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| 1 | +// RUN: %clang_cc1 -verify=expected,c-expected -std=c2y -Wall -pedantic %s |
| 2 | +// RUN: %clang_cc1 -verify=expected,c-expected,ped -std=c23 -Wall -pedantic %s |
| 3 | +// RUN: %clang_cc1 -verify=expected,cxx-expected,gnu -Wall -pedantic -x c++ %s |
| 4 | +// RUN: %clang_cc1 -verify=expected,c-expected,pre -std=c2y -Wpre-c2y-compat -Wall -pedantic %s |
| 5 | + |
| 6 | +/* WG14 N3370: Yes |
| 7 | + * Case range expressions v3.1 |
| 8 | + * |
| 9 | + * This introduces the ability to specify closed ranges in case statements in a |
| 10 | + * switch statement. This was already a well-supported Clang extension before |
| 11 | + * it was standardized. |
| 12 | + */ |
| 13 | + |
| 14 | +void correct(int i) { |
| 15 | + constexpr int j = 100, k = 200; |
| 16 | + switch (i) { |
| 17 | + case 12 ... 14: break; /* gnu-warning {{case ranges are a GNU extension}} |
| 18 | + ped-warning {{case ranges are a C2y extension}} |
| 19 | + pre-warning {{case ranges are incompatible with C standards before C2y}} |
| 20 | + */ |
| 21 | + // Implementations are encouraged to diagnose empty ranges. |
| 22 | + case 15 ... 11: break; /* expected-warning {{empty case range specified}} |
| 23 | + gnu-warning {{case ranges are a GNU extension}} |
| 24 | + ped-warning {{case ranges are a C2y extension}} |
| 25 | + pre-warning {{case ranges are incompatible with C standards before C2y}} |
| 26 | + */ |
| 27 | + // This is not an empty range, it's a range of a single value. |
| 28 | + case 10 ... 10: break; /* gnu-warning {{case ranges are a GNU extension}} |
| 29 | + ped-warning {{case ranges are a C2y extension}} |
| 30 | + pre-warning {{case ranges are incompatible with C standards before C2y}} |
| 31 | + */ |
| 32 | + case j ... k: break; /* gnu-warning {{case ranges are a GNU extension}} |
| 33 | + ped-warning {{case ranges are a C2y extension}} |
| 34 | + pre-warning {{case ranges are incompatible with C standards before C2y}} |
| 35 | + */ |
| 36 | + } |
| 37 | +} |
| 38 | + |
| 39 | +void incorrect(int i) { // cxx-expected-note 2 {{declared here}} |
| 40 | + switch (i) { |
| 41 | + // The values have to be integer constant expressions. Note that when the |
| 42 | + // initial value in the range is an error, we don't issue the warnings about |
| 43 | + // extensions or incompatibility. |
| 44 | + case i ... 10: break; /* c-expected-error {{expression is not an integer constant expression}} |
| 45 | + cxx-expected-error {{case value is not a constant expression}} |
| 46 | + cxx-expected-note {{function parameter 'i' with unknown value cannot be used in a constant expression}} |
| 47 | + */ |
| 48 | + case 10 ... i: break; /* c-expected-error {{expression is not an integer constant expression}} |
| 49 | + cxx-expected-error {{case value is not a constant expression}} |
| 50 | + cxx-expected-note {{function parameter 'i' with unknown value cannot be used in a constant expression}} |
| 51 | + gnu-warning {{case ranges are a GNU extension}} |
| 52 | + ped-warning {{case ranges are a C2y extension}} |
| 53 | + pre-warning {{case ranges are incompatible with C standards before C2y}} |
| 54 | + */ |
| 55 | + case 1.3f ... 10: break; /* c-expected-error {{integer constant expression must have integer type, not 'float'}} |
| 56 | + cxx-expected-error {{conversion from 'float' to 'int' is not allowed in a converted constant expression}} |
| 57 | + */ |
| 58 | + case 10 ... "a": break; /* c-expected-error {{integer constant expression must have integer type, not 'char[2]'}} |
| 59 | + cxx-expected-error {{value of type 'const char[2]' is not implicitly convertible to 'int'}} |
| 60 | + gnu-warning {{case ranges are a GNU extension}} |
| 61 | + ped-warning {{case ranges are a C2y extension}} |
| 62 | + pre-warning {{case ranges are incompatible with C standards before C2y}} |
| 63 | + */ |
| 64 | + } |
| 65 | + |
| 66 | + switch (i) { |
| 67 | + // Cannot have multiple cases covering the same value. |
| 68 | + // FIXME: diagnostic quality here is poor. The "previous case" note is |
| 69 | + // showing up on a subsequent line (I'd expect the error and note to be |
| 70 | + // reversed), and "duplicate case value 20" is showing up on a line where |
| 71 | + // there is no duplicate value 20 to begin with. |
| 72 | + case 10 ... 20: break; /* expected-error {{duplicate case value '11'}} |
| 73 | + expected-note {{previous case defined here}} |
| 74 | + gnu-warning {{case ranges are a GNU extension}} |
| 75 | + ped-warning {{case ranges are a C2y extension}} |
| 76 | + pre-warning {{case ranges are incompatible with C standards before C2y}} |
| 77 | + */ |
| 78 | + case 11: break; /* expected-note {{previous case defined here}} |
| 79 | + */ |
| 80 | + case 11 ... 14: break; /* expected-error {{duplicate case value '20'}} |
| 81 | + gnu-warning {{case ranges are a GNU extension}} |
| 82 | + ped-warning {{case ranges are a C2y extension}} |
| 83 | + pre-warning {{case ranges are incompatible with C standards before C2y}} |
| 84 | + */ |
| 85 | + } |
| 86 | + |
| 87 | + // The values specified by the range shall not change as a result of |
| 88 | + // conversion to the promoted type of the controlling expression. |
| 89 | + // FIXME: the overflow warnings seem like they probably should also trigger |
| 90 | + // in C++ as they do in C. |
| 91 | + switch ((unsigned char)i) { |
| 92 | + case 254 ... 256: break; /* c-expected-warning {{overflow converting case value to switch condition type (256 to 0)}} |
| 93 | + gnu-warning {{case ranges are a GNU extension}} |
| 94 | + ped-warning {{case ranges are a C2y extension}} |
| 95 | + pre-warning {{case ranges are incompatible with C standards before C2y}} |
| 96 | + */ |
| 97 | + case 257 ... 258: break; /* c-expected-warning {{overflow converting case value to switch condition type (257 to 1)}} |
| 98 | + c-expected-warning {{overflow converting case value to switch condition type (258 to 2)}} |
| 99 | + gnu-warning {{case ranges are a GNU extension}} |
| 100 | + ped-warning {{case ranges are a C2y extension}} |
| 101 | + pre-warning {{case ranges are incompatible with C standards before C2y}} |
| 102 | + */ |
| 103 | + } |
| 104 | +} |
| 105 | + |
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