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Fix 9948 and 10234: false negative: knownConditionTrueFalse and stlOutOfBounds (#3372)

This commit is contained in:
Paul Fultz II 2021-08-02 03:51:34 -05:00 committed by GitHub
parent 61ceff39f5
commit 3d19b33c3e
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GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 40 additions and 16 deletions
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19
lib/valueflow.cpp
View File

@ -2589,11 +2589,13 @@ static Analyzer::Result valueFlowForward(Token* startToken,
return valueFlowForwardExpression(startToken, endToken, expr, values, tokenlist, settings);
}
// *INDENT-OFF*
static Analyzer::Result valueFlowForward(Token* top,
const Token* exprTok,
const std::list<ValueFlow::Value>& values,
TokenList* const tokenlist,
const Settings* settings)
// *INDENT-ON*
{
Analyzer::Result result{};
for (const ValueFlow::Value& v : values) {
@ -4605,6 +4607,10 @@ struct ConditionHandler {
parent = nullptr;
}
if (parent) {
std::vector<Token*> nextExprs = {parent->astOperand2()};
if (astIsLHS(parent) && parent->astParent() && parent->astParent()->str() == parent->str()) {
nextExprs.push_back(parent->astParent()->astOperand2());
}
const std::string& op(parent->str());
std::list<ValueFlow::Value> values;
if (op == "&&")
@ -4613,18 +4619,21 @@ struct ConditionHandler {
values = elseValues;
if (Token::Match(tok, "==|!=") || (tok == cond.vartok && astIsBool(tok)))
changePossibleToKnown(values);
// *INDENT-OFF*
if (astIsFloat(cond.vartok, false) ||
(!cond.vartok->valueType() &&
std::all_of(values.begin(), values.end(), [](const ValueFlow::Value& v) {
return v.isIntValue() || v.isFloatValue();
})))
values.remove_if([&](const ValueFlow::Value& v) {
return v.isImpossible();
});
Analyzer::Result r = forward(parent->astOperand2(), cond.vartok, values, tokenlist, settings);
values.remove_if([&](const ValueFlow::Value& v) { return v.isImpossible(); });
for(Token* start:nextExprs) {
Analyzer::Result r = forward(start, cond.vartok, values, tokenlist, settings);
if (r.terminate != Analyzer::Terminate::None)
return;
}
// *INDENT-ON*
}
}
{
@ -6179,10 +6188,12 @@ static Analyzer::Result valueFlowContainerForward(Token* startToken,
return valueFlowGenericForward(startToken, endToken, a, tokenlist->getSettings());
}
// *INDENT-OFF*
static Analyzer::Result valueFlowContainerForwardRecursive(Token* top,
const Token* exprTok,
const ValueFlow::Value& value,
TokenList* tokenlist)
// *INDENT-ON*
{
ContainerExpressionAnalyzer a(exprTok, value, tokenlist);
return valueFlowGenericForward(top, a, tokenlist->getSettings());

6
test/testcondition.cpp
View File

@ -3727,6 +3727,12 @@ private:
" }\n"
"}\n");
ASSERT_EQUALS("", errout.str());
// #9948
check("bool f(bool a, bool b) {\n"
" return a || ! b || ! a;\n"
"}\n");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:2]: (style) Condition '!a' is always true\n", errout.str());
}
void alwaysTrueInfer() {

7
test/teststl.cpp
View File

@ -589,6 +589,13 @@ private:
" return 0;\n"
"}\n");
ASSERT_EQUALS("", errout.str());
checkNormal("void foo(const std::vector<int> &v) {\n"
" if(v.size() >=1 && v[0] == 4 && v[1] == 2){}\n"
"}\n");
ASSERT_EQUALS("test.cpp:2:warning:Either the condition 'v.size()>=1' is redundant or v size can be 1. Expression 'v[1]' cause access out of bounds.\n"
"test.cpp:2:note:condition 'v.size()>=1'\n"
"test.cpp:2:note:Access out of bounds\n", errout.str());
}
void outOfBoundsIndexExpression() {