| 1 | /* $Id: VBox-MakefileGuidelines.cpp 44529 2013-02-04 15:54:15Z vboxsync $ */
|
|---|
| 2 | /** @file
|
|---|
| 3 | * VBox - Makefile Guidelines.
|
|---|
| 4 | */
|
|---|
| 5 |
|
|---|
| 6 | /*
|
|---|
| 7 | * Copyright (C) 2009-2010 Oracle Corporation
|
|---|
| 8 | *
|
|---|
| 9 | * This file is part of VirtualBox Open Source Edition (OSE), as
|
|---|
| 10 | * available from http://www.virtualbox.org. This file is free software;
|
|---|
| 11 | * you can redistribute it and/or modify it under the terms of the GNU
|
|---|
| 12 | * General Public License (GPL) as published by the Free Software
|
|---|
| 13 | * Foundation, in version 2 as it comes in the "COPYING" file of the
|
|---|
| 14 | * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
|
|---|
| 15 | * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
|
|---|
| 16 | */
|
|---|
| 17 |
|
|---|
| 18 | /** @page pg_vbox_makefile_guidelines VBox Makefile Guidelines
|
|---|
| 19 | *
|
|---|
| 20 | * These guidelines apply to all the Makefile.kmk files in the tree.
|
|---|
| 21 | * No exceptions.
|
|---|
| 22 | *
|
|---|
| 23 | * All these makefiles are ultimately the responsiblity of bird. Since there are
|
|---|
| 24 | * currently more than two hundred files and the number is growing, they have to
|
|---|
| 25 | * be very kept uniform or it will become very difficult to maintain them and
|
|---|
| 26 | * impossible do bulk refactoring. Thus these guidelines have no bits that are
|
|---|
| 27 | * optional unlike the coding guidelines, and should be thought of as rules
|
|---|
| 28 | * rather than guidelines.
|
|---|
| 29 | *
|
|---|
| 30 | * Note! The guidelines do not apply to the other makefiles found in the source
|
|---|
| 31 | * tree, like the ones shipped in the SDK and the ones for the linux kernel
|
|---|
| 32 | * modules.
|
|---|
| 33 | *
|
|---|
| 34 | *
|
|---|
| 35 | * @section sec_vbox_makefile_guidelines_kbuild kBuild
|
|---|
| 36 | *
|
|---|
| 37 | * kBuild is way older than VirtualBox, at least as a concept, but the
|
|---|
| 38 | * VirtualBox project was a push to get something done about it again. It's
|
|---|
| 39 | * maintained by bird in his spare time because: "We don't make buildsystems, we
|
|---|
| 40 | * make virtual machines". So, kBuild makes progress when there is spare time or
|
|---|
| 41 | * when there is an urgent need for something.
|
|---|
| 42 | *
|
|---|
| 43 | * The kBuild docs are in the process of being written. The current items and
|
|---|
| 44 | * their status per 2009-04-19:
|
|---|
| 45 | * - kmk Quick Reference [completed]:
|
|---|
| 46 | * http://svn.netlabs.org/kbuild/wiki/kmk%20Quick%20Reference
|
|---|
| 47 | * - kBuild Quick Reference [just started]:
|
|---|
| 48 | * http://svn.netlabs.org/kbuild/wiki/kBuild%20Quick%20Reference
|
|---|
| 49 | *
|
|---|
| 50 | * Local copies of the docs can be found in kBuild/docs, just keep in mind that
|
|---|
| 51 | * they might be slightly behind the online version.
