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authorRoland McGrath <roland@gnu.org>1996-05-24 20:16:39 +0000
committerRoland McGrath <roland@gnu.org>1996-05-24 20:16:39 +0000
commit613a76ff52a680e71db772306a260b9cb7f95b49 (patch)
tree7c6ff1e04f1cadef4b95c93e295d3df2ad0631d0 /FAQ
parent510ca033d66c47e0dc54550928dece59799a0136 (diff)
downloadglibc-613a76ff52a680e71db772306a260b9cb7f95b49.tar.gz
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Fri May 24 02:31:36 1996 Ulrich Drepper <drepper@cygnus.com>
	* sysdeps/unix/sysv/linux/speed.c: Add new speed value 460800.

Thu May 23 23:09:33 1996  Ulrich Drepper  <drepper@cygnus.com>

	* FAQ: Add answer for 100% source code compatibility to Linux
	libc by David Mosberger-Tang.

	Update from bind-4.3.4-T3B.
	* inet/arpa/inet.h: Add prototypes for inet_pton, inet_ntop,
	inet_nsap_addr, and inet_nsap_ntoa.
	* resolv/gethnamaddr.c: Correct compatibility problems (sprintf),
	remove fourth argument to inet_pton and correct handling of
	host_addr passing.
	* resolv/inet_ntop.c: Correct compatibility problems (sprintf).
	* resolv/inet_pton.c: Remove fourth argument.
	* resolv/resolv.h: Remove prototypes for inet_nsap_addr and
	inet_nsap_ntoa.  Now on <arpa/inet.h>.

	* stdlib/gmp-impl.h: Add prototypes for internal functions.

Thu May 23 22:49:15 1996  Roland McGrath  <roland@delasyd.gnu.ai.mit.edu>

	* Rules (subdir_install): Remove dep on sor-$(subdir).
	(static-only-routines): Removed variable and associated rules.

	* sysdeps/unix/sysv/linux/alpha/Makefile (headers): Add
 	sysdeps/alpha/bsd-_setjmp.S, sysdeps/alpha/ffs.S,
 	sysdeps/unix/sysv/linux/alpha/sigsuspend.S,
 	sysdeps/unix/sysv/linux/alpha/start.S,
Diffstat (limited to 'FAQ')
-rw-r--r--FAQ78
1 files changed, 78 insertions, 0 deletions
diff --git a/FAQ b/FAQ
index 9334108afa..91e531dbf1 100644
--- a/FAQ
+++ b/FAQ
@@ -19,6 +19,28 @@ this document let me know.
 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
 [Q1]	``What systems the GNU C Library runs on?''
 
+[Q2]	``What compiler do I need to translate GNU libc?''
+
+[Q3]	``When starting make I get only errors messages.
+	  What's wrong?''
+
+[Q4]	``After I changed configure.in I get `Autoconf version X.Y.
+	  or higher is required for this script'.  What can I do?''
+
+[Q5]	``Do I need a special linker or archiver?''
+
+[Q6]	``Do I need some more things to compile GNU C Library?''
+
+[Q7]	``When I run `nm libc.so|grep " U "' on the produced library
+	  I still find unresolved symbols?  Can this be ok?''
+
+[Q8]	``I expect GNU libc to be 100% source code compatible with
+	  the old Linux based GNU libc.  Why isn't it like this?''
+
+
+~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
+[Q1]	``What systems the GNU C Library runs on?''
+
 [A1] {UD} This is difficult to answer.  The file `README' lists the
 architectures GNU libc is known to run *at some time*.  This does not
 mean that it still can be compiled and run on them in the moment.
@@ -128,11 +150,67 @@ errors while linking.
 
 
 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
+[Q8]	``I expect GNU libc to be 100% source code compatible with
+	  the old Linux based GNU libc.  Why isn't it like this?''
+
+[A8] {DMT} Not every extension in Linux libc's history was well
+thought.  In fact it had a lot of problems with standard compliance
+and cleanliness.  With the introduction of a new version number these
+errors now can be corrected.  The following list shows a list of the
+know source code incompatibilities.
+
+* _GNU_SOURCE: glibc does not automatically define _GNU_SOURCE.  Thus,
+  if a program depends on GNU extensions, it is necessary
+  to compile it with C compiler option -D_GNU_SOURCE.  This difference
+  normally mainfests itself in the form of missing prototypes and/or
+  data type definitions.  Thus, if you get such errors, the first thing you
+  should do is grep the header files in /usr/include and /usr/include/sys
+  to check whether the functions are really missing or whether it is
+  just necessary to add a define of _GNU_SOURCE.  Similar comments apply
+  to _BSD_SOURCE, _POSIX_SOURCE, _SVID_SOURCE etc (see
+  /usr/include/features.h).
+
+* reboot(): GNU libc sanitizes the interface of reboot() to be more
+  compatible with the interface used on other OSes.  In particular,
+  reboot() as implemented in glibc takes just one argument.  This argument
+  corresponds to the third argument of the Linux reboot system call.
+  That is, a call of the form reboot(a, b, c) needs to be changed into
+  reboot(c).
+
+* errno: If a program uses variable "errno", then it _must_ include header
+  file <errno.h>.  The old libc often (erroneously) declared this variable
+  implicitly as a side-effect of including other libc header files.  glibc
+  is careful to avoid such namespace pollution, which, in turn, means that
+  you really need to include the header files that you depend on.  This
+  difference normally manifests itself in the form of the compiler
+  complaining about the references of the undeclared symbol "errno".
+
+* Linux-specific syscalls: All Linux system calls now have appropriate
+  library wrappers and corresponding declarations in various header files.
+  This is because the syscall() macro that was traditionally used to
+  work around missing syscall wrappers are inherently non-portable and
+  error-prone.  The following tables lists all the new syscall stubs,
+  the header-file declaring their interface and the system call name.
+
+       syscall name:	wrapper name:	declaring header file:
+       -------------	-------------	----------------------
+       bdflush		bdflush		<unistd.h>
+       create_module	create_module	<sys/module.h>
+       delete_module	delete_module	<sys/module.h>
+       get_kernel_syms	get_kernel_syms	<sys/module.h>
+       init_module	init_module	<sys/module.h>
+       syslog		ksyslog_ctl	<unistd.h>
+
+  To get the Linux-specific declarations in <unistd.h>, you'll need
+  to define C pre-processor macro _LINUX_SOURCE during compilation.
 
 
+~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
+
 
 Answers were given by:
 {UD} Ulrich Drepper, <drepper@cygnus.com>
+{DMT} David Mosberger-Tang, <davidm@AZStarNet.com>
 
 
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