is_convertible<T*, const Token*> )>
Progress traverseConditional(T* tok, F f, bool traverseUnknown) {
if (Token::Match(tok, "?|&&|%oror%") && tok->astOperand1() && tok->astOperand2()) {
Analyzer::Action action = analyzer->analyze(tok, Analyzer::Direction::Forward);
if (action.isNone() && Token::Match(tok, "?|&&|%oror%") && tok->astOperand1() && tok->astOperand2()) {
const T* condTok = tok->astOperand1();
T* childTok = tok->astOperand2();
bool checkThen, checkElse;
Expand All @@ -227,12 +228,19 @@ namespace {
if (traverseRecursive(childTok, f, traverseUnknown) == Progress::Break)
return Break();
}
} else {
return f(tok, action);
}
return Progress::Continue;
}

Progress update(Token* tok) {
Analyzer::Action action = analyzer->analyze(tok, Analyzer::Direction::Forward);
return update(tok, action);
}

Progress update(Token* tok, Analyzer::Action action)
{
actions |= action;
if (!action.isNone() && !analyzeOnly)
analyzer->update(tok, action, Analyzer::Direction::Forward);
Expand All @@ -246,29 +254,54 @@ namespace {
return Progress::Continue;
}

struct AsUpdate {
ForwardTraversal* self = nullptr;

explicit AsUpdate(ForwardTraversal* self) : self(self) {}

template<class... Ts>
Progress operator()(Ts... xs) const
{
assert(self);
return self->update(xs ...);
}
};

Progress updateTok(Token* tok, Token** out = nullptr) {
auto f = [this](Token* tok2) {
return update(tok2);
};
return traverseTok(tok, f, false, out);
return traverseTok(tok, AsUpdate{this}, false, out);
}

Progress updateRecursive(Token* tok) {
auto f = [this](Token* tok2) {
return update(tok2);
};
return traverseRecursive(tok, f, false);
return traverseRecursive(tok, AsUpdate{this}, false);
}

struct AsAnalyze {
ForwardTraversal* self = nullptr;
Analyzer::Action* result = nullptr;

AsAnalyze(ForwardTraversal* self, Analyzer::Action* result) : self(self), result(result) {}

Progress operator()(const Token* tok) const
{
assert(self);
assert(result);
return (*this)(tok, self->analyzer->analyze(tok, Analyzer::Direction::Forward));
}

Progress operator()(const Token* /*unused*/, Analyzer::Action action) const
{
assert(self);
assert(result);
*result = action;
if (result->isModified() || result->isInconclusive())
return self->Break();
return Progress::Continue;
}
};

Analyzer::Action analyzeRecursive(const Token* start) {
Analyzer::Action result = Analyzer::Action::None;
auto f = [&](const Token* tok) {
result = analyzer->analyze(tok, Analyzer::Direction::Forward);
if (result.isModified() || result.isInconclusive())
return Break();
return Progress::Continue;
};
traverseRecursive(start, f, true);
traverseRecursive(start, AsAnalyze{this, &result}, true);
return result;
}

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8 changes: 8 additions & 0 deletions test/testvalueflow.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -6364,6 +6364,14 @@ class TestValueFlow : public TestFixture {
" return false;\n"
"}\n";
ASSERT_EQUALS(true, testValueOfXKnown(code, 6U, 0));

code = "bool f(bool b1, bool b2) {\n"
" if (b1 && b2)\n"
" return;\n"
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@orbitcowboy orbitcowboy Apr 13, 2025

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Nit: we should return a value here, e.g. return true;

" int x = b1 && b2;\n"
" return x;\n"
"}\n";
ASSERT_EQUALS(true, testValueOfXKnown(code, 5U, 0));
}

static std::string isPossibleContainerSizeValue(std::list<ValueFlow::Value> values,
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