|
|---|
| 52 | *
|
|---|
| 53 | *
|
|---|
| 54 | * @section sec_vbox_makefile_guidelines_example Example Makefiles
|
|---|
| 55 | *
|
|---|
| 56 | * Let me point to some good sample makefiles:
|
|---|
| 57 | * - src/VBox/Additions/common/VBoxService/Makefile.kmk
|
|---|
| 58 | * - src/VBox/Debugger/Makefile.kmk
|
|---|
| 59 | * - src/VBox/Disassembler/Makefile.kmk
|
|---|
| 60 | *
|
|---|
| 61 | * And some bad ones:
|
|---|
| 62 | * - src/lib/xpcom18a4/Makefile.kmk
|
|---|
| 63 | * - src/recompiler/Makefile.kmk
|
|---|
| 64 | * - src/VBox/Devices/Makefile.kmk
|
|---|
| 65 | * - src/VBox/Main/Makefile.kmk
|
|---|
| 66 | * - src/VBox/Runtime/Makefile.kmk
|
|---|
| 67 | *
|
|---|
| 68 | *
|
|---|
| 69 | * @section sec_vbox_makefile_guidelines Guidelines
|
|---|
| 70 | *
|
|---|
| 71 | * First one really important fact:
|
|---|
| 72 | *
|
|---|
| 73 | * Everything is global because all makefiles
|
|---|
| 74 | * are virtually one single makefile.
|
|---|
| 75 | *
|
|---|
| 76 | * The rules:
|
|---|
| 77 | *
|
|---|
| 78 | * - Using bits defined by a sub-makefile is fine, using anything defined
|
|---|
| 79 | * by a parent, sibling, uncle, cousine, or remoter relatives is not
|
|---|
| 80 | * Okay. It may break sub-tree building which is not acceptable.
|
|---|
| 81 | *
|
|---|
| 82 | * - Template names starts with VBOX and are all upper cased, no
|
|---|
| 83 | * underscores or other separators. (TODO: Change this to camel case.)
|
|---|
| 84 | *
|
|---|
| 85 | * - Makefile variables shall be prefixed with VBOX or VB to avoid clashes
|
|---|
| 86 | * with environment and kBuild variables.
|
|---|
| 87 | *
|
|---|
| 88 | * - Makefile variables are all upper cased and uses underscores to
|
|---|
| 89 | * separate the words.
|
|---|
| 90 | *
|
|---|
| 91 | * - All variables are global. Make sure they are globally unique, but try
|
|---|
| 92 | * not make them incredible long.
|
|---|
| 93 | *
|
|---|
| 94 | * - Makefile variables goes after the inclusion of the header and
|
|---|
| 95 | * usually after including sub-makefiles.
|
|---|
| 96 | *
|
|---|
| 97 | * - Variables that are used by more than one makefile usually belongs
|
|---|
| 98 | * in the monster file, Config.kmk.
|
|---|
| 99 | *
|
|---|
| 100 | * - Targets are lower or camel cased and as a rule the same as the
|
|---|
| 101 | * resulting binary.
|
|---|
| 102 | *
|
|---|
| 103 | * - Install targets frequently have a -inst in their name, and a name that
|
|---|
| 104 | * gives some idea what they install
|
|---|
| 105 | *
|
|---|
| 106 | * - Always use templates (mytarget_TEMPLATE = VBOXSOMETHING).
|
|---|
| 107 | *
|
|---|
| 108 | * - Comment each target with a 3+ line block as seen in
|
|---|
| 109 | * src/VBox/Debugger/Makefile.kmk.
|
|---|
| 110 | *
|
|---|
| 111 | * - No space between the comment block and the target definition.
|
|---|
| 112 | *
|
|---|
| 113 | * - Try fit all the custom recipes after the target they apply to.
|
|---|
| 114 | *
|
|---|
| 115 | * - Custom recipes that apply to more than one target should be placed at
|
|---|
| 116 | * the bottom of the makefile, before the footer inclusion when possible.
|
|---|
| 117 | *
|
|---|
| 118 | * - Do NOT use custom recipes to install stuff, use install targets.
|
|---|
| 119 | * Generate files to inst-target_0_OUTDIR. (Yes, there are a lot places
|
|---|
| 120 | * where we don't do this yet.)
