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Fix #11437 FP knownConditionTrueFalse when comparing clamped value #8751

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Fix #11437 FP knownConditionTrueFalse when comparing clamped value #8751

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129dba1
Update valueflow.cpp
chrchr-github Jul 23, 2026
2145c4a
Update testvalueflow.cpp
chrchr-github Jul 23, 2026
27cbb8c
Update testcondition.cpp
chrchr-github Jul 23, 2026
4daa356
Update testvalueflow.cpp
chrchr-github Jul 23, 2026
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13 changes: 0 additions & 13 deletions lib/valueflow.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1107,19 +1107,6 @@ static void valueFlowImpossibleValues(TokenList& tokenList, const Settings& sett
for (const Token* tok2 : tokens) {
if (const ValueFlow::Value* v = tok2->getKnownValue(ValueFlow::Value::ValueType::INT)) {
values.emplace_back(*v);
} else {
ValueFlow::Value symValue{};
symValue.valueType = ValueFlow::Value::ValueType::SYMBOLIC;
symValue.tokvalue = tok2;
values.push_back(std::move(symValue));
std::copy_if(tok2->values().cbegin(),
tok2->values().cend(),
std::back_inserter(values),
[](const ValueFlow::Value& v) {
if (!v.isKnown())
return false;
return v.isSymbolicValue();
});
}
}
const bool isMin = Token::Match(condTok, "<|<=") ^ flipped;
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6 changes: 6 additions & 0 deletions test/testcondition.cpp
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Expand Up @@ -5222,6 +5222,12 @@ class TestCondition : public TestFixture {
" if (c) {}\n"
"}\n");
ASSERT_EQUALS("", errout_str());

check("void f(int a, int b) {\n" // #11437
" a = a < b ? b : a;\n"
" if (a != b) {}\n"
"}\n");
ASSERT_EQUALS("", errout_str());
}

void alwaysTrueInfer() {
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62 changes: 0 additions & 62 deletions test/testvalueflow.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -166,7 +166,6 @@ class TestValueFlow : public TestFixture {
TEST_CASE(valueFlowSymbolicIdentity);
TEST_CASE(valueFlowSymbolicStrlen);
TEST_CASE(valueFlowSmartPointer);
TEST_CASE(valueFlowImpossibleMinMax);
TEST_CASE(valueFlowImpossibleIncDec);
TEST_CASE(valueFlowImpossibleUnknownConstant);
TEST_CASE(valueFlowContainerEqual);
Expand Down Expand Up @@ -9334,67 +9333,6 @@ class TestValueFlow : public TestFixture {
ASSERT_EQUALS(false, testValueOfX(code, 5U, 0));
}

void valueFlowImpossibleMinMax()
{
const char* code;

code = "void f(int a, int b) {\n"
" int x = a < b ? a : b;\n"
" return x;\n"
"}\n";
ASSERT_EQUALS(true, testValueOfXImpossible(code, 3U, "a", 1));

@chrchr-github chrchr-github Jul 23, 2026

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These values apparently give no benefit. Does this test assert that x cannot be a+1? Thaf is incorrect for a=1, b=2.

ASSERT_EQUALS(true, testValueOfXImpossible(code, 3U, "b", 1));

code = "void f(int a, int b) {\n"
" int x = a > b ? a : b;\n"
" return x;\n"
"}\n";
ASSERT_EQUALS(true, testValueOfXImpossible(code, 3U, "a", -1));
ASSERT_EQUALS(true, testValueOfXImpossible(code, 3U, "b", -1));

code = "void f(int a, int b) {\n"
" int x = a > b ? b : a;\n"
" return x;\n"
"}\n";
ASSERT_EQUALS(true, testValueOfXImpossible(code, 3U, "a", 1));
ASSERT_EQUALS(true, testValueOfXImpossible(code, 3U, "b", 1));

code = "void f(int a, int b) {\n"
" int x = a < b ? b : a;\n"
" return x;\n"
"}\n";
ASSERT_EQUALS(true, testValueOfXImpossible(code, 3U, "a", -1));
ASSERT_EQUALS(true, testValueOfXImpossible(code, 3U, "b", -1));

code = "void f(int a) {\n"
" int x = a < 0 ? a : 0;\n"
" return x;\n"
"}\n";
ASSERT_EQUALS(true, testValueOfXImpossible(code, 3U, "a", 1));
ASSERT_EQUALS(true, testValueOfXImpossible(code, 3U, 1));

code = "void f(int a) {\n"
" int x = a > 0 ? a : 0;\n"
" return x;\n"
"}\n";
ASSERT_EQUALS(true, testValueOfXImpossible(code, 3U, "a", -1));
ASSERT_EQUALS(true, testValueOfXImpossible(code, 3U, -1));

code = "void f(int a) {\n"
" int x = a > 0 ? 0 : a;\n"
" return x;\n"
"}\n";
ASSERT_EQUALS(true, testValueOfXImpossible(code, 3U, "a", 1));
ASSERT_EQUALS(true, testValueOfXImpossible(code, 3U, 1));

code = "void f(int a) {\n"
" int x = a < 0 ? 0 : a;\n"
" return x;\n"
"}\n";
ASSERT_EQUALS(true, testValueOfXImpossible(code, 3U, "a", -1));
ASSERT_EQUALS(true, testValueOfXImpossible(code, 3U, -1));
}

void valueFlowImpossibleIncDec()
{
const char* code;
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