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Fix 10532: False negative: dangling string_view when using ternary operator #4638

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Merged
orbitcowboy merged 3 commits into from
Dec 15, 2022
Merged

Fix 10532: False negative: dangling string_view when using ternary operator #4638

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Fix 10532: False negative: dangling string_view when using ternary op…
pfultz2 Dec 13, 2022
c3560aa
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pfultz2 Dec 13, 2022
db852b8
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pfultz2 Dec 14, 2022
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8 changes: 7 additions & 1 deletion lib/astutils.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -398,12 +398,18 @@ bool isTemporary(bool cpp, const Token* tok, const Library* library, bool unknow
return isTemporary(cpp, tok->astOperand2(), library);
if (tok->isCast() || (cpp && isCPPCast(tok)))
return isTemporary(cpp, tok->astOperand2(), library);
if (Token::Match(tok, "?|.|[|++|--|%name%|%assign%"))
if (Token::Match(tok, ".|[|++|--|%name%|%assign%"))
return false;
if (tok->isUnaryOp("*"))
return false;
if (Token::Match(tok, "&|<<|>>") && isLikelyStream(cpp, tok->astOperand1()))
return false;
if (Token::simpleMatch(tok, "?")) {
const Token* branchTok = tok->astOperand2();
if (!branchTok->astOperand1()->valueType())
return false;
return !branchTok->astOperand1()->valueType()->isTypeEqual(branchTok->astOperand2()->valueType());
}
if (Token::simpleMatch(tok, "(") && tok->astOperand1() &&
(tok->astOperand2() || Token::simpleMatch(tok->next(), ")"))) {
if (tok->valueType()) {
Expand Down
28 changes: 21 additions & 7 deletions lib/symboldatabase.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -6386,14 +6386,26 @@ void SymbolDatabase::setValueType(Token* tok, const ValueType& valuetype, Source
return;
}

if (vt1->pointer != 0U && vt2 && vt2->pointer == 0U) {
setValueType(parent, *vt1);
return;
}
if (parent->isArithmeticalOp()) {
if (vt1->pointer != 0U && vt2 && vt2->pointer == 0U) {
setValueType(parent, *vt1);
return;
}

if (vt1->pointer == 0U && vt2 && vt2->pointer != 0U) {
setValueType(parent, *vt2);
return;
if (vt1->pointer == 0U && vt2 && vt2->pointer != 0U) {
setValueType(parent, *vt2);
return;
}
} else if (ternary) {
if (vt1->pointer != 0U && vt2 && vt2->pointer == 0U) {
setValueType(parent, *vt2);
return;
}

if (vt1->pointer == 0U && vt2 && vt2->pointer != 0U) {
setValueType(parent, *vt1);
return;
}
}

if (vt1->pointer != 0U) {
Expand Down Expand Up @@ -7309,6 +7321,8 @@ MathLib::bigint ValueType::typeSize(const cppcheck::Platform &platform, bool p)

bool ValueType::isTypeEqual(const ValueType* that) const
{
if (!that)
return false;
auto tie = [](const ValueType* vt) {
return std::tie(vt->type, vt->container, vt->pointer, vt->typeScope, vt->smartPointer);
};
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9 changes: 9 additions & 0 deletions test/testautovariables.cpp
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Expand Up @@ -2757,6 +2757,15 @@ class TestAutoVariables : public TestFixture {
" return v[0];\n"
"}\n");
ASSERT_EQUALS("", errout.str());

// #10532
check("std::string f(std::string ss) {\n"
" std::string_view sv = true ? \"\" : ss;\n"
" std::string s = sv;\n"
" return s;\n"
"}\n");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:2] -> [test.cpp:3]: (error) Using object that is a temporary.\n",
errout.str());
}

void danglingLifetimeUniquePtr()
Expand Down