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Fix issue 9996: false negative: containerOutOfBounds with std::vector::front() and c++11 braced initializer (#2958)

This commit is contained in:
Paul Fultz II 2020-12-18 00:14:11 -06:00 committed by GitHub
parent 0b98053790
commit b044f9ba96
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2 changed files with 73 additions and 7 deletions
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44
lib/valueflow.cpp
View File

@ -5970,6 +5970,24 @@ static void valueFlowIteratorInfer(TokenList *tokenlist, const Settings *setting
}
}
static std::vector<ValueFlow::Value> getInitListSize(const Token* tok)
{
std::vector<const Token*> args = getArguments(tok);
if ((args.size() == 1 && astIsContainer(args[0]) && args[0]->valueType()->container == tok->valueType()->container) ||
(args.size() == 2 && astIsIterator(args[0]) && astIsIterator(args[1]))) {
std::vector<ValueFlow::Value> values;
std::copy_if(args[0]->values().begin(),
args[0]->values().end(),
std::back_inserter(values),
std::mem_fn(&ValueFlow::Value::isContainerSizeValue));
return values;
}
ValueFlow::Value value(args.size());
value.valueType = ValueFlow::Value::ValueType::CONTAINER_SIZE;
value.setKnown();
return {value};
}
static void valueFlowContainerSize(TokenList *tokenlist, SymbolDatabase* symboldatabase, ErrorLogger * /*errorLogger*/, const Settings *settings)
{
// declaration
@ -5978,22 +5996,27 @@ static void valueFlowContainerSize(TokenList *tokenlist, SymbolDatabase* symbold
continue;
if (!var->valueType() || !var->valueType()->container)
continue;
if (!Token::Match(var->nameToken(), "%name% ;"))
continue;
if (!astIsContainer(var->nameToken()))
continue;
if (var->nameToken()->hasKnownValue())
continue;
ValueFlow::Value value(0);
if (!Token::Match(var->nameToken(), "%name% ;") &&
!(Token::Match(var->nameToken(), "%name% {") && Token::simpleMatch(var->nameToken()->next()->link(), "} ;")))
continue;
std::vector<ValueFlow::Value> values{ValueFlow::Value{0}};
values.back().valueType = ValueFlow::Value::ValueType::CONTAINER_SIZE;
values.back().setKnown();
if (var->valueType()->container->size_templateArgNo >= 0) {
if (var->dimensions().size() == 1 && var->dimensions().front().known)
value.intvalue = var->dimensions().front().num;
values.back().intvalue = var->dimensions().front().num;
else
continue;
} else if (Token::simpleMatch(var->nameToken()->next(), "{")) {
const Token* initList = var->nameToken()->next();
values = getInitListSize(initList);
}
value.valueType = ValueFlow::Value::ValueType::CONTAINER_SIZE;
value.setKnown();
valueFlowContainerForward(var->nameToken()->next(), var, value, tokenlist);
for (const ValueFlow::Value& value : values)
valueFlowContainerForward(var->nameToken()->next(), var, value, tokenlist);
}
// after assignment
@ -6007,6 +6030,13 @@ static void valueFlowContainerSize(TokenList *tokenlist, SymbolDatabase* symbold
value.setKnown();
valueFlowContainerForward(containerTok->next(), containerTok->variable(), value, tokenlist);
}
} else if (Token::Match(tok, "%name%|;|{|}|> %var% = {") && Token::simpleMatch(tok->linkAt(3), "} ;")) {
const Token* containerTok = tok->next();
if (astIsContainer(containerTok)) {
std::vector<ValueFlow::Value> values = getInitListSize(tok->tokAt(3));
for (const ValueFlow::Value& value : values)
valueFlowContainerForward(containerTok->next(), containerTok->variable(), value, tokenlist);
}
} else if (Token::Match(tok, "%var% . %name% (") && tok->valueType() && tok->valueType()->container) {
Library::Container::Action action = tok->valueType()->container->getAction(tok->strAt(2));
if (action == Library::Container::Action::CLEAR) {

36
test/testvalueflow.cpp
View File

@ -4703,6 +4703,42 @@ private:
" }\n"
"}\n";
ASSERT_EQUALS(0U, tokenValues(code, "str . front").size());
code = "void f() {\n"
" std::vector<int> ints{};\n"
" ints.front();\n"
"}";
ASSERT_EQUALS("",
isKnownContainerSizeValue(tokenValues(code, "ints . front", ValueFlow::Value::CONTAINER_SIZE), 0));
code = "void f() {\n"
" std::vector<int> ints{1};\n"
" ints.front();\n"
"}";
ASSERT_EQUALS("",
isKnownContainerSizeValue(tokenValues(code, "ints . front", ValueFlow::Value::CONTAINER_SIZE), 1));
code = "void f() {\n"
" std::vector<int> ints{1};\n"
" std::vector<int> ints2{ints.begin(), ints.end()};\n"
" ints2.front();\n"
"}";
ASSERT_EQUALS(
"", isKnownContainerSizeValue(tokenValues(code, "ints2 . front", ValueFlow::Value::CONTAINER_SIZE), 1));
code = "void f() {\n"
" std::vector<int> ints = {};\n"
" ints.front();\n"
"}";
ASSERT_EQUALS("",
isKnownContainerSizeValue(tokenValues(code, "ints . front", ValueFlow::Value::CONTAINER_SIZE), 0));
code = "void f() {\n"
" std::vector<int> ints = {1};\n"
" ints.front();\n"
"}";
ASSERT_EQUALS("",
isKnownContainerSizeValue(tokenValues(code, "ints . front", ValueFlow::Value::CONTAINER_SIZE), 1));
}
void valueFlowDynamicBufferSize() {