Date: Wed, 13 Jul 2016 23:46:35 -0700 From: Mark Millard <markmi@dsl-only.net> To: Andrey Chernov <ache@freebsd.org> Cc: svn-src-head@freebsd.org, FreeBSD Current <freebsd-current@freebsd.org>, freebsd-stable@freebsd.org, freebsd-arm <freebsd-arm@freebsd.org>, FreeBSD PowerPC ML <freebsd-ppc@freebsd.org>, Bruce Evans <brde@optusnet.com.au>, FreeBSD Toolchain <freebsd-toolchain@freebsd.org> Subject: Re: svn commit: r302601 - in head/sys: arm/include arm64/include [clang 3.8.0: powerpc int instead of 32-bit SYSVR4's long and 64-bit ELF V2 long] Message-ID: <3DFF1DC9-2AE6-498A-9FE0-4970E76F8AB5@dsl-only.net> In-Reply-To: <a3f33812-1780-024e-4638-994c56e45c42@freebsd.org> References: <46153340-D2F4-48BD-B738-4792BC25FA3F@dsl-only.net> <b4d1b3d9-9577-3f89-c13e-8c46d1ddee95@freebsd.org> <38CF2C28-3BD1-4D09-939F-4DD0C2E8B58F@dsl-only.net> <a3f33812-1780-024e-4638-994c56e45c42@freebsd.org>
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On 2016-Jul-13, at 6:00 PM, Andrey Chernov <ache@freebsd.org> wrote: > On 13.07.2016 11:53, Mark Millard wrote: >> [The below does note that TARGET=3Dpowerpc has a mix of signed = wchar_t and unsigned char types and most architectures have both being = signed types.] >=20 > POSIX says nothing about wchar_t and char should be the same = (un)signed. > It is arm ABI docs may say so only. They are different entities > differently encoded and cross assigning between wchar_t and char is = not > recommended. [My "odd" would better have been the longer phrase "unusual for FreeBSD" = for the signed type mismatch point.] C11 (9899:2011[2012]) and C++11 (14882:2011(E)) agree with your POSIX = note: no constraint to have the same signed type status as char. But when I then looked at the "System V Application Binary Interface = PowerpC Processor Supplement" (1995-Sept SunSoft document) that I = believe FreeBSD uses for powerpc (32-bit only: TARGET_ARCH=3Dpowerpc) it = has: typedef long wchar_t; as part of: Figure 6-39 <stddef.h> (page labeled 6-38). While agreeing about the signed-type status for wchar_t this does not = agree with FreeBSD 11.0's use of int as the type: sys/powerpc/include/_types.h:typedef int ___wchar_t; sys/powerpc/include/_types.h:#define __WCHAR_MIN __INT_MIN = /* min value for a wchar_t */ sys/powerpc/include/_types.h:#define __WCHAR_MAX __INT_MAX = /* max value for a wchar_t */ # clang --target=3Dpowerpc-freebsd11 -std=3Dc99 -E -dM - < /dev/null | = more . . . #define __WCHAR_MAX__ 2147483647 #define __WCHAR_TYPE__ int #define __WCHAR_WIDTH__ 32 . . . I'm not as sure of which document is official for TARGET_ARCH=3Dpowerpc64 = but using "Power Architecture 64-bit ELF V2 ABI Specification" (Open = POWER ABI for Linux Supplement) as an example of what likely is common = for that context: 5.1.3 Types Defined in Standard header lists: typedef long wchar_t; which again does not agree with FreeBSD 11.0's use of int as the type: # clang --target=3Dpowerpc64-freebsd11 -std=3Dc99 -E -dM - < /dev/null = | more . . . #define __WCHAR_MAX__ 2147483647 #define __WCHAR_TYPE__ int #define __WCHAR_WIDTH__ 32 . . . =3D=3D=3D Mark Millard markmi at dsl-only.net >=20 > On 2016-Jul-11, at 8:57 PM, Andrey Chernov <ache at freebsd.org> = wrote: >=20 >> On 12.07.2016 5:44, Mark Millard wrote: >>> My understanding of the criteria for __WCHAR_MIN and __WCHAR_MAX: >>>=20 >>> A) __WCHAR_MIN and __WCHAR_MAX: same type as the integer promotion = of >>> ___wchar_t (if that is distinct). >>> B) __WCHAR_MIN is the low value for ___wchar_t as an integer type; = not >>> necessarily a valid char value >>> C) __WCHAR_MAX is the high value for ___wchar_t as an integer type; = not >>> necessarily a valid char value >>=20 >> It seems you are right about "not a valid char value", I'll back this >> change out. >>=20 >>> As far as I know arm FreeBSD uses unsigned character types (of = whatever >>> width). >>=20 >> Probably it should be unsigned for other architectures too, clang = does >> not generate negative values with L'<char>' literals and locale use = only >> positive values too. >=20 > Looking around: >=20 > # grep -i wchar sys/*/include/_types.h > sys/arm/include/_types.h:typedef unsigned int ___wchar_t; > sys/arm/include/_types.h:#define __WCHAR_MIN 0 = /* min value for a wchar_t */ > sys/arm/include/_types.h:#define __WCHAR_MAX __UINT_MAX = /* max value for a wchar_t */ > sys/arm64/include/_types.h:typedef unsigned int ___wchar_t; > sys/arm64/include/_types.h:#define __WCHAR_MIN 0 = /* min value for a wchar_t */ > sys/arm64/include/_types.h:#define __WCHAR_MAX __UINT_MAX = /* max value for a wchar_t */ > sys/mips/include/_types.h:typedef int ___wchar_t; > sys/mips/include/_types.h:#define __WCHAR_MIN __INT_MIN = /* min value for a wchar_t */ > sys/mips/include/_types.h:#define __WCHAR_MAX __INT_MAX = /* max value for a wchar_t */ > sys/powerpc/include/_types.h:typedef int ___wchar_t; > sys/powerpc/include/_types.h:#define __WCHAR_MIN __INT_MIN = /* min value for a wchar_t */ > sys/powerpc/include/_types.h:#define __WCHAR_MAX __INT_MAX = /* max value for a wchar_t */ > sys/riscv/include/_types.h:typedef int ___wchar_t; > sys/riscv/include/_types.h:#define __WCHAR_MIN __INT_MIN = /* min value for a wchar_t */ > sys/riscv/include/_types.h:#define __WCHAR_MAX __INT_MAX = /* max value for a wchar_t */ > sys/sparc64/include/_types.h:typedef int ___wchar_t; > sys/sparc64/include/_types.h:#define __WCHAR_MIN __INT_MIN = /* min value for a wchar_t */ > sys/sparc64/include/_types.h:#define __WCHAR_MAX __INT_MAX = /* max value for a wchar_t */ > sys/x86/include/_types.h:typedef int ___wchar_t; > sys/x86/include/_types.h:#define __WCHAR_MIN __INT_MIN = /* min value for a wchar_t */ > sys/x86/include/_types.h:#define __WCHAR_MAX __INT_MAX = /* max value for a wchar_t */ >=20 > So only arm and arm64 have unsigned wchar_t types. >=20 > [NOTE: __CHAR16_TYPE__ and __CHAR32_TYPE__ are always unsigned: in = C++11 terms char16_t is like std::uint_least16_t and char32_t is like = std::uint_least32_t despite being distinct types. So __CHAR16_TYPE__ and = __CHAR32_TYPE__ are ignored below.] >=20 > The clang 3.8.0 compiler output has an odd mix for TARGET_ARCH=3Dpowerpc= and TARGET_ARCH=3Dpowerpc64 . . . >=20 > armv6 has unsigned types for both char and __WCHAR_TYPE__. > aarch64 has unsigned types for both char and __WCHAR_TYPE__. > powerpc has unsigned for char but signed for __WCHAR_TYPE__. > powerpc64 has unsigned for char but signed for __WCHAR_TYPE__. > amd64 has signed types for both char and __WCHAR_TYPE__. > i386 has signed types for both char and __WCHAR_TYPE__. > mips has signed types for both char and __WCHAR_TYPE__. > sparc64 has signed types for both char and __WCHAR_TYPE__. > (riscv is not covered by clang as I understand) >=20 > The details via compiler #define's. . . >=20 > # clang --target=3Darmv6-freebsd11 -std=3Dc99 -E -dM - < /dev/null | = more > . . . > #define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__ > . . . > #define __CHAR_BIT__ 8 > #define __CHAR_UNSIGNED__ 1 > . . . > #define __WCHAR_MAX__ 4294967295U > #define __WCHAR_TYPE__ unsigned int > #define __WCHAR_UNSIGNED__ 1 > #define __WCHAR_WIDTH__ 32 > . . . >=20 > # clang --target=3Daarch64-freebsd11 -std=3Dc99 -E -dM - < /dev/null = | more > . . . > #define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__ > . . . > #define __CHAR_BIT__ 8 > #define __CHAR_UNSIGNED__ 1 > . . . > #define __WCHAR_MAX__ 4294967295U > #define __WCHAR_TYPE__ unsigned int > #define __WCHAR_UNSIGNED__ 1 > #define __WCHAR_WIDTH__ 32 > . . . >=20 > # clang --target=3Dpowerpc-freebsd11 -std=3Dc99 -E -dM - < /dev/null = | more > . . . > #define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__ > . . . > #define __CHAR_BIT__ 8 > #define __CHAR_UNSIGNED__ 1 > . . . > #define __WCHAR_MAX__ 2147483647 > #define __WCHAR_TYPE__ int > #define __WCHAR_WIDTH__ 32 > . . . (note the lack of __WCHAR_UNSIGNED__) . . . >=20 > Is powerpc wrong? >=20 > # clang --target=3Dpowerpc64-freebsd11 -std=3Dc99 -E -dM - < = /dev/null | more > . . . > #define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__ > . . . > #define __CHAR_BIT__ 8 > #define __CHAR_UNSIGNED__ 1 > . . . > #define __WCHAR_MAX__ 2147483647 > #define __WCHAR_TYPE__ int > #define __WCHAR_WIDTH__ 32 > . . . (note the lack of __WCHAR_UNSIGNED__) . . . >=20 > Is powerpc64 wrong? >=20 >=20 > # clang --target=3Damd64-freebsd11 -std=3Dc99 -E -dM - < /dev/null | = more > . . . > #define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__ > . . . > #define __CHAR_BIT__ 8 > . . . (note the lack of __CHAR_UNSIGNED__) . . . >=20 > #define __WCHAR_MAX__ 2147483647 > #define __WCHAR_TYPE__ int > #define __WCHAR_WIDTH__ 32 > . . . (note the lack of __WCHAR_UNSIGNED__) . . . >=20 > # clang --target=3Di386-freebsd11 -std=3Dc99 -E -dM - < /dev/null | = more > . . . > #define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__ > . . . > #define __CHAR_BIT__ 8 > . . . (note the lack of __CHAR_UNSIGNED__) . . . >=20 > #define __WCHAR_MAX__ 2147483647 > #define __WCHAR_TYPE__ int > #define __WCHAR_WIDTH__ 32 > . . . (note the lack of __WCHAR_UNSIGNED__) . . . >=20 >=20 > # clang --target=3Dmips-freebsd11 -std=3Dc99 -E -dM - < /dev/null | = more > . . . > #define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__ > . . . > #define __CHAR_BIT__ 8 > . . . (note the lack of __CHAR_UNSIGNED__) . . . >=20 > #define __WCHAR_MAX__ 2147483647 > #define __WCHAR_TYPE__ int > #define __WCHAR_WIDTH__ 32 > . . . (note the lack of __WCHAR_UNSIGNED__) . . . >=20 > # clang --target=3Dsparc64-freebsd11 -std=3Dc99 -E -dM - < /dev/null = | more > . . . > #define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__ > . . . > #define __CHAR_BIT__ 8 > . . . (note the lack of __CHAR_UNSIGNED__) . . . >=20 > #define __WCHAR_MAX__ 2147483647 > #define __WCHAR_TYPE__ int > #define __WCHAR_WIDTH__ 32 > . . . (note the lack of __WCHAR_UNSIGNED__) . . . >=20 >=20 >=20 > =3D=3D=3D > Mark Millard > markmi at dsl-only.net >=20
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