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robert reif: Fixed #1118 (new check: use empty() instead of checking size() against zero)

This commit is contained in:
Daniel Marjamäki 2009-12-19 15:24:59 +01:00
parent 69a98d81fc
commit 95f652a2b4
3 changed files with 123 additions and 0 deletions
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72
lib/checkstl.cpp
View File

@ -530,3 +530,75 @@ void CheckStl::findError(const Token *tok)
{
reportError(tok, Severity::error, "stlfind", "dangerous usage of find result");
}
bool CheckStl::isStlContainer(const Token *tok)
{
// check if this token is defined
if (tok->varId())
{
// find where this token is defined
const Token *type = Token::findmatch(_tokenizer->tokens(), "%varid%", tok->varId());
// find where this tokens type starts
while (type->previous() && !Token::Match(type->previous(), "[;{]"))
type = type->previous();
// discard namespace if supplied
if (Token::Match(type, "std ::"))
type = type->next()->next();
// all possible stl containers
static const char STL_CONTAINER_LIST[] = "bitset|deque|list|map|multimap|multiset|priority_queue|queue|set|stack|hash_map|hash_multimap|hash_set|vector";
// container template string
const std::string checkStr = (std::string(STL_CONTAINER_LIST) + " <");
// check if it's an stl template
if (Token::Match(type, checkStr.c_str()))
return true;
}
return false;
}
void CheckStl::size()
{
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (Token::Match(tok, "%var% . size ( )"))
{
if (Token::Match(tok->tokAt(5), "==|!=|> 0"))
{
if (isStlContainer(tok))
sizeError(tok);
}
else if ((tok->tokAt(5)->str() == ")" ||
tok->tokAt(5)->str() == "&&" ||
tok->tokAt(5)->str() == "||" ||
tok->tokAt(5)->str() == "!" ) &&
(tok->tokAt(-1)->str() == "(" ||
tok->tokAt(-1)->str() == "&&" ||
tok->tokAt(-1)->str() == "||" ||
tok->tokAt(-1)->str() == "!"))
{
if (tok->tokAt(-1)->str() == "(" &&
tok->tokAt(5)->str() == ")")
{
// check for passing size to function call
if (Token::Match(tok->tokAt(-2), "if|while"))
{
if (isStlContainer(tok))
sizeError(tok);
}
}
else if (isStlContainer(tok))
sizeError(tok);
}
}
}
}
void CheckStl::sizeError(const Token *tok)
{
reportError(tok, Severity::possibleStyle, "stlSize", "Replace size() check against 0 with empty(): " + tok->str());
}

11
lib/checkstl.h
View File

@ -54,6 +54,7 @@ public:
checkStl.pushback();
checkStl.stlBoundries();
checkStl.find();
checkStl.size();
}
@ -96,6 +97,12 @@ public:
/** usage of std::find */
void find();
/**
* Suggest using empty() instead of checking size() against zero for containers.
* Item 4 from Scott Meyers book "Effective STL".
*/
void size();
private:
/**
@ -113,6 +120,7 @@ private:
void invalidPointerError(const Token *tok, const std::string &pointer_name);
void stlBoundriesError(const Token *tok, const std::string &container_name);
void findError(const Token *tok);
void sizeError(const Token *tok);
void getErrorMessages()
{
@ -125,6 +133,7 @@ private:
invalidPointerError(0, "pointer");
stlBoundriesError(0, "container");
findError(0);
sizeError(0);
}
std::string name() const
@ -142,6 +151,8 @@ private:
" * for vectors: using iterator/pointer after push_back has been used\n"
" * dangerous usage of find";
}
bool isStlContainer(const Token *tok);
};
/// @}
//---------------------------------------------------------------------------

40
test/teststl.cpp
View File

@ -73,6 +73,8 @@ private:
// find
TEST_CASE(find1);
TEST_CASE(size1);
}
void check(const std::string &code)
@ -633,6 +635,44 @@ private:
ASSERT_EQUALS("", errout.str());
}
void size1()
{
check("void f()\n"
"{\n"
" std::list<int> x;\n"
" if (x.size() == 0) {}\n"
"}\n");
ASSERT_EQUALS("[test.cpp:4]: (possible style) Replace size() check against 0 with empty(): x\n", errout.str());
check("void f()\n"
"{\n"
" std::list<int> x;\n"
" if (x.size() != 0) {}\n"
"}\n");
ASSERT_EQUALS("[test.cpp:4]: (possible style) Replace size() check against 0 with empty(): x\n", errout.str());
check("void f()\n"
"{\n"
" std::list<int> x;\n"
" if (x.size() > 0) {}\n"
"}\n");
ASSERT_EQUALS("[test.cpp:4]: (possible style) Replace size() check against 0 with empty(): x\n", errout.str());
check("void f()\n"
"{\n"
" std::list<int> x;\n"
" if (x.size()) {}\n"
"}\n");
ASSERT_EQUALS("[test.cpp:4]: (possible style) Replace size() check against 0 with empty(): x\n", errout.str());
check("void f()\n"
"{\n"
" std::list<int> x;\n"
" fun(x.size());\n"
"}\n");
ASSERT_EQUALS("", errout.str());
}
};
REGISTER_TEST(TestStl)