5284dcf7de
While describing a package I though that the tab and 2 spaces was already doing the margin for wrapping the help test (ie 70 char when wrapping to 80) but apparently the full text need to fit 72 columns. So this patch propose to document that fact in the two places where the Config.in format is described. Signed-off-by: Julien Viard de Galbert <julien@vdg.name> Acked-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
144 lines
3.5 KiB
Plaintext
144 lines
3.5 KiB
Plaintext
// -*- mode:doc; -*-
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// vim: set syntax=asciidoc:
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== Coding style
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Overall, these coding style rules are here to help you to add new files in
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Buildroot or refactor existing ones.
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If you slightly modify some existing file, the important thing is
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to keep the consistency of the whole file, so you can:
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* either follow the potentially deprecated coding style used in this
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file,
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* or entirely rework it in order to make it comply with these rules.
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[[writing-rules-config-in]]
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=== +Config.in+ file
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+Config.in+ files contain entries for almost anything configurable in
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Buildroot.
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An entry has the following pattern:
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---------------------
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config BR2_PACKAGE_LIBFOO
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bool "libfoo"
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depends on BR2_PACKAGE_LIBBAZ
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select BR2_PACKAGE_LIBBAR
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help
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This is a comment that explains what libfoo is.
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http://foosoftware.org/libfoo/
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---------------------
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* The +bool+, +depends on+, +select+ and +help+ lines are indented
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with one tab.
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* The help text itself should be indented with one tab and two
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spaces.
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* The help text should be wrapped to fit 72 columns.
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The +Config.in+ files are the input for the configuration tool
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used in Buildroot, which is the regular _Kconfig_. For further
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details about the _Kconfig_ language, refer to
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http://kernel.org/doc/Documentation/kbuild/kconfig-language.txt[].
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[[writing-rules-mk]]
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=== The +.mk+ file
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* Header: The file starts with a header. It contains the module name,
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preferably in lowercase, enclosed between separators made of 80 hashes. A
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blank line is mandatory after the header:
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+
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---------------------
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################################################################################
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#
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# libfoo
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#
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################################################################################
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---------------------
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+
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* Assignment: use +=+ preceded and followed by one space:
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+
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---------------------
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LIBFOO_VERSION = 1.0
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LIBFOO_CONF_OPTS += --without-python-support
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---------------------
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+
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Do not align the +=+ signs.
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* Indentation: use tab only:
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+
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---------------------
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define LIBFOO_REMOVE_DOC
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$(RM) -fr $(TARGET_DIR)/usr/share/libfoo/doc \
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$(TARGET_DIR)/usr/share/man/man3/libfoo*
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endef
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---------------------
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+
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Note that commands inside a +define+ block should always start with a tab,
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so _make_ recognizes them as commands.
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* Optional dependency:
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** Prefer multi-line syntax.
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+
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YES:
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+
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---------------------
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ifeq ($(BR2_PACKAGE_PYTHON),y)
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LIBFOO_CONF_OPTS += --with-python-support
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LIBFOO_DEPENDENCIES += python
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else
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LIBFOO_CONF_OPTS += --without-python-support
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endif
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---------------------
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+
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NO:
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+
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---------------------
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LIBFOO_CONF_OPTS += --with$(if $(BR2_PACKAGE_PYTHON),,out)-python-support
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LIBFOO_DEPENDENCIES += $(if $(BR2_PACKAGE_PYTHON),python,)
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---------------------
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** Keep configure options and dependencies close together.
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* Optional hooks: keep hook definition and assignment together in one
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if block.
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+
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YES:
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+
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---------------------
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ifneq ($(BR2_LIBFOO_INSTALL_DATA),y)
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define LIBFOO_REMOVE_DATA
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$(RM) -fr $(TARGET_DIR)/usr/share/libfoo/data
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endef
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LIBFOO_POST_INSTALL_TARGET_HOOKS += LIBFOO_REMOVE_DATA
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endif
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---------------------
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+
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NO:
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+
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---------------------
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define LIBFOO_REMOVE_DATA
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$(RM) -fr $(TARGET_DIR)/usr/share/libfoo/data
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endef
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ifneq ($(BR2_LIBFOO_INSTALL_DATA),y)
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LIBFOO_POST_INSTALL_TARGET_HOOKS += LIBFOO_REMOVE_DATA
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endif
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---------------------
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=== The documentation
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The documentation uses the
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http://www.methods.co.nz/asciidoc/[asciidoc] format.
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For further details about the http://www.methods.co.nz/asciidoc/[asciidoc]
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syntax, refer to http://www.methods.co.nz/asciidoc/userguide.html[].
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