Skip to content

Fix #14949: FP leakNoVarFunctionCall when passing resource to constructor #8765

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
aadanen wants to merge 4 commits into
base: main
Choose a base branch
from
+30 −15
Open

Fix #14949: FP leakNoVarFunctionCall when passing resource to constructor #8765

Show file tree
Hide file tree
Changes from 3 commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
09d0cc4
Fix #14949: FP when passing resource to ctor
Jul 29, 2026
960641a
remove temp comment
Jul 29, 2026
9590471
remove else after continue
Jul 30, 2026
b8feb14
revert check for alloc in ctor
Jul 30, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
30 changes: 14 additions & 16 deletions lib/checkmemoryleak.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -517,7 +517,7 @@ void CheckMemoryLeakInClassImpl::check()
// only check classes and structures
for (const Scope * scope : symbolDatabase->classAndStructScopes) {
for (const Variable &var : scope->varlist) {
if (!var.isStatic() && (var.isPointer() || var.isPointerArray())) {
if (!var.isStatic()) {
Comment thread
ludviggunne marked this conversation as resolved.
Outdated
// allocation but no deallocation of private variables in public function..
const Token *tok = var.typeStartToken();
// Either it is of standard type or a non-derived type
Expand Down Expand Up @@ -1046,22 +1046,20 @@ void CheckMemoryLeakNoVarImpl::checkForUnreleasedInputArgument(const Scope *scop
const AllocType alloc = getAllocationType(arg, 0);
if (alloc == No)
continue;
if (alloc == New || alloc == NewArray) {
const Token* typeTok = arg->next();
bool bail = !typeTok->isStandardType() &&
(!typeTok->valueType() ||
(typeTok->valueType()->type < ValueType::Type::SMART_POINTER &&
typeTok->valueType()->type != ValueType::Type::POD)) &&
!mSettings.library.detectContainerOrIterator(typeTok) &&
!mSettings.library.podtype(typeTok->expressionString());
if (bail && typeTok->type() && typeTok->type()->classScope &&
typeTok->type()->classScope->numConstructors == 0 &&
typeTok->type()->classScope->getDestructor() == nullptr) {
bail = false;
}
if (bail)
continue;
const Token* typeTok = arg->next();

@ludviggunne ludviggunne Aug 5, 2026

Copy link
Copy Markdown
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I'm not so sure typeTok is meaningful if it's not preceded by new. I believe in the test cases it's just a (. If we want to bail out here I think it's enough to determine that it's passed to a constructor.

@aadanen aadanen Aug 5, 2026 •
edited
Loading

Copy link
Copy Markdown
Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I don't understand. Using git blame I traced those lines back to 23deadb370 and 54b9fa5523. It seems to me like they are there for a reason. Maybe they are unnecessary, but I feel that should be a separate PR.

Edit: nevermind sorry I see the issue. I will see about reducing these checks.

@aadanen aadanen Aug 5, 2026 •
edited
Loading

Copy link
Copy Markdown
Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I tried removing different subsets of the checks and something like

if (tok->function() && !tok->function()->isConstructor())
                continue;

based on your suggestion about checking if it's passed to a constructor but wasn't able to pass all test cases. I've got to do some other work so likely won't be able to solve this today. It might be a bit beyond my limited knowledge as most of my cppcheck hacking has been focused on the front end.

bool bail = !typeTok->isStandardType() &&
(!typeTok->valueType() ||
(typeTok->valueType()->type < ValueType::Type::SMART_POINTER &&
typeTok->valueType()->type != ValueType::Type::POD)) &&
!mSettings.library.detectContainerOrIterator(typeTok) &&
!mSettings.library.podtype(typeTok->expressionString());
if (bail && typeTok->type() && typeTok->type()->classScope &&
typeTok->type()->classScope->numConstructors == 0 &&
typeTok->type()->classScope->getDestructor() == nullptr) {
bail = false;
}
if (bail)
continue;
if (isReopenStandardStream(arg))
continue;
if (tok->function()) {
Expand Down
17 changes: 17 additions & 0 deletions test/testmemleak.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2628,6 +2628,23 @@ class TestMemleakNoVar : public TestFixture {
"[test.cpp:7:12]: (error) Allocation with f2, assert doesn't release it. [leakNoVarFunctionCall]\n"
"[test.cpp:8:12]: (error) Allocation with f3, assert doesn't release it. [leakNoVarFunctionCall]\n",
errout_str());
check("struct S {\n"
" explicit S(int fd) {\n"
" m_fd = fd;\n"
" }\n"
" ~S() {\n"
" if (m_fd >= 0)\n"
" close(m_fd); \n"
" }\n"
" int m_fd = -1;\n"
"};\n"
"S g(char *name) {\n"
" return S(mkostemp(name, 0));\n"
"}\n"
"void f(char* ptr) {\n"
" S s = g(ptr);\n"
"}\n");
ASSERT_EQUALS("", errout_str());
}

void missingAssignment() {
Expand Down
Loading