makerules - system programmers guide for compiling projects on different platforms

"SRCROOT= ..

"RULESDIR= RULES

"include $(SRCROOT)/$(RULESDIR)/rules.top

"local defines are here

"include $(SRCROOT)/$(RULESDIR)/rules.*

See chapter CURRENTLY SUPPORTED TARGET TYPES for possible values of rules.*.

Makerules is a set of rules that allows compiling of structured projects with small and uniformly structured makefiles. All rules are located in a central directory. Compiling the projects on different platforms can be done simultaneously without the need to modify any of the makefiles that are located in the projects directories.

Makerules is a set of high level portability tools superior to autoconf and easier to use.

Three make programs are currently supported: Sunpro make, GNU make and smake. If you want to add support for other make programs, read the sections about the minimum requirements for a make program and about the structure of the "make rule system.

This manual will help programmers who need to make modifications on the make rule system itself. If you want to know something on how to use the "makefile system have a look at makefiles(4).

The main design goal was to have no definition on more than place in the make rules. This implies that system programmers who want to add or modify rules must follow this goal in order not to destroy functionality in other places.

The visible result for the user is a set of small and easy to read makefiles, each located in the project's leaf directory and therefore called leaf-makefile.

Each of these leaf-makefiles, in fact contains no rule at all. It simply defines some macros for the make-program and includes two files from a central make rule depository. These included files define the rules that are needed to compile the project.

Each leaf-makefile is formed in a really simple way:

•

It first defines two macros that define the relative location of the project's root directory and the name of the directory that contains the complete set of of rules and then includes the rule file rules.top from the directory that forms the central rule depository. You only have to edit the macro SRCROOT to reflect the relative location of the project's root directory.

•

The next part of a leaf-makefile defines macros that describe the target and the source. You can only have one target per leaf-makefile. Of course, there may be many source files, that are needed to create that target. If you want to make more than one target in a specific directory, you have to put more than one makefile into that directory. This is the part of a makefile that describes a unique target. Edit this part to contain all source files, all local include files and all non global compile time flags that are needed for your target. For a typical target this is as simple as filling in a form.

•

Each leaf-makefile finally includes a file from the rules directory that contains rules for the appropriate type of target that is to be made from this leaf-makefile.

The makefile in each directory has to be called Makefile. If you want to have more than one makefile in a specific directory, you have to choose different names for the other makefiles.

There are rules for the following type of targets:

commands

The make rules for user level commands like cat, ls etc. are located in the file rules.cmd

drivers

The make rules for device drivers are located in the file rules.drv

libraries

The make rules for non shared libraries are located in the file rules.lib

shared libraries

The make rules for shared libraries are located in the file rules.shl

localized files

The make rules for localized files are located in the file rules.loc

nonlocalized files

The make rules for non localized files are located in the file rules.aux

shell scripts

The make rules for shell scripts (a variant of localized files) are located in the file rules.scr

manual pages

The make rules for manual pages (a variant of localized files) are located in the file rules.man

diverted makefiles

The make rules for projects that need to have more than one makefile in a specific directory are located in the file rules.mks It contains a rule that diverts to the listed sub makefiles. Each sub makefile may be of any type.

directories

The make rules for sub directories are located in the file rules.dir

The make rules currently have support for Sunpro make, GNU make and smake. If you like to add support for other make programs, they need to have some minimal features that go beyond the capabilities of the standard "UNIX make program. BSDmake could be supported if it supports pattern matching rules correctly.

include

The make program must be able to recursively include other files from within a makefile. The name if the file to include must be allowed to be a macro. The make program must be able to do this in a way that if the file that should be included may be a result of make rule. e.g if the file to be included does not exist or is outdated, it should be built before an attempt is made to actually include it.

appending to a macro

A macro reference of the form: "macro += addval should append addval to the string that is currently in macro.

suffix macro replacement

A macro reference of the form: "out= $(macro:string1=string2) should replace a suffix string1 to string2 in all words that are in macro, where string1 is either a suffix, or a word to be replaced in the macro definition, and string2 is the replacement suffix or word. String1 and string2 must be replaced correctly even if they are macros themselves. Words in a macro value are separated by SPACE, TAB, and escaped NEWLINE characters.

