xref: /titanic_41/usr/src/lib/README.Makefiles (revision f808c858fa61e7769218966759510a8b1190dfcf)
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27
28Writing Library Makefiles in ON
29===============================
30
31Introduction
32------------
33
34This document guides you through the gnarly process of writing library
35Makefiles for the ON consolidation.  It assumes that you're comfortable with
36make(1) and are somewhat familiar with the ON Makefile standards outlined in
37/shared/ON/general_docs/make_std.txt.
38
39Makefile Overview
40-----------------
41
42Your library should consist of a hierarchical collection of Makefiles:
43
44	lib/<library>/Makefile:
45
46	  This is your library's top-level Makefile.  It should contain rules
47	  for building any ISA-independent targets, such as installing header
48	  files and building message catalogs, but should defer all other
49	  targets to ISA-specific Makefiles.
50
51	lib/<library>/Makefile.com
52
53	  This is your library's common Makefile.  It should contain rules
54	  and macros which are common to all ISAs. This Makefile should never
55	  be built explicitly, but instead should be included (using the make
56	  include mechanism) by all of your ISA-specific Makefiles.
57
58	lib/<library>/<isa>/Makefile
59
60	  These are your library's ISA-specific Makefiles, one per ISA
61	  (usually sparc and i386, and often sparcv9 and amd64).  These
62	  Makefiles should include your common Makefile and then provide any
63	  needed ISA-specific rules and definitions, perhaps overriding those
64	  provided in your common Makefile.
65
66To simplify their maintenance and construction, $(SRC)/lib has a handful of
67provided Makefiles that yours must include; the examples provided throughout
68the document will show how to use them.  Please be sure to consult these
69Makefiles before introducing your own custom build macros or rules.
70
71	lib/Makefile.lib:
72
73	  This contains the bulk of the macros for building shared objects.
74
75	lib/Makefile.lib.64
76
77	  This contains macros for building 64-bit objects, and should be
78	  included in Makefiles for 64-bit native ISAs.
79
80	lib/Makefile.rootfs
81
82	  This contains macro overrides for libraries that install into /lib
83	  (rather than /usr/lib).
84
85	lib/Makefile.targ
86
87	  This contains rules for building shared objects.
88
89The remainder of this document discusses how to write each of your Makefiles
90in detail, and provides examples from the libinetutil library.
91
92The Library Top-level Makefile
93------------------------------
94
95As described above, your top-level library Makefile should contain
96rules for building ISA-independent targets, but should defer the
97building of all other targets to ISA-specific Makefiles.  The
98ISA-independent targets usually consist of:
99
100	install_h
101
102	  Install all library header files into the proto area.
103	  Can be omitted if your library has no header files.
104
105	check
106
107	  Check all library header files for hdrchk compliance.
108	  Can be omitted if your library has no header files.
109
110	_msg
111
112	  Build and install a message catalog.
113	  Can be omitted if your library has no message catalog.
114
115Of course, other targets (such as `cstyle') are fine as well, as long as
116they are ISA-independent.
117
118The ROOTHDRS and CHECKHDRS targets are provided in lib/Makefile.lib to make
119it easy for you to install and check your library's header files.  To use
120these targets, your Makefile must set the HDRS to the list of your library's
121header files to install and HDRDIR to the their location in the source tree.
122In addition, if your header files need to be installed in a location other
123than $(ROOT)/usr/include, your Makefile must also set ROOTHDRDIR to the
124appropriate location in the proto area.  Once HDRS, HDRDIR and (optionally)
125ROOTHDRDIR have been set, your Makefile need only contain
126
127	  install_h: $(ROOTHDRS)
128
129	  check: $(CHECKHDRS)
130
131to bind the provided targets to the standard `install_h' and `check' rules.
132
133Similar rules are provided (in $(SRC)/Makefile.msg.targ) to make it easy for
134you to build and install message catalogs from your library's source files.
