[libvirt] [PATCH] portability: don't include <endian.h>
Jim Meyering
jim at meyering.net
Wed Dec 17 12:55:59 UTC 2008
john.levon at sun.com wrote:
...
> diff --git a/configure.in b/configure.in
> --- a/configure.in
> +++ b/configure.in
> @@ -75,7 +75,7 @@ AC_CHECK_FUNCS([cfmakeraw regexec uname
> AC_CHECK_FUNCS([cfmakeraw regexec uname sched_getaffinity getuid getgid])
>
> dnl Availability of various common headers (non-fatal if missing).
> -AC_CHECK_HEADERS([pwd.h paths.h regex.h sys/syslimits.h sys/utsname.h sys/wait.h winsock2.h sched.h termios.h sys/poll.h])
> +AC_CHECK_HEADERS([pwd.h paths.h regex.h sys/syslimits.h sys/utsname.h sys/wait.h winsock2.h sched.h termios.h sys/poll.h endian.h])
>
> dnl Where are the XDR functions?
> dnl If portablexdr is installed, prefer that.
> diff --git a/src/storage_backend_fs.c b/src/storage_backend_fs.c
> --- a/src/storage_backend_fs.c
> +++ b/src/storage_backend_fs.c
> @@ -31,10 +31,14 @@
> #include <errno.h>
> #include <fcntl.h>
> #include <unistd.h>
> +#include <string.h>
> +
> +#ifdef HAVE_ENDIAN_H
> #include <endian.h>
> -#include <byteswap.h>
> -#include <mntent.h>
> -#include <string.h>
> +#else
> +#define __LITTLE_ENDIAN 1234
> +#define __BIG_ENDIAN 4321
> +#endif
>
> #include <libxml/parser.h>
> #include <libxml/tree.h>
> @@ -240,6 +244,9 @@ static int virStorageBackendProbeFile(vi
> }
>
> #if WITH_STORAGE_FS
> +
> +#include <mntent.h>
Adding the inclusions of <string.h> and <mntent.h> look fine,
but rather than testing for endian.h, it seems we can do away with
it altogether. Even the __LITTLE_ENDIAN and __BIG_ENDIAN
constants aren't really required. Rather, all you need is
an indication (dare I say boolean?) of whether a fileTypeInfo
entry is big- or little-endian. However, even though the
current code treats this field as effectively boolean
(testing a single value and then "else" for the rest),
we can leave it as a wider enum.
I propose this:
>From 65074e8d636a2eae10ceacf2619a6be77f45ee2a Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyering at redhat.com>
Date: Wed, 17 Dec 2008 13:54:04 +0100
Subject: [PATCH] portability: don't include <endian.h>
* src/storage_backend_fs.c: Don't include <endian.h>: not needed.
(LV_BIG_ENDIAN, LV_LITTLE_ENDIAN): Define.
Use those instead of __BIG_ENDIAN and __LITTLE_ENDIAN.
---
src/storage_backend_fs.c | 29 ++++++++++++++++-------------
1 files changed, 16 insertions(+), 13 deletions(-)
diff --git a/src/storage_backend_fs.c b/src/storage_backend_fs.c
index 91131e5..8bc77fc 100644
--- a/src/storage_backend_fs.c
+++ b/src/storage_backend_fs.c
@@ -31,7 +31,6 @@
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
-#include <endian.h>
#include <byteswap.h>
#include <mntent.h>
#include <string.h>
@@ -47,6 +46,10 @@
#include "memory.h"
#include "xml.h"
+enum lv_endian {
+ LV_LITTLE_ENDIAN = 1, /* 1234 */
+ LV_BIG_ENDIAN /* 4321 */
+};
