xref: /illumos-gate/usr/src/lib/README.Makefiles (revision b12258b69ac245658b0ca5ae070b3ff004186148)
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24
25Writing Library Makefiles in ON
26===============================
27
28Introduction
29------------
30
31This document guides you through the gnarly process of writing library
32Makefiles for the ON consolidation.  It assumes that you're comfortable with
33make(1) and are somewhat familiar with the ON Makefile standards outlined in
34/shared/ON/general_docs/make_std.txt.
35
36Makefile Overview
37-----------------
38
39Your library should consist of a hierarchical collection of Makefiles:
40
41	lib/<library>/Makefile:
42
43	  This is your library's top-level Makefile.  It should contain rules
44	  for building any ISA-independent targets, such as installing header
45	  files and building message catalogs, but should defer all other
46	  targets to ISA-specific Makefiles.
47
48	lib/<library>/Makefile.com
49
50	  This is your library's common Makefile.  It should contain rules
51	  and macros which are common to all ISAs. This Makefile should never
52	  be built explicitly, but instead should be included (using the make
53	  include mechanism) by all of your ISA-specific Makefiles.
54
55	lib/<library>/<isa>/Makefile
56
57	  These are your library's ISA-specific Makefiles, one per ISA
58	  (usually sparc and i386, and often sparcv9 and amd64).  These
59	  Makefiles should include your common Makefile and then provide any
60	  needed ISA-specific rules and definitions, perhaps overriding those
61	  provided in your common Makefile.
62
63To simplify their maintenance and construction, $(SRC)/lib has a handful of
64provided Makefiles that yours must include; the examples provided throughout
65the document will show how to use them.  Please be sure to consult these
66Makefiles before introducing your own custom build macros or rules.
67
68	lib/Makefile.lib:
69
70	  This contains the bulk of the macros for building shared objects.
71
72	lib/Makefile.lib.64
73
74	  This contains macros for building 64-bit objects, and should be
75	  included in Makefiles for 64-bit native ISAs.
76
77	lib/Makefile.rootfs
78
79	  This contains macro overrides for libraries that install into /lib
80	  (rather than /usr/lib).
81
82	lib/Makefile.targ
83
84	  This contains rules for building shared objects.
85
86The remainder of this document discusses how to write each of your Makefiles
87in detail, and provides examples from the libinetutil library.
88
89The Library Top-level Makefile
90------------------------------
91
92As described above, your top-level library Makefile should contain
93rules for building ISA-independent targets, but should defer the
94building of all other targets to ISA-specific Makefiles.  The
95ISA-independent targets usually consist of:
96
97	install_h
98
99	  Install all library header files into the proto area.
100	  Can be omitted if your library has no header files.
101
102	check
103
104	  Check all library header files for hdrchk compliance.
105	  Can be omitted if your library has no header files.
106
107	_msg
108
109	  Build and install a message catalog.
110	  Can be omitted if your library has no message catalog.
111
112Of course, other targets (such as `cstyle') are fine as well, as long as
113they are ISA-independent.
114
115The ROOTHDRS and CHECKHDRS targets are provided in lib/Makefile.lib to make
116it easy for you to install and check your library's header files.  To use
117these targets, your Makefile must set the HDRS to the list of your library's
118header files to install and HDRDIR to the their location in the source tree.
119In addition, if your header files need to be installed in a location other
120than $(ROOT)/usr/include, your Makefile must also set ROOTHDRDIR to the
121appropriate location in the proto area.  Once HDRS, HDRDIR and (optionally)
122ROOTHDRDIR have been set, your Makefile need only contain
123
124	  install_h: $(ROOTHDRS)
125
126	  check: $(CHECKHDRS)
127
128to bind the provided targets to the standard `install_h' and `check' rules.
129
130Similar rules are provided (in $(SRC)/Makefile.msg.targ) to make it easy for
131you to build and install message catalogs from your library's source files.
