/*

* Cppcheck - A tool for static C/C++ code analysis

* Copyright (C) 2007-2026 Cppcheck team.

*

* This program is free software: you can redistribute it and/or modify

* it under the terms of the GNU General Public License as published by

* the Free Software Foundation, either version 3 of the License, or

* (at your option) any later version.

*

* This program is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

* GNU General Public License for more details.

*

* You should have received a copy of the GNU General Public License

* along with this program. If not, see <http://www.gnu.org/licenses/>.

*/

#include "checkstring.h"

#include "errortypes.h"

#include "helpers.h"

#include "settings.h"

#include "fixture.h"

#include <cstddef>

#include <string>

class TestString : public TestFixture {

public:

TestString() : TestFixture("TestString") {}

private:

const Settings settings = settingsBuilder().severity(Severity::warning).severity(Severity::style).build();

void run() override {

mNewTemplate = true;

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(strPlusChar4); // L"/usr" + L'/'

TEST_CASE(snprintf1); // Dangerous usage of snprintf

TEST_CASE(sprintf1); // Dangerous usage of sprintf

TEST_CASE(sprintf2);

TEST_CASE(sprintf3);

TEST_CASE(sprintf4); // struct member

TEST_CASE(sprintf5); // another struct member

TEST_CASE(sprintf6); // (char*)

TEST_CASE(sprintf7); // (char*)(void*)

TEST_CASE(wsprintf1); // Dangerous usage of wsprintf

TEST_CASE(incorrectStringCompare);

TEST_CASE(deadStrcmp);

}

struct CheckOptions

{

bool cpp = true;

};

#define check(...) check_(__FILE__, __LINE__, __VA_ARGS__)

template<size_t size>

void check_(const char* file, int line, const char (&code)[size], const CheckOptions& options = make_default_obj()) {

SimpleTokenizer2 tokenizer(settings, *this, code, options.cpp ? "test.cpp" : "test.c");

// Tokenize..

ASSERT_LOC(tokenizer.simplifyTokens1(""), file, line);

CheckString check;

runChecks(check, tokenizer, *this);

}

void stringLiteralWrite() {

check("void f() {\n"

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

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

"}");

ASSERT_EQUALS("[test.cpp:3:3] -> [test.cpp:2:15]: (error) Modifying string literal \"abc\" directly or indirectly is undefined behaviour. [stringLiteralWrite]\n", errout_str());

check("void f() {\n"

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

" *abc = 'a';\n"

"}");

ASSERT_EQUALS("[test.cpp:3:4] -> [test.cpp:2:15]: (error) Modifying string literal \"abc\" directly or indirectly is undefined behaviour. [stringLiteralWrite]\n", errout_str());

check("void f() {\n"

" char *abc = \"A very long string literal\";\n"

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

"}");

ASSERT_EQUALS("[test.cpp:3:3] -> [test.cpp:2:15]: (error) Modifying string literal \"A very long stri..\" directly or indirectly is undefined behaviour. [stringLiteralWrite]\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:2:3] -> [test.cpp:5:13]: (error) Modifying string literal \"Y\" directly or indirectly is undefined behaviour. [stringLiteralWrite]\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());

check("void f() {\n"

" wchar_t *abc = L\"abc\";\n"

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

"}");

ASSERT_EQUALS("[test.cpp:3:3] -> [test.cpp:2:18]: (error) Modifying string literal L\"abc\" directly or indirectly is undefined behaviour. [stringLiteralWrite]\n", errout_str());

check("void f() {\n"

" char16_t *abc = u\"abc\";\n"

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

"}");

ASSERT_EQUALS("[test.cpp:3:3] -> [test.cpp:2:19]: (error) Modifying string literal u\"abc\" directly or indirectly is undefined behaviour. [stringLiteralWrite]\n", errout_str());

check("void foo() {\n" // #8332

" int i;\n"

" char *p = \"string literal\";\n"

" for( i = 0; i < strlen(p); i++) {\n"

" p[i] = \'X\';\n" // <<

" }\n"

" printf(\"%s\\n\", p);\n"

"}");

