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[PATCH 23/25] vfprintf: Rewrite printf_positional to use struct scratch_buffer
- From: Florian Weimer <fweimer at redhat dot com>
- To: libc-alpha at sourceware dot org
- Date: Sun, 1 Mar 2015 23:13:03 +0100
- Subject: [PATCH 23/25] vfprintf: Rewrite printf_positional to use struct scratch_buffer
- Authentication-results: sourceware.org; auth=none
- References: <cover dot 1425285061 dot git dot fweimer at redhat dot com>
---
stdio-common/vfprintf.c | 48 ++++++++++--------------------------------------
1 file changed, 10 insertions(+), 38 deletions(-)
diff --git a/stdio-common/vfprintf.c b/stdio-common/vfprintf.c
index 6bf59ff..839de8e 100644
--- a/stdio-common/vfprintf.c
+++ b/stdio-common/vfprintf.c
@@ -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. */
@@ -2093,6 +2064,7 @@ printf_positional (_IO_FILE *s, const CHAR_T *format, int readonly_format,
all_done:
if (__glibc_unlikely (workstart != NULL))
free (workstart);
+ scratch_buffer_free (&specsbuf);
return done;
}
--
2.1.0