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Handle reverse conditions in isOppositeCond function #8408

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Handle reverse conditions in isOppositeCond function #8408

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63 changes: 49 additions & 14 deletions lib/astutils.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1810,21 +1810,32 @@
return commutativeEquals;
}

static bool isZeroBoundCond(const Token * const cond)
static bool isZeroBoundCond(const Token * const cond, bool reverse)
{
if (cond == nullptr)
return false;
// Assume unsigned
// TODO: Handle reverse conditions
const bool isZero = cond->astOperand2()->getValue(0);
if (cond->str() == "==" || cond->str() == ">=")
return isZero;
if (cond->str() == "<=")
return true;
if (cond->str() == "<")
return !isZero;
if (cond->str() == ">")
return false;
const bool isZero = reverse ? cond->astOperand1()->getValue(0) : cond->astOperand2()->getValue(0);

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A cast should not convert a pointer type to an integral type Warning

A cast should not convert a pointer type to an integral type
if (reverse) {
if (cond->str() == "==" || cond->str() == "<=")
return isZero;
if (cond->str() == ">=")
return true;
if (cond->str() == ">")
return !isZero;
if (cond->str() == "<")
return false;
} else {
if (cond->str() == "==" || cond->str() == ">=")
return isZero;
if (cond->str() == "<=")
return true;
if (cond->str() == "<")
return !isZero;
if (cond->str() == ">")
return false;
}

return false;
}

Expand Down Expand Up @@ -1888,7 +1899,7 @@
if (isSameExpression(true, cond1->astOperand2(), cond2->astOperand2(), settings, pure, followVar, errors))
return isDifferentKnownValues(cond1->astOperand1(), cond2->astOperand1());
}
// TODO: Handle reverse conditions

if (Library::isContainerYield(cond1, Library::Container::Yield::EMPTY, "empty") &&
Library::isContainerYield(cond2->astOperand1(), Library::Container::Yield::SIZE, "size") &&
isSameExpression(true,
Expand All @@ -1898,7 +1909,19 @@
pure,
followVar,
errors)) {
return !isZeroBoundCond(cond2);
return !isZeroBoundCond(cond2, false);
}

if (Library::isContainerYield(cond1, Library::Container::Yield::EMPTY, "empty") &&
Library::isContainerYield(cond2->astOperand2(), Library::Container::Yield::SIZE, "size") &&
isSameExpression(true,
cond1->astOperand1()->astOperand1(),
cond2->astOperand2()->astOperand1()->astOperand1(),
settings,
pure,
followVar,
errors)) {
return !isZeroBoundCond(cond2, true);
}

if (Library::isContainerYield(cond2, Library::Container::Yield::EMPTY, "empty") &&
Expand All @@ -1910,7 +1933,19 @@
pure,
followVar,
errors)) {
return !isZeroBoundCond(cond1);
return !isZeroBoundCond(cond1, false);
}

if (Library::isContainerYield(cond2, Library::Container::Yield::EMPTY, "empty") &&
Library::isContainerYield(cond1->astOperand2(), Library::Container::Yield::SIZE, "size") &&
isSameExpression(true,
cond2->astOperand1()->astOperand1(),
cond1->astOperand2()->astOperand1()->astOperand1(),
settings,
pure,
followVar,
errors)) {
return !isZeroBoundCond(cond1, true);
}
}

Expand Down
6 changes: 6 additions & 0 deletions test/testcondition.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2674,6 +2674,12 @@ class TestCondition : public TestFixture {
check("void f1(const std::string &s) { if(s.size() >= 0) if(s.empty()) {}} "); // CheckOther says: Unsigned expression 's.size()' can't be negative so it is unnecessary to test it. [unsignedPositive]
ASSERT_EQUALS("", errout_str());

check("void f1(const std::string &s) { if(42 < s.size()) if(s.empty()) {}}");
ASSERT_EQUALS("[test.cpp:1:39] -> [test.cpp:1:61]: (warning) Opposite inner 'if' condition leads to a dead code block. [oppositeInnerCondition]\n", errout_str());

check("void f1(const std::string &s) { if(s.empty()) if(42 < s.size()) {}}");
ASSERT_EQUALS("[test.cpp:1:43] -> [test.cpp:1:53]: (warning) Opposite inner 'if' condition leads to a dead code block. [oppositeInnerCondition]\n", errout_str());

// TODO: These are identical condition since size cannot be negative
check("void f1(const std::string &s) { if(s.size() <= 0) if(s.empty()) {}}");
ASSERT_EQUALS("", errout_str());
Expand Down
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