ASSERT_EQUALS("[test.cpp:5:9] -> [test.cpp:3:16]: (error) Modifying string literal \"string literal\" directly or indirectly is undefined behaviour. [stringLiteralWrite]\n", 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:2:7]: (warning) Unnecessary comparison of static strings. [staticStringCompare]\n"

"[test.cpp:3:7]: (warning) Unnecessary comparison of static strings. [staticStringCompare]\n"

"[test.cpp:4:7]: (warning) Unnecessary comparison of static strings. [staticStringCompare]\n"

"[test.cpp:5:7]: (warning) Unnecessary comparison of static strings. [staticStringCompare]\n"

"[test.cpp:6:7]: (warning) Unnecessary comparison of static strings. [staticStringCompare]\n"

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

"[test.cpp:8:7]: (warning) Unnecessary comparison of static strings. [staticStringCompare]\n"

"[test.cpp:9:7]: (warning) Unnecessary comparison of static strings. [staticStringCompare]\n"

"[test.cpp:10:7]: (warning) Unnecessary comparison of static strings. [staticStringCompare]\n"

"[test.cpp:11:7]: (warning) Unnecessary comparison of static strings. [staticStringCompare]\n"

"[test.cpp:12:7]: (warning) Unnecessary comparison of static strings. [staticStringCompare]\n"

"[test.cpp:13:7]: (warning) Unnecessary comparison of static strings. [staticStringCompare]\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 f(void) {\n" // #13527

" const wchar_t* str1 = L\"Hello\";\n"

" return wcsicmp(str1, str1);\n" // <<

"}");

ASSERT_EQUALS("[test.cpp:3:12]: (warning) Comparison of identical string variables. [stringCompare]\n", errout_str());

check("int main()\n"

"{\n"

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

" {"

" std::cout << \"Equal\";"

" }"

"}");

ASSERT_EQUALS("[test.cpp:3:7]: (warning) Unnecessary comparison of static strings. [staticStringCompare]\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\";"

" }"

"}");

ASSERT_EQUALS("[test.cpp:3:7]: (warning) Unnecessary comparison of static strings. [staticStringCompare]\n", errout_str());

check("int main()\n"

"{\n"

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

" {"

" std::cout << \"Equal\";"

" }"

"}");

ASSERT_EQUALS("[test.cpp:3:7]: (warning) Unnecessary comparison of static strings. [staticStringCompare]\n", errout_str());

check("int main()\n"

"{\n"

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

" {"

" std::cout << \"Equal\";"

" }"

"}");

ASSERT_EQUALS("", errout_str());

check("int main()\n"

"{\n"

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

" {"

" std::cout << \"Equal\";"

" }"

"}");

ASSERT_EQUALS("[test.cpp:3:7]: (warning) Unnecessary comparison of static strings. [staticStringCompare]\n", errout_str());

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

"{\n"

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

" {"

" std::cout << \"Equal\";"

" }"

"}");

ASSERT_EQUALS("[test.cpp:3:7]: (warning) Comparison of identical string variables. [stringCompare]\n", errout_str());

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

"{\n"

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

" {"

" std::cout << \"Equal\";"

" }"

"}");

ASSERT_EQUALS("[test.cpp:3:7]: (warning) Comparison of identical string variables. [stringCompare]\n", errout_str());

check("int main() {\n"

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

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

" }\n"

"}");

ASSERT_EQUALS("[test.cpp:2:6]: (warning) Unnecessary comparison of static strings. [staticStringCompare]\n", errout_str());

check("int main() {\n"

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

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

" }\n"

"}");

ASSERT_EQUALS("[test.cpp:2:6]: (warning) Unnecessary comparison of static strings. [staticStringCompare]\n", errout_str());

check("int main() {\n"

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

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

" }\n"

"}");

ASSERT_EQUALS("", errout_str());

}

void suspiciousStringCompare() {

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

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

"}");

ASSERT_EQUALS("[test.cpp:2:14]: (warning) String literal compared with variable 'c'. Did you intend to use strcmp() instead? [literalWithCharPtrCompare]\n", errout_str());

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

" return c[3] == \"x\";\n"

"}");

