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Refactored checkNegativeBitwiseShift() so it uses ast and valueflow

This commit is contained in:
Daniel Marjamäki 2014-03-29 13:01:30 +01:00
parent d1b1699bb0
commit 407c9fdf9d
2 changed files with 38 additions and 14 deletions
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44
lib/checkother.cpp
View File

@ -3299,22 +3299,46 @@ void CheckOther::redundantCopyError(const Token *tok,const std::string& varname)
void CheckOther::checkNegativeBitwiseShift()
{
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
const std::size_t functions = symbolDatabase->functionScopes.size();
for (std::size_t i = 0; i < functions; ++i) {
const Scope * scope = symbolDatabase->functionScopes[i];
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
if (tok->str() != "<<" && tok->str() != ">>")
continue;
if ((Token::Match(tok,"%var% >>|<< %num%") || Token::Match(tok,"%num% >>|<< %num%")) && !Token::Match(tok->previous(),">>|<<")) {
if (tok->isName()) {
const Variable *var = tok->variable();
if (var && var->typeStartToken()->isStandardType() && (tok->strAt(2))[0] == '-')
negativeBitwiseShiftError(tok);
} else {
if ((tok->strAt(2))[0] == '-')
negativeBitwiseShiftError(tok);
if (!tok->astOperand1() || !tok->astOperand2())
continue;
// don't warn if lhs is a class. this is an overloaded operator then
if (_tokenizer->isCPP()) {
const Token *rhs = tok->astOperand1();
while (Token::Match(rhs, "::|."))
rhs = rhs->astOperand2();
if (!rhs)
continue;
if (!rhs->isNumber() && !rhs->variable())
continue;
if (!rhs->variable()->typeStartToken()->isStandardType())
continue;
}
// Get negative rhs value. preferably a value which doesn't have 'condition'.
const ValueFlow::Value *value = nullptr;
for (std::list<ValueFlow::Value>::const_iterator it = tok->astOperand2()->values.begin();
it != tok->astOperand2()->values.end();
++it) {
if (it->intvalue < 0) {
if (value == nullptr || it->condition == nullptr)
value = &(*it);
if (value->condition == nullptr)
break;
}
}
if (!value)
continue;
negativeBitwiseShiftError(tok);
}
}
}
@ -3322,7 +3346,7 @@ void CheckOther::checkNegativeBitwiseShift()
void CheckOther::negativeBitwiseShiftError(const Token *tok)
{
reportError(tok, Severity::error, "shiftNegative", "Shifting by a negative value.");
reportError(tok, Severity::error, "shiftNegative", "Shifting by a negative value is undefined behaviour");
}

8
test/testother.cpp
View File

@ -6177,25 +6177,25 @@ private:
" int a; a = 123;\n"
" a << -1;\n"
"}");
ASSERT_EQUALS("[test.cpp:4]: (error) Shifting by a negative value.\n", errout.str());
ASSERT_EQUALS("[test.cpp:4]: (error) Shifting by a negative value is undefined behaviour\n", errout.str());
check("void foo()\n"
"{\n"
" int a; a = 123;\n"
" a >> -1;\n"
"}");
ASSERT_EQUALS("[test.cpp:4]: (error) Shifting by a negative value.\n", errout.str());
ASSERT_EQUALS("[test.cpp:4]: (error) Shifting by a negative value is undefined behaviour\n", errout.str());
check("void foo()\n"
"{\n"
" int a; a = 123;\n"
" a <<= -1;\n"
"}");
ASSERT_EQUALS("[test.cpp:4]: (error) Shifting by a negative value.\n", errout.str());
ASSERT_EQUALS("[test.cpp:4]: (error) Shifting by a negative value is undefined behaviour\n", errout.str());
check("void foo()\n"
"{\n"
" int a; a = 123;\n"
" a >>= -1;\n"
"}");
ASSERT_EQUALS("[test.cpp:4]: (error) Shifting by a negative value.\n", errout.str());
ASSERT_EQUALS("[test.cpp:4]: (error) Shifting by a negative value is undefined behaviour\n", errout.str());
check("void foo()\n"
"{\n"
" std::cout << -1;\n"