HACKS revision 1.16 
1# $NetBSD: HACKS,v 1.16 2003/10/28 02:01:46 cl Exp $
2#
3# This file is intended to document workarounds for currently unsolved
4# (mostly) compiler bugs.
5#
6# Format:
7#   hack		title
8#   cdate		creation date
9#   mdate		mod date
10#   who			responsible developer
11#   port		...
12#  	  affected ports, space separated, if not "all"
13#   file		affected file : revision : line from : line to
14#  	  affected files and revision and line numbers describing hack
15#  	  multiple lines if necessary.
16#   pr			NNNN ...
17#  	  problem reports this hack works around, if known. Space
18#  	  separated.
19#   regress		src/regress/directory/where/test/found
20#  	  regression test directories, if available.
21#   descr
22#  	  insert short informal description (multi-line). (Longer ones
23#  	  should be in the PR database. More formal descriptions might
24#  	  be in the regress tree. See above).
25#   kcah
26#  	  closing bracket.
27#
28# this is a comment.
29
30hack	gcc 2.95/vax cannot handle __builtin_ffs()
31cdate	Fri Aug 23 21:31:15 CEST 2002
32who	ragge
33port	vax
34file	sys/lib/libkern/libkern.h : 1.42
35descr
36	__builtin_ffs() is ifdef'd away if __vax__. Matt Thomas has added
37	this feature to GCC 3 so it can be removed when switching.
38kcah
39
40hack	binutil-2.11-sparc64-pltrela
41mdate	14 Aug 2001
42who	eeh
43port	sparc64
44file	libexec/ld.elf_so/reloc.c: 1.41 : 597 : 619
45descr
46	The first for PLT entries are reserved.  There is some disagreement
47	whether they should have associated relocation entries.  Both the
48	SPARC 32-bit and 64-bit ELF specifications say that they should have
49	relocation entries, but the 32-bit SPARC binutils do not generate
50	them, and now the 64-bit SPARC binutils have stopped generating them
51	too.
52
53	To provide binary compatibility, we will check the first entry, if it
54	is reserved it should not be of the type JMP_SLOT.  If it is JMP_SLOT,
55	then the 4 reserved entries were not generated and our index is 4
56	entries too far, so we frob the rela pointer.
57kcah
58
59hack	netstat ieee1394 address printing.
60mdate	14 Nov 2000
61who	matt
62file	lib/libc/net/getnameinfo.c	: 1.32 : 497 : 503
63descr
64	Because the current implementation of IP over IEEE1394, the
65	fw device address contains more than just the IEEE1394 EUI-64.
66	So when printing out IEEE1394 addresses, ignore the extra stuff.
67kcah
68
69hack	xterm vs. libterm
70mdate	01 Aug 2000
71who	jdc
72file	xsrc/xc/programs/xterm/main.c	: 1.2 : 3609 : 3614
73pr	10383
74descr
75	In order to extend the termcap string over 1023 bytes, a ZZ entry was
76	introduced to point to a memory location containing the full entry.
77	Without this hack, xterm will export a termcap containing the ZZ
78	entry, which will then be ignored by libterm.  As xterm modifies the
79	exported termcap, this would cause those modifications to be ignored.
80kcah
81
82hack	gcc-sh3-sed
83mdate	23 Apr 2002
84who	thorpej
85file	usr.bin/sed/Makefile	: 1.9 : 9 : 13
86descr
87	The in-tree GCC 2.95.3-based compiler ICEs when building
88	with optimization for SuperH.  Hack is to biuld with -O0.
89kcah
90
91hack	gcc-unsigned-compare
92cdate	09 Mar 2002
93mdate	18 Mar 2002
94who	bjh21
95port	arm
96file	dist/bind/lib/nameser/ns_parse.c : 1.3
97file	dist/dhcp/minires/ns_parse.c : 1.3
98file	dist/dhcp/omapip/result.c : 1.2
99file	dist/dhcp/server/failover.c : 1.3
100file	gnu/dist/gawk/eval.c : 1.4
101file	gnu/dist/toolchain/bfd/bfd.c : 1.2
102file	gnu/dist/toolchain/bfd/format.c : 1.2
103file	gnu/dist/toolchain/gdb/target.c : 1.2
104file	sys/kern/vfs_subr.c : 1.172
105descr	When checking that a potentially-unsigned enum is >= 0, assign it
106	to an int first.  This is necessary to avoid "comparison is always
107	true" warnings with -fshort-enums.  Casting to an int really should
108	be enough, but turns out not to be.
109kcah
110
111hack	wi-at-big-endian-bus
112cdate	15 Mar 2002
113who	martin
114file	dev/ic/wireg.h
115descr	Add an option to access the underlying bus in big endian byte order
116	to work around deficiencies in bus_space_{read,write}_* macros.
117	Those don't allow the implementation of a proper pcmcia bus space
118	tag.
