// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wtautological-constant-in-range-compare -DTEST=2 -verify %s // RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wtautological-constant-in-range-compare -DTEST=2 -verify -x c++ %s // RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wtautological-type-limit-compare -DTEST -verify %s // RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wtautological-type-limit-compare -DTEST -verify -x c++ %s // RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wtype-limits -DTEST -verify %s // RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wtype-limits -DTEST -verify -x c++ %s // RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wextra -Wno-sign-compare -verify=silent %s // RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wextra -Wno-sign-compare -verify=silent -x c++ %s // RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wall -verify=silent %s // RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wall -verify=silent -x c++ %s // RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -verify=silent %s // RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -verify=silent -x c++ %s #ifndef TEST // silent-no-diagnostics #endif int value(void); #define macro(val) val #ifdef __cplusplus template void TFunc() { // Make sure that we do warn for normal variables in template functions ! unsigned char c = value(); #ifdef TEST if (c > 255) // expected-warning {{comparison 'unsigned char' > 255 is always false}} return; #else if (c > 255) return; #endif if (c > macro(255)) return; T v = value(); if (v > 255) return; if (v > 32767) return; } #endif int main(void) { #ifdef __cplusplus TFunc(); TFunc(); #endif short s = value(); #ifdef TEST if (s == 32767) return 0; if (s != 32767) return 0; if (s < 32767) return 0; if (s <= 32767) // expected-warning {{comparison 'short' <= 32767 is always true}} return 0; if (s > 32767) // expected-warning {{comparison 'short' > 32767 is always false}} return 0; if (s >= 32767) return 0; if (32767 == s) return 0; if (32767 != s) return 0; if (32767 < s) // expected-warning {{comparison 32767 < 'short' is always false}} return 0; if (32767 <= s) return 0; if (32767 > s) return 0; if (32767 >= s) // expected-warning {{comparison 32767 >= 'short' is always true}} return 0; // FIXME: assumes two's complement if (s == -32768) return 0; if (s != -32768) return 0; if (s < -32768) // expected-warning {{comparison 'short' < -32768 is always false}} return 0; if (s <= -32768) return 0; if (s > -32768) return 0; if (s >= -32768) // expected-warning {{comparison 'short' >= -32768 is always true}} return 0; if (-32768 == s) return 0; if (-32768 != s) return 0; if (-32768 < s) return 0; if (-32768 <= s) // expected-warning {{comparison -32768 <= 'short' is always true}} return 0; if (-32768 > s) // expected-warning {{comparison -32768 > 'short' is always false}} return 0; if (-32768 >= s) return 0; // Note: both sides are promoted to unsigned long prior to the comparison, so // it is perfectly possible for a short to compare greater than 32767UL. if (s == 32767UL) return 0; if (s != 32767UL) return 0; if (s < 32767UL) return 0; if (s <= 32767UL) return 0; if (s > 32767UL) return 0; if (s >= 32767UL) return 0; if (32767UL == s) return 0; if (32767UL != s) return 0; if (32767UL < s) return 0; if (32767UL <= s) return 0; if (32767UL > s) return 0; if (32767UL >= s) return 0; enum { ULONG_MAX = (2UL * (unsigned long)__LONG_MAX__ + 1UL) }; if (s == 2UL * (unsigned long)__LONG_MAX__ + 1UL) return 0; if (s != 2UL * (unsigned long)__LONG_MAX__ + 1UL) return 0; if (s < 2UL * (unsigned long)__LONG_MAX__ + 1UL) return 0; if (s <= 2UL * (unsigned long)__LONG_MAX__ + 1UL) // expected-warning-re {{comparison 'short' <= {{.