132
133To install a catalog into the catalog directory in the proto area, define the
134POFILE macro to be the name of your catalog, and specify that the _msg target
135depends on $(MSGDOMAINPOFILE).  The examples below should clarify this.
136
137To build a message catalog from arbitrarily many message source files, use
138the BUILDPO.msgfiles macro.
139
140	  include ../Makefile.lib
141
142	  POFILE =	  libfoo.po
143	  MSGFILES =	  $(OBJECTS:%.o=%.i)
144
145	  # ...
146
147	  $(POFILE): $(MSGFILES)
148		$(BUILDPO.msgfiles)
149
150	  _msg: $(MSGDOMAINPOFILE)
151
152	  include $(SRC)/Makefile.msg.targ
153
154Note that this example doesn't use grep to find message files, since that can
155mask unreferenced files, and potentially lead to the inclusion of unwanted
156messages or omission of intended messages in the catalogs.  As such, MSGFILES
157should be derived from a known list of objects or sources.
158
159It is usually preferable to run the source through the C preprocessor prior
160to extracting messages.  To do this, use the ".i" suffix, as shown in the
161above example.  If you need to skip the C preprocessor, just use the native
162(.[ch]) suffix.
163
164The only time you shouldn't use BUILDPO.msgfiles as the preferred means of
165extracting messages is when you're extracting them from shell scripts; in
166that case, you can use the BUILDPO.pofiles macro as explained below.
167
168To build a message catalog from other message catalogs, or from source files
169that include shell scripts, use the BUILDPO.pofiles macro:
170
171	  include ../Makefile.lib
172
173	  SUBDIRS =	  $(MACH)
174
175	  POFILE =	  libfoo.po
176	  POFILES =	  $(SUBDIRS:%=%/_%.po)
177
178	  _msg :=	  TARGET = _msg
179
180	  # ...
181
182	  $(POFILE): $(POFILES)
183		$(BUILDPO.pofiles)
184
185	  _msg: $(MSGDOMAINPOFILE)
186
187	  include $(SRC)/Makefile.msg.targ
188
189The Makefile above would work in conjunction with the following in its
190subdirectories' Makefiles:
191
192	  POFILE =	  _thissubdir.po
193	  MSGFILES =	  $(OBJECTS:%.o=%.i)
194
195	  $(POFILE):	  $(MSGFILES)
196		  $(BUILDPO.msgfiles)
197
198	  _msg:		  $(POFILE)
199
200	  include $(SRC)/Makefile.msg.targ
201
202Since this POFILE will be combined with those in other subdirectories by the
203parent Makefile and that merged file will be installed into the proto area
204via MSGDOMAINPOFILE, there is no need to use MSGDOMAINPOFILE in this Makefile
205(in fact, using it would lead to duplicate messages in the catalog).
206
207When using any of these targets, keep in mind that other macros, like
208XGETFLAGS and TEXT_DOMAIN may also be set in your Makefile to override or
209augment the defaults provided in higher-level Makefiles.
210
211As previously mentioned, you should defer all ISA-specific targets to your
212ISA-specific Makefiles.  You can do this by:
213
214	1. Setting SUBDIRS to the list of directories to descend into:
215
216		SUBDIRS = $(MACH)
217
218	   Note that if your library is also built 64-bit, then you should
219	   also specify
220
221		$(BUILD64)SUBDIRS += $(MACH64)
222
223	   so that SUBDIRS contains $(MACH64) if and only if you're compiling
224	   on a 64-bit ISA.
225
226	2. Providing a common "descend into SUBDIRS" rule:
227
228		$(SUBDIRS): FRC
229			@cd $@; pwd; $(MAKE) $(TARGET)
230
231		FRC:
232
233	3. Providing a collection of conditional assignments that set TARGET
234	   appropriately:
235
236		all	:= TARGET= all
237		clean	:= TARGET= clean
238		clobber := TARGET= clobber
239		install := TARGET= install
240		lint	:= TARGET= lint
241
242	   The order doesn't matter, but alphabetical is preferable.
243
244	4. Having the aforementioned targets depend on SUBDIRS:
245
246		all clean clobber install lint: $(SUBDIRS)
247
248	   The `all' target must be listed first so that make uses it as the
249	   default target; the others might as well be listed alphabetically.
