TestString() : TestFixture("TestString") {

}

Settings settings;

void run() {

settings.addEnabled("warning");

settings.addEnabled("style");

TEST_CASE(stringLiteralWrite);

TEST_CASE(alwaysTrueFalseStringCompare);

TEST_CASE(suspiciousStringCompare);

TEST_CASE(suspiciousStringCompare_char);

TEST_CASE(strPlusChar1); // "/usr" + '/'

TEST_CASE(strPlusChar2); // "/usr" + ch

TEST_CASE(strPlusChar3); // ok: path + "/sub" + '/'

TEST_CASE(sprintf1); // Dangerous usage of sprintf

TEST_CASE(sprintf2);

TEST_CASE(sprintf3);

TEST_CASE(sprintf4); // struct member

TEST_CASE(incorrectStringCompare);

}

void check(const char code[], const char filename[] = "test.cpp") {

// Clear the error buffer..

errout.str("");

// Tokenize..

Tokenizer tokenizer(&settings, this);

std::istringstream istr(code);

tokenizer.tokenize(istr, filename);

// Check char variable usage..

CheckString checkString(&tokenizer, &settings, this);

checkString.runChecks(&tokenizer, &settings, this);

tokenizer.simplifyTokenList2();

checkString.runSimplifiedChecks(&tokenizer, &settings, this);

}

void stringLiteralWrite() {

check("void f() {\n"

" char *abc = \"abc\";\n"

" abc[0] = 'a';\n"

"}");

ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:2]: (error) Modifying string literal \"abc\" directly or indirectly is undefined behaviour.\n", errout.str());

check("void f() {\n"

" char *abc = \"abc\";\n"

" *abc = 'a';\n"

"}");

ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:2]: (error) Modifying string literal \"abc\" directly or indirectly is undefined behaviour.\n", errout.str());

check("void f() {\n"

" QString abc = \"abc\";\n"

" abc[0] = 'a';\n"

"}");

ASSERT_EQUALS("", errout.str());

check("void foo_FP1(char *p) {\n"

" p[1] = 'B';\n"

"}\n"

"void foo_FP2(void) {\n"

" char* s = \"Y\";\n"

" foo_FP1(s);\n"

"}");

ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:5]: (error) Modifying string literal \"Y\" directly or indirectly is undefined behaviour.\n", errout.str());

check("void foo_FP1(char *p) {\n"

" p[1] = 'B';\n"

"}\n"

"void foo_FP2(void) {\n"

" char s[10] = \"Y\";\n"

" foo_FP1(s);\n"

"}");

ASSERT_EQUALS("", errout.str());

}

void alwaysTrueFalseStringCompare() {

check("void f() {\n"

" if (strcmp(\"A\",\"A\")){}\n"

" if (strncmp(\"A\",\"A\",1)){}\n"

" if (strcasecmp(\"A\",\"A\")){}\n"

" if (strncasecmp(\"A\",\"A\",1)){}\n"

" if (memcmp(\"A\",\"A\",1)){}\n"

" if (strverscmp(\"A\",\"A\")){}\n"

" if (bcmp(\"A\",\"A\",1)){}\n"

" if (wcsncasecmp(L\"A\",L\"A\",1)){}\n"

" if (wcsncmp(L\"A\",L\"A\",1)){}\n"

" if (wmemcmp(L\"A\",L\"A\",1)){}\n"

" if (wcscmp(L\"A\",L\"A\")){}\n"

" if (wcscasecmp(L\"A\",L\"A\")){}\n"

"}");

ASSERT_EQUALS("[test.cpp:2]: (warning) Unnecessary comparison of static strings.\n"

"[test.cpp:3]: (warning) Unnecessary comparison of static strings.\n"

"[test.cpp:4]: (warning) Unnecessary comparison of static strings.\n"

"[test.cpp:5]: (warning) Unnecessary comparison of static strings.\n"

"[test.cpp:6]: (warning) Unnecessary comparison of static strings.\n"

"[test.cpp:7]: (warning) Unnecessary comparison of static strings.\n"

"[test.cpp:8]: (warning) Unnecessary comparison of static strings.\n"

