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Improved checks in CheckStl: 

- Generalized check for inefficient emptiness check to detect !%var%.size() calls also outside of if and while; detect it also for %var%.size() when linked with && or ||.
Refactorizations in CheckStl:
- Removed an indendation counter and an offset variable
- Reduced distance given to tokAt calls in CheckStl::redundantCondition
- Rearranged code in CheckStl::missingComparison to use more efficient comparision of varIds instead of variable names. Use varId in pattern instead of variable name.
This commit is contained in:
PKEuS 2012-04-04 19:44:57 +02:00
parent bef2caf489
commit d6cfbc6483
2 changed files with 34 additions and 38 deletions
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63
lib/checkstl.cpp
View File

@ -884,13 +884,11 @@ void CheckStl::size()
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (Token::Match(tok, "%var% . size ( )") ||
Token::Match(tok, "%var% . %var% . size ( )")) {
int offset = 5;
const Token *tok1 = tok;
unsigned int varid = 0;
// get the variable id
if (tok->strAt(2) != "size") {
offset = 7;
tok1 = tok1->tokAt(2);
// found a.b.size(), lookup class/struct variable
@ -912,18 +910,20 @@ void CheckStl::size()
} else
varid = tok1->varId();
const Token* const end = tok1->tokAt(5);
if (varid) {
// check for comparison to zero
if (Token::Match(tok->tokAt(offset), "==|!=|> 0") ||
Token::Match(tok->tokAt(-2), "0 ==|!=|<")) {
if (Token::Match(end, "==|<=|!=|> 0") ||
Token::Match(tok->tokAt(-2), "0 ==|>=|!=|<")) {
if (isStlContainer(varid))
sizeError(tok1);
}
// check for using as boolean expression
else if ((Token::Match(tok->tokAt(-2), "if|while (") ||
Token::Match(tok->tokAt(-3), "if|while ( !")) &&
tok->strAt(offset) == ")") {
else if (tok->strAt(-1) == "!" ||
(Token::Match(tok->tokAt(-2), "if|while (") && end->str() == ")") ||
(Token::Match(tok->previous(), "&&|%oror%") && Token::Match(end, "&&|)|%oror%"))) {
if (isStlContainer(varid))
sizeError(tok1);
}
@ -945,19 +945,17 @@ void CheckStl::sizeError(const Token *tok)
void CheckStl::redundantCondition()
{
const char pattern[] = "if ( %var% . find ( %any% ) != %var% . end|rend ( ) ) "
const char pattern[] = "if ( %var% . find ( %any% ) != %var% . end|rend|cend|crend ( ) ) "
"{"
" %var% . remove ( %any% ) ;";
const Token *tok = Token::findmatch(_tokenizer->tokens(), pattern);
while (tok) {
bool b(tok->strAt(15) == "{");
// Get tokens for the fields %var% and %any%
const Token *var1 = tok->tokAt(2);
const Token *any1 = tok->tokAt(6);
const Token *var2 = tok->tokAt(9);
const Token *var3 = tok->tokAt(b ? 16 : 15);
const Token *any2 = tok->tokAt(b ? 20 : 19);
const Token *any1 = var1->tokAt(4);
const Token *var2 = any1->tokAt(3);
const Token *var3 = var2->tokAt(7);
const Token *any2 = var3->tokAt(4);
// Check if all the "%var%" fields are the same and if all the "%any%" are the same..
if (var1->str() == var2->str() &&
@ -993,38 +991,29 @@ void CheckStl::missingComparison()
if (!Token::Match(tok2, "%var% = %var% . begin|rbegin|cbegin|crbegin ( ) ; %var% != %var% . end|rend|cend|crend ( ) ; ++| %var% ++| ) {"))
continue;
// same iterator name
if (tok2->str() != tok2->strAt(8))
continue;
// same container
if (tok2->strAt(2) != tok2->strAt(10))
continue;
break;
const unsigned int iteratorId(tok2->varId());
if (iteratorId == 0)
break;
// same iterator
if (iteratorId == tok2->tokAt(10)->varId())
break;
// increment iterator
if (!Token::simpleMatch(tok2->tokAt(16), ("++ " + tok2->str() + " )").c_str()) &&
!Token::simpleMatch(tok2->tokAt(16), (tok2->str() + " ++ )").c_str())) {
continue;
if (!Token::Match(tok2->tokAt(16), "++ %varid% )", iteratorId) &&
!Token::Match(tok2->tokAt(16), "%varid% ++ )", iteratorId)) {
break;
}
const unsigned int &iteratorId(tok2->varId());
if (iteratorId == 0)
continue;
const Token *incrementToken = 0;
// Count { and } for tok3
unsigned int indentlevel = 0;
// Parse loop..
for (const Token *tok3 = tok2->tokAt(20); tok3; tok3 = tok3->next()) {
if (tok3->str() == "{")
++indentlevel;
else if (tok3->str() == "}") {
if (indentlevel == 0)
break;
--indentlevel;
} else if (Token::Match(tok3, "%varid% ++", iteratorId))
for (const Token *tok3 = i->classStart; tok3 != i->classEnd; tok3 = tok3->next()) {
if (Token::Match(tok3, "%varid% ++", iteratorId))
incrementToken = tok3;
else if (Token::Match(tok3->previous(), "++ %varid% !!.", iteratorId))
incrementToken = tok3;

9
test/teststl.cpp
View File

@ -1335,7 +1335,14 @@ private:
" std::list<int> x;\n"
" fun(!x.size());\n"
"}\n");
ASSERT_EQUALS("", errout.str());
ASSERT_EQUALS("[test.cpp:4]: (performance) Possible inefficient checking for 'x' emptiness.\n", errout.str());
check("void f()\n"
"{\n"
" std::list<int> x;\n"
" fun(a && x.size());\n"
"}\n");
ASSERT_EQUALS("[test.cpp:4]: (performance) Possible inefficient checking for 'x' emptiness.\n", errout.str());
}
void redundantCondition1() {