Fixed #485 (detect when code is checking for null after dereferencing)

This commit is contained in:
Daniel Marjamäki 2009-07-20 18:53:41 +02:00
parent f0afdf3582
commit b7ba49114c
2 changed files with 50 additions and 0 deletions

View File

@ -1024,6 +1024,32 @@ void CheckOther::nullPointer()
tok2 = tok2->next(); tok2 = tok2->next();
} }
} }
// Dereferencing a pointer and then checking if it's NULL..
for (const Token *tok1 = _tokenizer->tokens(); tok1; tok1 = tok1->next())
{
if (Token::Match(tok1, "%var% . %var%"))
{
const unsigned int varid1(tok1->varId());
unsigned int indentlevel2 = 0;
for (const Token *tok2 = tok1->tokAt(3); tok2; tok2 = tok2->next())
{
if (tok2->str() == "{")
++indentlevel2;
else if (tok2->str() == "}")
{
if (indentlevel2 == 0)
break;
--indentlevel2;
}
else if (tok2->str() == "if")
{
if (Token::Match(tok2, "if ( !| %varid% )", varid1))
nullPointerError(tok1);
}
}
}
}
} }

View File

@ -58,6 +58,8 @@ private:
TEST_CASE(nullpointer1); TEST_CASE(nullpointer1);
TEST_CASE(nullpointer2); TEST_CASE(nullpointer2);
TEST_CASE(nullpointer3);
TEST_CASE(nullpointer4);
TEST_CASE(oldStylePointerCast); TEST_CASE(oldStylePointerCast);
} }
@ -444,6 +446,28 @@ private:
ASSERT_EQUALS("", errout.str()); ASSERT_EQUALS("", errout.str());
} }
void nullpointer3()
{
checkNullPointer("void foo(struct ABC *abc)\n"
"{\n"
" int *a = abc->a;\n"
" if (!abc)\n"
" ;\n"
"}\n");
ASSERT_EQUALS("[test.cpp:3]: (error) Possible null pointer dereference\n", errout.str());
}
void nullpointer4()
{
checkNullPointer("void foo(struct ABC *abc)\n"
"{\n"
" int *a = abc->a;\n"
" if (abc)\n"
" ;\n"
"}\n");
ASSERT_EQUALS("[test.cpp:3]: (error) Possible null pointer dereference\n", errout.str());
}
void checkOldStylePointerCast(const char code[]) void checkOldStylePointerCast(const char code[])
{ {
// Tokenize.. // Tokenize..