Adding upstream version 6.1.22-dfsg.upstream/6.1.22-dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 206 insertions, 0 deletions

diff --git a/doc/VBox-MakefileGuidelines.cpp b/doc/VBox-MakefileGuidelines.cpp
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+/* $Id: VBox-MakefileGuidelines.cpp $ */
+/** @file
+ * VBox - Makefile Guidelines.
+ */
+
+/*
+ * Copyright (C) 2009-2020 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ */
+
+/** @page pg_vbox_makefile_guidelines      VBox Makefile Guidelines
+ *
+ * These guidelines apply to all the Makefile.kmk files in the tree.
+ * No exceptions.
+ *
+ * All these makefiles are ultimately the responsiblity of bird.  Since there
+ * are currently more than three hundred files and the number is growing, they
+ * have to be very kept uniform or it will become very difficult to maintain
+ * them and impossible do bulk refactoring.  Thus these guidelines have no bits
+ * that are optional unlike the coding guidelines, and should be thought of as
+ * rules rather than guidelines.
+ *
+ * Note! The guidelines do not apply to the non-kBuild makefiles found in the
+ *       source tree, like the ones shipped in the SDK and the ones for the
+ *       linux kernel modules.
+ *
+ *
+ * @section sec_vbox_makefile_guidelines_kbuild         kBuild
+ *
+ * kBuild is way older than VirtualBox, at least as a concept, but the
+ * VirtualBox project was a push to get something done about it again.  It's
+ * maintained by bird in his spare time because: "We don't make buildsystems, we
+ * make virtual machines".  So, kBuild makes progress when there is spare time
+ * or when there is an urgent need for something.
+ *
+ * The kBuild docs are in the process of being written.  The current items and
+ * their status per 2018-10-29:
+ *      - kmk Quick Reference [completed]:
+ *        http://svn.netlabs.org/kbuild/wiki/kmk%20Quick%20Reference
+ *      - kBuild Quick Reference [just started]:
+ *        http://svn.netlabs.org/kbuild/wiki/kBuild%20Quick%20Reference
+ *
+ * Local copies of the docs can be found in kBuild/docs, just keep in mind that
+ * they might be slightly behind the online version.
+ *
+ *
+ * @section sec_vbox_makefile_guidelines_example        Example Makefiles
+ *
+ * Let me point to some good sample makefiles:
+ *      - src/VBox/Additions/common/VBoxService/Makefile.kmk
+ *      - src/VBox/Debugger/Makefile.kmk
+ *      - src/VBox/Disassembler/Makefile.kmk
+ *
+ * And some bad ones:
+ *      - src/lib/xpcom18a4/Makefile.kmk
+ *      - src/recompiler/Makefile.kmk
+ *      - src/VBox/Devices/Makefile.kmk
+ *      - src/VBox/Main/Makefile.kmk
+ *      - src/VBox/Runtime/Makefile.kmk
+ *
+ *
+ * @section sec_vbox_makefile_guidelines                Guidelines
+ *
+ *  First one really important fact:
+ *
+ *       Everything is global because all makefiles
+ *       are virtually one single makefile.
+ *
+ *  The rules:
+ *
+ *      - Using bits defined by a sub-makefile is fine, using anything defined
+ *        by a parent, sibling, uncle, cousine, or remoter relatives is not
+ *        Okay. It may break sub-tree building which is not acceptable.
+ *
+ *      - Template names starts with VBox and are camel cased, no
+ *        underscores or other separators.  (Note this used to be all upper
+ *        case, fixing this incomplete.)
+ *
+ *      - Makefile variables shall be prefixed with VBOX or VB to avoid clashes
+ *        with environment and kBuild variables.
+ *
+ *      - Makefile variables are all upper cased and uses underscores to
+ *        separate the words.
+ *
+ *      - All variables are global. Make sure they are globally unique, but try
+ *        not make them incredible long.
+ *
+ *      - Makefile variables goes after the inclusion of the header and
+ *        usually after including sub-makefiles.
+ *
+ *      - Variables that are used by more than one makefile usually ends up
+ *        in the monster file, Config.kmk.  However, see if there are any
+ *        sub-tree specific Config.kmk files that could do the job first.
+ *
+ *      - Targets are lower or camel cased and as a rule the same as the
+ *        resulting binary.
