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Fix issue 9485: knownConditionTrueFalse false positive with integer constants #2447

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Merged
danmar merged 2 commits into from
Dec 14, 2019
Merged

Fix issue 9485: knownConditionTrueFalse false positive with integer constants #2447

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Fix issue 9485: knownConditionTrueFalse false positive with integer c…
pfultz2 Dec 13, 2019
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pfultz2 Dec 13, 2019
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38 changes: 34 additions & 4 deletions lib/checkother.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1987,7 +1987,15 @@ void CheckOther::checkDuplicateExpression()
if (tok->isOp() && tok->astOperand1() && !Token::Match(tok, "+|*|<<|>>|+=|*=|<<=|>>=")) {
if (Token::Match(tok, "==|!=|-") && astIsFloat(tok->astOperand1(), true))
continue;
if (isSameExpression(mTokenizer->isCPP(), true, tok->astOperand1(), tok->astOperand2(), mSettings->library, true, true, &errorPath)) {
const bool followVar = !isConstVarExpression(tok) || Token::Match(tok, "%comp%|%oror%|&&");
if (isSameExpression(mTokenizer->isCPP(),
true,
tok->astOperand1(),
tok->astOperand2(),
mSettings->library,
true,
followVar,
&errorPath)) {
if (isWithoutSideEffects(mTokenizer->isCPP(), tok->astOperand1())) {
const bool assignment = tok->str() == "=";
if (assignment && warningEnabled)
Expand All @@ -2005,17 +2013,39 @@ void CheckOther::checkDuplicateExpression()
duplicateExpressionError(tok->astOperand1(), tok->astOperand2(), tok, errorPath);
}
}
} else if (tok->str() == "=" && Token::simpleMatch(tok->astOperand2(), "=") && isSameExpression(mTokenizer->isCPP(), false, tok->astOperand1(), tok->astOperand2()->astOperand1(), mSettings->library, true, false)) {
} else if (tok->str() == "=" && Token::simpleMatch(tok->astOperand2(), "=") &&
isSameExpression(mTokenizer->isCPP(),
false,
tok->astOperand1(),
tok->astOperand2()->astOperand1(),
mSettings->library,
true,
false)) {
if (warningEnabled && isWithoutSideEffects(mTokenizer->isCPP(), tok->astOperand1())) {
selfAssignmentError(tok, tok->astOperand1()->expressionString());
}
} else if (styleEnabled &&
isOppositeExpression(mTokenizer->isCPP(), tok->astOperand1(), tok->astOperand2(), mSettings->library, false, true, &errorPath) &&
isOppositeExpression(mTokenizer->isCPP(),
tok->astOperand1(),
tok->astOperand2(),
mSettings->library,
false,
true,
&errorPath) &&
!Token::Match(tok, "=|-|-=|/|/=") &&
isWithoutSideEffects(mTokenizer->isCPP(), tok->astOperand1())) {
oppositeExpressionError(tok, errorPath);
} else if (!Token::Match(tok, "[-/%]")) { // These operators are not associative
if (styleEnabled && tok->astOperand2() && tok->str() == tok->astOperand1()->str() && isSameExpression(mTokenizer->isCPP(), true, tok->astOperand2(), tok->astOperand1()->astOperand2(), mSettings->library, true, true, &errorPath) && isWithoutSideEffects(mTokenizer->isCPP(), tok->astOperand2()))
if (styleEnabled && tok->astOperand2() && tok->str() == tok->astOperand1()->str() &&
isSameExpression(mTokenizer->isCPP(),
true,
tok->astOperand2(),
tok->astOperand1()->astOperand2(),
mSettings->library,
true,
followVar,
&errorPath) &&
isWithoutSideEffects(mTokenizer->isCPP(), tok->astOperand2()))
duplicateExpressionError(tok->astOperand2(), tok->astOperand1()->astOperand2(), tok, errorPath);
else if (tok->astOperand2() && isConstExpression(tok->astOperand1(), mSettings->library, true, mTokenizer->isCPP())) {
const Token *ast1 = tok->astOperand1();
Expand Down
13 changes: 13 additions & 0 deletions test/testother.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -139,6 +139,7 @@ class TestOther : public TestFixture {
TEST_CASE(duplicateExpression7);
TEST_CASE(duplicateExpression8);
TEST_CASE(duplicateExpression9); // #9320
TEST_CASE(duplicateExpression10); // #9485
TEST_CASE(duplicateExpressionLoop);
TEST_CASE(duplicateValueTernary);
TEST_CASE(duplicateExpressionTernary); // #6391
Expand Down Expand Up @@ -4657,6 +4658,18 @@ class TestOther : public TestFixture {
ASSERT_EQUALS("", errout.str());
}

void duplicateExpression10()
{
// #9485
check("int f() {\n"
" const int a = 1;\n"
" const int b = a-1;\n"
" const int c = a+1;\n"
" return c;\n"
"}\n");
ASSERT_EQUALS("", errout.str());
}

void duplicateExpressionLoop() {
check("void f() {\n"
" int a = 1;\n"
Expand Down