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[PATCH 13/17] posix: Use dynarray for globname in glob
- From: Adhemerval Zanella <adhemerval dot zanella at linaro dot org>
- To: libc-alpha at sourceware dot org
- Date: Thu, 8 Jun 2017 18:13:27 -0300
- Subject: [PATCH 13/17] posix: Use dynarray for globname in glob
- Authentication-results: sourceware.org; auth=none
- References: <1496956411-25594-1-git-send-email-adhemerval.zanella@linaro.org>
This patch uses dynarray at glob internal glob_in_dir function to manage
the various matched patterns. It simplify and removes all the boilerplate
buffer managements required. It also removes the glob_use_alloca, since
it is not used anymore.
Checked on x86_64-linux-gnu.
* posix/glob.c (glob_use_alloca): Remove.
(glob_in_dir): Use dynarray for globnames.
---
posix/glob.c | 155 +++++++++++++++--------------------------------------------
1 file changed, 38 insertions(+), 117 deletions(-)
diff --git a/posix/glob.c b/posix/glob.c
index beeb639..62be373 100644
--- a/posix/glob.c
+++ b/posix/glob.c
@@ -237,33 +237,6 @@ convert_dirent64 (const struct dirent64 *source)
((void) (buf), (void) (len), (void) (newlen), (void) (avar), (void *) 0)
#endif
-/* Set *R = A + B. Return true if the answer is mathematically
- incorrect due to overflow; in this case, *R is the low order
- bits of the correct answer.. */
-
-static bool size_add_wrapv (size_t a, size_t b, size_t *r);
-static bool glob_use_alloca (size_t alloca_used, size_t len);
-
-/* We must not compile this function twice. */
-static bool
-size_add_wrapv (size_t a, size_t b, size_t *r)
-{
-#if 5 <= __GNUC__
- return __builtin_add_overflow (a, b, r);
-#else
- *r = a + b;
- return *r < a;
-#endif
-}
-
-static bool
-glob_use_alloca (size_t alloca_used, size_t len)
-{
- size_t size;
- return (!size_add_wrapv (alloca_used, len, &size)
- && __libc_use_alloca (size));
-}
-
static int glob_in_dir (const char *pattern, const char *directory,
int flags, int (*errfunc) (const char *, int),
glob_t *pglob, size_t alloca_used);
@@ -1262,6 +1235,20 @@ prefix_array (const char *dirname, char **array, size_t n)
return 0;
}
+struct globnames_result
+{
+ char **names;
+ size_t length;
+};
+
+/* Create a dynamic array for C string representing the glob name found. */
+#define DYNARRAY_STRUCT globnames_array
+#define DYNARRAY_ELEMENT_FREE(ptr) free (*ptr)
+#define DYNARRAY_ELEMENT char *
+#define DYNARRAY_PREFIX globnames_array_
+#define DYNARRAY_FINAL_TYPE struct globnames_result
+#define DYNARRAY_INITIAL_SIZE 64
+#include <malloc/dynarray-skeleton.c>
/* Like `glob', but PATTERN is a final pathname component,
and matches are searched for in DIRECTORY.