"[test.cpp:9]: (warning) Unnecessary comparison of static strings.\n"

"[test.cpp:10]: (warning) Unnecessary comparison of static strings.\n"

"[test.cpp:11]: (warning) Unnecessary comparison of static strings.\n"

"[test.cpp:12]: (warning) Unnecessary comparison of static strings.\n"

"[test.cpp:13]: (warning) Unnecessary comparison of static strings.\n", errout.str());

// avoid false positives when the address is modified #6415

check("void f(void *p, int offset) {\n"

" if (!memcmp(p, p + offset, 42)){}\n"

" if (!memcmp(p + offset, p, 42)){}\n"

" if (!memcmp(offset + p, p, 42)){}\n"

" if (!memcmp(p, offset + p, 42)){}\n"

"}");

ASSERT_EQUALS("", errout.str());

// avoid false positives when the address is modified #6415

check("void f(char *c, int offset) {\n"

" if (!memcmp(c, c + offset, 42)){}\n"

" if (!memcmp(c + offset, c, 42)){}\n"

" if (!memcmp(offset + c, c, 42)){}\n"

" if (!memcmp(c, offset + c, 42)){}\n"

"}");

ASSERT_EQUALS("", errout.str());

// avoid false positives when the address is modified #6415

check("void f(std::string s, int offset) {\n"

" if (!memcmp(s.c_str(), s.c_str() + offset, 42)){}\n"

" if (!memcmp(s.c_str() + offset, s.c_str(), 42)){}\n"

" if (!memcmp(offset + s.c_str(), s.c_str(), 42)){}\n"

" if (!memcmp(s.c_str(), offset + s.c_str(), 42)){}\n"

"}");

ASSERT_EQUALS("", errout.str());

check("int main()\n"

"{\n"

" if (strcmp(\"00FF00\", \"00FF00\") == 0)"

" {"

" std::cout << \"Equal\n\""

" }"

"}");

ASSERT_EQUALS("[test.cpp:3]: (warning) Unnecessary comparison of static strings.\n", errout.str());

check("void f() {\n"

" if (strcmp($\"00FF00\", \"00FF00\") == 0) {}"

"}");

ASSERT_EQUALS("", errout.str());

check("void f() {\n"

" if ($strcmp(\"00FF00\", \"00FF00\") == 0) {}"

"}");

ASSERT_EQUALS("", errout.str());

check("int main()\n"

"{\n"

" if (stricmp(\"hotdog\",\"HOTdog\") == 0)"

" {"

" std::cout << \"Equal\n\""

" }"

"}");

ASSERT_EQUALS("[test.cpp:3]: (warning) Unnecessary comparison of static strings.\n", errout.str());

check("int main()\n"

"{\n"

" if (QString::compare(\"Hamburger\", \"Hotdog\") == 0)"

" {"

" std::cout << \"Equal\n\""

" }"

"}");

ASSERT_EQUALS("[test.cpp:3]: (warning) Unnecessary comparison of static strings.\n", errout.str());

check("int main()\n"

"{\n"

" if (QString::compare(argv[2], \"hotdog\") == 0)"

" {"

" std::cout << \"Equal\n\""

" }"

"}");

ASSERT_EQUALS("", errout.str());

check("int main()\n"

"{\n"

" if (strncmp(\"hotdog\",\"hotdog\", 6) == 0)"

" {"

" std::cout << \"Equal\n\""

" }"

"}");

ASSERT_EQUALS("[test.cpp:3]: (warning) Unnecessary comparison of static strings.\n", errout.str());

check("int foo(const char *buf)\n"

"{\n"

" if (strcmp(buf, buf) == 0)"

" {"

" std::cout << \"Equal\n\""

" }"

"}");

ASSERT_EQUALS("[test.cpp:3]: (warning) Comparison of identical string variables.\n", errout.str());

check("int foo(const std::string& buf)\n"

"{\n"

" if (stricmp(buf.c_str(), buf.c_str()) == 0)"

" {"

" std::cout << \"Equal\n\""

" }"

"}");

ASSERT_EQUALS("[test.cpp:3]: (warning) Comparison of identical string variables.\n", errout.str());

check("int main() {\n"