*}} is always true}} return 0; if (s > 2UL * (unsigned long)__LONG_MAX__ + 1UL) // expected-warning-re {{comparison 'short' > {{.*}} is always false}} return 0; if (s >= 2UL * (unsigned long)__LONG_MAX__ + 1UL) return 0; if (2UL * (unsigned long)__LONG_MAX__ + 1UL == s) return 0; if (2UL * (unsigned long)__LONG_MAX__ + 1UL != s) return 0; if (2UL * (unsigned long)__LONG_MAX__ + 1UL < s) // expected-warning-re {{comparison {{.*}} < 'short' is always false}} return 0; if (2UL * (unsigned long)__LONG_MAX__ + 1UL <= s) return 0; if (2UL * (unsigned long)__LONG_MAX__ + 1UL > s) return 0; if (2UL * (unsigned long)__LONG_MAX__ + 1UL >= s) // expected-warning-re {{comparison {{.*}} >= 'short' is always true}} return 0; // FIXME: assumes two's complement if (s == -32768L) return 0; if (s != -32768L) return 0; if (s < -32768L) // expected-warning {{comparison 'short' < -32768 is always false}} return 0; if (s <= -32768L) return 0; if (s > -32768L) return 0; if (s >= -32768L) // expected-warning {{comparison 'short' >= -32768 is always true}} return 0; if (-32768L == s) return 0; if (-32768L != s) return 0; if (-32768L < s) return 0; if (-32768L <= s) // expected-warning {{comparison -32768 <= 'short' is always true}} return 0; if (-32768L > s) // expected-warning {{comparison -32768 > 'short' is always false}} return 0; if (-32768L >= s) return 0; #else if (s == 32767) return 0; if (s != 32767) return 0; if (s < 32767) return 0; if (s <= 32767) return 0; if (s > 32767) return 0; if (s >= 32767) return 0; if (32767 == s) return 0; if (32767 != s) return 0; if (32767 < s) return 0; if (32767 <= s) return 0; if (32767 > s) return 0; if (32767 >= s) return 0; // FIXME: assumes two's complement if (s == -32768) return 0; if (s != -32768) return 0; if (s < -32768) return 0; if (s <= -32768) return 0; if (s > -32768) return 0; if (s >= -32768) return 0; if (-32768 == s) return 0; if (-32768 != s) return 0; if (-32768 < s) return 0; if (-32768 <= s) return 0; if (-32768 > s) return 0; if (-32768 >= s) return 0; if (s == 32767UL) return 0; if (s != 32767UL) return 0; if (s < 32767UL) return 0; if (s <= 32767UL) return 0; if (s > 32767UL) return 0; if (s >= 32767UL) return 0; if (32767UL == s) return 0; if (32767UL != s) return 0; if (32767UL < s) return 0; if (32767UL <= s) return 0; if (32767UL > s) return 0; if (32767UL >= s) return 0; // FIXME: assumes two's complement if (s == -32768L) return 0; if (s != -32768L) return 0; if (s < -32768L) return 0; if (s <= -32768L) return 0; if (s > -32768L) return 0; if (s >= -32768L) return 0; if (-32768L == s) return 0; if (-32768L != s) return 0; if (-32768L < s) return 0; if (-32768L <= s) return 0; if (-32768L > s) return 0; if (-32768L >= s) return 0; #endif if (s == 0) return 0; if (s != 0) return 0; if (s < 0) return 0; if (s <= 0) return 0; if (s > 0) return 0; if (s >= 0) return 0; if (0 == s) return 0; if (0 != s) return 0; if (0 < s) return 0; if (0 <= s) return 0; if (0 > s) return 0; if (0 >= s) return 0; unsigned short us = value(); #ifdef TEST if (us == 65535) return 0; if (us != 65535) return 0; if (us < 65535) return 0; if (us <= 65535) // expected-warning {{comparison 'unsigned short' <= 65535 is always true}} return 0; if (us > 65535) // expected-warning {{comparison 'unsigned short' > 65535 is always false}} return 0; if (us >= 65535) return 0; if (65535 == us) return 0; if (65535 != us) return 0; if (65535 < us) // expected-warning {{comparison 65535 < 'unsigned short' is always false}} return 0; if (65535 <= us) return 0; if (65535 > us) return 0; if (65535 >= us) // expected-warning {{comparison 65535 >= 'unsigned short' is always true}} return 0; if (us == 65535UL) return 0; if (us != 65535UL) return 0; if (us < 65535UL) return 0; if (us <= 65535UL) // expected-warning {{comparison 'unsigned short' <= 65535 is always true}} return 0; if (us > 65535UL) // expected-warning {{comparison 'unsigned short' > 65535 is always false}} return 0; if (us >= 65535UL) return 0; if (65535UL == us) return 0; if (65535UL != us) return 0; if (65535UL < us) // expected-warning {{comparison 65535 < 'unsigned short' is always false}} return 0; if (65535UL <= us) return 0; if (65535UL > us) return 0; if (65535UL >= us) // expected-warning {{comparison 65535 >= 'unsigned short' is always true}} return 0; #else if (us == 65535) return 0; if (us != 65535) return 0; if (us < 65535) return 0; if (us <= 65535) return 0; if (us > 65535) return 0; if (us >= 65535) return 0; if (65535 == us) return 0; if (65535 != us) return 0; if (65535 < us) return 0; if (65535 <= us) return 0; if (65535 > us) return 0; if (65535 >= us) return 0; if (us == 65535UL) return 0; if (us != 65535UL) return 0; if (us < 65535UL) return 0; if (us <= 65535UL) return 0; if (us > 65535UL) return 0; if (us >= 65535UL) return 0; if (65535UL == us) return 0; if (65535UL != us) return 0; if (65535UL < us) return 0; if (65535UL <= us) return 0; if (65535UL > us) return 0; if (65535UL >= us) return 0; #endif if (us == 32767) return 0; if (us != 32767) return 0; if (us < 32767) return 0; if (us <= 32767) return 0; if (us > 32767) return 0; if (us >= 32767) return 0; if (32767 == us) return 0; if (32767 != us) return 0; if (32767 < us) return 0; if (32767 <= us) return 0; if (32767 > us) return 0; if (32767 >= us) return 0; if (us == 32767UL) return 0; if (us != 32767UL) return 0; if (us < 32767UL) return 0; if (us <= 32767UL) return 0; if (us > 32767UL) return 0; if (us >= 32767UL) return 0; if (32767UL == us) return 0; if (32767UL != us) return 0; if (32767UL < us) return 0; if (32767UL <= us) return 0; if (32767UL > us) return 0; if (32767UL >= us) return 0; #if __SIZEOF_INT128__ __int128 i128 = value(); if (i128 == -1) // used to crash return 0; #endif enum E { yes, no, maybe }; enum E e = (enum E)value(); if (e == yes) return 0; if (e != yes) return 0; if (e < yes) return 0; if (e <= yes) return 0; if (e > yes) return 0; if (e >= yes) return 0; if (yes == e) return 0; if (yes != e) return 0; if (yes < e) return 0; if (yes <= e) return 0; if (yes > e) return 0; if (yes >= e) return 0; if (e == maybe) return 0; if (e != maybe) return 0; if (e < maybe) return 0; if (e <= maybe) return 0; if (e > maybe) return 0; if (e >= maybe) return 0; if (maybe == e) return 0; if (maybe != e) return 0; if (maybe < e) return 0; if (maybe <= e) return 0; if (maybe > e) return 0; if (maybe >= e) return 0; // We only warn on out-of-range bitfields and expressions with limited range // under -Wtantological-in-range-compare, not under -Wtype-limits, because // the warning is not based on the type alone. struct A { int a : 3; unsigned b : 3; long c : 3; unsigned long d : 3; } a; if (a.a < 3) {} if (a.a < 4) {} // #bitfield1 if (a.b < 7) {} if (a.b < 8) {} // #bitfield2 if (a.c < 3) {} if (a.c < 4) {} // #bitfield3 if (a.d < 7) {} if (a.d < 8) {} // #bitfield4 #if TEST == 2 // expected-warning@#bitfield1 {{comparison of 3-bit signed value < 4 is always true}} // expected-warning@#bitfield2 {{comparison of 3-bit unsigned value < 8 is always true}} // expected-warning@#bitfield3 {{comparison of 3-bit signed value < 4 is always true}} // expected-warning@#bitfield4 {{comparison of 3-bit unsigned value < 8 is always true}} #endif if ((s & 0xff) < 0) {} // #valuerange1 if ((s & 0xff) < 1) {} if ((s & -3) < -4) {} if ((s & -3) < -3) {} if ((s & -3) < 4u) {} if ((s & -3) > 4u) {} if ((s & -3) == 4u) {} if ((s & -3) == 3u) {} // FIXME: Impossible. if ((s & -3) == -5u) {} if ((s & -3) == -4u) {} #if TEST == 2 // expected-warning@#valuerange1 {{comparison of 8-bit unsigned value < 0 is always false}} #endif // FIXME: Our bit-level width tracking comes unstuck here: the second of the // conditions below is also tautological, but we can't tell that because we // don't track the actual range, only the bit-width. if ((s ? 