250
251As an example of how all of this goes together, here's libinetutil's
252top-level library Makefile (license notice and copyright omitted):
253
254	include ../Makefile.lib
255
256	HDRS =		libinetutil.h
257	HDRDIR =	common
258	SUBDIRS =	$(MACH)
259	$(BUILD64)SUBDIRS += $(MACH64)
260
261	all :=		TARGET = all
262	clean :=	TARGET = clean
263	clobber :=	TARGET = clobber
264	install :=	TARGET = install
265	lint :=		TARGET = lint
266
267	.KEEP_STATE:
268
269	all clean clobber install lint: $(SUBDIRS)
270
271	install_h:	$(ROOTHDRS)
272
273	check:		$(CHECKHDRS)
274
275	$(SUBDIRS): FRC
276		@cd $@; pwd; $(MAKE) $(TARGET)
277
278	FRC:
279
280	include ../Makefile.targ
281
282The Common Makefile
283-------------------
284
285In concept, your common Makefile should contain all of the rules and
286definitions that are the same on all ISAs.  However, for reasons of
287maintainability and cleanliness, you're encouraged to place even
288ISA-dependent rules and definitions, as long you express them in an
289ISA-independent way (e.g., by using $(MACH), $(TARGETMACH), and their kin).
290(TARGETMACH is the same as MACH for 32-bit targets, and the same as MACH64
291for 64-bit targets).
292
293The common Makefile can be conceptually split up into four sections:
294
295	1. A copyright and comments section.  Please see the prototype
296	   files in usr/src/prototypes for examples of how to format the
297	   copyright message properly.  For brevity and clarity, this
298	   section has been omitted from the examples shown here.
299
300	2. A list of macros that must be defined prior to the inclusion of
301	   Makefile.lib.  This section is conceptually terminated by the
302	   inclusion of Makefile.lib, followed, if necessary, by the
303	   inclusion of Makefile.rootfs (only if the library is to be
304	   installed in /lib rather than the default /usr/lib).
305
306	3. A list of macros that need not be defined prior to the inclusion
307	   of Makefile.lib (or which must be defined following the inclusion
308	   of Makefile.lib, to override or augment its definitions).  This
309	   section is conceptually terminated by the .KEEP_STATE directive.
310
311	4. A list of targets.
312
313The first section is self-explanatory.  The second typically consists of the
314following macros:
315
316	LIBRARY
317
318	  Set to the name of the static version of your library, such
319	  as `libinetutil.a'.  You should always specify the `.a' suffix,
320	  since pattern-matching rules in higher-level Makefiles rely on it,
321	  even though static libraries are not normally built in ON, and
322	  are never installed in the proto area.  Note that the LIBS macro
323	  (described below) controls the types of libraries that are built
324	  when building your library.
325
326	  If you are building a loadable module (i.e., a shared object that
327	  is only linked at runtime with dlopen(3dl)), specify the name of
328	  the loadable module with a `.a' suffix, such as `devfsadm_mod.a'.
329
330	VERS
331
332	  Set to the version of your shared library, such as `.1'.  You
333	  actually do not need to set this prior to the inclusion of
334	  Makefile.lib, but it is good practice to do so since VERS and
335	  LIBRARY are so closely related.
336
337	OBJECTS
338
339	  Set to the list of object files contained in your library, such as
340	  `a.o b.o'.  Usually, this will be the same as your library's source
341	  files (except with .o extensions), but if your library compiles
342	  source files outside of the library directory itself, it will
343	  differ.  We'll see an example of this with libinetutil.
