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cppcheck
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STL check: Detect return of implict string conversion + .c_str() 

Examples are:

    std::string msg;
    return ("ERROR: " + msg).c_str();

or

    return ("ERROR: " + std::string("crash me")).c_str();
This commit is contained in:
Thomas Jarosch 2011-10-26 22:14:47 +02:00
parent c4dabd61e9
commit 43e9c1f0bd
2 changed files with 30 additions and 0 deletions
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18
lib/checkstl.cpp
View File

@ -1030,6 +1030,24 @@ void CheckStl::string_c_str()
} else if (Token::simpleMatch(tok, "return std :: string (") && } else if (Token::simpleMatch(tok, "return std :: string (") &&
Token::Match(tok->tokAt(4)->link(), ") . c_str ( ) ;")) { Token::Match(tok->tokAt(4)->link(), ") . c_str ( ) ;")) {
string_c_strError(tok); string_c_strError(tok);
} else if (Token::simpleMatch(tok, "return (") &&
Token::Match(tok->next()->link(), ") . c_str ( ) ;")) {
// Check for "+ localvar" or "+ std::string(" inside the bracket
bool is_implicit_std_string = false;
const Token *search_end = tok->next()->link();
for (const Token *search_tok = tok->tokAt(2); search_tok != search_end; search_tok = search_tok->next()) {
if (Token::Match(search_tok, "+ %var%") && search_tok->next()->varId() > 0 &&
localvar.find(search_tok->next()->varId()) != localvar.end()) {
is_implicit_std_string = true;
break;
} else if (Token::simpleMatch(search_tok, "+ std :: string (")) {
is_implicit_std_string = true;
break;
}
}
if (is_implicit_std_string)
string_c_strError(tok);
} else if (Token::Match(tok, "[;{}] %var% = %var% . str ( ) . c_str ( ) ;") && } else if (Token::Match(tok, "[;{}] %var% = %var% . str ( ) . c_str ( ) ;") &&
tok->next()->varId() > 0 && tok->next()->varId() > 0 &&
pointers.find(tok->next()->varId()) != pointers.end()) { pointers.find(tok->next()->varId()) != pointers.end()) {

12
test/teststl.cpp
View File

@ -1329,6 +1329,18 @@ private:
"}"); "}");
ASSERT_EQUALS("[test.cpp:3]: (error) Dangerous usage of c_str()\n", errout.str()); ASSERT_EQUALS("[test.cpp:3]: (error) Dangerous usage of c_str()\n", errout.str());
check("const char *get_msg() {\n"
" std::string errmsg;\n"
" return (\"ERROR: \" + errmsg).c_str();\n"
"}");
ASSERT_EQUALS("[test.cpp:3]: (error) Dangerous usage of c_str()\n", errout.str());
check("const char *get_msg() {\n"
" std::string errmsg;\n"
" return (\"ERROR: \" + std::string(\"crash me\")).c_str();\n"
"}");
ASSERT_EQUALS("[test.cpp:3]: (error) Dangerous usage of c_str()\n", errout.str());
check("void f() {\n" check("void f() {\n"
" std::ostringstream errmsg;\n" " std::ostringstream errmsg;\n"
" const char *c = errmsg.str().c_str();\n" " const char *c = errmsg.str().c_str();\n"