1 : 0) + (us ? 1 : 0) > 1) {} if ((s ? 1 : 0) + (us ? 1 : 0) > 2) {} if ((s ? 1 : 0) + (us ? 1 : 0) > 3) {} // #addrange1 #if TEST == 2 // expected-warning@#addrange1 {{comparison of 2-bit unsigned value > 3 is always false}} #endif // FIXME: The second and third comparisons are also tautological; 0x40000000 // is the greatest value that multiplying two int16s can produce. if (s * s > 0x3fffffff) {} if (s * s > 0x40000000) {} if (s * s > 0x7ffffffe) {} if (s * s > 0x7fffffff) {} // expected-warning {{result of comparison 'int' > 2147483647 is always false}} if ((s & 0x3ff) * (s & 0x1f) > 0x7be0) {} if ((s & 0x3ff) * (s & 0x1f) > 0x7be1) {} // FIXME if ((s & 0x3ff) * (s & 0x1f) > 0x7ffe) {} // FIXME if ((s & 0x3ff) * (s & 0x1f) > 0x7fff) {} // #mulrange1 #if TEST == 2 // expected-warning@#mulrange1 {{comparison of 15-bit unsigned value > 32767 is always false}} #endif if (a.a * a.b > 21) {} // FIXME if (a.a * a.b > 31) {} // #mulrange2 #if TEST == 2 // expected-warning@#mulrange2 {{comparison of 6-bit signed value > 31 is always false}} #endif if (a.a - (s & 1) < -4) {} if (a.a - (s & 1) < -7) {} // FIXME if (a.a - (s & 1) < -8) {} // #subrange1 if (a.a - (s & 1) > 3) {} // FIXME: Can be < -4 but not > 3. if (a.a - (s & 1) > 7) {} // #subrange2 if (a.a - (s & 7) < -8) {} if (a.a - (s & 7) > 7) {} // FIXME: Can be < -8 but not > 7. if (a.a - (s & 7) < -15) {} if (a.a - (s & 7) < -16) {} // #subrange3 if (a.a - (s & 7) > 15) {} // #subrange4 if (a.b - (s & 1) > 6) {} if (a.b - (s & 1) > 7) {} // #subrange5 if (a.b - (s & 7) < -8) {} // #subrange6 if (a.b - (s & 15) < -8) {} if (a.b - (s & 15) < -16) {} // #subrange7 #if TEST == 2 // expected-warning@#subrange1 {{comparison of 4-bit signed value < -8 is always false}} // expected-warning@#subrange2 {{comparison of 4-bit signed value > 7 is always false}} // expected-warning@#subrange3 {{comparison of 5-bit signed value < -16 is always false}} // expected-warning@#subrange4 {{comparison of 5-bit signed value > 15 is always false}} // expected-warning@#subrange5 {{comparison of 4-bit signed value > 7 is always false}} // expected-warning@#subrange6 {{comparison of 4-bit signed value < -8 is always false}} // expected-warning@#subrange7 {{comparison of 5-bit signed value < -16 is always false}} #endif // a.a % 3 is in range [-2, 2], which we expand to [-4, 4) if (a.a % 3 > 2) {} if (a.a % 3 > 3) {} // #remrange1 if (a.a % 3 == -1) {} if (a.a % 3 == -2) {} if (a.a % 3 < -3) {} // FIXME if (a.a % 3 < -4) {} // #remrange2 // a.b % 3 is in range [0, 3), which we expand to [0, 4) if (a.b % 3 > 2) {} if (a.b % 3 > 3) {} // #remrange3 if (a.b % 3 < 0) {} // #remrange4 #if TEST == 2 // expected-warning@#remrange1 {{comparison of 3-bit signed value > 3 is always false}} // expected-warning@#remrange2 {{comparison of 3-bit signed value < -4 is always false}} // expected-warning@#remrange3 {{comparison of 2-bit unsigned value > 3 is always false}} // expected-warning@#remrange4 {{comparison of 2-bit unsigned value < 0 is always false}} #endif // Don't warn on non-constant-expression values that end up being a constant // 0; we generally only want to warn when one side of the comparison is // effectively non-constant. if ("x"[1] == 0) {} if (((void)s, 0) == 0) {} return 1; }