Documentation: allow sourcing generated includes from separate dir

Our documentation uses "include::" directives to include parts that are
either reused across multiple documents or parts that we generate at
build time. Unfortunately, top-level includes are only ever resolved
relative to the base directory, which is typically the directory of the
including document. Most importantly, it is not possible to have either
asciidoc or asciidoctor search multiple directories.

It follows that both kinds of includes must live in the same directory.
This is of course a bummer for out-of-tree builds, because here the
dynamically-built includes live in the build directory whereas the
static includes live in the source directory.

Introduce a `build_dir` attribute and prepend it to all of our includes
for dynamically-built files. This attribute gets set to the build
directory and thus converts the include path to an absolute path, which
asciidoc and asciidoctor know how to resolve.

Note that this change also requires us to update "build-docdep.perl",
which tries to figure out included files such our Makefile can set up
proper build-time dependencies. This script simply scans through the
source files for any lines that match "^include::" and treats the
remainder of the line as included file path. But given that those may
now contain the "{build_dir}" variable we have to teach the script to
replace that attribute with the actual build directory.

Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: pks-t

Documentation/Makefile

@@ -224,6 +224,7 @@ SHELL_PATH ?= $(SHELL)
 # Shell quote;
 SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))
 
+ASCIIDOC_EXTRA += -abuild_dir='$(shell pwd)'
 ifdef DEFAULT_PAGER
 DEFAULT_PAGER_SQ = $(subst ','\'',$(DEFAULT_PAGER))
 ASCIIDOC_EXTRA += -a 'git-default-pager=$(DEFAULT_PAGER_SQ)'
@@ -289,7 +290,7 @@ docdep_prereqs = \
 	cmd-list.made $(cmds_txt)
 
 doc.dep : $(docdep_prereqs) $(DOC_DEP_TXT) build-docdep.perl
-	$(QUIET_GEN)$(PERL_PATH) ./build-docdep.perl >$@ $(QUIET_STDERR)
+	$(QUIET_GEN)$(PERL_PATH) ./build-docdep.perl "$(shell pwd)" >$@ $(QUIET_STDERR)
 
 ifneq ($(MAKECMDGOALS),clean)
 -include doc.dep

Documentation/build-docdep.perl

@@ -1,5 +1,6 @@
 #!/usr/bin/perl
 
+my ($build_dir) = @ARGV;
 my %include = ();
 my %included = ();
 
@@ -10,6 +11,7 @@
 	    chomp;
 	    s/^include::\s*//;
 	    s/\[\]//;
+	    s/{build_dir}/${build_dir}/;
 	    $include{$text}{$_} = 1;
 	    $included{$_} = 1;
 	}

Documentation/config/diff.txt

@@ -218,7 +218,7 @@ endif::git-diff[]
 	Set this option to `true` to make the diff driver cache the text
 	conversion outputs.  See linkgit:gitattributes[5] for details.
 
-include::../mergetools-diff.txt[]
+include::{build_dir}/mergetools-diff.txt[]
 
 `diff.indentHeuristic`::
 	Set this option to `false` to disable the default heuristics

Documentation/config/merge.txt

@@ -101,7 +101,7 @@ merge.guitool::
 	Any other value is treated as a custom merge tool and requires that a
 	corresponding mergetool.<guitool>.cmd variable is defined.
 
-include::../mergetools-merge.txt[]
+include::{build_dir}/mergetools-merge.txt[]
 
 merge.verbosity::
 	Controls the amount of output shown by the recursive merge

Documentation/git.txt

@@ -245,17 +245,17 @@ ancillary user utilities.
 Main porcelain commands
 ~~~~~~~~~~~~~~~~~~~~~~~
 
-include::cmds-mainporcelain.txt[]
+include::{build_dir}/cmds-mainporcelain.txt[]
 
 Ancillary Commands
 ~~~~~~~~~~~~~~~~~~
 Manipulators:
 
-include::cmds-ancillarymanipulators.txt[]
+include::{build_dir}/cmds-ancillarymanipulators.txt[]
 
 Interrogators:
 
-include::cmds-ancillaryinterrogators.txt[]
+include::{build_dir}/cmds-ancillaryinterrogators.txt[]
 
 
 Interacting with Others
@@ -264,7 +264,7 @@ Interacting with Others
 These commands are to interact with foreign SCM and with other
 people via patch over e-mail.
 
-include::cmds-foreignscminterface.txt[]
+include::{build_dir}/cmds-foreignscminterface.txt[]
 
 Reset, restore and revert
 ~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -313,13 +313,13 @@ repositories.
 Manipulation commands
 ~~~~~~~~~~~~~~~~~~~~~
 
-include::cmds-plumbingmanipulators.txt[]
+include::{build_dir}/cmds-plumbingmanipulators.txt[]
 
 
 Interrogation commands
 ~~~~~~~~~~~~~~~~~~~~~~
 
-include::cmds-plumbinginterrogators.txt[]
+include::{build_dir}/cmds-plumbinginterrogators.txt[]
 
 In general, the interrogate commands do not touch the files in
 the working tree.
@@ -328,12 +328,12 @@ the working tree.
 Syncing repositories
 ~~~~~~~~~~~~~~~~~~~~
 
-include::cmds-synchingrepositories.txt[]
+include::{build_dir}/cmds-synchingrepositories.txt[]
 
 The following are helper commands used by the above; end users
 typically do not use them directly.
 
-include::cmds-synchelpers.txt[]
+include::{build_dir}/cmds-synchelpers.txt[]
 
 
 Internal helper commands
@@ -342,14 +342,14 @@ Internal helper commands
 These are internal helper commands used by other commands; end
 users typically do not use them directly.
 
-include::cmds-purehelpers.txt[]
+include::{build_dir}/cmds-purehelpers.txt[]
 
 Guides
 ------
 
 The following documentation pages are guides about Git concepts.
 
-include::cmds-guide.txt[]
+include::{build_dir}/cmds-guide.txt[]
 
 Repository, command and file interfaces
 ---------------------------------------
@@ -358,7 +358,7 @@ This documentation discusses repository and command interfaces which
 users are expected to interact with directly. See `--user-formats` in
 linkgit:git-help[1] for more details on the criteria.
 
-include::cmds-userinterfaces.txt[]
+include::{build_dir}/cmds-userinterfaces.txt[]
 
 File formats, protocols and other developer interfaces
 ------------------------------------------------------
@@ -367,7 +367,7 @@ This documentation discusses file formats, over-the-wire protocols and
 other git developer interfaces. See `--developer-interfaces` in
 linkgit:git-help[1].
 
-include::cmds-developerinterfaces.txt[]
+include::{build_dir}/cmds-developerinterfaces.txt[]
 
 Configuration Mechanism
 -----------------------