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[PATCH 03/25] sys/types.h: Don’t define u_intN_t or register_t unless __USE_MISC.
- From: Zack Weinberg <zackw at panix dot com>
- To: libc-alpha at sourceware dot org
- Cc: joseph at codesourcery dot com, carlos at redhat dot com
- Date: Wed, 26 Jun 2019 13:49:48 -0400
- Subject: [PATCH 03/25] sys/types.h: Don’t define u_intN_t or register_t unless __USE_MISC.
- References: <20190626174954.8009-1-zackw@panix.com>
sys/types.h unconditionally defines u_int8_t, u_int16_t, u_int32_t,
u_int64_t, and register_t. These are not part of any standard. The
u_intXX_t types are superseded by C99’s uintXX_t types (defined in
stdint.h). I’m not aware of a standardized exact equivalent of
register_t, but also I’ve never seen anyone use it for anything.
I could be persuaded to leave that one alone.
sys/types.h also unconditionally defines int8_t, int16_t, int32_t, and
int64_t, which are the same as the C99 exact-width signed types in
stdint.h. POSIX doesn’t require these to appear in sys/types.h, so in
principle they ought to be brought under __USE_MISC also. But, when I
tried that it broke about two dozen files just in our own source tree,
and POSIX doesn’t *forbid* sys/types.h to define these types, so I
think we should leave them alone.
* posix/sys/types.h (u_int8_t, u_int16_t, u_int32_t, u_int64_t)
(register_t): Move under #ifdef __USE_MISC.
Consolidate adjacent #ifdef __USE_MISC blocks.
* scripts/check_obsolete_constructs.py: Add register_t to the
set of obsolete typedefs that our headers should not use
(but sys/types.h may still define).
---
NEWS | 8 ++++++++
posix/sys/types.h | 16 ++++++++--------
scripts/check-obsolete-constructs.py | 1 +
3 files changed, 17 insertions(+), 8 deletions(-)
diff --git a/NEWS b/NEWS
index 8a2fecef47..edf7739293 100644
--- a/NEWS
+++ b/NEWS
@@ -45,6 +45,14 @@ Deprecated and removed features, and other changes affecting compatibility:
* The obsolete and never-implemented XSI STREAMS header files <stropts.h>
and <sys/stropts.h> have been removed.
+* The typedefs u_int8_t, u_int16_t, u_int32_t, u_int64_t, and register_t
+ are no longer defined by <sys/types.h> in strict conformance modes.
+ These types were historically provided by <sys/types.h> on BSD systems,
+ but are not part of the POSIX specification for that header. Applications
+ requiring fixed-width unsigned integer types should use the similarly
+ named uint8_t, uint16_t, etc. from <stdint.h>. There is no standardized
+ replacement for register_t.
+
* Support for the "inet6" option in /etc/resolv.conf and the RES_USE_INET6
resolver flag (deprecated in glibc 2.25) have been removed.
diff --git a/posix/sys/types.h b/posix/sys/types.h
index 1bbd896ad4..7327904346 100644
--- a/posix/sys/types.h
+++ b/posix/sys/types.h
@@ -143,18 +143,20 @@ typedef __suseconds_t suseconds_t;
#define __need_size_t
#include <stddef.h>
+/* POSIX does not require intN_t to be defined in this header, so
+ technically this ought to be under __USE_MISC, but it doesn't
+ forbid them to be defined here either, and much existing code
+ expects them to be defined here. */
+#include <bits/stdint-intn.h>
+
#ifdef __USE_MISC
/* Old compatibility names for C types. */
typedef unsigned long int ulong;
typedef unsigned short int ushort;
typedef unsigned int uint;
-#endif
-/* These size-specific names are used by some of the inet code. */
-
-#include <bits/stdint-intn.h>
-
-/* These were defined by ISO C without the first `_'. */
+/* These size-specific names are used by some of the inet code.
+ They were defined by ISO C without the first `_'. */
typedef __uint8_t u_int8_t;
typedef __uint16_t u_int16_t;
typedef __uint32_t u_int32_t;
@@ -167,8 +169,6 @@ typedef __register_t register_t;
defined. */
#define __BIT_TYPES_DEFINED__ 1
-
-#ifdef __USE_MISC
/* In BSD <sys/types.h> is expected to define BYTE_ORDER. */
# include <endian.h>
diff --git a/scripts/check-obsolete-constructs.py b/scripts/check-obsolete-constructs.py
index 89d21dea6e..4dc52761c5 100755
--- a/scripts/check-obsolete-constructs.py
+++ b/scripts/check-obsolete-constructs.py
@@ -254,6 +254,7 @@ class NoCheck(ConstructChecker):
OBSOLETE_TYPE_RE_ = re.compile(r"""\A
(__)?
( quad_t
+ | register_t
| u(?: short | int | long
| _(?: char | short | int(?:[0-9]+_t)? | long | quad_t )))
\Z""", re.VERBOSE)
--
2.20.1