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Fixed #3266 (False positive on dangerous usage of .c_str())

This commit is contained in:
Thomas Jarosch 2011-11-04 19:21:19 +01:00
parent 682aae3196
commit 4342fd254c
3 changed files with 36 additions and 23 deletions
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46
lib/checkstl.cpp
View File

@ -1019,17 +1019,36 @@ void CheckStl::string_c_str()
tok->next()->varId() > 0 && tok->next()->varId() > 0 &&
localvar.find(tok->next()->varId()) != localvar.end()) { localvar.find(tok->next()->varId()) != localvar.end()) {
string_c_strError(tok); string_c_strError(tok);
} else if (Token::Match(tok, "return %var% . c_str ( ) ;") && } else if (Token::Match(tok, "[;{}] %var% = %var% . str ( ) . c_str ( ) ;") &&
tok->next()->varId() > 0 && tok->next()->varId() > 0 &&
localvar.find(tok->next()->varId()) != localvar.end()) { pointers.find(tok->next()->varId()) != pointers.end()) {
string_c_strError(tok); string_c_strError(tok);
} else if (Token::Match(tok, "[;{}] %var% = %var% (") &&
Token::simpleMatch(tok->tokAt(4)->link(), ") . c_str ( ) ;") &&
tok->next()->varId() > 0 &&
pointers.find(tok->next()->varId()) != pointers.end() &&
Token::findmatch(_tokenizer->tokens(), ("std :: string " + tok->strAt(3) + " (").c_str())) {
string_c_strError(tok);
}
// This part is inconclusive as the return type of the function
// might convert it to another string class implicitly.
// TODO: As soon as the symbol database stores the return value
// of a function, we can check if it's const char* and output a real error.
if (!_settings->inconclusive)
continue;
if (Token::Match(tok, "return %var% . c_str ( ) ;") &&
tok->next()->varId() > 0 &&
localvar.find(tok->next()->varId()) != localvar.end()) {
string_c_strError(tok, true);
} else if (Token::Match(tok, "return %var% . str ( ) . c_str ( ) ;") && } else if (Token::Match(tok, "return %var% . str ( ) . c_str ( ) ;") &&
tok->next()->varId() > 0 && tok->next()->varId() > 0 &&
localvar.find(tok->next()->varId()) != localvar.end()) { localvar.find(tok->next()->varId()) != localvar.end()) {
string_c_strError(tok); string_c_strError(tok, true);
} else if (Token::simpleMatch(tok, "return std :: string (") && } else if (Token::simpleMatch(tok, "return std :: string (") &&
Token::simpleMatch(tok->tokAt(4)->link(), ") . c_str ( ) ;")) { Token::simpleMatch(tok->tokAt(4)->link(), ") . c_str ( ) ;")) {
string_c_strError(tok); string_c_strError(tok, true);
} else if (Token::simpleMatch(tok, "return (") && } else if (Token::simpleMatch(tok, "return (") &&
Token::simpleMatch(tok->next()->link(), ") . c_str ( ) ;")) { Token::simpleMatch(tok->next()->link(), ") . c_str ( ) ;")) {
// Check for "+ localvar" or "+ std::string(" inside the bracket // Check for "+ localvar" or "+ std::string(" inside the bracket
@ -1047,26 +1066,19 @@ void CheckStl::string_c_str()
} }
if (is_implicit_std_string) if (is_implicit_std_string)
string_c_strError(tok); string_c_strError(tok, true);
} else if (Token::Match(tok, "[;{}] %var% = %var% . str ( ) . c_str ( ) ;") &&
tok->next()->varId() > 0 &&
pointers.find(tok->next()->varId()) != pointers.end()) {
string_c_strError(tok);
} else if (Token::Match(tok, "[;{}] %var% = %var% (") &&
Token::simpleMatch(tok->tokAt(4)->link(), ") . c_str ( ) ;") &&
tok->next()->varId() > 0 &&
pointers.find(tok->next()->varId()) != pointers.end() &&
Token::findmatch(_tokenizer->tokens(), ("std :: string " + tok->strAt(3) + " (").c_str())) {
string_c_strError(tok);
} }
} }
} }
} }
} }
void CheckStl::string_c_strError(const Token *tok) void CheckStl::string_c_strError(const Token* tok, bool is_inconlusive)
{ {
reportError(tok, Severity::error, "stlcstr", "Dangerous usage of c_str()"); if (is_inconlusive)
reportInconclusiveError(tok, Severity::error, "stlcstr", "Possible dangerous usage of c_str()");
else
reportError(tok, Severity::error, "stlcstr", "Dangerous usage of c_str()");
} }