ASSERT_EQUALS("[test.cpp:2:17]: (warning) String literal compared with variable 'c[3]'. Did you intend to use strcmp() instead? [literalWithCharPtrCompare]\n", errout_str());

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

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

"}");

ASSERT_EQUALS("[test.cpp:2:14]: (warning) String literal compared with variable 'c'. Did you intend to use wcscmp() instead? [literalWithCharPtrCompare]\n", errout_str());

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

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

"}");

ASSERT_EQUALS("[test.cpp:2:16]: (warning) String literal compared with variable 'c'. Did you intend to use strcmp() instead? [literalWithCharPtrCompare]\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"

"}");

ASSERT_EQUALS("", errout_str());

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

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

"}", dinit(CheckOptions, $.cpp = false));

ASSERT_EQUALS("[test.c:2:16]: (warning) String literal compared with variable 'c+foo'. Did you intend to use strcmp() instead? [literalWithCharPtrCompare]\n", errout_str());

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

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

"}");

ASSERT_EQUALS("", errout_str());

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

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

"}", dinit(CheckOptions, $.cpp = false));

ASSERT_EQUALS("[test.c:2:16]: (warning) String literal compared with variable 'c.foo'. Did you intend to use strcmp() instead? [literalWithCharPtrCompare]\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", dinit(CheckOptions, $.cpp = false));

ASSERT_EQUALS("[test.c:3:12]: (warning) String literal compared with variable '*str'. Did you intend to use strcmp() instead? [literalWithCharPtrCompare]\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\"; }", dinit(CheckOptions, $.cpp = false));

ASSERT_EQUALS("[test.c:3:12]: (warning) String literal compared with variable '*str'. Did you intend to use strcmp() instead? [literalWithCharPtrCompare]\n", errout_str());

// Ticket #4257

check("bool foo() {\n"

"MyString str=OtherGetter2();\n"

"return &str==\"bug\"; }", dinit(CheckOptions, $.cpp = false));

ASSERT_EQUALS("[test.c:3:12]: (warning) String literal compared with variable '&str'. Did you intend to use strcmp() instead? [literalWithCharPtrCompare]\n", errout_str());

// Ticket #5734

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

"return c == '4';}");

ASSERT_EQUALS("", errout_str());

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

"return c == '4';}", dinit(CheckOptions, $.cpp = false));

ASSERT_EQUALS("", errout_str());

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

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

ASSERT_EQUALS("", errout_str());

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

"return c == \"42\"[0];}", dinit(CheckOptions, $.cpp = false));

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");

ASSERT_EQUALS("[test.cpp:6:23]: (warning) String literal compared with variable 'example.buffer'. Did you intend to use strcmp() instead? [literalWithCharPtrCompare]\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", dinit(CheckOptions, $.cpp = false));

ASSERT_EQUALS("[test.c:6:23]: (warning) String literal compared with variable 'example.buffer'. Did you intend to use strcmp() instead? [literalWithCharPtrCompare]\n", errout_str());

// #9726

check("void f(std::vector<std::string> theArgs) {\n"

" std::string arg1(*theArgs.begin());\n"

" if(arg1 == \"aaa\") {}\n"

"}");

ASSERT_EQUALS("", errout_str());

}

void suspiciousStringCompare_char() {

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

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

"}");

ASSERT_EQUALS("[test.cpp:2:14]: (warning) Char literal compared with pointer 'c'. Did you intend to dereference it? [charLiteralWithCharPtrCompare]\n", errout_str());

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

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

"}");

ASSERT_EQUALS("[test.cpp:2:14]: (warning) Char literal compared with pointer 'c'. Did you intend to dereference it? [charLiteralWithCharPtrCompare]\n", errout_str());

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

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

"}");

ASSERT_EQUALS("[test.cpp:2:17]: (warning) Char literal compared with pointer 'c'. Did you intend to dereference it? [charLiteralWithCharPtrCompare]\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] == '\\0';\n"

"}");

ASSERT_EQUALS("", errout_str());

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

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

"}");

ASSERT_EQUALS("[test.cpp:2:17]: (warning) Char literal compared with pointer 'c[0]'. Did you intend to dereference it? [charLiteralWithCharPtrCompare]\n", errout_str());

