11b2ad2fd9e2d5352144481aa1fd995d333d9adc9Argyrios Kyrtzidis// RUN: %clang_cc1 -fsyntax-only -verify %s -Wno-unreachable-code 25f016e2cb5d11daeb237544de1c5d59f20fe1a6eReid Spencer 35f016e2cb5d11daeb237544de1c5d59f20fe1a6eReid Spencerint foo(int X, int Y); 45f016e2cb5d11daeb237544de1c5d59f20fe1a6eReid Spencer 5c31176d5ebbcd407aa512bbd5f717e35da629e7dDan Gohmandouble sqrt(double X); // implicitly const because of no -fmath-errno! 65bef8ddabfe157aa6f1f9010d3d144215b3e731aChris Lattner 75f016e2cb5d11daeb237544de1c5d59f20fe1a6eReid Spencervoid bar(volatile int *VP, int *P, int A, 85f016e2cb5d11daeb237544de1c5d59f20fe1a6eReid Spencer _Complex double C, volatile _Complex double VC) { 95f016e2cb5d11daeb237544de1c5d59f20fe1a6eReid Spencer 10651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines VP < P; // expected-warning {{relational comparison result unused}} 116e844adbe981e549ac0ad2300ea942832aad5ef6Chris Lattner (void)A; 125f016e2cb5d11daeb237544de1c5d59f20fe1a6eReid Spencer (void)foo(1,2); // no warning. 135f016e2cb5d11daeb237544de1c5d59f20fe1a6eReid Spencer 14651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines A < foo(1, 2); // expected-warning {{relational comparison result unused}} 155f016e2cb5d11daeb237544de1c5d59f20fe1a6eReid Spencer 165f016e2cb5d11daeb237544de1c5d59f20fe1a6eReid Spencer foo(1,2)+foo(4,3); // expected-warning {{expression result unused}} 175f016e2cb5d11daeb237544de1c5d59f20fe1a6eReid Spencer 185f016e2cb5d11daeb237544de1c5d59f20fe1a6eReid Spencer 195f016e2cb5d11daeb237544de1c5d59f20fe1a6eReid Spencer *P; // expected-warning {{expression result unused}} 205f016e2cb5d11daeb237544de1c5d59f20fe1a6eReid Spencer *VP; // no warning. 215f016e2cb5d11daeb237544de1c5d59f20fe1a6eReid Spencer P[4]; // expected-warning {{expression result unused}} 225f016e2cb5d11daeb237544de1c5d59f20fe1a6eReid Spencer VP[4]; // no warning. 235f016e2cb5d11daeb237544de1c5d59f20fe1a6eReid Spencer 247d84c76648792cf1035bfc4d60559f5a4544edb1Chris Lattner __real__ C; // expected-warning {{expression result unused}} 257d84c76648792cf1035bfc4d60559f5a4544edb1Chris Lattner __real__ VC; 265bef8ddabfe157aa6f1f9010d3d144215b3e731aChris Lattner 27c31176d5ebbcd407aa512bbd5f717e35da629e7dDan Gohman // We know this can't change errno because of no -fmath-errno. 28bc8d42c6f1565c0b2f93ad524edebfd7a4e6cac6Chris Lattner sqrt(A); // expected-warning {{ignoring return value of function declared with const attribute}} 295f016e2cb5d11daeb237544de1c5d59f20fe1a6eReid Spencer} 305f016e2cb5d11daeb237544de1c5d59f20fe1a6eReid Spencer 316e844adbe981e549ac0ad2300ea942832aad5ef6Chris Lattnerextern void t1(); 326e844adbe981e549ac0ad2300ea942832aad5ef6Chris Lattnerextern void t2(); 336e844adbe981e549ac0ad2300ea942832aad5ef6Chris Lattnervoid t3(int c) { 346e844adbe981e549ac0ad2300ea942832aad5ef6Chris Lattner c ? t1() : t2(); 356e844adbe981e549ac0ad2300ea942832aad5ef6Chris Lattner} 366e844adbe981e549ac0ad2300ea942832aad5ef6Chris Lattner 3798414c1b7d1944a57156d52e29bd41c005de09acChris Lattner// This shouldn't warn: the expr at the end of the stmtexpr really is used. 3898414c1b7d1944a57156d52e29bd41c005de09acChris Lattnerint stmt_expr(int x, int y) { 3998414c1b7d1944a57156d52e29bd41c005de09acChris Lattner return ({int _a = x, _b = y; _a > _b ? _a : _b; }); 4098414c1b7d1944a57156d52e29bd41c005de09acChris Lattner} 4198414c1b7d1944a57156d52e29bd41c005de09acChris Lattner 