[PATCH] Created platform.c with replacements for common functions (was Re: Supplying unavailable functions)
Dan Fandrich
dan at coneharvesters.com
Fri Oct 16 06:38:48 UTC 2009
On Tue, Sep 15, 2009 at 11:57:18PM +0200, Denys Vlasenko wrote:
> On Saturday 12 September 2009 09:42, Dan Fandrich wrote:
> > There is half-hearted support in a few places in BusyBox for environments
> > that don't supply some of the glibc and BSD-specific functions that it
> > requires.
>
> Sure. Please send a patch. But this will also require autoconf-like
> machinery to detect a platform, and we don't have it.
Here's a patch that makes the current replacement functions more consistent
and usable. Rather than using a kind of autoconf mechanism, the
code continues to rely on detection by compiler macros in platform.h. If
this approach is deemed acceptable, I'll add a few new, similar functions
later.
Platform-specific checks in platform.h determine which of these
functions are needed. These functions are generally common but
non-standard so cannot be relied upon to exist on all platforms.
---
include/platform.h | 62 +++++++++++++++++++++++++++++++++---------------
libbb/Kbuild | 1 +
libbb/platform.c | 57 +++++++++++++++++++++++++++++++++++++++++++++
libbb/xfuncs_printf.c | 45 -----------------------------------
4 files changed, 100 insertions(+), 65 deletions(-)
create mode 100644 libbb/platform.c
diff --git a/include/platform.h b/include/platform.h
index 7c88d1b..1fa2ece 100644
--- a/include/platform.h
+++ b/include/platform.h
@@ -7,6 +7,13 @@
#ifndef BB_PLATFORM_H
#define BB_PLATFORM_H 1
+/* Assume all these functions exist by default. Platforms where it is not
+ * true will #undef them below.
+ */
+#define HAVE_FDPRINTF 1
+#define HAVE_STRCHRNUL 1
+#define HAVE_VASPRINTF 1
+
/* Convenience macros to test the version of gcc. */
#undef __GNUC_PREREQ
#if defined __GNUC__ && defined __GNUC_MINOR__
@@ -126,7 +133,6 @@
# define __BIG_ENDIAN__ (BYTE_ORDER == BIG_ENDIAN)
# define __BYTE_ORDER BYTE_ORDER
#elif defined __FreeBSD__
-char *strchrnul(const char *s, int c);
# include <sys/resource.h> /* rlimit */
# include <machine/endian.h>
# define bswap_64 __bswap64
@@ -148,7 +154,7 @@ char *strchrnul(const char *s, int c);
# define BB_BIG_ENDIAN 0
# define BB_LITTLE_ENDIAN 1
#else
-# error "Can't determine endiannes"
+# error "Can't determine endianness"
#endif
/* SWAP_LEnn means "convert CPU<->little_endian by swapping bytes" */
@@ -293,24 +299,6 @@ typedef unsigned smalluint;
# define USE_FOR_MMU(...) __VA_ARGS__
#endif
-/* Platforms that haven't got dprintf need to implement fdprintf() in
- * libbb. This would require a platform.c. It's not going to be cleaned
- * out of the tree, so stop saying it should be. */
-#if !defined(__dietlibc__)
-/* Needed for: glibc */
-/* Not needed for: dietlibc */
-/* Others: ?? (add as needed) */
-# define fdprintf dprintf
-#endif
-
-#if defined(__dietlibc__)
-static ALWAYS_INLINE char* strchrnul(const char *s, char c)
-{
- while (*s && *s != c) ++s;
- return (char*)s;
-}
-#endif
-
/* Don't use lchown with glibc older than 2.1.x */
#if defined(__GLIBC__) && __GLIBC__ <= 2 && __GLIBC_MINOR__ < 1
# define lchown chown
@@ -342,5 +330,39 @@ static ALWAYS_INLINE char* strchrnul(const char *s, char c)
#endif
+#if defined(__GLIBC__)
+# define fdprintf dprintf
+#endif
+
+#if defined(__dietlibc__)
+#undef HAVE_STRCHRNUL
+#endif
+
+#if defined(__WATCOMC__)
+#undef HAVE_FDPRINTF
+#undef HAVE_STRCHRNUL
+#undef HAVE_VASPRINTF
+#endif
+
+#if defined(__FreeBSD__)
+#undef HAVE_STRCHRNUL
+#endif
+
+/*
+ * Now, define prototypes for all the functions defined in platform.c
+ * These must come after all the HAVE_* macros are defined (or not)
+ */
+
+#ifndef HAVE_STRCHRNUL
+extern char *strchrnul(const char *s, int c) FAST_FUNC;
+#endif
+
+#ifndef HAVE_VASPRINTF
+extern int vasprintf(char **string_ptr, const char *format, va_list p) FAST_FUNC;
+#endif
+
+#ifndef HAVE_FDPRINTF
+extern int fdprintf(int fd, const char *format, ...);
+#endif
#endif
diff --git a/libbb/Kbuild b/libbb/Kbuild
index 8c7a189..c3c02b3 100644
--- a/libbb/Kbuild
+++ b/libbb/Kbuild
@@ -71,6 +71,7 @@ lib-y += perror_msg_and_die.o
lib-y += perror_nomsg.o
lib-y += perror_nomsg_and_die.o
lib-y += pidfile.o
+lib-y += platform.o
lib-y += printable.o
lib-y += print_flags.o
lib-y += process_escape_sequence.o
diff --git a/libbb/platform.c b/libbb/platform.c
new file mode 100644
index 0000000..470185a
--- /dev/null
+++ b/libbb/platform.c
@@ -0,0 +1,57 @@
+/*
+ * Replacements for common but usually nonstandard functions that aren't
+ * supplied by all platforms.