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

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

"}");

ASSERT_EQUALS("[test.cpp:2:15]: (warning) Char literal compared with pointer '*c'. Did you intend to dereference it? [charLiteralWithCharPtrCompare]\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"

"}", dinit(CheckOptions, $.cpp = false));

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:2:10]: (warning) Char literal compared with pointer 'c'. Did you intend to dereference it? [charLiteralWithCharPtrCompare]\n", errout_str());

check("void f() {\n"

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

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

"}");

ASSERT_EQUALS("[test.cpp:3:18]: (warning) Char literal compared with pointer 'a.x.str'. Did you intend to dereference it? [charLiteralWithCharPtrCompare]\n", errout_str());

check("void f() {\n"

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

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

"}");

ASSERT_EQUALS("", errout_str());

}

void snprintf1() {

check("void foo()\n"

"{\n"

" char buf[100];\n"

" snprintf(buf,100,\"%s\",buf);\n"

"}");

ASSERT_EQUALS("[test.cpp:4:27]: (error) Undefined behavior: Variable 'buf' is used as parameter and destination in snprintf(). [sprintfOverlappingData]\n", errout_str());

}

void sprintf1() {

check("void foo()\n"

"{\n"

" char buf[100];\n"

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

"}");

ASSERT_EQUALS("[test.cpp:4:22]: (error) Undefined behavior: Variable 'buf' is used as parameter and destination in sprintf(). [sprintfOverlappingData]\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 sprintf5() {

check("struct A\n"

"{\n"

" char filename[128];\n"

"};\n"

"\n"

"void foo(struct A *a)\n"

"{\n"

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

"}");

ASSERT_EQUALS("[test.cpp:8:39]: (error) Undefined behavior: Variable 'a->filename' is used as parameter and destination in snprintf(). [sprintfOverlappingData]\n", errout_str());

}

void sprintf6() {

check("void foo()\n"

"{\n"

" char buf[100];\n"

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

"}");

ASSERT_EQUALS("[test.cpp:4:29]: (error) Undefined behavior: Variable 'buf' is used as parameter and destination in sprintf(). [sprintfOverlappingData]\n", errout_str());

}

void sprintf7() {

check("void foo()\n"

"{\n"

" char buf[100];\n"

" sprintf((char*)(void*)buf,\"%s\",(void*)(char*)buf);\n"

"}");

ASSERT_EQUALS("[test.cpp:4:36]: (error) Undefined behavior: Variable 'buf' is used as parameter and destination in sprintf(). [sprintfOverlappingData]\n", errout_str());

}

void wsprintf1() {

check("void foo()\n"

"{\n"

" wchar_t buf[100];\n"

" swprintf(buf,10, \"%s\",buf);\n"

"}");

ASSERT_EQUALS("[test.cpp:4:27]: (error) Undefined behavior: Variable 'buf' is used as parameter and destination in swprintf(). [sprintfOverlappingData]\n", errout_str());

}

void strPlusChar1() {

// Strange looking pointer arithmetic..

check("void foo()\n"

"{\n"

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

"}");

ASSERT_EQUALS("[test.cpp:3:28]: (error) Unusual pointer arithmetic. A value of type 'char' is added to a string literal. [strPlusChar]\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 strPlusChar4() {

// Strange looking pointer arithmetic, wide char..

check("void foo()\n"

"{\n"

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

"}");

ASSERT_EQUALS("[test.cpp:3:32]: (error) Unusual pointer arithmetic. A value of type 'wchar_t' is added to a string literal. [strPlusChar]\n", errout_str());

check("void foo(wchar_t c)\n"

"{\n"

" const wchar_t *p = L\"/usr\" + c;\n"

"}");

ASSERT_EQUALS("[test.cpp:3:32]: (error) Unusual pointer arithmetic. A value of type 'wchar_t' is added to a string literal. [strPlusChar]\n", errout_str());

}

void incorrectStringCompare() {

check("int f() {\n"

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

"}");

ASSERT_EQUALS("[test.cpp:2:17]: (warning) String literal \"Hello\" doesn't match length argument for substr(). [incorrectStringCompare]\n", errout_str());

check("int f() {\n"