119kcah
120
121hack	gcc-vax-libbz2
122mdate	27 Jun 2002
123who	thorpej
124port	vax
125file	lib/libbz2/Makefile
126descr
127	libbz2 is mis-compiled with optimization with GCC 2.95.3
128	on VAX.  -O0 works around this problem.
129kcah
130
131hack	egcs-pc532-ip6_mroute
132cdate	09 Jul 2002
133who	simonb
134port	pc532
135file	sys/arch/pc532/conf/Makefile.pc532 : 1.70
136file	sys/arch/pc532/conf/files.pc532 : 1.47
137descr
138	egcs 1.1.2 gets an "internal error--insn does not satisfy its
139	constraints" error compiling ip6_mroute.c with -O2 or greater.
140	-O1 works around this problem.
141kcah
142
143hack	SuperH SH5 Toolchain Bugs
144cdate	11 Jul 2002
145who	scw
146port	sh5
147file	usr.sbin/ndbootd/ndbootd.c : 1.6
148file	usr.sbin/traceroute/traceroute.c : 1.48
149descr
150	The SuperH SH5 toolchain (2.97-sh5-010522) gets an internal
151	compiler error when assigning a bit-wise inverted value
152	under some circumstances.
153	Work around it by splitting the statement into two.
154kcah
155
156hack	vax Toolchain bug
157cdate	28 Mar 2003
158who	he
159port	vax
160file	sys/arch/vax/vax/intvec.S : 1.5
161descr
162	Workaround for PR toolchain/20924.  The assembler apparently
163	tries to range-check byte offsets when it doesn't have
164	sufficient information to make that decision.
165	Workaround uses `brw' instead of `brb' instruction.
166kcah
167
168hack	specific knowledge of colours in curses code
169cdate	Sun Apr  6 11:05:24 BST 2003
170who	jdc
171port	all
172file	lib/libcurses/color.c : r1.24
173descr
174	Swap red/blue and yellow/cyan colours for COLOR_OTHER.
175	Fix is to enhance libtermcap to understand terminfo-style % sequences.
176	See also:
177	    http://mail-index.NetBSD.org/tech-userlevel/2003/04/06/0000.html
178kcah
179
180hack	SuperH SH5 Toolchain Bugs
181cdate	17 May 2003
182who	scw
183port	sh5
184file	lib/libpthread/pthread_lock.c : 1.7
185descr
186	The SuperH SH5 toolchain generates incorrect PIC code when faced
187	with a symbol which is declared extern, but has local scope due
188	to being defined within an asm() statement (without being declared
189	.globl in that statement). Work around it by adding the .globl.
190kcah
191
192hack	Compensation for differing types of LINUX_USRSTACK and USRSTACK
193cdate	21 Aug 2003
194who	he
195file	sys/miscfs/procfs/procfs_linux.c : 1.14
196descr
197	Not all ports have LINUX_USRSTACK and/or USRSTACK defined as
198	literals/constants, but refer to variables of a type which is
199	not "unsigned long", causing compilation of procfs_linux.c to
200	fail with "makes integer from pointer without a cast".  This
201	is observed on e.g. the sun3 port.  Ideally the "types" for
202	symbols should be consistent across all ports.
203kcah
204
205hack	gcc 3.3.x bug
206cdate	Sun Oct 26 01:50:16 UTC 2003
207who	lukem
208port	MACHINE_ARCH == arm
209file	usr.bin/newsyslog/newsyslog.c
210pr	22986 23002 23217
211descr
212	newsyslog fails with
213		newsyslog: config line 7: bad flags
214	solved when compiled with -fno-gcse-lm
215kcah
216
217hack	gcc-pc532-duffs_device
218cdate	Mon Oct 27 07:23:05 UTC 2003
219who	simonb
220port	pc532
221file	sys/arch/pc532/conf/Makefile.pc532 : 1.71
222file	sys/arch/pc532/conf/files.pc532 : 1.52
223pr	GCC PR optimization/5230
224descr
225	gcc incorrectly gives an "unreachable code at beginning of switch
226	statement" for a Duff's device construct in arch/pc532/dev/ncr.c.
227	There is no way to disable just this warning, so -Wno-error is
228	turned on for this file.
229kcah
230
231hack	gcc 3.3.2 m68k {u,}int64_t uninitialized bug
232cdate	Tue Oct 28 02:46:46 CET 2003
233who	cl
234port	MACHINE_ARCH == m68k
235file	sys/dev/scsipi/sd.c : 1.212 : 686
236file	sys/dev/ata/wd.c : 1.265 : 483
237file	sys/nfs/nfs_serv.c : 1.84 : 3290
238descr
239	gcc incorrectly reports {u,}int64_t variables as used uninitialized.
240	Work around by adding explicit initializers.
241	gcc bug report at http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12792
242kcah
243