2
lib/checkstl.h
View File

@ -133,7 +133,7 @@ public:
/** Check for common mistakes when using the function string::c_str() */ /** Check for common mistakes when using the function string::c_str() */
void string_c_str(); void string_c_str();
void string_c_strError(const Token *tok); void string_c_strError(const Token *tok, bool is_inconlusive=false);
/** @brief %Check for use and copy auto pointer */ /** @brief %Check for use and copy auto pointer */
void checkAutoPointer(); void checkAutoPointer();

11
test/teststl.cpp
View File

@ -122,6 +122,7 @@ private:
Settings settings; Settings settings;
settings.addEnabled("style"); settings.addEnabled("style");
settings.addEnabled("performance"); settings.addEnabled("performance");
settings.inconclusive = true;
// Tokenize.. // Tokenize..
Tokenizer tokenizer(&settings, this); Tokenizer tokenizer(&settings, this);
@ -1315,31 +1316,31 @@ private:
" std::string errmsg;\n" " std::string errmsg;\n"
" return errmsg.c_str();\n" " return errmsg.c_str();\n"
"}"); "}");
ASSERT_EQUALS("[test.cpp:3]: (error) Dangerous usage of c_str()\n", errout.str()); ASSERT_EQUALS("[test.cpp:3]: (error) Possible dangerous usage of c_str()\n", errout.str());
check("const char *get_msg() {\n" check("const char *get_msg() {\n"
" std::ostringstream errmsg;\n" " std::ostringstream errmsg;\n"
" return errmsg.str().c_str();\n" " return errmsg.str().c_str();\n"
"}"); "}");
ASSERT_EQUALS("[test.cpp:3]: (error) Dangerous usage of c_str()\n", errout.str()); ASSERT_EQUALS("[test.cpp:3]: (error) Possible dangerous usage of c_str()\n", errout.str());
check("const char *get_msg() {\n" check("const char *get_msg() {\n"
" std::string errmsg;\n" " std::string errmsg;\n"
" return std::string(\"ERROR: \" + errmsg).c_str();\n" " return std::string(\"ERROR: \" + errmsg).c_str();\n"
"}"); "}");
ASSERT_EQUALS("[test.cpp:3]: (error) Dangerous usage of c_str()\n", errout.str()); ASSERT_EQUALS("[test.cpp:3]: (error) Possible dangerous usage of c_str()\n", errout.str());
check("const char *get_msg() {\n" check("const char *get_msg() {\n"
" std::string errmsg;\n" " std::string errmsg;\n"
" return (\"ERROR: \" + errmsg).c_str();\n" " return (\"ERROR: \" + errmsg).c_str();\n"
"}"); "}");
ASSERT_EQUALS("[test.cpp:3]: (error) Dangerous usage of c_str()\n", errout.str()); ASSERT_EQUALS("[test.cpp:3]: (error) Possible dangerous usage of c_str()\n", errout.str());
check("const char *get_msg() {\n" check("const char *get_msg() {\n"
" std::string errmsg;\n" " std::string errmsg;\n"
" return (\"ERROR: \" + std::string(\"crash me\")).c_str();\n" " return (\"ERROR: \" + std::string(\"crash me\")).c_str();\n"
"}"); "}");
ASSERT_EQUALS("[test.cpp:3]: (error) Dangerous usage of c_str()\n", errout.str()); ASSERT_EQUALS("[test.cpp:3]: (error) Possible dangerous usage of c_str()\n", errout.str());
check("void f() {\n" check("void f() {\n"
" std::ostringstream errmsg;\n" " std::ostringstream errmsg;\n"