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

"}");

ASSERT_EQUALS("[test.cpp:2:17]: (warning) String literal L\"Hello\" doesn't match length argument for substr(). [incorrectStringCompare]\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:2:28]: (warning) String literal \"Hello\" doesn't match length argument for substr(). [incorrectStringCompare]\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:2:43]: (warning) String literal \"Hello\" doesn't match length argument for substr(). [incorrectStringCompare]\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:2:9]: (warning) Conversion of string literal \"Hello\" to bool always evaluates to true. [incorrectStringBooleanError]\n", errout_str());

check("int f() {\n"

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

"}");

ASSERT_EQUALS("[test.cpp:2:9]: (warning) Conversion of string literal \"Hello\" to bool always evaluates to true. [incorrectStringBooleanError]\n", errout_str());

check("int f() {\n"

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

"}");

ASSERT_EQUALS("[test.cpp:2:17]: (warning) Conversion of string literal \"Hello\" to bool always evaluates to true. [incorrectStringBooleanError]\n", errout_str());

check("int f() {\n"

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

"}");

ASSERT_EQUALS("[test.cpp:2:12]: (warning) Conversion of string literal \"Hello\" to bool always evaluates to true. [incorrectStringBooleanError]\n", errout_str());

check("int f() {\n"

" return \"Hello\" ? 1 : 2;\n"

"}");

ASSERT_EQUALS("[test.cpp:2:12]: (warning) Conversion of string literal \"Hello\" to bool always evaluates to true. [incorrectStringBooleanError]\n", errout_str());

check("int f() {\n"

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

"}");

ASSERT_EQUALS("[test.cpp:2:21]: (warning) Conversion of string literal \"Hello\" to bool always evaluates to true. [incorrectStringBooleanError]\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:2:13]: (warning) Conversion of string literal \"Hello\" to bool always evaluates to true. [incorrectStringBooleanError]\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());

// #7750 warn about char literals in boolean expressions

check("void f() {\n"

" if('a'){}\n"

" if(L'b'){}\n"

" if(1 && 'c'){}\n"

" int x = 'd' ? 1 : 2;\n"

"}");

ASSERT_EQUALS("[test.cpp:2:6]: (warning) Conversion of char literal 'a' to bool always evaluates to true. [incorrectCharBooleanError]\n"

"[test.cpp:3:6]: (warning) Conversion of char literal L'b' to bool always evaluates to true. [incorrectCharBooleanError]\n"

"[test.cpp:4:11]: (warning) Conversion of char literal 'c' to bool always evaluates to true. [incorrectCharBooleanError]\n"

"[test.cpp:5:11]: (warning) Conversion of char literal 'd' to bool always evaluates to true. [incorrectCharBooleanError]\n"

, errout_str());

check("void f() {\n"

" if('\\0'){}\n"

" if(L'\\0'){}\n"

"}");

ASSERT_EQUALS("[test.cpp:2:6]: (warning) Conversion of char literal '\\0' to bool always evaluates to false. [incorrectCharBooleanError]\n"

"[test.cpp:3:6]: (warning) Conversion of char literal L'\\0' to bool always evaluates to false. [incorrectCharBooleanError]\n",

errout_str());

check("void f() {\n"

" if('\\0' || cond){}\n"

" if(L'\\0' || cond){}\n"

"}");

ASSERT_EQUALS("[test.cpp:2:6]: (warning) Conversion of char literal '\\0' to bool always evaluates to false. [incorrectCharBooleanError]\n"

"[test.cpp:3:6]: (warning) Conversion of char literal L'\\0' to bool always evaluates to false. [incorrectCharBooleanError]\n", errout_str());

check("void f(bool b);\n" // #9450

"void f(std::string s);\n"

"void g() {\n"

" f(\"abc\");\n"

"}\n");

ASSERT_EQUALS("[test.cpp:4:7]: (warning) Conversion of string literal \"abc\" to bool always evaluates to true. [incorrectStringBooleanError]\n", errout_str());

check("void g(bool);\n"

" void f(std::map<std::string, std::vector<int>>&m) {\n"

" if (m.count(\"abc\"))\n"