/* Either 'magic' or 'extension' *must* be provided */
struct FileTypeInfo {
@@ -54,7 +57,7 @@ struct FileTypeInfo {
const char *magic; /* Optional string of file magic
* to check at head of file */
const char *extension; /* Optional file extension to check */
- int endian; /* Endianness of file format */
+ enum lv_endian endian; /* Endianness of file format */
int versionOffset; /* Byte offset from start of file
* where we find version number,
* -1 to skip version test */
@@ -69,16 +72,16 @@ const struct FileTypeInfo const fileTypeInfo[] = {
/* Bochs */
/* XXX Untested
{ VIR_STORAGE_VOL_BOCHS, "Bochs Virtual HD Image", NULL,
- __LITTLE_ENDIAN, 64, 0x20000,
+ LV_LITTLE_ENDIAN, 64, 0x20000,
32+16+16+4+4+4+4+4, 8, 1 },*/
/* CLoop */
/* XXX Untested
{ VIR_STORAGE_VOL_CLOOP, "#!/bin/sh\n#V2.0 Format\nmodprobe cloop file=$0 && mount -r -t iso9660 /dev/cloop $1\n", NULL,
- __LITTLE_ENDIAN, -1, 0,
+ LV_LITTLE_ENDIAN, -1, 0,
-1, 0, 0 }, */
/* Cow */
{ VIR_STORAGE_VOL_FILE_COW, "OOOM", NULL,
- __BIG_ENDIAN, 4, 2,
+ LV_BIG_ENDIAN, 4, 2,
4+4+1024+4, 8, 1 },
/* DMG */
/* XXX QEMU says there's no magic for dmg, but we should check... */
@@ -92,31 +95,31 @@ const struct FileTypeInfo const fileTypeInfo[] = {
/* Parallels */
/* XXX Untested
{ VIR_STORAGE_VOL_FILE_PARALLELS, "WithoutFreeSpace", NULL,
- __LITTLE_ENDIAN, 16, 2,
+ LV_LITTLE_ENDIAN, 16, 2,
16+4+4+4+4, 4, 512 },
*/
/* QCow */
{ VIR_STORAGE_VOL_FILE_QCOW, "QFI", NULL,
- __BIG_ENDIAN, 4, 1,
+ LV_BIG_ENDIAN, 4, 1,
4+4+8+4+4, 8, 1 },
/* QCow 2 */
{ VIR_STORAGE_VOL_FILE_QCOW2, "QFI", NULL,
- __BIG_ENDIAN, 4, 2,
+ LV_BIG_ENDIAN, 4, 2,
4+4+8+4+4, 8, 1 },
/* VMDK 3 */
/* XXX Untested
{ VIR_STORAGE_VOL_FILE_VMDK, "COWD", NULL,
- __LITTLE_ENDIAN, 4, 1,
+ LV_LITTLE_ENDIAN, 4, 1,
4+4+4, 4, 512 },
*/
/* VMDK 4 */
{ VIR_STORAGE_VOL_FILE_VMDK, "KDMV", NULL,
- __LITTLE_ENDIAN, 4, 1,
+ LV_LITTLE_ENDIAN, 4, 1,
4+4+4, 8, 512 },
/* Connectix / VirtualPC */
/* XXX Untested
{ VIR_STORAGE_VOL_FILE_VPC, "conectix", NULL,
- __BIG_ENDIAN, -1, 0,
+ LV_BIG_ENDIAN, -1, 0,
-1, 0, 0},
*/
};
@@ -173,7 +176,7 @@ static int virStorageBackendProbeFile(virConnectPtr conn,
if (fileTypeInfo[i].versionNumber != -1) {
int version;
- if (fileTypeInfo[i].endian == __LITTLE_ENDIAN) {
+ if (fileTypeInfo[i].endian == LV_LITTLE_ENDIAN) {
version = (head[fileTypeInfo[i].versionOffset+3] << 24) |
(head[fileTypeInfo[i].versionOffset+2] << 16) |
(head[fileTypeInfo[i].versionOffset+1] << 8) |
@@ -190,7 +193,7 @@ static int virStorageBackendProbeFile(virConnectPtr conn,
/* Optionally extract capacity from file */
if (fileTypeInfo[i].sizeOffset != -1) {
- if (fileTypeInfo[i].endian == __LITTLE_ENDIAN) {
+ if (fileTypeInfo[i].endian == LV_LITTLE_ENDIAN) {
def->capacity =
((unsigned long long)head[fileTypeInfo[i].sizeOffset+7] << 56) |
((unsigned long long)head[fileTypeInfo[i].sizeOffset+6] << 48) |
--
1.6.1.rc2.316.geb2f0
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