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vfprintf: Rewrite printf_positional to use struct scratch_buffer

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This commit is contained in:
Florian Weimer 2015-10-17 12:05:12 +02:00
parent 52fb79d6cd
commit db8ad8fac3
2 changed files with 15 additions and 40 deletions
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5
ChangeLog
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@ -1,3 +1,8 @@
2015-10-17 Florian Weimer <fweimer@redhat.com>
* stdio-common/vfprintf.c (printf_positional): Rewrite to use
struct scratch_buffer instead of extend_alloca.
2015-10-17 Florian Weimer <fweimer@redhat.com>
* sysdeps/unix/sysv/linux/kernel-features.h

50
stdio-common/vfprintf.c
View File

@ -29,6 +29,7 @@
#include <_itoa.h>
#include <locale/localeinfo.h>
#include <stdio.h>
#include <scratch_buffer.h>
/* This code is shared between the standard stdio implementation found
in GNU C library and the libio implementation originally found in
@ -1698,18 +1699,15 @@ printf_positional (_IO_FILE *s, const CHAR_T *format, int readonly_format,
void *args_malloced = NULL;
/* For positional argument handling. */
struct printf_spec *specs;
/* Track if we malloced the SPECS array and thus must free it. */
bool specs_malloced = false;
struct scratch_buffer specsbuf;
scratch_buffer_init (&specsbuf);
struct printf_spec *specs = specsbuf.data;
size_t specs_limit = specsbuf.length / sizeof (specs[0]);
/* Array with information about the needed arguments. This has to
be dynamically extensible. */
size_t nspecs = 0;
/* A more or less arbitrary start value. */
size_t nspecs_size = 32 * sizeof (struct printf_spec);
specs = alloca (nspecs_size);
/* The number of arguments the format string requests. This will
determine the size of the array needed to store the argument
attributes. */
@ -1746,42 +1744,15 @@ printf_positional (_IO_FILE *s, const CHAR_T *format, int readonly_format,
for (const UCHAR_T *f = lead_str_end; *f != L_('\0');
f = specs[nspecs++].next_fmt)
{
if (nspecs * sizeof (*specs) >= nspecs_size)
if (nspecs == specs_limit)
{
/* Extend the array of format specifiers. */
if (nspecs_size * 2 < nspecs_size)
if (!scratch_buffer_grow_preserve (&specsbuf))
{
__set_errno (ENOMEM);
done = -1;
goto all_done;
}
struct printf_spec *old = specs;
if (__libc_use_alloca (2 * nspecs_size))
specs = extend_alloca (specs, nspecs_size, 2 * nspecs_size);
else
{
nspecs_size *= 2;
specs = malloc (nspecs_size);
if (specs == NULL)
{
__set_errno (ENOMEM);
specs = old;
done = -1;
goto all_done;
}
}
/* Copy the old array's elements to the new space. */
memmove (specs, old, nspecs * sizeof (*specs));
/* If we had previously malloc'd space for SPECS, then
release it after the copy is complete. */
if (specs_malloced)
free (old);
/* Now set SPECS_MALLOCED if needed. */
if (!__libc_use_alloca (nspecs_size))
specs_malloced = true;
specs = specsbuf.data;
specs_limit = specsbuf.length / sizeof (specs[0]);
}
/* Parse the format specifier. */
@ -2091,12 +2062,11 @@ printf_positional (_IO_FILE *s, const CHAR_T *format, int readonly_format,
- specs[nspecs_done].end_of_fmt);
}
all_done:
if (__glibc_unlikely (specs_malloced))
free (specs);
if (__glibc_unlikely (args_malloced != NULL))
free (args_malloced);
if (__glibc_unlikely (workstart != NULL))
free (workstart);
scratch_buffer_free (&specsbuf);
return done;
}