pattern macro replacement

A macro reference of the form: "out= $(macro:op%os=np%ns) should replace a central pattern in macro, where op is the existing (old) prefix and os is the existing (old) suffix, np and ns are the new prefix and new suffix, respectively, and the pattern matched by % (a string of zero or more characters), is carried forward from the value being replaced. For example: "PROGRAM=fabricate

"DEBUG= $(PROGRAM:%=tmp/%-g) sets the value of DEBUG to tmp/fabricate-g. Op, os, np and ns must be replaced correctly even if they are macros themselves.

One of the basic algorithms used in the make rule system is needed to set an undefined macro to a guaranteed default value. Because not all make programs have support for "if then else structures, a different method has to be used.

The method used in "make rules is implemented by using "suffix macro replacement and pattern macro replacement.

First, a macro that contains a unique suffix is defined: " # Define magic unique cookie

" _UNIQ= .XxZzy- This macro is used for all places where it is necessary to have a macro with a guaranteed default value. The following example shows the basic algorithm that is used to implement the phrase: If $(MAKE_NAME) contains a value, then $(XMAKEPROG) will be set to $(MAKE_NAME) else $(XMAKEPROG) will be set to $(MAKEPROG). " _MAKEPROG= $(_UNIQ)$(MAKE_NAME)

" __MAKEPROG= $(_MAKEPROG:$(_UNIQ)=$(MAKEPROG))

" XMAKEPROG= $(__MAKEPROG:$(_UNIQ)%=%) The first line in this example, sets the macro _MAKEPROG to the concatenation of the value of MAKE_NAME and .XxZzy-. If the macro MAKE_NAME is empty at this time, _MAKEPROG will contain only .XxZzy-.

In the second line, __MAKEPROG is set to the value of _MAKEPROG. If _MAKEPROG contains only .XxZzy- this implies, that .XxZzy- is the suffix. This suffix is then replaced by the value of MAKEPROG, in this case __MAKEPROG will contain the unmodified value of MAKEPROG. If _MAKEPROG contains a concatenation of .XxZzy- and something else, .XxZzy- will not be a suffix, but a prefix of _MAKEPROG and for this reason __MAKEPROG will contain the unmodified value of _MAKEPROG, which is a concatenation of .XxZzy- and the value of MAKE_NAME.

In the third line, XMAKEPROG is set to the value of __MAKEPROG. If __MAKEPROG has the prefix .XxZzy- at this time, .XxZzy- is stripped of.

The names used for "make macros are structured in a way that allows to use grep(1) to look for the names in the make rules. To allow this, no name must be a substring of another name.

If a command needs options that have to be specified in macros, there is a "make macro that is named XXXFLAGS. This is compliant to usual make file rules. The are internal "make macros called XXXOPTS and XXXOPTX that will be combined for XXXFLAGS: "LDFLAGS= $(LDOPTS) $(LDOPTX) Where XXXOPTS is the name of the macro that is used internally and XXXOPTX is the name of the macro that may be used from the command line of the make program. XXXOPTX therefore is used to append to the content of XXXFLAGS If the value of XXXFLAGS need to be overwritten, XXXOPTS may be used within the command line flags of the make program.

The file RULES/rules.top first includes a rule file that depends on the make program that is used. The name of this file is RULES/mk-makeprog.id where makeprog has to be replaced by the real name of the makeprogram e.g. make, gmake, smake. The purpose of this file is to set up a list of macros that identify the system where the project is currently built. These macros have values that contain only lower case letters and define:

the processor architecture

If two systems run the same operating system, this is a unique value if a simple user level program will not need to be recompiled in order to run on the other system. Possible values are sparc, mc68020, pentium. This is the output of uname -p. The value is stored in P_ARCH.

the kernel architecture

If two systems may use the same value for P_ARCH but a heavily system dependent user level program need to be recompiled in order to run on the other system, These two systems have different kernel architectures. This is the output of uname -m. Possible values are sun3, sun4c, sun4m. The value is stored in K_ARCH.

