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ValueFlow: dont set dynamic values in unreachable code (#6973)

This commit is contained in:
Daniel Marjamäki 2015-11-30 16:15:58 +01:00
parent 1b0bb02f1d
commit 8fb6f33aca
2 changed files with 33 additions and 9 deletions
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27
lib/valueflow.cpp
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@ -1353,15 +1353,24 @@ static bool valueFlowForward(Token * const startToken,
const Token *op2 = tok2->astOperand2();
if (!condition || !op2) // Ticket #6713
continue;
std::list<ValueFlow::Value>::const_iterator it;
for (it = values.begin(); it != values.end(); ++it) {
const ProgramMemory programMemory(getProgramMemory(tok2, varid, *it));
if (conditionIsTrue(condition, programMemory))
valueFlowAST(const_cast<Token*>(op2->astOperand1()), varid, *it);
else if (conditionIsFalse(condition, programMemory))
valueFlowAST(const_cast<Token*>(op2->astOperand2()), varid, *it);
else
valueFlowAST(const_cast<Token*>(op2), varid, *it);
if (condition->values.size() == 1U && condition->values.front().isKnown() && !condition->values.front().tokvalue) {
const ValueFlow::Value &condValue = condition->values.front();
const Token *expr = (condValue.intvalue != 0) ? op2->astOperand1() : op2->astOperand2();
std::list<ValueFlow::Value>::const_iterator it;
for (it = values.begin(); it != values.end(); ++it)
valueFlowAST(const_cast<Token*>(expr), varid, *it);
} else {
std::list<ValueFlow::Value>::const_iterator it;
for (it = values.begin(); it != values.end(); ++it) {
const ProgramMemory programMemory(getProgramMemory(tok2, varid, *it));
if (conditionIsTrue(condition, programMemory))
valueFlowAST(const_cast<Token*>(op2->astOperand1()), varid, *it);
else if (conditionIsFalse(condition, programMemory))
valueFlowAST(const_cast<Token*>(op2->astOperand2()), varid, *it);
else
valueFlowAST(const_cast<Token*>(op2), varid, *it);
}
}
// Skip conditional expressions..
while (tok2->astOperand1() || tok2->astOperand2()) {

15
test/testvalueflow.cpp
View File

@ -805,6 +805,21 @@ private:
"}\n";
ASSERT_EQUALS(false, testValueOfX(code, 4U, 0));
// ?:
code = "void f() {\n"
" int x = 8;\n"
" a = ((x > 10) ?\n"
" x : 0);\n" // <- x is not 8
"}";
ASSERT_EQUALS(false, testValueOfX(code, 4U, 8));
code = "void f() {\n" // #6973
" char *x = \"\";\n"
" a = ((x[0] == 'U') ?\n"
" x[1] : 0);\n" // <- x is not ""
"}";
ASSERT_EQUALS(false, testValueOfX(code, 4U, "\"\""));
// if/else
code = "void f() {\n"
" int x = 123;\n"