135
136To install a catalog into the catalog directory in the proto area, define the
137POFILE macro to be the name of your catalog, and specify that the _msg target
138depends on $(MSGDOMAINPOFILE).  The examples below should clarify this.
139
140To build a message catalog from arbitrarily many message source files, use
141the BUILDPO.msgfiles macro.
142
143	  include ../Makefile.lib
144
145	  POFILE =	  libfoo.po
146	  MSGFILES =	  $(OBJECTS:%.o=%.i)
147
148	  # ...
149
150	  $(POFILE): $(MSGFILES)
151		$(BUILDPO.msgfiles)
152
153	  _msg: $(MSGDOMAINPOFILE)
154
155	  include $(SRC)/Makefile.msg.targ
156
157Note that this example doesn't use grep to find message files, since that can
158mask unreferenced files, and potentially lead to the inclusion of unwanted
159messages or omission of intended messages in the catalogs.  As such, MSGFILES
160should be derived from a known list of objects or sources.
161
162It is usually preferable to run the source through the C preprocessor prior
163to extracting messages.  To do this, use the ".i" suffix, as shown in the
164above example.  If you need to skip the C preprocessor, just use the native
165(.[ch]) suffix.
166
167The only time you shouldn't use BUILDPO.msgfiles as the preferred means of
168extracting messages is when you're extracting them from shell scripts; in
169that case, you can use the BUILDPO.pofiles macro as explained below.
170
171To build a message catalog from other message catalogs, or from source files
172that include shell scripts, use the BUILDPO.pofiles macro:
173
174	  include ../Makefile.lib
175
176	  SUBDIRS =	  $(MACH)
177
178	  POFILE =	  libfoo.po
179	  POFILES =	  $(SUBDIRS:%=%/_%.po)
180
181	  _msg :=	  TARGET = _msg
182
183	  # ...
184
185	  $(POFILE): $(POFILES)
186		$(BUILDPO.pofiles)
187
188	  _msg: $(MSGDOMAINPOFILE)
189
190	  include $(SRC)/Makefile.msg.targ
191
192The Makefile above would work in conjunction with the following in its
193subdirectories' Makefiles:
194
195	  POFILE =	  _thissubdir.po
196	  MSGFILES =	  $(OBJECTS:%.o=%.i)
197
198	  $(POFILE):	  $(MSGFILES)
199		  $(BUILDPO.msgfiles)
200
201	  _msg:		  $(POFILE)
202
203	  include $(SRC)/Makefile.msg.targ
204
205Since this POFILE will be combined with those in other subdirectories by the
206parent Makefile and that merged file will be installed into the proto area
207via MSGDOMAINPOFILE, there is no need to use MSGDOMAINPOFILE in this Makefile
208(in fact, using it would lead to duplicate messages in the catalog).
209
210When using any of these targets, keep in mind that other macros, like
211XGETFLAGS and TEXT_DOMAIN may also be set in your Makefile to override or
212augment the defaults provided in higher-level Makefiles.
213
214As previously mentioned, you should defer all ISA-specific targets to your
215ISA-specific Makefiles.  You can do this by:
216
217	1. Setting SUBDIRS to the list of directories to descend into:
218
219		SUBDIRS = $(MACH)
220
221	   Note that if your library is also built 64-bit, then you should
222	   also specify
223
224		$(BUILD64)SUBDIRS += $(MACH64)
225
226	   so that SUBDIRS contains $(MACH64) if and only if you're compiling
227	   on a 64-bit ISA.
228
229	2. Providing a common "descend into SUBDIRS" rule:
230
231		$(SUBDIRS): FRC
232			@cd $@; pwd; $(MAKE) $(TARGET)
233
234		FRC:
235
236	3. Providing a collection of conditional assignments that set TARGET
237	   appropriately:
238
239		all	:= TARGET= all
240		clean	:= TARGET= clean
241		clobber := TARGET= clobber
242		install := TARGET= install
243		lint	:= TARGET= lint
244
245	   The order doesn't matter, but alphabetical is preferable.
246
247	4. Having the aforementioned targets depend on SUBDIRS:
248
249		all clean clobber install lint: $(SUBDIRS)
250
251	   The `all' target must be listed first so that make uses it as the
252	   default target; the others might as well be listed alphabetically.