the machine architecture

An outdated macro that is useful only on sun systems. Do not use this, use P_ARCH instead. This is the output of arch. Possible values are sun3, sun4. The value is stored in M_ARCH.

the hostname

The name of the machine where the compilation takes place. This is the output of uname -n. The value is stored in HOSTNAME.

the name of the operating system

This is the output of uname -s. Possible values are sunos, dgux, hp-ux, irix. The value is stored in OSNAME.

the release of the operating system

This is the output of uname -r. Possible values are 5.5, 4.1.4. The value is stored in OSREL.

The next file to be included from RULES/rules.top is RULES/os-operating system.id. It defines the macros O_ARCH and -O_ARCH and may modify one of the macros that are defined in RULES/mk-makeprog.id. The macros O_ARCH and -O_ARCH are used to distinguish between different operating systems. The names of the compiler configuration files have -O_ARCH as a central part. On some operating systems e.g. SunOS and DG-UX it is necessary to distinguish between "SunOS 4.x and "SunOS 5.x or "DG-UX 3.x and "DG-UX 4.x.

The next file to be included from RULES/rules.top is Defaults. It defines the macros DEFCCOM , DEFINCDIRS , LDPATH , RUNPATH , INS_BASE and INS_KBASE. If the definitions have to be different on different systems, this file may contain a line int the form: include $(SRCROOT)/Defaults.$(O_ARCH) The actual definitions then have to be moved into these files.

Next, after setting up some internal defaults, RULES/rules.top includes the compiler configuration file with the name: $(SRCROOT)/$(RULESDIR)/$(XARCH).rul This file contains all necessary system dependent stuff that is needed to configure the C-compiler on the appropriate system. It is a bad idea to create a new one from scratch. Have a look at the other compiler configuration files and modify a similar file for your needs. Note that there are basically two criterias to that are important in a compiler configuration file. One is whether the system uses the ELF header format or not. The other is whether the system uses shared libraries or not.

The application specific rule files are designed in such a way that they include all necessary stuff that is needed for that specific task. The application specific rule files are:

$(RULES)/rules.aux

Rules for installing non localized auxiliary files.

$(RULES)/rules.cmd

Rules for commands like sh.

$(RULES)/rules.dir

Rules for sub directories.

$(RULES)/rules.drv

Rules for lodable drivers.

$(RULES)/rules.lib

Rules for static libraries.

$(RULES)/rules.loc

Rules for installing localized auxiliary files.

$(RULES)/rules.man

Rules for installing localized manual pages.

$(RULES)/rules.mks

Rules for sub makefiles.

$(RULES)/rules.mod

Rules for lodable stream modules.

$(RULES)/rules.scr

Rules for installing localized shell scripts.

$(RULES)/rules.shl

Rules for shared libraries.

To understand the structure of the "make rule system while doing changes, try to use the -xM flag in the smake program. This flag will print out the include dependency list (i.e. a list that tell you which make rules is included from which other rule).

Note that some of the rules are make program dependent. If you want to make changes to these rules you may need to place the definitions into separate rule files each for the appropriate make program. Have a look into the RULES directory for some examples.

.../RULES/*

.../DEFAULTS/*

.../TARGETS/*

.../TEMPLATES/*

makefiles(4), make(1), gmake(1), smake(1).

Diagnostic messages depend on the make program. Have a look at the appropriate man page.

The make rules can be used with Sunpro make, Gnu make and smake. Although Gnu make runs on many platforms, it has no useful debug output.

Use Sunpro make or smake if you have problems with a makefile. Sunpro make and smake, both have a -D flag, that allows you to watch the makefiles after the first expansion. Use this option, if you are in doubt if your makefile gets expanded the right way and if the right rules are included. There is also a -d option that gives debugging output while make is running. If you want more output, use -dd, -ddd and so on.

Smake has an option -xM that shows you the include dependency for make rules.