" if (\"str\" == \"str\") {\n"

" std::cout << \"Equal\n\"\n"

" }\n"

"}");

ASSERT_EQUALS("[test.cpp:2]: (warning) Unnecessary comparison of static strings.\n", errout.str());

check("int main() {\n"

" if (\"str\" != \"str\") {\n"

" std::cout << \"Equal\n\"\n"

" }\n"

"}");

ASSERT_EQUALS("[test.cpp:2]: (warning) Unnecessary comparison of static strings.\n", errout.str());

check("int main() {\n"

" if (a+\"str\" != \"str\"+b) {\n"

" std::cout << \"Equal\n\"\n"

" }\n"

"}");

ASSERT_EQUALS("", errout.str());

}

void suspiciousStringCompare() {

check("bool foo(char* c) {\n"

" return c == \"x\";\n"

"}");

ASSERT_EQUALS("[test.cpp:2]: (warning) String literal compared with variable 'c'. Did you intend to use strcmp() instead?\n", errout.str());

check("bool foo(const char* c) {\n"

" return \"x\" == c;\n"

"}");

ASSERT_EQUALS("[test.cpp:2]: (warning) String literal compared with variable 'c'. Did you intend to use strcmp() instead?\n", errout.str());

check("bool foo(char* c) {\n"

" return foo+\"x\" == c;\n"

"}");

ASSERT_EQUALS("", errout.str());

check("bool foo(char* c) {\n"

" return \"x\" == c+foo;\n"

"}", "test.cpp");

ASSERT_EQUALS("", errout.str());

check("bool foo(char* c) {\n"

" return \"x\" == c+foo;\n"

"}", "test.c");

ASSERT_EQUALS("[test.c:2]: (warning) String literal compared with variable 'c'. Did you intend to use strcmp() instead?\n", errout.str());

check("bool foo(Foo c) {\n"

" return \"x\" == c.foo;\n"

"}", "test.cpp");

ASSERT_EQUALS("", errout.str());

check("bool foo(Foo c) {\n"

" return \"x\" == c.foo;\n"

"}", "test.c");

ASSERT_EQUALS("[test.c:2]: (warning) String literal compared with variable 'c.foo'. Did you intend to use strcmp() instead?\n", errout.str());

check("bool foo(const std::string& c) {\n"

" return \"x\" == c;\n"

"}");

ASSERT_EQUALS("", errout.str());

check("bool foo(const Foo* c) {\n"

" return \"x\" == c->bar();\n" // #4314

"}");

ASSERT_EQUALS("", errout.str());

// Ticket #4257

check("bool foo() {\n"

"MyString *str=Getter();\n"

"return *str==\"bug\"; }\n", "test.c");

ASSERT_EQUALS("[test.c:3]: (warning) String literal compared with variable '*str'. Did you intend to use strcmp() instead?\n", errout.str());

// Ticket #4257

check("bool foo() {\n"

"MyString *str=Getter();\n"

"return *str==\"bug\"; }");

ASSERT_EQUALS("", errout.str());

// Ticket #4257

check("bool foo() {\n"

"MyString **str=OtherGetter();\n"

"return *str==\"bug\"; }");

TODO_ASSERT_EQUALS("[test.cpp:2]: (warning) String literal compared with variable 'c'. Did you intend to use strcmp() instead?\n",

"",

errout.str());

// Ticket #4257

check("bool foo() {\n"

"MyString str=OtherGetter2();\n"

"return &str==\"bug\"; }");

TODO_ASSERT_EQUALS("[test.cpp:2]: (warning) String literal compared with variable 'c'. Did you intend to use strcmp() instead?\n",

"",

errout.str());

// Ticket #5734

check("int foo(char c) {\n"

"return c == '4';}", "test.cpp");

ASSERT_EQUALS("", errout.str());

check("int foo(char c) {\n"

"return c == '4';}", "test.c");

ASSERT_EQUALS("", errout.str());

check("int foo(char c) {\n"

"return c == \"42\"[0];}", "test.cpp");

ASSERT_EQUALS("", errout.str());

check("int foo(char c) {\n"