344
345The third section typically consists of the following macros:
346
347	LIBS
348
349	  Set to the list of the types of libraries to build when building
350	  your library.  For dynamic libraries, you should set this to
351	  `$(DYNLIB) $(LINTLIB)' so that a dynamic library and lint library
352	  are built.  For loadable modules, you should just list DYNLIB,
353	  since there's no point in building a lint library for libraries
354	  that are never linked at compile-time.
355
356	  If your library needs to be built as a static library (typically
357	  to be used in other parts of the build), you should set LIBS to
358	  `$(LIBRARY)'.  However, you should do this only when absolutely
359	  necessary, and you must *never* ship static libraries to customers.
360
361	ROOTLIBDIR (if your library installs to a nonstandard directory)
362
363	  Set to the directory your 32-bit shared objects will install into
364	  with the standard $(ROOTxxx) macros.  Since this defaults to
365	  $(ROOT)/usr/lib ($(ROOT)/lib if you included Makefile.rootfs),
366	  you usually do not need to set this.
367
368	ROOTLIBDIR64 (if your library installs to a nonstandard directory)
369
370	  Set to the directory your 64-bit shared objects will install into
371	  with the standard $(ROOTxxx64) macros.  Since this defaults to
372	  $(ROOT)/usr/lib/$(MACH64) ($(ROOT)/lib/$(MACH64) if you included
373	  Makefile.rootfs), you usually do not need to set this.
374
375	SRCDIR
376
377	  Set to the directory containing your library's source files, such
378	  as `../common'.  Because this Makefile is actually included from
379	  your ISA-specific Makefiles, make sure you specify the directory
380	  relative to your library's <isa> directory.
381
382	SRCS (if necessary)
383
384	  Set to the list of source files required to build your library.
385	  This defaults to $(OBJECTS:%.o=$(SRCDIR)/%.c) in Makefile.lib, so
386	  you only need to set this when source files from directories other
387	  than SRCDIR are needed.  Keep in mind that SRCS should be set to a
388	  list of source file *pathnames*, not just a list of filenames.
389
390	LINTLIB-specific SRCS (required if building a lint library)
391
392	  Set to a special "lint stubs" file to use when constructing your
393	  library's lint library.  The lint stubs file must be used to
394	  guarantee that programs that link against your library will be able
395	  to lint clean.  To do this, you must conditionally set SRCS to use
396	  your stubs file by specifying `LINTLIB := SRCS= $(SRCDIR)/$(LINTSRC)'
397	  in your Makefile.  Of course, you do not need to set this if your
398	  library does not build a lint library.
399
400	LDLIBS
401
402	  Appended with the list of libraries and library directories needed
403	  to build your library; minimally "-lc".  Note that this should
404	  *never* be set, since that will inadvertently clear the library
405	  search path, causing the linker to look in the wrong place for
406	  the libraries.
407
408	  Since lint targets also make use of LDLIBS, LDLIBS *must* only
409	  contain -l and -L directives; all other link-related directives
410	  should be put in DYNFLAGS (if they apply only to shared object
411	  construction) or LDFLAGS (if they apply in general).
412
413	MAPFILES (if necessary)
414
415	  Set to the list of mapfiles used to link each ISA-specific version
416	  of your library.  This defaults to `$(SRCDIR)/mapfile-vers' in
417	  Makefile.lib, so you only need to change this if you have additional
418	  mapfiles or your mapfile doesn't follow the standard naming
419	  convention.  If you have supplemental ISA-dependent mapfiles that
420	  reside in the respective <isa> directories, you can augment
421	  MAPFILES like this:
422
423		MAPFILES += mapfile-vers
424
425	CPPFLAGS (if necessary)
426
427	   Appended with any flags that need to be passed to the C
428	   preprocessor (typically -D and -I flags).  Since lint macros use
429	   CPPFLAGS, CPPFLAGS *must* only contain directives known to the C
430	   preprocessor.  When compiling MT-safe code, CPPFLAGS *must*
431	   include -D_REENTRANT.  When compiling large file aware code,
432	   CPPFLAGS *must* include -D_FILE_OFFSET_BITS=64.
433
434	CFLAGS
435
436	   Appended with any flags that need to be passed to the C compiler.
437	   Minimally, append `$(CCVERBOSE)'.  Keep in mind that you should
438	   add any C preprocessor flags to CPPFLAGS, not CFLAGS.