+ *
+ * Copyright (C) 2009 by Dan Fandrich <dan at coneharvesters.com>, et. al.
+ *
+ * Licensed under the GPL version 2, see the file LICENSE in this tarball.
+ */
+
+#include "libbb.h"
+
+#ifndef HAVE_STRCHRNUL
+char * FAST_FUNC strchrnul(const char *s, int c)
+{
+ while (*s && *s != c) ++s;
+ return (char*)s;
+}
+#endif
+
+#ifndef HAVE_VASPRINTF
+int FAST_FUNC vasprintf(char **string_ptr, const char *format, va_list p)
+{
+ int r;
+ va_list p2;
+
+ va_copy(p2, p);
+ r = vsnprintf(NULL, 0, format, p);
+ va_end(p);
+ *string_ptr = xmalloc(r+1);
+ if (!*string_ptr)
+ r = -1;
+ else
+ r = vsnprintf(*string_ptr, r+1, format, p2);
+ va_end(p2);
+
+ return r;
+}
+#endif
+
+#ifndef HAVE_FDPRINTF
+int fdprintf(int fd, const char *format, ...)
+{
+ va_list p;
+ int r;
+ char *string_ptr;
+
+ va_start(p, format);
+ r = vasprintf(&string_ptr, format, p);
+ va_end(p);
+ if (r >= 0) {
+ r = full_write(fd, string_ptr, r);
+ free(string_ptr);
+ }
+ return r;
+}
+#endif
+
diff --git a/libbb/xfuncs_printf.c b/libbb/xfuncs_printf.c
index aaf9989..345c842 100644
--- a/libbb/xfuncs_printf.c
+++ b/libbb/xfuncs_printf.c
@@ -283,60 +283,15 @@ char* FAST_FUNC xasprintf(const char *format, ...)
int r;
char *string_ptr;
-#if 1
- // GNU extension
va_start(p, format);
r = vasprintf(&string_ptr, format, p);
va_end(p);
-#else
- // Bloat for systems that haven't got the GNU extension.
- va_start(p, format);
- r = vsnprintf(NULL, 0, format, p);
- va_end(p);
- string_ptr = xmalloc(r+1);
- va_start(p, format);
- r = vsnprintf(string_ptr, r+1, format, p);
- va_end(p);
-#endif
if (r < 0)
bb_error_msg_and_die(bb_msg_memory_exhausted);
return string_ptr;
}
-#if 0 /* If we will ever meet a libc which hasn't [f]dprintf... */
-int FAST_FUNC fdprintf(int fd, const char *format, ...)
-{
- va_list p;
- int r;
- char *string_ptr;
-
-#if 1
- // GNU extension
- va_start(p, format);
- r = vasprintf(&string_ptr, format, p);
- va_end(p);
-#else
- // Bloat for systems that haven't got the GNU extension.
- va_start(p, format);
- r = vsnprintf(NULL, 0, format, p) + 1;
- va_end(p);
- string_ptr = malloc(r);
- if (string_ptr) {
- va_start(p, format);
- r = vsnprintf(string_ptr, r, format, p);
- va_end(p);
- }
-#endif
-
- if (r >= 0) {
- full_write(fd, string_ptr, r);
- free(string_ptr);
- }
- return r;
-}
-#endif
-
void FAST_FUNC xsetenv(const char *key, const char *value)
{
if (setenv(key, value, 1))
--
1.5.3.2
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