253
254As an example of how all of this goes together, here's libinetutil's
255top-level library Makefile (license notice and copyright omitted):
256
257	include ../Makefile.lib
258
259	HDRS =		libinetutil.h
260	HDRDIR =	common
261	SUBDIRS =	$(MACH)
262	$(BUILD64)SUBDIRS += $(MACH64)
263
264	all :=		TARGET = all
265	clean :=	TARGET = clean
266	clobber :=	TARGET = clobber
267	install :=	TARGET = install
268	lint :=		TARGET = lint
269
270	.KEEP_STATE:
271
272	all clean clobber install lint: $(SUBDIRS)
273
274	install_h:	$(ROOTHDRS)
275
276	check:		$(CHECKHDRS)
277
278	$(SUBDIRS): FRC
279		@cd $@; pwd; $(MAKE) $(TARGET)
280
281	FRC:
282
283	include ../Makefile.targ
284
285The Common Makefile
286-------------------
287
288In concept, your common Makefile should contain all of the rules and
289definitions that are the same on all ISAs.  However, for reasons of
290maintainability and cleanliness, you're encouraged to place even
291ISA-dependent rules and definitions, as long you express them in an
292ISA-independent way (e.g., by using $(MACH), $(TARGETMACH), and their kin).
293(TARGETMACH is the same as MACH for 32-bit targets, and the same as MACH64
294for 64-bit targets).
295
296The common Makefile can be conceptually split up into four sections:
297
298	1. A copyright and comments section.  Please see the prototype
299	   files in usr/src/prototypes for examples of how to format the
300	   copyright message properly.  For brevity and clarity, this
301	   section has been omitted from the examples shown here.
302
303	2. A list of macros that must be defined prior to the inclusion of
304	   Makefile.lib.  This section is conceptually terminated by the
305	   inclusion of Makefile.lib, followed, if necessary, by the
306	   inclusion of Makefile.rootfs (only if the library is to be
307	   installed in /lib rather than the default /usr/lib).
308
309	3. A list of macros that need not be defined prior to the inclusion
310	   of Makefile.lib (or which must be defined following the inclusion
311	   of Makefile.lib, to override or augment its definitions).  This
312	   section is conceptually terminated by the .KEEP_STATE directive.
313
314	4. A list of targets.
315
316The first section is self-explanatory.  The second typically consists of the
317following macros:
318
319	LIBRARY
320
321	  Set to the name of the static version of your library, such
322	  as `libinetutil.a'.  You should always specify the `.a' suffix,
323	  since pattern-matching rules in higher-level Makefiles rely on it,
324	  even though static libraries are not normally built in ON, and
325	  are never installed in the proto area.  Note that the LIBS macro
326	  (described below) controls the types of libraries that are built
327	  when building your library.
328
329	  If you are building a loadable module (i.e., a shared object that
330	  is only linked at runtime with dlopen(3dl)), specify the name of
331	  the loadable module with a `.a' suffix, such as `devfsadm_mod.a'.
332
333	VERS
334
335	  Set to the version of your shared library, such as `.1'.  You
336	  actually do not need to set this prior to the inclusion of
337	  Makefile.lib, but it is good practice to do so since VERS and
338	  LIBRARY are so closely related.
339
340	OBJECTS
341
342	  Set to the list of object files contained in your library, such as
343	  `a.o b.o'.  Usually, this will be the same as your library's source
344	  files (except with .o extensions), but if your library compiles
345	  source files outside of the library directory itself, it will
346	  differ.  We'll see an example of this with libinetutil.
