Skip to content

Fix #12773 FP accessMoved using try_emplace() together with std::move() #8421

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
chrchr-github wants to merge 3 commits into
base: main
Choose a base branch
from
+29 −1
Open

Fix #12773 FP accessMoved using try_emplace() together with std::move() #8421

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
914aa16
Update valueflow.cpp
chrchr-github Apr 7, 2026
5e769b3
Update testother.cpp
chrchr-github Apr 7, 2026
57029cb
Update valueflow.cpp
chrchr-github Apr 7, 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
18 changes: 17 additions & 1 deletion lib/valueflow.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1843,9 +1843,9 @@
const bool isCpp = (src && src->isCpp()) || (dst && dst->isCpp());
if (isNotEqual(decl, parentdecl) && !(isCpp && (Token::simpleMatch(decl.first, "auto") || Token::simpleMatch(parentdecl.first, "auto"))))
return true;
if (isNotEqual(decl, dst->valueType(), isCpp, settings))

Check failure on line 1846 in lib/valueflow.cpp

View check run for this annotation

SonarQubeCloud / SonarCloud Code Analysis

Called C++ object pointer is null 


See more on https://sonarcloud.io/project/issues?id=danmar_cppcheck&issues=AZ1oZdPDF56l7c_-6NR5&open=AZ1oZdPDF56l7c_-6NR5&pullRequest=8421
return true;
if (isNotEqual(parentdecl, src->valueType(), isCpp, settings))

Check failure on line 1848 in lib/valueflow.cpp

View check run for this annotation

SonarQubeCloud / SonarCloud Code Analysis

Called C++ object pointer is null 


See more on https://sonarcloud.io/project/issues?id=danmar_cppcheck&issues=AZ1oZdPDF56l7c_-6NR6&open=AZ1oZdPDF56l7c_-6NR6&pullRequest=8421
return true;
}
return false;
Expand Down Expand Up @@ -3223,6 +3223,14 @@
return nextAfterAstRightmostLeaf(parent);
}

static bool isTryEmplace(const Token* tok)
{
if (tok->str() != "(" || !Token::simpleMatch(tok->astOperand1(), ".") || !tok->astOperand1()->astOperand1() || !Token::simpleMatch(tok->astOperand1()->astOperand2(), "try_emplace"))
return false;
const ValueType* vt = tok->astOperand1()->astOperand1()->valueType();
return vt && vt->container && vt->container->stdAssociativeLike;
}

static void valueFlowAfterMove(const TokenList& tokenlist, const SymbolDatabase& symboldatabase, ErrorLogger& errorLogger, const Settings& settings)
{
if (!tokenlist.isCPP() || settings.standards.cpp < Standards::CPP11)
Expand Down Expand Up @@ -3265,9 +3273,17 @@
const nonneg int varId = varTok->varId();
// x is not MOVED after assignment if code is: x = ... std::move(x) .. ;
const Token *parent = tok->astParent();
bool bail = false;
while (parent && parent->str() != "=" && parent->str() != "return" &&
!(parent->str() == "(" && isOpenParenthesisMemberFunctionCallOfVarId(parent, varId)))
!(parent->str() == "(" && isOpenParenthesisMemberFunctionCallOfVarId(parent, varId))) {
if (isTryEmplace(parent)) {
bail = true;
break;
}
parent = parent->astParent();
}
if (bail)
continue;
if (parent &&
(parent->str() == "return" || // MOVED in return statement
parent->str() == "(")) // MOVED in self assignment, isOpenParenthesisMemberFunctionCallOfVarId == true
Expand Down
12 changes: 12 additions & 0 deletions test/testother.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -304,6 +304,7 @@ class TestOther : public TestFixture {
TEST_CASE(moveForRange);
TEST_CASE(moveTernary);
TEST_CASE(movePointerAlias);
TEST_CASE(moveTryEmplace);

TEST_CASE(funcArgNamesDifferent);
TEST_CASE(funcArgOrderDifferent);
Expand Down Expand Up @@ -12730,6 +12731,17 @@ class TestOther : public TestFixture {
ASSERT_EQUALS("[test.cpp:5:8]: (warning) Access of moved variable '.'. [accessMoved]\n", errout_str());
}

void moveTryEmplace()
{
check("void f(std::map<std::string, std::string>& m, std::string& s) {\n" // #12773
" bool b = m.try_emplace(\"a\", std::move(s)).second;\n"
" if (!b) {\n"
" std::cout << s;\n"
" }\n"
"}\n");
ASSERT_EQUALS("", errout_str());
}

void funcArgNamesDifferent() {
check("void func1(int a, int b, int c);\n"
"void func1(int a, int b, int c) { }\n"
Expand Down
Loading