[PATCH] Remove unnecessary zero-initialisations from *io.c

[Colin Watson]

This patch removes explicit zero-initialisations from *io.c in favour of
grub_zalloc.  Is there any good reason to initialise these explicitly?
This reduces the size of all four of these modules on i386-pc as
follows:

  bufio         -56
  gzio          -24
  lzopio        -20
  xzio          -64

2013-01-01  Colin Watson  <address@hidden>

        * grub-core/io/bufio.c (grub_bufio_open): Use grub_zalloc instead of
          explicitly zeroing elements.
        * grub-core/io/gzio.c (grub_gzio_open): Likewise.
        * grub-core/io/lzopio.c (grub_lzopio_open): Remove explicit zeroing
          of elements in a structure already allocated using grub_zalloc.
        * grub-core/io/xzio.c (grub_xzio_open): Likewise.

=== modified file 'grub-core/io/bufio.c'
--- grub-core/io/bufio.c        2011-12-25 14:43:15 +0000
+++ grub-core/io/bufio.c        2013-01-01 14:38:07 +0000
@@ -48,7 +48,7 @@ grub_bufio_open (grub_file_t io, int siz
   grub_file_t file;
   grub_bufio_t bufio = 0;
 
-  file = (grub_file_t) grub_malloc (sizeof (*file));
+  file = (grub_file_t) grub_zalloc (sizeof (*file));
   if (! file)
     return 0;
 
@@ -61,7 +61,7 @@ grub_bufio_open (grub_file_t io, int siz
     size = ((io->size > GRUB_BUFIO_MAX_SIZE) ? GRUB_BUFIO_MAX_SIZE :
             io->size);
 
-  bufio = grub_malloc (sizeof (struct grub_bufio) + size);
+  bufio = grub_zalloc (sizeof (struct grub_bufio) + size);
   if (! bufio)
     {
       grub_free (file);
@@ -70,14 +70,10 @@ grub_bufio_open (grub_file_t io, int siz
 
   bufio->file = io;
   bufio->block_size = size;
-  bufio->buffer_len = 0;
-  bufio->buffer_at = 0;
 
   file->device = io->device;
-  file->offset = 0;
   file->size = io->size;
   file->data = bufio;
-  file->read_hook = 0;
   file->fs = &grub_bufio_fs;
   file->not_easily_seekable = io->not_easily_seekable;
 

=== modified file 'grub-core/io/gzio.c'
--- grub-core/io/gzio.c 2012-03-06 13:11:10 +0000
+++ grub-core/io/gzio.c 2013-01-01 14:38:03 +0000
@@ -1130,7 +1130,7 @@ grub_gzio_open (grub_file_t io)
   grub_file_t file;
   grub_gzio_t gzio = 0;
 
-  file = (grub_file_t) grub_malloc (sizeof (*file));
+  file = (grub_file_t) grub_zalloc (sizeof (*file));
   if (! file)
     return 0;
 
@@ -1144,9 +1144,7 @@ grub_gzio_open (grub_file_t io)
   gzio->file = io;
 
   file->device = io->device;
-  file->offset = 0;
   file->data = gzio;
-  file->read_hook = 0;
   file->fs = &grub_gzio_fs;
   file->not_easily_seekable = 1;
 

=== modified file 'grub-core/io/lzopio.c'
--- grub-core/io/lzopio.c       2012-04-07 17:54:51 +0000
+++ grub-core/io/lzopio.c       2013-01-01 14:38:26 +0000
@@ -428,9 +428,7 @@ grub_lzopio_open (grub_file_t io)
   lzopio->file = io;
 
   file->device = io->device;
-  file->offset = 0;
   file->data = lzopio;
-  file->read_hook = 0;
   file->fs = &grub_lzopio_fs;
   file->size = GRUB_FILE_SIZE_UNKNOWN;
   file->not_easily_seekable = 1;

=== modified file 'grub-core/io/xzio.c'
--- grub-core/io/xzio.c 2012-02-12 14:25:25 +0000
+++ grub-core/io/xzio.c 2013-01-01 14:39:38 +0000
@@ -186,12 +186,9 @@ grub_xzio_open (grub_file_t io)
     }
 
   xzio->file = io;
-  xzio->saved_offset = 0;
 
   file->device = io->device;
-  file->offset = 0;
   file->data = xzio;
-  file->read_hook = 0;
   file->fs = &grub_xzio_fs;
   file->size = GRUB_FILE_SIZE_UNKNOWN;
   file->not_easily_seekable = 1;
@@ -210,10 +207,7 @@ grub_xzio_open (grub_file_t io)
     }
 
   xzio->buf.in = xzio->inbuf;
-  xzio->buf.in_pos = 0;
-  xzio->buf.in_size = 0;
   xzio->buf.out = xzio->outbuf;
-  xzio->buf.out_pos = 0;
   xzio->buf.out_size = XZBUFSIZ;
 
   /* FIXME: don't test footer on not easily seekable files.  */

Thanks,

-- 
Colin Watson                                       address@hidden