1 /* Keeping a unique copy of strings.
2 
3    Copyright (C) 2002-2003, 2008-2012 Free Software Foundation, Inc.
4 
5    This file is part of Bison, the GNU Compiler Compiler.
6 
7    This program is free software: you can redistribute it and/or modify
8    it under the terms of the GNU General Public License as published by
9    the Free Software Foundation, either version 3 of the License, or
10    (at your option) any later version.
11 
12    This program is distributed in the hope that it will be useful,
13    but WITHOUT ANY WARRANTY; without even the implied warranty of
14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15    GNU General Public License for more details.
16 
17    You should have received a copy of the GNU General Public License
18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
19 
20 #ifndef UNIQSTR_H_
21 # define UNIQSTR_H_
22 
23 /*-----------------------------------------.
24 | Pointers to unique copies of C strings.  |
25 `-----------------------------------------*/
26 
27 typedef char const *uniqstr;
28 
29 /* Return the uniqstr for STR.  */
30 uniqstr uniqstr_new (char const *str);
31 
32 /* Return a uniqstr built by vsprintf.  In order to simply concatenate
33    strings, use UNIQSTR_CONCAT, which is a convenient wrapper around
34    this function.  */
35 uniqstr uniqstr_vsprintf (char const *format, ...)
36   __attribute__ ((__format__ (__printf__, 1, 2)));
37 
38 /* Two uniqstr values have the same value iff they are the same.  */
39 #define UNIQSTR_EQ(USTR1, USTR2) (!!((USTR1) == (USTR2)))
40 
41 /* Compare two uniqstr a la strcmp: negative for <, nul for =, and
42    positive for >.  Undefined order, relies on addresses.  */
43 #define UNIQSTR_CMP(USTR1, USTR2) ((USTR1) - (USTR2))
44 
45 /*--------------------------------------.
46 | Initializing, destroying, debugging.  |
47 `--------------------------------------*/
48 
49 /* Create the string table.  */
50 void uniqstrs_new (void);
51 
52 /* Die if STR is not a uniqstr.  */
53 void uniqstr_assert (char const *str);
54 
55 /* Free all the memory allocated for symbols.  */
56 void uniqstrs_free (void);
57 
58 /* Report them all.  */
59 void uniqstrs_print (void);
60 
61 /*----------------.
62 | Concatenation.  |
63 `----------------*/
64 
65 /* Concatenate at most 20 strings and return a uniqstr.  The goal of
66    this macro is to make the caller's code a little more succinct
67    without a trivial uniqstr_vsprintf format string to maintain
68    (for example, "%s%s%s") while still benefitting from gcc's type
69    checking.  Unfortunately, because of the missing format string in the
70    macro invocation, the argument number reported by gcc for a bad
71    argument type is 1 too large.  */
72 #define UNIQSTR_CONCAT(...)                                            \
73   uniqstr_vsprintf (UNIQSTR_GEN_FORMAT (__VA_ARGS__,                   \
74                                         "%s", "%s", "%s", "%s", "%s",  \
75                                         "%s", "%s", "%s", "%s", "%s",  \
76                                         "%s", "%s", "%s", "%s", "%s",  \
77                                         "%s", "%s", "%s", "%s", "%s"), \
78                     __VA_ARGS__)
79 
80 #define UNIQSTR_GEN_FORMAT(F1,  F2,  F3,  F4,  F5,  \
81                            F6,  F7,  F8,  F9,  F10, \
82                            F11, F12, F13, F14, F15, \
83                            F16, F17, F18, F19, F20, \
84                            ...)                     \
85   UNIQSTR_GEN_FORMAT_ (__VA_ARGS__,                 \
86                        "", "", "", "", "",          \
87                        "", "", "", "", "",          \
88                        "", "", "", "", "",          \
89                        "", "", "", "", "")
90 
91 #define UNIQSTR_GEN_FORMAT_(F1,  F2,  F3,  F4,  F5,       \
92                             F6,  F7,  F8,  F9,  F10,      \
93                             F11, F12, F13, F14, F15,      \
94                             F16, F17, F18, F19, F20, ...) \
95   F1  F2  F3  F4  F5  F6  F7  F8  F9  F10                 \
96   F11 F12 F13 F14 F15 F16 F17 F18 F19 F20
97 
98 #endif /* ! defined UNIQSTR_H_ */
99