347
348The third section typically consists of the following macros:
349
350	LIBS
351
352	  Set to the list of the types of libraries to build when building
353	  your library.  For dynamic libraries, you should set this to
354	  `$(DYNLIB) $(LINTLIB)' so that a dynamic library and lint library
355	  are built.  For loadable modules, you should just list DYNLIB,
356	  since there's no point in building a lint library for libraries
357	  that are never linked at compile-time.
358
359	  If your library needs to be built as a static library (typically
360	  to be used in other parts of the build), you should set LIBS to
361	  `$(LIBRARY)'.  However, you should do this only when absolutely
362	  necessary, and you must *never* ship static libraries to customers.
363
364	ROOTLIBDIR (if your library installs to a nonstandard directory)
365
366	  Set to the directory your 32-bit shared objects will install into
367	  with the standard $(ROOTxxx) macros.  Since this defaults to
368	  $(ROOT)/usr/lib ($(ROOT)/lib if you included Makefile.rootfs),
369	  you usually do not need to set this.
370
371	ROOTLIBDIR64 (if your library installs to a nonstandard directory)
372
373	  Set to the directory your 64-bit shared objects will install into
374	  with the standard $(ROOTxxx64) macros.  Since this defaults to
375	  $(ROOT)/usr/lib/$(MACH64) ($(ROOT)/lib/$(MACH64) if you included
376	  Makefile.rootfs), you usually do not need to set this.
377
378	SRCDIR
379
380	  Set to the directory containing your library's source files, such
381	  as `../common'.  Because this Makefile is actually included from
382	  your ISA-specific Makefiles, make sure you specify the directory
383	  relative to your library's <isa> directory.
384
385	SRCS (if necessary)
386
387	  Set to the list of source files required to build your library.
388	  This defaults to $(OBJECTS:%.o=$(SRCDIR)/%.c) in Makefile.lib, so
389	  you only need to set this when source files from directories other
390	  than SRCDIR are needed.  Keep in mind that SRCS should be set to a
391	  list of source file *pathnames*, not just a list of filenames.
392
393	LINTLIB-specific SRCS (required if building a lint library)
394
395	  Set to a special "lint stubs" file to use when constructing your
396	  library's lint library.  The lint stubs file must be used to
397	  guarantee that programs that link against your library will be able
398	  to lint clean.  To do this, you must conditionally set SRCS to use
399	  your stubs file by specifying `LINTLIB := SRCS= $(SRCDIR)/$(LINTSRC)'
400	  in your Makefile.  Of course, you do not need to set this if your
401	  library does not build a lint library.
402
403	LDLIBS
404
405	  Appended with the list of libraries and library directories needed
406	  to build your library; minimally "-lc".  Note that this should
407	  *never* be set, since that will inadvertently clear the library
408	  search path, causing the linker to look in the wrong place for
409	  the libraries.
410
411	  Since lint targets also make use of LDLIBS, LDLIBS *must* only
412	  contain -l and -L directives; all other link-related directives
413	  should be put in DYNFLAGS (if they apply only to shared object
414	  construction) or LDFLAGS (if they apply in general).
415
416	MAPFILES (if necessary)
417
418	  Set to the list of mapfiles used to link each ISA-specific version
419	  of your library.  This defaults to `$(SRCDIR)/mapfile-vers' in
420	  Makefile.lib, so you only need to change this if you have additional
421	  mapfiles or your mapfile doesn't follow the standard naming
422	  convention.  If you have supplemental ISA-dependent mapfiles that
423	  reside in the respective <isa> directories, you can augment
424	  MAPFILES like this:
425
426		MAPFILES += mapfile-vers
427
428	CPPFLAGS (if necessary)
429
430	   Appended with any flags that need to be passed to the C
431	   preprocessor (typically -D and -I flags).  Since lint macros use
432	   CPPFLAGS, CPPFLAGS *must* only contain directives known to the C
433	   preprocessor.  When compiling MT-safe code, CPPFLAGS *must*
434	   include -D_REENTRANT.  When compiling large file aware code,
435	   CPPFLAGS *must* include -D_FILE_OFFSET_BITS=64.
436
437	CFLAGS
438
439	   Appended with any flags that need to be passed to the C compiler.
440	   Minimally, append `$(CCVERBOSE)'.  Keep in mind that you should
441	   add any C preprocessor flags to CPPFLAGS, not CFLAGS.