439
440	CFLAGS64 (if necessary)
441
442	   Appended with any flags that need to be passed to the C compiler
443	   when compiling 64-bit code.  Since all 64-bit code is compiled
444	   $(CCVERBOSE), you usually do not need to modify CFLAGS64.
445
446	COPTFLAG (if necessary)
447
448	   Set to control the optimization level used by the C compiler when
449	   compiling 32-bit code.  You should only set this if absolutely
450	   necessary, and it should only contain optimization-related
451	   settings (or -g).
452
453	COPTFLAG64 (if necessary)
454
455	   Set to control the optimization level used by the C compiler when
456	   compiling 64-bit code.  You should only set this if absolutely
457	   necessary, and it should only contain optimization-related
458	   settings (or -g).
459
460	LINTFLAGS (if necessary)
461
462	   Appended with any flags that need to be passed to lint when
463	   linting 32-bit code.  You should only modify LINTFLAGS in
464	   rare instances where your code cannot (or should not) be fixed.
465
466	LINTFLAGS64 (if necessary)
467
468	   Appended with any flags that need to be passed to lint when
469	   linting 64-bit code.  You should only modify LINTFLAGS64 in
470	   rare instances where your code cannot (or should not) be fixed.
471
472Of course, you may use other macros as necessary.
473
474The fourth section typically consists of the following targets:
475
476	all
477
478	  Build all of the types of the libraries named by LIBS.  Must always
479	  be the first real target in common Makefile.  Since the
480	  higher-level Makefiles already contain rules to build all of the
481	  different types of libraries, you can usually just specify
482
483		all: $(LIBS)
484
485	  though it should be listed as an empty target if LIBS is set by your
486	  ISA-specific Makefiles (see above).
487
488	lint
489
490	  Use the `lintcheck' rule provided by lib/Makefile.targ to lint the
491	  actual library sources.  Historically, this target has also been
492	  used to build the lint library (using LINTLIB), but that usage is
493	  now discouraged.  Thus, this rule should be specified as
494
495		lint: lintcheck
496
497Conspicuously absent from this section are the `clean' and `clobber' targets.
498These targets are already provided by lib/Makefile.targ and thus should not
499be provided by your common Makefile.  Instead, your common Makefile should
500list any additional files to remove during a `clean' and `clobber' by
501appending to the CLEANFILES and CLOBBERFILES macros.
502
503Once again, here's libinetutil's common Makefile, which shows how many of
504these directives go together.  Note that Makefile.rootfs is included to
505cause libinetutil.so.1 to be installed in /lib rather than /usr/lib:
506
507	LIBRARY =	libinetutil.a
508	VERS =		.1
509	OBJECTS =	octet.o inetutil4.o ifspec.o ifaddrlist.o eh.o tq.o
510
511	include ../../Makefile.lib
512	include ../../Makefile.rootfs
513
514	LIBS =		$(DYNLIB) $(LINTLIB)
515
516	SRCDIR =	../common
517	COMDIR =	$(SRC)/common/net/dhcp
518	SRCS =		$(COMDIR)/octet.c $(SRCDIR)/inetutil4.c \
519			$(SRCDIR)/ifspec.c $(SRCDIR)/eh.c $(SRCDIR)/tq.c \
520			$(SRCDIR)/ifaddrlist.c
521
522	$(LINTLIB):=	SRCS = $(SRCDIR)/$(LINTSRC)
523	LDLIBS +=	-lsocket -lc
524
525	CFLAGS +=	$(CCVERBOSE)
526	CPPFLAGS +=	-I$(SRCDIR)
527
528	.KEEP_STATE:
529
530	all: $(LIBS)
531
532	lint: lintcheck
533
534	pics/%.o: $(COMDIR)/%.c
535		$(COMPILE.c) -o $@ $<
536		$(POST_PROCESS_O)
537
538	include ../../Makefile.targ
539
540The mapfile for libinetutil is named `mapfile-vers' and resides in $(SRCDIR),
541so the MAPFILES definition is omitted, defaulting to $(SRCDIR)/mapfile-vers.
