ssize_t [patch]

[Zack Weinberg]

On Tue, Apr 25, 2000 at 02:35:04PM -0400, Kaveh R. Ghazi wrote:
>  > From: Zack Weinberg <zack@wolery.cumb.org>
>  > 
>  > ssize_t is the return type of read().  What does read return on your
>  > SunOS box?
> 
> int

Then I'd better make it default to int.

AC_CHECK_TYPE doesn't autogenerate config.h.in entries... how lame.

>  > This looks good.  Do you want me to put in just the minimum amount of
>  > glue for what I need to do, or provide a wider set of these, as sys2.h
>  > does?
>  > zw
> 
> IMHO TYPE_MAXIMUM, and the macros it calls, are enough.

which is TYPE_MINIMUM and TYPE_SIGNED.  Right.

> We probably don't need all the fallback *_MIN/*_MAX defaults unless
> somebody has a platform which complains.  I don't think we really use
> any of these anywhere yet in gcc anyway, except INT_MAX.

Sounds good to me.

Here is a patch which provides (a) a default definition of ssize_t;
(b) SSIZE_MAX and UCHAR_MAX definitions in system.h; (c) the
infrastructure to define more _MAX/_MIN macros should we need them.
cpplib is already using UCHAR_MAX, and will need ssize_t/SSIZE_MAX
shortly (as in this week).  Ok to commit?

zw

	* configure.in: Add check for ssize_t.
	* acconfig.h: Add template for ssize_t.  Remove @TOP@, put
	@BOTTOM@ before all the NEED_DECLARATION_* macros.
	* system.h: Add TYPE_MAXIMUM, TYPE_MINIMUM, TYPE_SIGNED
	macros.  Provide default definitions of UCHAR_MAX and
	SSIZE_MAX.
	* cpplex.c: Remove default definition of UCHAR_MAX.

===================================================================
Index: configure.in
--- configure.in	2000/04/25 20:30:14	1.361
+++ configure.in	2000/04/25 21:04:14
@@ -431,6 +431,11 @@ AC_CHECK_FUNCS(strtoul bsearch putenv po
 # Make sure wchar_t is available
 #AC_CHECK_TYPE(wchar_t, unsigned int)
 
+# The default for this is int, because the default for size_t is 
+# unsigned int; also, historical systems (SunOS 4) that didn't have
+# ssize_t used int in its place.
+AC_CHECK_TYPE(ssize_t, int)
+
 gcc_AC_FUNC_VFPRINTF_DOPRNT
 gcc_AC_FUNC_PRINTF_PTR
 
===================================================================
Index: acconfig.h
--- acconfig.h	2000/04/25 20:30:14	1.47
+++ acconfig.h	2000/04/25 21:04:14
@@ -23,6 +23,13 @@
 /* Define as 1 if you have the stpcpy function.  */
 #undef HAVE_STPCPY
 
+/* Define to `int' if <sys/types.h> doesn't define.  */
+#undef ssize_t
+
+/* autoheader does not understand GCC_NEED_DECLARATION[S].  Put all
+   NEED_DECLARATION_foobar entries _after_ the BOTTOM marker.  Put all
+   other entries _before_ it.  */
+@BOTTOM@
 /* Whether malloc must be declared even if <stdlib.h> is included.  */
 #undef NEED_DECLARATION_MALLOC
 
@@ -94,5 +101,3 @@
 
 /* Whether environ must be declared.  */
 #undef NEED_DECLARATION_ENVIRON
-
-@TOP@
===================================================================
Index: system.h
--- system.h	2000/04/25 11:21:13	1.65
+++ system.h	2000/04/25 21:04:14
@@ -236,6 +236,25 @@ extern int errno;
 # endif /* defined(HOST_BITS_PER_LONG) && defined(HOST_BITS_PER_LONGLONG) */
 #endif /* ! HOST_WIDEST_INT */
 
+/* Capability for creating _MAX and _MIN macros if they do not already
+   exist.  Currently we only need SSIZE_MAX and UCHAR_MAX, but... */
+
+/* The extra casts work around common compiler bugs.  */
+#define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
+/* The outer cast is needed to work around a bug in Cray C 5.0.3.0.
+   It is necessary at least when t == time_t.  */
+#define TYPE_MINIMUM(t) ((t) (TYPE_SIGNED (t) \
+			      ? ~ (t) 0 << (sizeof(t) * CHAR_BIT - 1) : (t) 0))
+#define TYPE_MAXIMUM(t) ((t) (~ (t) 0 - TYPE_MINIMUM (t)))
+
+#ifndef UCHAR_MAX
+#define UCHAR_MAX TYPE_MAXIMUM (unsigned char)
+#endif
+
+#ifndef SSIZE_MAX
+#define SSIZE_MAX TYPE_MAXIMUM (ssize_t)
+#endif
+
 #ifdef TIME_WITH_SYS_TIME
 # include <sys/time.h>
 # include <time.h>
Index: cpplex.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/cpplex.c,v
retrieving revision 1.25
diff -u -p -r1.25 cpplex.c
--- cpplex.c	2000/04/25 19:32:36	1.25
+++ cpplex.c	2000/04/25 21:04:17
@@ -1729,10 +1729,6 @@ find_position (start, limit, linep)
    designated initializers, it can be constant data; otherwise, it is
    set up at runtime by _cpp_init_input_buffer.  */
 
-#ifndef UCHAR_MAX
-#define UCHAR_MAX 255	/* assume 8-bit bytes */
-#endif
-
 #if (GCC_VERSION >= 2007) || (__STDC_VERSION__ >= 199901L)
 #define init_chartab()  /* nothing */
 #define CHARTAB static const unsigned char chartab[UCHAR_MAX + 1] = {