442
443	CFLAGS64 (if necessary)
444
445	   Appended with any flags that need to be passed to the C compiler
446	   when compiling 64-bit code.  Since all 64-bit code is compiled
447	   $(CCVERBOSE), you usually do not need to modify CFLAGS64.
448
449 	COPTFLAG (if necessary)
450
451	   Set to control the optimization level used by the C compiler when
452	   compiling 32-bit code.  You should only set this if absolutely
453	   necessary, and it should only contain optimization-related
454	   settings (or -g).
455
456 	COPTFLAG64 (if necessary)
457
458	   Set to control the optimization level used by the C compiler when
459	   compiling 64-bit code.  You should only set this if absolutely
460	   necessary, and it should only contain optimization-related
461	   settings (or -g).
462
463	LINTFLAGS (if necessary)
464
465	   Appended with any flags that need to be passed to lint when
466	   linting 32-bit code.  You should only modify LINTFLAGS in
467	   rare instances where your code cannot (or should not) be fixed.
468
469	LINTFLAGS64 (if necessary)
470
471	   Appended with any flags that need to be passed to lint when
472	   linting 64-bit code.  You should only modify LINTFLAGS64 in
473	   rare instances where your code cannot (or should not) be fixed.
474
475Of course, you may use other macros as necessary.
476
477The fourth section typically consists of the following targets:
478
479	all
480
481	  Build all of the types of the libraries named by LIBS.  Must always
482	  be the first real target in common Makefile.  Since the
483	  higher-level Makefiles already contain rules to build all of the
484	  different types of libraries, you can usually just specify
485
486		all: $(LIBS)
487
488	  though it should be listed as an empty target if LIBS is set by your
489	  ISA-specific Makefiles (see above).
490
491	lint
492
493	  Use the `lintcheck' rule provided by lib/Makefile.targ to lint the
494	  actual library sources.  Historically, this target has also been
495	  used to build the lint library (using LINTLIB), but that usage is
496	  now discouraged.  Thus, this rule should be specified as
497
498		lint: lintcheck
499
500Conspicuously absent from this section are the `clean' and `clobber' targets.
501These targets are already provided by lib/Makefile.targ and thus should not
502be provided by your common Makefile.  Instead, your common Makefile should
503list any additional files to remove during a `clean' and `clobber' by
504appending to the CLEANFILES and CLOBBERFILES macros.
505
506Once again, here's libinetutil's common Makefile, which shows how many of
507these directives go together.  Note that Makefile.rootfs is included to
508cause libinetutil.so.1 to be installed in /lib rather than /usr/lib:
509
510	LIBRARY =	libinetutil.a
511	VERS =		.1
512	OBJECTS =	octet.o inetutil4.o ifspec.o ifaddrlist.o eh.o tq.o
513
514	include ../../Makefile.lib
515	include ../../Makefile.rootfs
516
517	LIBS =		$(DYNLIB) $(LINTLIB)
518
519	SRCDIR =	../common
520	COMDIR =	$(SRC)/common/net/dhcp
521	SRCS =		$(COMDIR)/octet.c $(SRCDIR)/inetutil4.c \
522			$(SRCDIR)/ifspec.c $(SRCDIR)/eh.c $(SRCDIR)/tq.c \
523			$(SRCDIR)/ifaddrlist.c
524
525	$(LINTLIB):=	SRCS = $(SRCDIR)/$(LINTSRC)
526	LDLIBS +=	-lsocket -lc
527
528	CFLAGS +=	$(CCVERBOSE)
529	CPPFLAGS +=	-I$(SRCDIR)
530
531	.KEEP_STATE:
532
533	all: $(LIBS)
534
535	lint: lintcheck
536
537	pics/%.o: $(COMDIR)/%.c
538		$(COMPILE.c) -o $@ $<
539		$(POST_PROCESS_O)
540
541	include ../../Makefile.targ
542
543The mapfile for libinetutil is named `mapfile-vers' and resides in $(SRCDIR),
544so the MAPFILES definition is omitted, defaulting to $(SRCDIR)/mapfile-vers.