424be1f47de20525ad90f02ba8682a7e2cbd3205d1Eli Friedmanvoid nowarn(unsigned char* a, unsigned char* b) 434be1f47de20525ad90f02ba8682a7e2cbd3205d1Eli Friedman{ 444be1f47de20525ad90f02ba8682a7e2cbd3205d1Eli Friedman unsigned char c = 1; 454be1f47de20525ad90f02ba8682a7e2cbd3205d1Eli Friedman *a |= c, *b += c; 46fb84664349ca6f37f5ec4df440f6c362cca62470Chris Lattner 47fb84664349ca6f37f5ec4df440f6c362cca62470Chris Lattner 48fb84664349ca6f37f5ec4df440f6c362cca62470Chris Lattner // PR4633 49fb84664349ca6f37f5ec4df440f6c362cca62470Chris Lattner int y, x; 50fb84664349ca6f37f5ec4df440f6c362cca62470Chris Lattner ((void)0), y = x; 514be1f47de20525ad90f02ba8682a7e2cbd3205d1Eli Friedman} 52fb84664349ca6f37f5ec4df440f6c362cca62470Chris Lattner 53754431107b61a0523df5271c2876a73dd5a051e9Anders Carlssonvoid t4(int a) { 54754431107b61a0523df5271c2876a73dd5a051e9Anders Carlsson int b = 0; 55754431107b61a0523df5271c2876a73dd5a051e9Anders Carlsson 56754431107b61a0523df5271c2876a73dd5a051e9Anders Carlsson if (a) 57651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines b < 1; // expected-warning{{relational comparison result unused}} 58754431107b61a0523df5271c2876a73dd5a051e9Anders Carlsson else 59651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines b < 2; // expected-warning{{relational comparison result unused}} 60754431107b61a0523df5271c2876a73dd5a051e9Anders Carlsson 61754431107b61a0523df5271c2876a73dd5a051e9Anders Carlsson while (1) 62651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines b < 3; // expected-warning{{relational comparison result unused}} 63754431107b61a0523df5271c2876a73dd5a051e9Anders Carlsson 64754431107b61a0523df5271c2876a73dd5a051e9Anders Carlsson do 65651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines b < 4; // expected-warning{{relational comparison result unused}} 66754431107b61a0523df5271c2876a73dd5a051e9Anders Carlsson while (1); 67754431107b61a0523df5271c2876a73dd5a051e9Anders Carlsson 68754431107b61a0523df5271c2876a73dd5a051e9Anders Carlsson for (;;) 69651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines b < 5; // expected-warning{{relational comparison result unused}} 703af708ff19e4ae2bf9e40550548361b00e5916bfAnders Carlsson 71651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines for (b < 1;;) {} // expected-warning{{relational comparison result unused}} 72ec8058f64bbcd79bd47748f4cf8628123dd3bae6Chandler Carruth for (;b < 1;) {} 73651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines for (;;b < 1) {} // expected-warning{{relational comparison result unused}} 74754431107b61a0523df5271c2876a73dd5a051e9Anders Carlsson} 75754431107b61a0523df5271c2876a73dd5a051e9Anders Carlsson 76bc8d42c6f1565c0b2f93ad524edebfd7a4e6cac6Chris Lattner// rdar://7186119 77bc8d42c6f1565c0b2f93ad524edebfd7a4e6cac6Chris Lattnerint t5f(void) __attribute__((warn_unused_result)); 78bc8d42c6f1565c0b2f93ad524edebfd7a4e6cac6Chris Lattnervoid t5() { 79bc8d42c6f1565c0b2f93ad524edebfd7a4e6cac6Chris Lattner t5f(); // expected-warning {{ignoring return value of function declared with warn_unused_result}} 80bc8d42c6f1565c0b2f93ad524edebfd7a4e6cac6Chris Lattner} 819079cd31061b00f30c7ced7874c45e15f8dd044eChris Lattner 829079cd31061b00f30c7ced7874c45e15f8dd044eChris Lattner 839079cd31061b00f30c7ced7874c45e15f8dd044eChris Lattnerint fn1() __attribute__ ((warn_unused_result)); 849079cd31061b00f30c7ced7874c45e15f8dd044eChris Lattnerint fn2() __attribute__ ((pure)); 85a7846852ba8b2b53664a674a41d116e0419d8768Fariborz Jahanianint fn3() __attribute__ ((__const)); 867909fee36cb2c4737e5c74bf683913bf5ab09815Chris Lattner// rdar://6587766 879079cd31061b00f30c7ced7874c45e15f8dd044eChris Lattnerint t6() { 889079cd31061b00f30c7ced7874c45e15f8dd044eChris Lattner if (fn1() < 0 || fn2(2,1) < 0 || fn3(2) < 0) // no warnings 899079cd31061b00f30c7ced7874c45e15f8dd044eChris Lattner return -1; 90f857798fa77ac50c6d0a262d96ad6176187190e3Nuno Lopes 919079cd31061b00f30c7ced7874c45e15f8dd044eChris Lattner fn1(); // expected-warning {{ignoring return value of function declared with warn_unused_result attribute}} 929079cd31061b00f30c7ced7874c45e15f8dd044eChris Lattner fn2(92, 21); // expected-warning {{ignoring return value of function declared with pure attribute}} 939079cd31061b00f30c7ced7874c45e15f8dd044eChris Lattner fn3(42); // expected-warning {{ignoring return value of function declared with const attribute}} 94651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines __builtin_abs(0); // expected-warning {{ignoring return value of function declared with const attribute}} 95a6115068cde719142eb394db88612c185cabd05bEli Friedman (void)0, fn1(); // expected-warning {{ignoring return value of function declared with warn_unused_result attribute}} 969079cd31061b00f30c7ced7874c45e15f8dd044eChris Lattner return 0; 979079cd31061b00f30c7ced7874c45e15f8dd044eChris Lattner} 989079cd31061b00f30c7ced7874c45e15f8dd044eChris Lattner 99d6b8de0e7b01196bd2bee207feb81bc409a5baf9John McCallint t7 __attribute__ ((warn_unused_result)); // expected-warning {{'warn_unused_result' attribute only applies to functions}} 1009079cd31061b00f30c7ced7874c45e15f8dd044eChris Lattner 101d20254f2875d0004c57ee766f258dbcee29f4841Nuno Lopes// PR4010 102d20254f2875d0004c57ee766f258dbcee29f4841Nuno Lopesint (*fn4)(void) __attribute__ ((warn_unused_result)); 103d20254f2875d0004c57ee766f258dbcee29f4841Nuno Lopesvoid t8() { 104d20254f2875d0004c57ee766f258dbcee29f4841Nuno Lopes fn4(); // expected-warning {{ignoring return value of function declared with warn_unused_result attribute}} 105d20254f2875d0004c57ee766f258dbcee29f4841Nuno Lopes} 106f857798fa77ac50c6d0a262d96ad6176187190e3Nuno Lopes 107f857798fa77ac50c6d0a262d96ad6176187190e3Nuno Lopesvoid t9() __attribute__((warn_unused_result)); // expected-warning {{attribute 'warn_unused_result' cannot be applied to functions without return value}} 108209acbd6d0c1b4444eb8c1682717753e1cbe38deJohn McCall 109209acbd6d0c1b4444eb8c1682717753e1cbe38deJohn McCall// rdar://7410924 110209acbd6d0c1b4444eb8c1682717753e1cbe38deJohn McCallvoid *some_function(void); 111209acbd6d0c1b4444eb8c1682717753e1cbe38deJohn McCallvoid t10() { 112209acbd6d0c1b4444eb8c1682717753e1cbe38deJohn McCall (void*) some_function(); //expected-warning {{expression result unused; should this cast be to 'void'?}} 113209acbd6d0c1b4444eb8c1682717753e1cbe38deJohn McCall} 114c6dfe194f623b02c123759f235b504d4850fc178Douglas Gregor 115c6dfe194f623b02c123759f235b504d4850fc178Douglas Gregorvoid f(int i, ...) { 116c6dfe194f623b02c123759f235b504d4850fc178Douglas Gregor __builtin_va_list ap; 117c6dfe194f623b02c123759f235b504d4850fc178Douglas Gregor 118c6dfe194f623b02c123759f235b504d4850fc178Douglas Gregor __builtin_va_start(ap, i); 119c6dfe194f623b02c123759f235b504d4850fc178Douglas Gregor __builtin_va_arg(ap, int); 120c6dfe194f623b02c123759f235b504d4850fc178Douglas Gregor __builtin_va_end(ap); 121c6dfe194f623b02c123759f235b504d4850fc178Douglas Gregor} 1221f4295b966870fff784faa5a5eba3fe9e27a6406Gabor Greif 1231f4295b966870fff784faa5a5eba3fe9e27a6406Gabor Greif// PR8371 1241f4295b966870fff784faa5a5eba3fe9e27a6406Gabor Greifint fn5() __attribute__ ((__const)); 125c7db84d0146a6f22b19949fb0128e2148aa92467Matt Beaumont-Gay 12687b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay// Don't warn for unused expressions in macro bodies; however, do warn for 12787b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay// unused expressions in macro arguments. Macros below are reduced from code 12887b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay// found in the wild. 12987b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay#define NOP(a) (a) 1306d919fb67bf6aa3db09608fb2948b558977c6929Matt Beaumont-Gay#define M1(a, b) (long)foo((a), (b)) 1316d919fb67bf6aa3db09608fb2948b558977c6929Matt Beaumont-Gay#define M2 (long)0; 13287b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay#define M3(a) (t3(a), fn2()) 13387b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay#define M4(a, b) (foo((a), (b)) ? 0 : t3(a), 1) 13487b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay#define M5(a, b) (foo((a), (b)), 1) 1359016bb771265a10f188c76342254badecc695253Matt Beaumont-Gay#define M6() fn1() 1369016bb771265a10f188c76342254badecc695253Matt Beaumont-Gay#define M7() fn2() 137c7db84d0146a6f22b19949fb0128e2148aa92467Matt Beaumont-Gayvoid t11(int i, int j) { 1386d919fb67bf6aa3db09608fb2948b558977c6929Matt Beaumont-Gay M1(i, j); // no warning 13987b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay NOP((long)foo(i, j)); // expected-warning {{expression result unused}} 14087b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay M2; // no warning 14187b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay NOP((long)0); // expected-warning {{expression result unused}} 14287b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay M3(i); // no warning 14387b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay NOP((t3(i), fn2())); // expected-warning {{ignoring return value}} 14487b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay M4(i, j); // no warning 14587b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay NOP((foo(i, j) ? 0 : t3(i), 1)); // expected-warning {{expression result unused}} 14687b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay M5(i, j); // no warning 14787b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay NOP((foo(i, j), 1)); // expected-warning {{expression result unused}} 1489016bb771265a10f188c76342254badecc695253Matt Beaumont-Gay M6(); // expected-warning {{ignoring return value}} 1499016bb771265a10f188c76342254badecc695253Matt Beaumont-Gay M7(); // no warning 150c7db84d0146a6f22b19949fb0128e2148aa92467Matt Beaumont-Gay} 15187b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay#undef NOP 1526d919fb67bf6aa3db09608fb2948b558977c6929Matt Beaumont-Gay#undef M1 1536d919fb67bf6aa3db09608fb2948b558977c6929Matt Beaumont-Gay#undef M2 15487b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay#undef M3 15587b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay#undef M4 15687b73ba920f523ef13f2420cbdb958a281aa6f33Matt Beaumont-Gay#undef M5 1579016bb771265a10f188c76342254badecc695253Matt Beaumont-Gay#undef M6 1589016bb771265a10f188c76342254badecc695253Matt Beaumont-Gay#undef M7 159