542
543Note that for libinetutil, not all of the object files come from SRCDIR.  To
544support this, an alternate source file directory named COMDIR is defined, and
545the source files listed in SRCS are specified using both COMDIR and SRCDIR.
546Additionally, a special build rule is provided to build object files from the
547sources in COMDIR; the rule uses COMPILE.c and POST_PROCESS_O so that any
548changes to the compilation and object-post-processing phases will be
549automatically picked up.
550
551The ISA-Specific Makefiles
552--------------------------
553
554As the name implies, your ISA-specific Makefiles should contain macros and
555rules that cannot be expressed in an ISA-independent way.  Usually, the only
556rule you will need to put here is `install', which has different dependencies
557for 32-bit and 64-bit libraries.  For instance, here are the ISA-specific
558Makefiles for libinetutil:
559
560	sparc/Makefile:
561
562		include ../Makefile.com
563
564		install: all $(ROOTLIBS) $(ROOTLINKS) $(ROOTLINT)
565
566	sparcv9/Makefile:
567
568		include ../Makefile.com
569		include ../../Makefile.lib.64
570
571		install: all $(ROOTLIBS64) $(ROOTLINKS64)
572
573	i386/Makefile:
574
575		include ../Makefile.com
576
577		install: all $(ROOTLIBS) $(ROOTLINKS) $(ROOTLINT)
578
579	amd64/Makefile:
580
581		include ../Makefile.com
582		include ../../Makefile.lib.64
583
584		install: all $(ROOTLIBS64) $(ROOTLINKS64)
585
586Observe that there is no .KEEP_STATE directive in these Makefiles, since all
587of these Makefiles include libinetutil/Makefile.com, and it already has a
588.KEEP_STATE directive.  Also, note that the 64-bit Makefiles also include
589Makefile.lib.64, which overrides some of the definitions contained in the
590higher level Makefiles included by the common Makefile so that 64-bit
591compiles work correctly.
592
593CTF Data in Libraries
594---------------------
595
596By default, all position-independent objects are built with CTF data using
597ctfconvert, which is then merged together using ctfmerge when the shared
598object is built.  All C-source objects processed via ctfmerge need to be
599processed via ctfconvert or the build will fail.  Objects built from non-C
600sources (such as assembly or C++) are silently ignored for CTF processing.
601
602Filter libraries that have no source files will need to explicitly disable
603CTF by setting CTFMERGE_LIB to ":"; see libw/Makefile.com for an example.
604
605More Information
606----------------
607
608Other issues and questions will undoubtedly arise while you work on your
609library's Makefiles.  To help in this regard, a number of libraries of
610varying complexity have been updated to follow the guidelines and practices
611outlined in this document:
612
613	lib/libdhcputil
614
615	  Example of a simple 32-bit only library.
616
617	lib/libdhcpagent
618
619	  Example of a simple 32/64-bit library that obtains its sources
620	  from multiple directories.
621
622	lib/ncad_addr
623
624	  Example of a simple loadable module.
625
626	lib/libipmp
627
628	  Example of a simple library that builds a message catalog.
629
630	lib/libdhcpsvc
631
632	  Example of a Makefile hierarchy for a library and a collection
633	  of related pluggable modules.
634
635	lib/lvm
636
637	  Example of a Makefile hierarchy for a collection of related
638	  libraries and pluggable modules.
639
640	  Also an example of a Makefile hierarchy that supports the
641	  _dc target for domain and category specific messages.
642
643Of course, if you still have questions, please do not hesitate to send email
644to the ON gatekeepers.
645