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Fix 9760: False positive: constParameter on parameter used to take non-const pointer via array decaying (#3660)

This commit is contained in:
Paul Fultz II 2022-01-02 01:15:38 -06:00 committed by GitHub
parent 71a44395c8
commit 01a8890d6d
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 34 additions and 16 deletions
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46
lib/astutils.cpp
View File

@ -2326,28 +2326,40 @@ static bool isExpressionChangedAt(const F& getExprTok,
bool cpp,
int depth)
{
if (depth < 0)
return true;
if (tok->exprId() != exprid) {
if (globalvar && Token::Match(tok, "%name% ("))
// TODO: Is global variable really changed by function call?
return true;
// Is aliased function call or alias passed to function
if ((Token::Match(tok, "%var% (") || isVariableChangedByFunctionCall(tok, 1, settings)) &&
std::any_of(tok->values().begin(), tok->values().end(), std::mem_fn(&ValueFlow::Value::isLifetimeValue))) {
bool aliased = false;
// If we can't find the expression then assume it was modified
if (!getExprTok())
return true;
visitAstNodes(getExprTok(), [&](const Token* childTok) {
if (childTok->varId() > 0 && isAliasOf(tok, childTok->varId())) {
aliased = true;
return ChildrenToVisit::done;
const bool pointer = astIsPointer(tok);
bool aliased = false;
// If we can't find the expression then assume it is an alias
if (!getExprTok())
aliased = true;
if (!aliased) {
aliased = findAstNode(getExprTok(), [&](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();
}))
return true;
}
}
return ChildrenToVisit::op1_and_op2;
return false;
});
// TODO: Try to traverse the lambda function
if (aliased)
return true;
}
if (!aliased)
return false;
if (isVariableChanged(tok, 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));
@ -2398,7 +2410,7 @@ bool isVariableChanged(const Variable * var, const Settings *settings, bool cpp,
return false;
if (Token::Match(start, "; %varid% =", var->declarationId()))
start = start->tokAt(2);
return isVariableChanged(start->next(), var->scope()->bodyEnd, var->declarationId(), var->isGlobal(), settings, cpp, depth);
return isExpressionChanged(var->nameToken(), start->next(), var->scope()->bodyEnd, settings, cpp, depth);
}
bool isVariablesChanged(const Token* start,
@ -2458,6 +2470,8 @@ bool isThisChanged(const Token* start, const Token* end, int indirect, const Set
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) {

4
test/testother.cpp
View File

@ -2623,6 +2623,10 @@ private:
check("struct S { void f(); int i; };\n"
"void call_f(S& s) { (s.*(&S::f))(); }\n");
ASSERT_EQUALS("", errout.str());
check("struct S { int a[1]; };\n"
"void f(S& s) { int* p = s.a; *p = 0; }\n");
ASSERT_EQUALS("", errout.str());
}
void constParameterCallback() {