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Fix issue 9849: false positive: containerOutOfBounds (#2753)

This commit is contained in:
Paul Fultz II 2020-08-25 00:12:41 -05:00 committed by GitHub
parent 2028591ecf
commit ec89c57a90
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 77 additions and 3 deletions
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25
lib/valueflow.cpp
View File

@ -4158,6 +4158,17 @@ static void insertImpossible(std::list<ValueFlow::Value>& values, const std::lis
std::transform(input.begin(), input.end(), std::back_inserter(values), &asImpossible);
}
static void insertNegateKnown(std::list<ValueFlow::Value>& values, const std::list<ValueFlow::Value>& input)
{
for(ValueFlow::Value value:input) {
if (!value.isIntValue() && !value.isContainerSizeValue())
continue;
value.intvalue = !value.intvalue;
value.setKnown();
values.push_back(value);
}
}
static std::vector<const Variable*> getExprVariables(const Token* expr,
const TokenList* tokenlist,
const SymbolDatabase* symboldatabase,
@ -4177,8 +4188,9 @@ struct ValueFlowConditionHandler {
const Token *vartok;
std::list<ValueFlow::Value> true_values;
std::list<ValueFlow::Value> false_values;
bool inverted = false;
Condition() : vartok(nullptr), true_values(), false_values() {}
Condition() : vartok(nullptr), true_values(), false_values(), inverted(false) {}
};
std::function<bool(Token* start, const Token* stop, const Token* exprTok, const std::list<ValueFlow::Value>& values, bool constValue)>
forward;
@ -4278,16 +4290,22 @@ struct ValueFlowConditionHandler {
std::list<ValueFlow::Value> thenValues;
std::list<ValueFlow::Value> elseValues;
if (!Token::Match(tok, "!=|=") && tok != cond.vartok) {
if (!Token::Match(tok, "!=|=|(|.") && tok != cond.vartok) {
thenValues.insert(thenValues.end(), cond.true_values.begin(), cond.true_values.end());
if (isConditionKnown(tok, false))
insertImpossible(elseValues, cond.false_values);
}
if (!Token::Match(tok, "==|!")) {
elseValues.insert(elseValues.end(), cond.false_values.begin(), cond.false_values.end());
if (isConditionKnown(tok, true))
if (isConditionKnown(tok, true)) {
insertImpossible(thenValues, cond.true_values);
if (Token::Match(tok, "(|.|%var%") && astIsBool(tok))
insertNegateKnown(thenValues, cond.true_values);
}
}
if (cond.inverted)
std::swap(thenValues, elseValues);
// start token of conditional code
Token* startTokens[] = {nullptr, nullptr};
@ -6020,6 +6038,7 @@ static void valueFlowContainerAfterCondition(TokenList *tokenlist,
cond.true_values.emplace_back(value);
cond.false_values.emplace_back(std::move(value));
cond.vartok = vartok;
cond.inverted = true;
return cond;
}
// String compare

55
test/testvalueflow.cpp
View File

@ -2479,6 +2479,39 @@ private:
ASSERT_EQUALS(false, testValueOfX(code, 4U, 123));
ASSERT_EQUALS(false, testValueOfX(code, 4U, 124));
ASSERT_EQUALS(false, testValueOfX(code, 4U, 125));
code = "struct A {\n"
" bool g() const;\n"
"};\n"
"void f(A a) {\n"
" if (a.g()) {\n"
" bool x = a.g();\n"
" bool a = x;\n"
" }\n"
"}\n";
ASSERT_EQUALS(false, testValueOfXKnown(code, 7U, 0));
code = "struct A {\n"
" bool g() const;\n"
"};\n"
"void f(A a) {\n"
" if (a.g()) {\n"
" bool x = !a.g();\n"
" bool a = x;\n"
" }\n"
"}\n";
ASSERT_EQUALS(true, testValueOfXKnown(code, 7U, 0));
code = "struct A {\n"
" bool g() const;\n"
"};\n"
"void f(A a) {\n"
" if (!a.g()) {\n"
" bool x = a.g();\n"
" bool a = x;\n"
" }\n"
"}\n";
ASSERT_EQUALS(true, testValueOfXKnown(code, 7U, 0));
}
void valueFlowAfterConditionSeveralNot() {
@ -4111,6 +4144,28 @@ private:
"}";
ASSERT(tokenValues(code, "params [ 2 ]").empty());
// valueFlowAfterCondition
code = "void f(const std::vector<std::string>& v) {\n"
" if(v.empty()) {\n"
" v.front();\n"
" }\n"
"}\n";
ASSERT_EQUALS("", isKnownContainerSizeValue(tokenValues(code, "v . front"), 0));
code = "void f(const std::vector<std::string>& v) {\n"
" if(!v.empty()) {\n"
" v.front();\n"
" }\n"
"}\n";
ASSERT_EQUALS("", isImpossibleContainerSizeValue(tokenValues(code, "v . front"), 0));
code = "void f(const std::vector<std::string>& v) {\n"
" if(!v.empty() && v[0] != \"\") {\n"
" v.front();\n"
" }\n"
"}\n";
ASSERT_EQUALS("", isImpossibleContainerSizeValue(tokenValues(code, "v . front"), 0));
// valueFlowContainerForward
code = "void f(const std::list<int> &ints) {\n"
" if (ints.empty()) {}\n"