The following outline gives a quick tour through a typical source hierarchy:

.../

root directory of the source tree

Makefile

the top Makefile

Defaults

default definitions for that source tree. System dependent definitions are in .../DEFAULTS/

Targetdirs

a file containing a list of directories that are needed for that project. If the system needs different target lists depending on the target system architecture , use target specific files in .../TARGETS/

...

.../RULES/

the location of makefiles (included rules)

rules.top

the mandatory include rules (needed to setup basic rules)

rules.aux

rules needed to install a non localized auxiliary file

rules.cmd

rules needed to make an ordinary command (like /bin/sh)

rules.drv

rules needed to make a device driver

rules.lib

rules needed to make a standard (nonshared) library

rules.loc

rules needed to install a localized auxiliary file

rules.man

rules needed to install a localized manual page

rules.scr

rules needed to install a localized shell script

rules.shl

rules needed to make a shared library

rules.mks

rules needed to make more than one target in a specific directory

rules.dir

rules needed to make targets that are located in sub directories to the current directory

...

.../DEFAULTS/

default definitions for various target architectures are located in this directory. Templates for some architectures can be found in the .../TEMPLATES/ directory.

.../TARGETS/

target list definitions for various target architectures are located in this directory.

.../TEMPLATES/

templates that should be used inside the project (rename to Makefile, if it is the only makefile on that directory, rename to target.mk, if there is more than one target in that directory)

Defaults

Defaults file for the source root directory

Defaults.linux

Defaults file for linux. This sould be installed in the .../DEFAULTS/ directory.

Makefile.root

Makefile for the source root directory

Makefile.aux

Makefile for a non localized auxiliary file

Makefile.cmd

Makefile for an ordinary command (like /bin/sh)

Makefile.lib

Makefile for a standard (nonshared) library

Makefile.loc

Makefile for a localized auxiliary file

Makefile.man

Makefile for a localized manual page

Makefile_de.man

Makefile for a localized manual page in the german locale

Makefile.scr

Makefile for a localized shell script

Makefile.shl

Makefile for a shared library

Makefile.drv

Makefile for a device driver

Makefile.mks

Makefile for more than one target in a specific directory

Makefile.dir

Makefile for targets that are located in sub directories to the current directory

...

.../cmd/

source tree for normal commands

Makefile

the makefile for the cmd sub directory

Targetdirs.sun4m

a file containing a list of directories like myprog (see below) that are needed for that specific architecture.

myprog/

directory where the sources for a specific command are located

Makefile

makefile for myprog

Makefile.man

makefile for the manual page of myprog

mprog.c

source for myprog

mprog.tr

troff source for the manual page of myprog

OBJ/

directory where system specific sub directories are located

sparc-sunos5-cc/

directory for binaries that belong to a specific system

...

...

...

.../lib/

directory where the sources for a libraries are located

Makefile

the makefile for the lib sub directory

Targetdirs.sun4m

a file containing a list of directories like libfoo (see below) that are needed for that specific architecture.

libfoo/

directory where all source files for libfoo are located

...

.../kernel

directory for kernel modules

Makefile

the makefile for the kernel sub directory

Targetdirs.sun4m

a file containing a list of directories like drv (see below) that are needed for that specific architecture.

drv/

directory where drivers are located

Makefile

the makefile for the drv sub directory

Targetdirs.sun4m

a file containing a list of directories like mydrv (see below) that are needed for that specific architecture.

mydrv/

source for a specific driver

...

...

.../include

directory for global include files that are used in that project

.../bins

directory for binary programs that are created/needed while compiling the project

sparc-sunos5-cc/

directory for binaries that belong to a specific system

...

.../libs

directory for libraries that are created/needed while compiling the project

sparc-sunos5-cc/

directory for libraries that belong to a specific system

...

.../incs

directory for include files that are created/needed while compiling the project

sparc-sunos5-cc/

directory for include files that belong to a specific system

...

...

Jorg Schilling
Seestr. 110
D-13353 Berlin
Germany

Mail bugs and suggestions to:

joerg@schily.isdn.cs.tu-berlin.de or js@cs.tu-berlin.de or jes@fokus.gmd.de