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uniqstr: avoid need for VLAs

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C11 no longer requires support for variable-length arrays, and
VS2015 does not have them.  Redo UNIQSTR_CONCAT to use a method
that is simpler and better anyway.
* src/uniqstr.c (uniqstr_vsprintf): Remove; no longer needed.
* src/uniqstr.h (UNIQSTR_GEN_FORMAT, UNIQSTR_GEN_FORMAT_):
* src/uniqstr.c (uniqstr_concat): New function.
* src/uniqstr.h (UNIQSTR_CONCAT): Use it instead of using
uniqstr_vsprintf.
This commit is contained in:
Paul Eggert
2018-09-28 16:05:51 -07:00
parent 2d07940325
commit 973c456f63
2 changed files with 30 additions and 45 deletions
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33
src/uniqstr.c
View File

@@ -56,19 +56,36 @@ uniqstr_new (char const *str)
} }
uniqstr uniqstr
uniqstr_vsprintf (char const *format, ...) uniqstr_concat (int nargs, ...)
{ {
va_list args; va_list args;
size_t length;
va_start (args, format); va_start (args, nargs);
length = vsnprintf (NULL, 0, format, args); size_t reslen = 0;
for (int i = 0; i < nargs; i++)
reslen += strlen (va_arg (args, char const *));
va_end (args); va_end (args);
char res[length + 1]; char *str = xmalloc (reslen + 1);
va_start (args, format); char *p = str;
vsprintf (res, format, args);
va_start (args, nargs);
for (int i = 0; i < nargs; i++)
{
char const *arg = va_arg (args, char const *);
size_t arglen = strlen (arg);
memcpy (p, arg, arglen);
p += arglen;
}
va_end (args); va_end (args);
return uniqstr_new (res);
*p = '\0';
uniqstr res = hash_insert (uniqstrs_table, str);
if (!res)
xalloc_die ();
if (res != str)
free (str);
return res;
} }
/*------------------------------. /*------------------------------.

42
src/uniqstr.h
View File

@@ -32,12 +32,6 @@ typedef char const *uniqstr;
/* Return the uniqstr for STR. */ /* Return the uniqstr for STR. */
uniqstr uniqstr_new (char const *str); uniqstr uniqstr_new (char const *str);
/* Return a uniqstr built by vsprintf. In order to simply concatenate
strings, use UNIQSTR_CONCAT, which is a convenient wrapper around
this function. */
uniqstr uniqstr_vsprintf (char const *format, ...)
_GL_ATTRIBUTE_FORMAT_PRINTF (1, 2);
/* Two uniqstr values have the same value iff they are the same. */ /* Two uniqstr values have the same value iff they are the same. */
# define UNIQSTR_EQ(Ustr1, Ustr2) (!!((Ustr1) == (Ustr2))) # define UNIQSTR_EQ(Ustr1, Ustr2) (!!((Ustr1) == (Ustr2)))
@@ -52,38 +46,12 @@ void uniqstr_assert (char const *str);
| Concatenation. | | Concatenation. |
`----------------*/ `----------------*/
/* Concatenate at most 20 strings and return a uniqstr. The goal of /* Concatenate strings and return a uniqstr. The goal of
this macro is to make the caller's code a little more succinct this macro is to make the caller's code a little more succinct. */
without a trivial uniqstr_vsprintf format string to maintain
(for example, "%s%s%s") while still benefitting from gcc's type
checking. Unfortunately, because of the missing format string in the
macro invocation, the argument number reported by gcc for a bad
argument type is 1 too large. */
# define UNIQSTR_CONCAT(...) \ # define UNIQSTR_CONCAT(...) \
uniqstr_vsprintf (UNIQSTR_GEN_FORMAT (__VA_ARGS__, \ uniqstr_concat (ARRAY_CARDINALITY (((char const *[]) {__VA_ARGS__})), \
"%s", "%s", "%s", "%s", "%s", \ __VA_ARGS__)
"%s", "%s", "%s", "%s", "%s", \ uniqstr uniqstr_concat (int nargs, ...);
"%s", "%s", "%s", "%s", "%s", \
"%s", "%s", "%s", "%s", "%s"), \
__VA_ARGS__)
# define UNIQSTR_GEN_FORMAT(F1, F2, F3, F4, F5, \
F6, F7, F8, F9, F10, \
F11, F12, F13, F14, F15, \
F16, F17, F18, F19, F20, \
...) \
UNIQSTR_GEN_FORMAT_ (__VA_ARGS__, \
"", "", "", "", "", \
"", "", "", "", "", \
"", "", "", "", "", \
"", "", "", "", "")
# define UNIQSTR_GEN_FORMAT_(F1, F2, F3, F4, F5, \
F6, F7, F8, F9, F10, \
F11, F12, F13, F14, F15, \
F16, F17, F18, F19, F20, ...) \
F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 \
F11 F12 F13 F14 F15 F16 F17 F18 F19 F20
/*--------------------. /*--------------------.
| Table of uniqstrs. | | Table of uniqstrs. |