/*
 * Cppcheck - A tool for static C/C++ code analysis
 * Copyright (C) 2007-2020 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 "settings.h"
#include "testsuite.h"
#include "tokenize.h"


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

private:
 Settings settings;

 void run() OVERRIDE {
 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(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);
 }

 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);
 }

 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"
 " char *abc = \"A very long string literal\";\n"
 " abc[0] = 'a';\n"
 "}");
 ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:2]: (error) Modifying string literal \"A very long stri..\" 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());

 check("void f() {\n"
 " wchar_t *abc = L\"abc\";\n"
 " abc[0] = u'a';\n"
 "}");
 ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:2]: (error) Modifying string literal L\"abc\" directly or indirectly is undefined behaviour.\n", errout.str());

 check("void f() {\n"
 " char16_t *abc = u\"abc\";\n"
 " abc[0] = 'a';\n"
 "}");
 ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:2]: (error) Modifying string literal u\"abc\" directly or indirectly is undefined behaviour.\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]: (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\";"
 " }"
 "}");
 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\";"
 " }"
 "}");
 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\";"
 " }"
 "}");
 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\";"
 " }"
 "}");
 ASSERT_EQUALS("", errout.str());

 check("int main()\n"
 "{\n"
 " if (strncmp(\"hotdog\",\"hotdog\", 6) == 0)"
 " {"
 " std::cout << \"Equal\";"
 " }"
 "}");
 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\";"
 " }"
 "}");
 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\";"
 " }"
 "}");
 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"
 "}");
 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"
 "}");
 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"
 "}");
 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(wchar_t* c) {\n"
 " return c == L\"x\";\n"
 "}");
 ASSERT_EQUALS("[test.cpp:2]: (warning) String literal compared with variable 'c'. Did you intend to use wcscmp() 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());

 // #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]: (warning) Char literal compared with pointer 'c'. Did you intend to dereference it?\n", errout.str());

 check("bool foo(wchar_t* c) {\n"
 " return c == L'x';\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 snprintf1() {
 check("void foo()\n"
 "{\n"
 " char buf[100];\n"
 " snprintf(buf,100,\"%s\",buf);\n"
 "}");
 ASSERT_EQUALS("[test.cpp:4]: (error) Undefined behavior: Variable 'buf' is used as parameter and destination in snprintf().\n", 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 sprintf().\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]: (error) Undefined behavior: Variable 'a->filename' is used as parameter and destination in snprintf().\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]: (error) Undefined behavior: Variable 'buf' is used as parameter and destination in sprintf().\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]: (error) Undefined behavior: Variable 'buf' is used as parameter and destination in sprintf().\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]: (error) Undefined behavior: Variable 'buf' is used as parameter and destination in swprintf().\n", 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 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]: (error) Unusual pointer arithmetic. A value of type 'wchar_t' is added to a string literal.\n", errout.str());

 check("void foo(wchar_t c)\n"
 "{\n"
 " const wchar_t *p = L\"/usr\" + c;\n"
 "}");
 ASSERT_EQUALS("[test.cpp:3]: (error) Unusual pointer arithmetic. A value of type 'wchar_t' is added to a string literal.\n", 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 , 4 ) == L\"Hello\" ? 0 : 1 ;\n"
 "}");
 ASSERT_EQUALS("[test.cpp:2]: (warning) String literal L\"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"
 " return \"Hello\" ? 1 : 2;\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());

 // #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]: (warning) Conversion of char literal 'a' to bool always evaluates to true.\n"
 "[test.cpp:3]: (warning) Conversion of char literal L'b' to bool always evaluates to true.\n"
 "[test.cpp:4]: (warning) Conversion of char literal 'c' to bool always evaluates to true.\n"
 "[test.cpp:5]: (warning) Conversion of char literal 'd' to bool always evaluates to true.\n"
 , errout.str());

 check("void f() {\n"
 " if('\\0'){}\n"
 " if(L'\\0'){}\n"
 "}");
 ASSERT_EQUALS("", errout.str());

 check("void f() {\n"
 " if('\\0' || cond){}\n"
 " if(L'\\0' || cond){}\n"
 "}");
 ASSERT_EQUALS("[test.cpp:2]: (warning) Conversion of char literal '\\0' to bool always evaluates to false.\n"
 "[test.cpp:3]: (warning) Conversion of char literal L'\\0' to bool always evaluates to false.\n", 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]: (warning) The expression 'strcmp(str,\"def\") != 0' is suspicious. It overlaps 'strcmp(str,\"abc\") == 0'.\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]: (warning) The expression 'wcscmp(str,L\"def\") != 0' is suspicious. It overlaps 'wcscmp(str,L\"abc\") == 0'.\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]: (warning) The expression 'strcmp(x->str,\"def\") != 0' is suspicious. It overlaps 'strcmp(x->str,\"abc\") == 0'.\n", errout.str());
 }
};

REGISTER_TEST(TestString)