" g(m[\"abc\"][0] ? true : false);\n"

"}\n");

ASSERT_EQUALS("", errout_str());

check("void g(bool b);\n"

"void f() {\n"

" g('\\0');\n"

" g('a');\n"

"}\n");

ASSERT_EQUALS("[test.cpp:3:7]: (warning) Conversion of char literal '\\0' to bool always evaluates to false. [incorrectCharBooleanError]\n"

"[test.cpp:4:7]: (warning) Conversion of char literal 'a' to bool always evaluates to true. [incorrectCharBooleanError]\n",

errout_str());

check("#define ERROR(msg) if (msg) printf(\"%s\\n\", msg);\n"

"void f() {\n"

" ERROR(\"abc\")\n"

"}\n");

ASSERT_EQUALS("", errout_str());

check("void g(int, bool);\n"

"void f() {\n"

" MyAssert(!\"abc\");\n"

" g(2, !\"def\");\n"

"}\n");

ASSERT_EQUALS("[test.cpp:4:11]: (warning) Conversion of string literal \"def\" to bool always evaluates to true. [incorrectStringBooleanError]\n", errout_str());

check("bool f(const char *p) {\n"

" if (*p == '\\0')\n"

" return *p == '\\0';\n"

" return false;\n"

"}\n");

ASSERT_EQUALS("", errout_str());

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

" assert((p != NULL && q != NULL) || !\"abc\");\n"

" ASSERT((void*)(\"def\") == 0);\n"

"}\n");

ASSERT_EQUALS("", errout_str());

check("class C {\n" // #6109

" void check(const char code[], bool validate = true, const char* filename = \"test.cpp\");\n"

" void f() {\n"

" check(\"class A<B&, C>;\", \"test.C\");\n"

" }\n"

"};\n");

ASSERT_EQUALS("[test.cpp:4:34]: (warning) Conversion of string literal \"test.C\" to bool always evaluates to true. [incorrectStringBooleanError]\n", errout_str());

check("#define MACRO(C) if(!(C)) { error(__FILE__, __LINE__, __FUNCTION__, #C); return; }\n" // #13067

"void f() {\n"

" MACRO(false && \"abc\");\n"

"}\n");

ASSERT_EQUALS("", errout_str());

check("#define strequ(s1,s2) ((void *)s1 && (void *)s2 && strcmp(s1, s2) == 0)\n" // #13093

"void f(const char* p) {\n"

" if (strequ(p, \"ALL\")) {}\n"

"}\n");

ASSERT_EQUALS("", errout_str());

check("void f(std::string_view);\n"

"void f(bool);\n"

"void g() {\n"

" f(\"\"sv);\n"

"}\n");

ASSERT_EQUALS("", errout_str());

}

void deadStrcmp() {

check("void f(const char *str) {\n"

" if (strcmp(str, \"abc\") == 0 || strcmp(str, \"def\")) {}\n"

"}");

ASSERT_EQUALS("[test.cpp:2:40]: (warning) The expression 'strcmp(str,\"def\") != 0' is suspicious. It overlaps 'strcmp(str,\"abc\") == 0'. [overlappingStrcmp]\n", errout_str());

check("void f(const wchar_t *str) {\n"

" if (wcscmp(str, L\"abc\") == 0 || wcscmp(str, L\"def\")) {}\n"

"}");

ASSERT_EQUALS("[test.cpp:2:41]: (warning) The expression 'wcscmp(str,L\"def\") != 0' is suspicious. It overlaps 'wcscmp(str,L\"abc\") == 0'. [overlappingStrcmp]\n", errout_str());

check("struct X {\n"

" char *str;\n"

"};\n"

"\n"

"void f(const struct X *x) {\n"

" if (strcmp(x->str, \"abc\") == 0 || strcmp(x->str, \"def\")) {}\n"

"}");

ASSERT_EQUALS("[test.cpp:6:43]: (warning) The expression 'strcmp(x->str,\"def\") != 0' is suspicious. It overlaps 'strcmp(x->str,\"abc\") == 0'. [overlappingStrcmp]\n", errout_str());

}

};

REGISTER_TEST(TestString)