@@ -1273,26 +1260,13 @@ glob_in_dir (const char *pattern, const char *directory, int flags,
glob_t *pglob, size_t alloca_used)
{
void *stream = NULL;
- struct globnames
- {
- struct globnames *next;
- size_t count;
- char *name[64];
- };
-#define INITIAL_COUNT sizeof (init_names.name) / sizeof (init_names.name[0])
- struct globnames init_names;
- struct globnames *names = &init_names;
- struct globnames *names_alloca = &init_names;
+ struct globnames_array globnames;
size_t nfound = 0;
- size_t cur = 0;
int meta;
int save;
int result;
- alloca_used += sizeof (init_names);
-
- init_names.next = NULL;
- init_names.count = INITIAL_COUNT;
+ globnames_array_init (&globnames);
meta = __glob_pattern_type (pattern, !(flags & GLOB_NOESCAPE));
if (meta == 0 && (flags & (GLOB_NOCHECK|GLOB_NOMAGIC)))
@@ -1379,30 +1353,10 @@ glob_in_dir (const char *pattern, const char *directory, int flags,
if (fnmatch (pattern, d.name, fnm_flags) == 0)
{
- if (cur == names->count)
- {
- struct globnames *newnames;
- size_t count = names->count * 2;
- size_t size = (sizeof (struct globnames)
- + ((count - INITIAL_COUNT)
- * sizeof (char *)));
- if (glob_use_alloca (alloca_used, size))
- newnames = names_alloca
- = alloca_account (size, alloca_used);
- else if ((newnames = malloc (size)) == NULL)
- goto memory_error;
- newnames->count = count;
- newnames->next = names;
- names = newnames;
- cur = 0;
- }
- names->name[cur] = strdup (d.name);
- if (names->name[cur] == NULL)
- goto memory_error;
- ++cur;
- ++nfound;
- if (SIZE_MAX - pglob->gl_offs <= nfound)
- goto memory_error;
+ globnames_array_add (&globnames, strdup (d.name));
+ if (globnames_array_has_failed (&globnames))
+ goto memory_error;
+ nfound++;
}
}
}
@@ -1412,10 +1366,13 @@ glob_in_dir (const char *pattern, const char *directory, int flags,
{
size_t len = strlen (pattern);
nfound = 1;
- names->name[cur] = malloc (len + 1);
- if (names->name[cur] == NULL)
+ char *newp = malloc (len + 1);
+ if (newp == NULL)
+ goto memory_error;
+ *((char *) mempcpy (newp, pattern, len)) = '\0';
+ globnames_array_add (&globnames, newp);
+ if (globnames_array_has_failed (&globnames))
goto memory_error;
- *((char *) mempcpy (names->name[cur++], pattern, len)) = '\0';
}
result = GLOB_NOMATCH;
@@ -1436,61 +1393,25 @@ glob_in_dir (const char *pattern, const char *directory, int flags,
if (new_gl_pathv == NULL)
{
memory_error:
- while (1)
- {
- struct globnames *old = names;
- size_t i;
- for (i = 0; i < cur; ++i)
- free (names->name[i]);
- names = names->next;
- /* NB: we will not leak memory here if we exit without
- freeing the current block assigned to OLD. At least
- the very first block is always allocated on the stack
- and this is the block assigned to OLD here. */
- if (names == NULL)
- {
- assert (old == &init_names);
- break;
- }
- cur = names->count;
- if (old == names_alloca)
- names_alloca = names;
- else
- free (old);
- }
+ globnames_array_free (&globnames);
result = GLOB_NOSPACE;
}
else
{
- while (1)
+ struct globnames_result ret = { .names = 0, .length = -1 };
+ if (!globnames_array_finalize (&globnames, &ret))
+ result = GLOB_NOSPACE;
+ else
{
- struct globnames *old = names;
- size_t i;
- for (i = 0; i < cur; ++i)
+ for (size_t i = 0; i < ret.length; ++i)
new_gl_pathv[pglob->gl_offs + pglob->gl_pathc++]
- = names->name[i];
- names = names->next;
- /* NB: we will not leak memory here if we exit without
- freeing the current block assigned to OLD. At least
- the very first block is always allocated on the stack
- and this is the block assigned to OLD here. */
- if (names == NULL)
- {
- assert (old == &init_names);
- break;
- }
- cur = names->count;
- if (old == names_alloca)
- names_alloca = names;
- else
- free (old);
- }
-
- pglob->gl_pathv = new_gl_pathv;
+ = ret.names[i];
- pglob->gl_pathv[pglob->gl_offs + pglob->gl_pathc] = NULL;
-
- pglob->gl_flags = flags;
+ pglob->gl_pathv = new_gl_pathv;
+ pglob->gl_pathv[pglob->gl_offs + pglob->gl_pathc] = NULL;
+ pglob->gl_flags = flags;
+ }
+ free (ret.names);
}
}
--
2.7.4