xref: /llvm-project/clang/test/C/C99/n717.c (revision 2606c87788153bf33d854fa5c3a03e16d544c5d7)
1 // RUN: %clang_cc1 -verify -std=c99 %s
2 // RUN: %clang_cc1 -verify -std=c99 -fno-dollars-in-identifiers %s
3 
4 /* WG14 N717: Clang 17
5  * Extended identifiers
6  */
7 
8 // Used as a sink for UCNs.
9 #define M(arg)
10 
11 // C99 6.4.3p1 specifies the grammar for UCNs. A \u must be followed by exactly
12 // four hex digits, and \U must be followed by exactly eight.
13 M(\u1)    // expected-warning {{incomplete universal character name; treating as '\' followed by identifier}}
14 M(\u12)   // expected-warning {{incomplete universal character name; treating as '\' followed by identifier}}
15 M(\u123)  // expected-warning {{incomplete universal character name; treating as '\' followed by identifier}}
16 M(\u1234) // Okay
17 M(\u12345)// Okay, two tokens (UCN followed by 5)
18 
19 M(\U1)         // expected-warning {{incomplete universal character name; treating as '\' followed by identifier}}
20 M(\U12)        // expected-warning {{incomplete universal character name; treating as '\' followed by identifier}}
21 M(\U123)       // expected-warning {{incomplete universal character name; treating as '\' followed by identifier}}
22 M(\U1234)      // expected-warning {{incomplete universal character name; treating as '\' followed by identifier}} \
23                   expected-note {{did you mean to use '\u'?}}
24 M(\U12345)     // expected-warning {{incomplete universal character name; treating as '\' followed by identifier}}
25 M(\U123456)    // expected-warning {{incomplete universal character name; treating as '\' followed by identifier}}
26 M(\U1234567)   // expected-warning {{incomplete universal character name; treating as '\' followed by identifier}}
27 M(\U12345678)  // Okay
28 M(\U123456789) // Okay-ish, two tokens (valid-per-spec-but-actually-invalid UCN followed by 9)
29 
30 // Now test the ones that should work. Note, these work in C17 and earlier but
31 // are part of the basic character set in C23 and thus should be diagnosed in
32 // that mode. They're valid in a character constant, but not valid in an
33 // identifier, except for U+0024 which is allowed if -fdollars-in-identifiers
34 // is enabled.
35 // FIXME: These three should be handled the same way, and should be accepted
36 // when dollar signs are allowed in identifiers, rather than rejected, see
37 // GH87106.
38 M(\u0024) // expected-error {{character '$' cannot be specified by a universal character name}}
39 M(\U00000024) // expected-error {{character '$' cannot be specified by a universal character name}}
40 M($)
41 
42 // These should always be rejected because they're not valid identifier
43 // characters.
44 // FIXME: the diagnostic could be improved to make it clear this is an issue
45 // with forming an identifier rather than a UCN.
46 M(\u0040) // expected-error {{character '@' cannot be specified by a universal character name}}
47 M(\u0060) // expected-error {{character '`' cannot be specified by a universal character name}}
48 M(\U00000040) // expected-error {{character '@' cannot be specified by a universal character name}}
49 M(\U00000060) // expected-error {{character '`' cannot be specified by a universal character name}}
50 
51 // UCNs outside of identifiers are handled in Phase 5 of translation, so we
52 // cannot use the macro expansion to test their behavior.
53 
54 // This is outside of the range of values specified by ISO 10646.
55 const char *c1 = "\U00110000"; // expected-error {{invalid universal character}}
56 // This does not fall outside of the range
57 const char *c2 = "\U0010FFFF";
58 
59 // These should always be accepted because they're a valid in a character
60 // constant.
61 int c3 = '\u0024';
62 int c4 = '\u0040';
63 int c5 = '\u0060';
64 
65 int c6 = '\U00000024';
66 int c7 = '\U00000040';
67 int c8 = '\U00000060';
68 
69 // Valid lone surrogates.
70 M(\uD799)
71 const char *c9 = "\U0000E000";
72 
73 // Invalid lone surrogates, which are excluded explicitly by 6.4.3p2.
74 M(\uD800) // expected-error {{invalid universal character}}
75 const char *c10  = "\U0000DFFF"; // expected-error {{invalid universal character}}
76