Add thread-safety to libc, so that libc_r will build (on i386 at least).

All POSIX libc api now there (to P1003.1c/D10)
  (more md stuff is needed for other libc/arch/*)
  (setlogin is no longer a special syscall)
Add -pthread option to gcc (that makes it use -lc_r and -D_POSIX_THREADS).
Doc some re-entrant routines
Add libc_r to intro(3)
dig() uses some libc srcs and an extra -I was needed there.
Add more md stuff to libc_r.
Update includes for the pthreads api
Update libc_r TODO

1 files changed, 65 insertions, 9 deletions

diff --git a/lib/libc/arch/i386/SYS.h b/lib/libc/arch/i386/SYS.h
index 1cf818fd304..e02d5cf985f 100644
--- a/lib/libc/arch/i386/SYS.h
+++ b/lib/libc/arch/i386/SYS.h
@@ -33,24 +33,80 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$OpenBSD: SYS.h,v 1.3 1996/08/19 08:12:12 tholo Exp $
+ *	$OpenBSD: SYS.h,v 1.4 1998/11/20 11:18:29 d Exp $
  */
 
 #include <machine/asm.h>
 #include <sys/syscall.h>
 
 #ifdef __STDC__
+# define    __ENTRY(p,x)	ENTRY(p##x)
+# define    __DO_SYSCALL(x)				\
+				movl $(SYS_##x),%eax;	\
+				int $0x80
+# define    __LABEL2(p,x)	_C_LABEL(p##x)
+#else
+# define    __ENTRY(p,x)	ENTRY(p/**/x)
+# define    __DO_SYSCALL(x)				\
+				movl $(SYS_/**/x),%eax;	\
+				int $0x80
+# define    __LABEL2(p,x)	_C_LABEL(p/**/x)
+#endif
 
-#define	SYSCALL(x)	.text; .align 2; 2: jmp PIC_PLT(cerror); ENTRY(x); movl $(SYS_ ## x),%eax; int $0x80; jc 2b
-#define	RSYSCALL(x)	SYSCALL(x); ret
-#define	PSEUDO(x,y)	ENTRY(x); movl $(SYS_ ## y),%eax; int $0x80; ret
+/* perform a syscall, set errno */
+#define	    __SYSCALL(p,x)				\
+			.text;				\
+			.align 2;			\
+		2:					\
+			jmp PIC_PLT(cerror);		\
+		__ENTRY(p,x);				\
+			__DO_SYSCALL(x);		\
+			jc 2b
 
-#else /* !__STDC__ */
+/* perform a syscall, set errno, return */
+# define    __RSYSCALL(p,x)	__SYSCALL(p,x); ret
 
-#define	SYSCALL(x)	.text; .align 2; 2: jmp PIC_PLT(cerror); ENTRY(x); movl $(SYS_/**/x),%eax; int $0x80; jc 2b
-#define	RSYSCALL(x)	SYSCALL(x); ret
-#define	PSEUDO(x,y)	ENTRY(x); movl $(SYS_/**/y),%eax; int $0x80; ret
+/* perform a syscall, return */
+# define    __PSEUDO(p,x,y)				\
+		__ENTRY(p,x);				\
+			__DO_SYSCALL(y);		\
+			ret
 
-#endif
+/* jump to the real syscall */
+/* XXX shouldn't be here */
+# define    __PASSTHRU(p,x)				\
+			.globl __LABEL2(p,x);		\
+		ENTRY(x);				\
+			jmp PIC_PLT(__LABEL2(p,x))
 
+/*
+ * Design note:
+ *
+ * When the syscalls need to be renamed so they can be handled
+ * specially by the threaded library, these macros insert `_thread_sys_'
+ * in front of their name. This avoids the need to #ifdef _THREAD_SAFE 
+ * everywhere that the renamed function needs to be called.
+ * The PASSTHRU macro is later used for system calls that don't need
+ * wrapping. (XXX its a shame the loader can't do this aliasing)
+ */
+#ifdef _THREAD_SAFE
+/*
+ * For the thread_safe versions, we prepend _thread_sys_ to the function
+ * name so that the 'C' wrapper can go around the real name.
+ */
+# define SYSCALL(x)	__SYSCALL(_thread_sys_,x)
+# define RSYSCALL(x)	__RSYSCALL(_thread_sys_,x)
+# define PSEUDO(x,y)	__PSEUDO(_thread_sys_,x,y)
+# define SYSENTRY(x)	__ENTRY(_thread_sys_,x)
+# define PASSTHRU(x)	__PASSTHRU(_thread_sys_,x)
+#else _THREAD_SAFE
+/*
+ * The non-threaded library defaults to traditional syscalls where
+ * the function name matches the syscall name.
+ */
+# define SYSCALL(x)	__SYSCALL(,x)
+# define RSYSCALL(x)	__RSYSCALL(,x)
+# define PSEUDO(x,y)	__PSEUDO(,x,y)
+# define SYSENTRY(x)	__ENTRY(,x)
+#endif _THREAD_SAFE
 	.globl	cerror