545
546Note that for libinetutil, not all of the object files come from SRCDIR.  To
547support this, an alternate source file directory named COMDIR is defined, and
548the source files listed in SRCS are specified using both COMDIR and SRCDIR.
549Additionally, a special build rule is provided to build object files from the
550sources in COMDIR; the rule uses COMPILE.c and POST_PROCESS_O so that any
551changes to the compilation and object-post-processing phases will be
552automatically picked up.
553
554The ISA-Specific Makefiles
555--------------------------
556
557As the name implies, your ISA-specific Makefiles should contain macros and
558rules that cannot be expressed in an ISA-independent way.  Usually, the only
559rule you will need to put here is `install', which has different dependencies
560for 32-bit and 64-bit libraries.  For instance, here are the ISA-specific
561Makefiles for libinetutil:
562
563	sparc/Makefile:
564
565		include ../Makefile.com
566
567		install: all $(ROOTLIBS) $(ROOTLINKS) $(ROOTLINT)
568
569	sparcv9/Makefile:
570
571		include ../Makefile.com
572		include ../../Makefile.lib.64
573
574		install: all $(ROOTLIBS64) $(ROOTLINKS64)
575
576	i386/Makefile:
577
578		include ../Makefile.com
579
580		install: all $(ROOTLIBS) $(ROOTLINKS) $(ROOTLINT)
581
582	amd64/Makefile:
583
584		include ../Makefile.com
585		include ../../Makefile.lib.64
586
587		install: all $(ROOTLIBS64) $(ROOTLINKS64)
588
589Observe that there is no .KEEP_STATE directive in these Makefiles, since all
590of these Makefiles include libinetutil/Makefile.com, and it already has a
591.KEEP_STATE directive.  Also, note that the 64-bit Makefiles also include
592Makefile.lib.64, which overrides some of the definitions contained in the
593higher level Makefiles included by the common Makefile so that 64-bit
594compiles work correctly.
595
596CTF Data in Libraries
597---------------------
598
599By default, all position-independent objects are built with CTF data using
600ctfconvert, which is then merged together using ctfmerge when the shared
601object is built.  All C-source objects processed via ctfmerge need to be
602processed via ctfconvert or the build will fail.  Objects built from non-C
603sources (such as assembly or C++) are silently ignored for CTF processing.
604
605Filter libraries that have no source files will need to explicitly disable
606CTF by setting CTFMERGE_LIB to ":"; see libw/Makefile.com for an example.
607
608More Information
609----------------
610
611Other issues and questions will undoubtedly arise while you work on your
612library's Makefiles.  To help in this regard, a number of libraries of
613varying complexity have been updated to follow the guidelines and practices
614outlined in this document:
615
616	lib/libdhcputil
617
618	  Example of a simple 32-bit only library.
619
620	lib/libdhcpagent
621
622	  Example of a simple 32-bit only library that obtains its sources
623	  from multiple directories.
624
625	lib/ncad_addr
626
627	  Example of a simple loadable module.
628
629	lib/libipmp
630
631	  Example of a simple library that builds a message catalog.
632
633	lib/libdhcpsvc
634
635	  Example of a Makefile hierarchy for a library and a collection
636	  of related pluggable modules.
637
638	lib/lvm
639
640	  Example of a Makefile hierarchy for a collection of related
641	  libraries and pluggable modules.
642
643	  Also an example of a Makefile hierarchy that supports the
644	  _dc target for domain and category specific messages.
645
646Of course, if you still have questions, please do not hesitate to send email
647to the ON gatekeepers.
648