"return c == \"42\"[0];}", "test.c");

ASSERT_EQUALS("", errout.str());

// 5639 String literal compared with char buffer in a struct

check("struct Example {\n"

" char buffer[200];\n"

"};\n"

"void foo() {\n"

" struct Example example;\n"

" if (example.buffer == \"test\") ;\n"

"}\n", "test.cpp");

ASSERT_EQUALS("[test.cpp:6]: (warning) String literal compared with variable 'example.buffer'. Did you intend to use strcmp() instead?\n", errout.str());

check("struct Example {\n"

" char buffer[200];\n"

"};\n"

"void foo() {\n"

" struct Example example;\n"

" if (example.buffer == \"test\") ;\n"

"}\n", "test.c");

ASSERT_EQUALS("[test.c:6]: (warning) String literal compared with variable 'example.buffer'. Did you intend to use strcmp() instead?\n", errout.str());

}

void suspiciousStringCompare_char() {

check("bool foo(char* c) {\n"

" return c == '\\0';\n"

"}");

ASSERT_EQUALS("[test.cpp:2]: (warning) Char literal compared with pointer 'c'. Did you intend to dereference it?\n", errout.str());

check("bool foo(char* c) {\n"

" return '\\0' != c;\n"

"}");

ASSERT_EQUALS("[test.cpp:2]: (warning) Char literal compared with pointer 'c'. Did you intend to dereference it?\n", errout.str());

check("bool foo(char c) {\n"

" return c == '\\0';\n"

"}");

ASSERT_EQUALS("", errout.str());

check("bool foo(char c) {\n"

" return c == 0;\n"

"}");

ASSERT_EQUALS("", errout.str());

check("bool foo(char* c) {\n"

" return *c == 0;\n"

"}", "test.c");

ASSERT_EQUALS("", errout.str());

check("bool foo(char* c) {\n"

" return *c == 0;\n"

"}");

ASSERT_EQUALS("", errout.str());

check("bool foo(Foo* c) {\n"

" return 0 == c->x;\n"

"}");

ASSERT_EQUALS("", errout.str());

check("void foo(char* c) {\n"

" if(c == '\\0') bar();\n"

"}");

ASSERT_EQUALS("[test.cpp:2]: (warning) Char literal compared with pointer 'c'. Did you intend to dereference it?\n", errout.str());

check("void f() {\n"

" struct { struct { char *str; } x; } a;\n"

" return a.x.str == '\\0';"

"}");

ASSERT_EQUALS("[test.cpp:3]: (warning) Char literal compared with pointer 'a.x.str'. Did you intend to dereference it?\n", errout.str());

check("void f() {\n"

" struct { struct { char *str; } x; } a;\n"

" return *a.x.str == '\\0';"

"}");

ASSERT_EQUALS("", errout.str());

}

void sprintf1() {

check("void foo()\n"

"{\n"

" char buf[100];\n"

" sprintf(buf,\"%s\",buf);\n"

"}");

ASSERT_EQUALS("[test.cpp:4]: (error) Undefined behavior: Variable 'buf' is used as parameter and destination in s[n]printf().\n", errout.str());

}

void sprintf2() {

check("void foo()\n"

"{\n"

" char buf[100];\n"

" sprintf(buf,\"%i\",sizeof(buf));\n"

"}");

ASSERT_EQUALS("", errout.str());

}

void sprintf3() {

check("void foo()\n"

"{\n"

" char buf[100];\n"

" sprintf(buf,\"%i\",sizeof(buf));\n"

" if (buf[0]);\n"

"}");

ASSERT_EQUALS("", errout.str());

}

void sprintf4() {

check("struct A\n"

"{\n"

" char filename[128];\n"

"};\n"

"\n"

"void foo()\n"

"{\n"

" const char* filename = \"hello\";\n"

" struct A a;\n"

" snprintf(a.filename, 128, \"%s\", filename);\n"

"}");

ASSERT_EQUALS("", errout.str());

}

void strPlusChar1() {

// Strange looking pointer arithmetic..

check("void foo()\n"

"{\n"

" const char *p = \"/usr\" + '/';\n"

"}");