+ *
+ *      - Install targets frequently have a -inst in their name, and a name that
+ *        gives some idea what they install
+ *
+ *      - Always use templates (mytarget_TEMPLATE = VBoxSomething).
+ *
+ *      - Comment each target with a 3+ line block as seen in
+ *        src/VBox/Debugger/Makefile.kmk.
+ *
+ *      - No space between the comment block and the target definition.
+ *
+ *      - Try fit all the custom recipes after the target they apply to.
+ *
+ *      - Custom recipes that apply to more than one target should be placed at
+ *        the bottom of the makefile, before the footer inclusion when possible.
+ *
+ *      - Do NOT use custom recipes to install stuff, use install targets.
+ *        Generate files to inst-target_0_OUTDIR. (Yes, there are a lot places
+ *        where we don't do this yet.)
+ *
+ *      - Always break SOURCES, LIBS, long target list and other lists the
+ *        manner Debugger_SOURCES is broken into multiple lines in
+ *        src/VBox/Debugger/Makefile.kmk. I.e. exactly one tab, the file name /
+ *        list item, another space, the slash and then the newline.
+ *
+ *      - Line continuation slashes shall never ever be aligned vertically (that
+ *        always goes crooked sooner or later), but have exactly one space
+ *        before them.
+ *
+ *      - The last element of an broken list shall not have a slash-newline,
+ *        otherwise we risk getting the next variable into the list.
+ *
+ *      - When if'ed blocks come into play, we will only indent the conditional
+ *        makefile directives (if, ifeq, ifneq, if1of, ifn1of, ifdef, ifndef,
+ *        else, endif, ++), one space for each level.  (Note! We used to indent
+ *        non-directives, which made emacs upset as we'd have both tabs and
+ *        spaces on as indentation on the same line.  There are a lot of cases
+ *        of this still around.)
+ *
+ *      - \$(NO_SUCH_VARIABLE) should be when you need to put nothing somewhere,
+ *        for instance to prevent inherting an attribute.
+ *
+ *      - Always put the defines in the DEFS properties, never use the FLAGS
+ *        properties for this.  Doing so may screw up depenencies and object
+ *        caches.
+ *
+ *      - Mark each section and target of the file with a 3+ lines comment
+ *        block.
+ *
+ *      - Document variables that are not immediately obvious using double hash
+ *        comments, doxygen style.
+ *
+ *      - Each an every Makefile.kmk shall have a file header with Id, file
+ *        description and copyright/license exactly like in the examples.  (The
+ *        SCM tool will complain if you don't.)
+ *
+ *      - Multiple blank lines in a makefile is very seldom there without a
+ *        reason and shall be preserved.
+ *
+ *      - Inserting blank lines between target properties is all right if the
+ *        target definition is long and/or crooked.
+ *
+ *      - if1of and ifn1of shall always have a space after the comma, while ifeq
+ *        and ifneq shall not. That way they are easier to tell apart.
+ *
+ *      - Do a svn diff before committing makefile changes.
+ *
+ *
+ * @section sec_vbox_makefile_guidelines_reminders      Helpful reminders
+ *
+ *      - Do not be afraid to ask for help on IRC or in the defect you're
+ *        working on. There are usually somebody around that know how to best do
+ *        something.
+ *
+ *      - Watch out for "Heads Up!" bugtracker messages concerning the build
+ *        system.
+ *
+ *      - To remove bits from a template you're using you have to create a new
+ *        template that extends the existing one and creatively use
+ *        \$(filter-out) or \$(patsubst).
+ *
+ *      - You can build sub-trees.
+ *
+ *      - You don't have to cd into sub-trees: kmk -C src/recompiler
+ *
+ *      - You can build individual targets: kmk VBoxRT
+ *
+ *      - Even install targets: kmk nobin
+ *
+ *      - You can compile individual source files: kmk ConsoleImpl.o
+ *
+ *      - You can tell kmk to continue on failure: kmk -k
+ *
+ *      - You can tell kmk to run at low priority: kmk --nice
+ *
+ *      - The --pretty-command-printing option is useful for seeing exactly
+ *        what's passed to the tools.
+ *
+ *      - You can invoke recipes in the root makefile more efficiently via the
+ *        Maintenance.kmk file: kmk -f Maintenance.kmk incs
+ *
+ */
+