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Fix #11546 FP danglingTemporaryLifetime with unknown member #5256

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Merged
chrchr-github merged 6 commits into from
Aug 14, 2023
Merged

Fix #11546 FP danglingTemporaryLifetime with unknown member #5256

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e9f369d
Fix #11546 FP danglingTemporaryLifetime with unknown member
chrchr-github Jul 20, 2023
de7096e
Update valueflow.cpp
chrchr-github Jul 29, 2023
f66896e
Update valueflow.cpp
chrchr-github Jul 29, 2023
532f789
Merge branch 'main' into chr_Fix11546
chrchr-github Aug 7, 2023
574ad3a
Address reviewer comments
chrchr-github Aug 7, 2023
ad02e13
Format
chrchr-github Aug 7, 2023
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27 changes: 16 additions & 11 deletions lib/valueflow.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -4243,28 +4243,33 @@ struct LifetimeStore {
}
};

static bool isOwningVariables(const std::list<Variable>& vars, int depth = 10)
static bool hasBorrowingVariables(const std::list<Variable>& vars, const std::vector<const Token*>& args, int depth = 10)
{
if (depth < 0)
return false;
return vars.empty() || std::all_of(vars.cbegin(), vars.cend(), [&](const Variable& var) {
if (var.isReference() || var.isPointer())
return false;
return std::any_of(vars.cbegin(), vars.cend(), [&](const Variable& var) {
const ValueType* vt = var.valueType();
if (vt) {
if (vt->pointer > 0)
if (vt->pointer > 0 &&
std::none_of(args.begin(), args.end(), [vt](const Token* arg) {
return arg->valueType() && arg->valueType()->type == vt->type;
}))
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@pfultz2 pfultz2 Jul 20, 2023

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I think this check can only be done with pointers. Another user class or container view could still borrow the lifetime.

return false;
if (vt->isPrimitive())
if (vt->pointer > 0)
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@pfultz2 pfultz2 Jul 20, 2023

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If its a pointer then its not an owning variable.

return true;
if (vt->isEnum())
if (vt->reference != Reference::None)
return true;
if (vt->isPrimitive())
return false;
if (vt->isEnum())
return false;
// TODO: Check container inner type
if (vt->type == ValueType::CONTAINER && vt->container)
return !vt->container->view;
return vt->container->view;
if (vt->typeScope)
return isOwningVariables(vt->typeScope->varlist, depth - 1);
return hasBorrowingVariables(vt->typeScope->varlist, args, depth - 1);
}
return false;
return true;
});
}

Expand Down Expand Up @@ -4341,7 +4346,7 @@ static void valueFlowLifetimeUserConstructor(Token* tok,
else
ls.byVal(tok, tokenlist, errorLogger, settings);
});
} else if (!isOwningVariables(constructor->nestedIn->varlist)) {
} else if (hasBorrowingVariables(constructor->nestedIn->varlist, args)) {
LifetimeStore::forEach(args,
"Passed to constructor of '" + name + "'.",
ValueFlow::Value::LifetimeKind::SubObject,
Expand Down
13 changes: 13 additions & 0 deletions test/testautovariables.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3647,6 +3647,19 @@ class TestAutoVariables : public TestFixture {
"}\n",
true);
ASSERT_EQUALS("", errout.str());

check("struct S {\n"
" explicit S(const char* p) { m = p; }\n"
" void g();\n"
" std::string m;\n"
" int* t{};\n"
"};\n"
"void f(const std::stringstream& buffer) {\n"
" S s(buffer.str().c_str());\n"
" s.g();\n"
"}\n",
true);
ASSERT_EQUALS("", errout.str());
}

void danglingLifetimeAggegrateConstructor() {
Expand Down