|
|---|
| 121 | *
|
|---|
| 122 | * - Always break SOURCES, LIBS, long target list and other lists the
|
|---|
| 123 | * manner Debugger_SOURCES is broken into multiple lines in
|
|---|
| 124 | * src/VBox/Debugger/Makefile.kmk. I.e. exactly one tab, the file name /
|
|---|
| 125 | * list item, another space, the slash and then the newline.
|
|---|
| 126 | *
|
|---|
| 127 | * - The last element of an broken list should not have a slash-newline,
|
|---|
| 128 | * otherwise we risk getting the next variable into the list.
|
|---|
| 129 | *
|
|---|
| 130 | * - Indentation of if'ed blocks is done in 1 space increments, this also
|
|---|
| 131 | * applies to broken lists. It does not apply to the commands in a
|
|---|
| 132 | * recipes of course, because that would make kmk choke. (Yes, there are
|
|---|
| 133 | * plenty examples of doing this differently, but these will be weeded
|
|---|
| 134 | * out over time.)
|
|---|
| 135 | *
|
|---|
| 136 | * - \$(NO_SUCH_VARIABLE) should be when you need to put nothing somewhere,
|
|---|
| 137 | * for instance to prevent inherting an attribute.
|
|---|
| 138 | *
|
|---|
| 139 | * - Always put the defines in the DEFS properties, never use the FLAGS
|
|---|
| 140 | * properties for this. Doing so may screw up depenencies and object
|
|---|
| 141 | * caches.
|
|---|
| 142 | *
|
|---|
| 143 | * - Mark each section and target of the file with a 3+ lines comment
|
|---|
| 144 | * block.
|
|---|
| 145 | *
|
|---|
| 146 | * - Document variables that are not obvious using double hash comments.
|
|---|
| 147 | *
|
|---|
| 148 | * - Each an every Makefile.kmk shall have a file header with Id, file
|
|---|
| 149 | * description and copyright/license exactly like in the examples.
|
|---|
| 150 | *
|
|---|
| 151 | * - Multiple blank lines in a makefile is very seldom there without a
|
|---|
| 152 | * reason and shall be preserved.
|
|---|
| 153 | *
|
|---|
| 154 | * - Inserting blank lines between target properties is all right if the
|
|---|
| 155 | * target definition is long and/or crooked.
|
|---|
| 156 | *
|
|---|
| 157 | * - if1of and ifn1of shall always have a space after the comma, while ifeq
|
|---|
| 158 | * and ifneq shall not. That way they are easier to tell apart.
|
|---|
| 159 | *
|
|---|
| 160 | * - Do a svn diff before committing makefile changes.
|
|---|
| 161 | *
|
|---|
| 162 | *
|
|---|
| 163 | * @section sec_vbox_makefile_guidelines_reminders Helpful reminders
|
|---|
| 164 | *
|
|---|
| 165 | * - Do not be afraid to ask for help on IRC or in the defect you're
|
|---|
| 166 | * working on. There are usually somebody around that know how to best do
|
|---|
| 167 | * something.
|
|---|
| 168 | *
|
|---|
| 169 | * - Watch out for "Heads Up!" bugtracker messages concerning the build
|
|---|
| 170 | * system.
|
|---|
| 171 | *
|
|---|
| 172 | * - To remove bits from a template you're using you have to create a new
|
|---|
| 173 | * template that extends the existing one and creatively use
|
|---|
| 174 | * \$(filter-out) or \$(patsubst).
|
|---|
| 175 | *
|
|---|
| 176 | * - You can build sub-trees.
|
|---|
| 177 | *
|
|---|
| 178 | * - You don't have to cd into sub-trees: kmk -C src/recompiler
|
|---|
| 179 | *
|
|---|
| 180 | * - You can build individual targets: kmk VBoxRT
|
|---|
| 181 | *
|
|---|
| 182 | * - Even install targets: kmk nobin
|
|---|
| 183 | *
|
|---|
| 184 | * - You can compile individual source files: kmk ConsoleImpl.o
|
|---|
| 185 | *
|
|---|
| 186 | */
|
|---|
| 187 |
|
|---|