ASSERT_EQUALS("[test.cpp:3]: (error) Unusual pointer arithmetic. A value of type 'char' is added to a string literal.\n", errout.str());

}

void strPlusChar2() {

// Strange looking pointer arithmetic..

check("void foo()\n"

"{\n"

" char ch = 1;\n"

" const char *p = ch + \"/usr\";\n"

"}");

ASSERT_EQUALS("", errout.str());

// Strange looking pointer arithmetic..

check("void foo()\n"

"{\n"

" int i = 1;\n"

" const char* psz = \"Bla\";\n"

" const std::string str = i + psz;\n"

"}");

ASSERT_EQUALS("", errout.str());

}

void strPlusChar3() {

// Strange looking pointer arithmetic..

check("void foo()\n"

"{\n"

" std::string temp = \"/tmp\";\n"

" std::string path = temp + '/' + \"sub\" + '/';\n"

"}");

ASSERT_EQUALS("", errout.str());

}

void incorrectStringCompare() {

check("int f() {\n"

" return test.substr( 0 , 4 ) == \"Hello\" ? : 0 : 1 ;\n"

"}");

ASSERT_EQUALS("[test.cpp:2]: (warning) String literal \"Hello\" doesn't match length argument for substr().\n", errout.str());

check("int f() {\n"

" return test.substr( 0 , 5 ) == \"Hello\" ? : 0 : 1 ;\n"

"}");

ASSERT_EQUALS("", errout.str());

check("int f() {\n"

" return \"Hello\" == test.substr( 0 , 4 ) ? : 0 : 1 ;\n"

"}");

ASSERT_EQUALS("[test.cpp:2]: (warning) String literal \"Hello\" doesn't match length argument for substr().\n", errout.str());

check("int f() {\n"

" return \"Hello\" == foo.bar<int>().z[1].substr(i+j*4, 4) ? : 0 : 1 ;\n"

"}");

ASSERT_EQUALS("[test.cpp:2]: (warning) String literal \"Hello\" doesn't match length argument for substr().\n", errout.str());

check("int f() {\n"

" return \"Hello\" == test.substr( 0 , 5 ) ? : 0 : 1 ;\n"

"}");

ASSERT_EQUALS("", errout.str());

check("int f() {\n"

" if (\"Hello\") { }\n"

"}");

ASSERT_EQUALS("[test.cpp:2]: (warning) Conversion of string literal \"Hello\" to bool always evaluates to true.\n", errout.str());

check("int f() {\n"

" if (\"Hello\" && test) { }\n"

"}");

ASSERT_EQUALS("[test.cpp:2]: (warning) Conversion of string literal \"Hello\" to bool always evaluates to true.\n", errout.str());

check("int f() {\n"

" if (test && \"Hello\") { }\n"

"}");

ASSERT_EQUALS("[test.cpp:2]: (warning) Conversion of string literal \"Hello\" to bool always evaluates to true.\n", errout.str());

check("int f() {\n"

" while (\"Hello\") { }\n"

"}");

ASSERT_EQUALS("[test.cpp:2]: (warning) Conversion of string literal \"Hello\" to bool always evaluates to true.\n", errout.str());

check("int f() {\n"

" assert (test || \"Hello\");\n"

"}");

ASSERT_EQUALS("[test.cpp:2]: (warning) Conversion of string literal \"Hello\" to bool always evaluates to true.\n", errout.str());

check("int f() {\n"

" assert (test && \"Hello\");\n"

"}");

ASSERT_EQUALS("", errout.str());

check("int f() {\n"

" assert (\"Hello\" || test);\n"

"}");

ASSERT_EQUALS("[test.cpp:2]: (warning) Conversion of string literal \"Hello\" to bool always evaluates to true.\n", errout.str());

check("int f() {\n"

" assert (\"Hello\" && test);\n"

"}");

ASSERT_EQUALS("", errout.str());

check("int f() {\n"

" BOOST_ASSERT (\"Hello\" && test);\n"

"}");

ASSERT_EQUALS("", errout.str());

check("int f() {\n"

" return f2(\"Hello\");\n"

"}");

ASSERT_EQUALS("", errout.str());

}