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fix #13773: False positive: should not warn when different ternary 2nd and 3rd expressions happens to have same value #7523

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fix #13773: False positive: should not warn when different ternary 2nd and 3rd expressions happens to have same value #7523

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618a09f
add test
ludviggunne May 11, 2025
9c383ca
fix #13773
ludviggunne May 11, 2025
bce3fbe
simplify test + add positive test
ludviggunne May 12, 2025
6821726
refactor tests
ludviggunne May 12, 2025
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11 changes: 10 additions & 1 deletion lib/checkother.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2663,6 +2663,14 @@ isStaticAssert(const Settings &settings, const Token *tok)
return false;
}

static bool isSizeof(const Token *tok)
{
if (!Token::simpleMatch(tok, "("))
return false;

return Token::simpleMatch(tok->astOperand1(), "sizeof");
}

void CheckOther::checkDuplicateExpression()
{
{
Expand Down Expand Up @@ -2846,7 +2854,8 @@ void CheckOther::checkDuplicateExpression()
} else if (tok->astOperand1() && tok->astOperand2() && tok->str() == ":" && tok->astParent() && tok->astParent()->str() == "?") {
if (!tok->astOperand1()->values().empty() && !tok->astOperand2()->values().empty() && isEqualKnownValue(tok->astOperand1(), tok->astOperand2()) &&
!isVariableChanged(tok->astParent(), /*indirect*/ 0, *mSettings) &&
isConstStatement(tok->astOperand1(), mSettings->library) && isConstStatement(tok->astOperand2(), mSettings->library))
isConstStatement(tok->astOperand1(), mSettings->library) && isConstStatement(tok->astOperand2(), mSettings->library) &&
!isSizeof(tok->astOperand1()) && !isSizeof(tok->astOperand2()))
duplicateValueTernaryError(tok);
else if (isSameExpression(true, tok->astOperand1(), tok->astOperand2(), *mSettings, false, true, &errorPath))
duplicateExpressionTernaryError(tok, std::move(errorPath));
Expand Down
15 changes: 15 additions & 0 deletions test/testother.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -306,6 +306,8 @@ class TestOther : public TestFixture {

TEST_CASE(knownConditionFloating);
TEST_CASE(knownConditionPrefixed);

TEST_CASE(ternarySameValueSizeof); // #13773
}

#define check(...) check_(__FILE__, __LINE__, __VA_ARGS__)
Expand Down Expand Up @@ -13093,6 +13095,19 @@ class TestOther : public TestFixture {
"[test.cpp:2:13] -> [test.cpp:3:11]: (style) The comparison 'i > +1' is always false. [knownConditionTrueFalse]\n",
errout_str());
}

void ternarySameValueSizeof() // #13773
{
check("void f(void) {\n"
" b = a ? sizeof(unsigned int) : sizeof(uint32_t);\n"
"}\n");
ASSERT_EQUALS("", errout_str());

check("void f(void) {\n"
" b = a ? sizeof(uint32_t) : sizeof(uint32_t);\n"
"}\n");
ASSERT_EQUALS("[test.cpp:2:30]: (style) Same expression in both branches of ternary operator. [duplicateExpressionTernary]\n", errout_str());
}
};

REGISTER_TEST(TestOther)
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