[PATCH 4/8] posix: Remove alloca usage on glob dirname

[Adhemerval Zanella <adhemerval.zanella@linaro.org>]

This patch replaces the alloca/malloc usage for dirname creation
by the char_array struct.

Checked on x86_64-linux-gnu.
---
 posix/glob.c | 28 +++++++++-------------------
 1 file changed, 9 insertions(+), 19 deletions(-)

diff --git a/posix/glob.c b/posix/glob.c
index 41e1aeacad..d734ca977c 100644
--- a/posix/glob.c
+++ b/posix/glob.c
@@ -1212,7 +1212,6 @@ glob_in_dir (const char *pattern, const char *directory, int flags,
              int (*errfunc) (const char *, int),
              glob_t *pglob, size_t alloca_used)
 {
-  size_t dirlen = strlen (directory);
   void *stream = NULL;
 # define GLOBNAMES_MEMBERS(nnames) \
     struct globnames *next; size_t count; char *name[nnames];
@@ -1244,32 +1243,23 @@ glob_in_dir (const char *pattern, const char *directory, int flags,
     }
   else if (meta == GLOBPAT_NONE)
     {
-      size_t patlen = strlen (pattern);
-      size_t fullsize;
-      bool alloca_fullname
-        = (! size_add_wrapv (dirlen + 1, patlen + 1, &fullsize)
-           && glob_use_alloca (alloca_used, fullsize));
-      char *fullname;
-      if (alloca_fullname)
-        fullname = alloca_account (fullsize, alloca_used);
-      else
+      struct char_array fullname;
+
+      if (!char_array_init_str (&fullname, directory)
+          || !char_array_append_str (&fullname, "/")
+          || !char_array_append_str (&fullname, pattern))
         {
-          fullname = malloc (fullsize);
-          if (fullname == NULL)
-            return GLOB_NOSPACE;
+          char_array_free (&fullname);
+          return GLOB_NOSPACE;
         }
 
-      mempcpy (mempcpy (mempcpy (fullname, directory, dirlen),
-                        "/", 1),
-               pattern, patlen + 1);
-      if (glob_lstat (pglob, flags, fullname) == 0
+      if (glob_lstat (pglob, flags, char_array_str (&fullname)) == 0
           || errno == EOVERFLOW)
         /* We found this file to be existing.  Now tell the rest
            of the function to copy this name into the result.  */
         flags |= GLOB_NOCHECK;
 
-      if (__glibc_unlikely (!alloca_fullname))
-        free (fullname);
+      char_array_free (&fullname);
     }
   else
     {
-- 
2.25.1