[PATCH] bootstrap: Provide a hook for submodule _SRCDIR setup

[Arsen Arsenović]

* top/bootstrap-funclib.sh (bootstrap_srcdirs_hook): Define a hook
for user-specified submodule directory paths.
* top/bootstrap: Call bootstrap_srcdirs_hook after setting up
GNULIB_SRCDIR.
* top/autogen.sh: Likewise.
* top/autopull.sh: Likewise.
* build-aux/bootstrap: Regenerate.
---
Hi there,

While updating Gnulib in poke, I ran into a slight hurdle: there was no
exact way to add setup for non-Gnulib SRCDIR variables (such as that of
Jitter, which integrates in the poke build system similarly to how
Gnulib does).  The solution proposed here lets Jitter be integrated via:

  # Set up the Jitter path.
  bootstrap_srcdirs_hook () {
    # Pass JITTER_SRCDIR to subprocesses.
    export JITTER_SRCDIR
  
    # We already have something. Don't touch it.
    test -n "$JITTER_SRCDIR" && return 0
  
    case "$me" in
      *autogen.sh*)
        # If we're in autogen, we want to simply default to ./jitter, since
        # that's the common default when just regenerating.
        : "${JITTER_SRCDIR:=jitter}"
        ;;
      *autopull.sh*|*bootstrap*)
        # However, if also pulling, we want the use_git logic.
        $use_git || test -n "$JITTER_SRCDIR" \
          || die "Error: --no-git requires \$JITTER_SRCDIR environment variable 
or --jitter-srcdir option"
        $use_git && : "${JITTER_SRCDIR:=jitter}"  # A reasonable default.
        test -z "$JITTER_SRCDIR" || test -d "$JITTER_SRCDIR" \
          || die "Error: \$JITTER_SRCDIR environment variable or 
--jitter-srcdir option is specified, but does not denote a directory"
        ;;
    esac
  }

... and the existing post-import hooks, plus the post-pull hook that
Bruno recommended here:
https://lists.gnu.org/archive/html/poke-devel/2022-07/msg00098.html

I'm still not sure how I feel about that default in the autogen.sh case,
though.  Maybe we should go with some other idiom?  Or maybe I
overlooked some existing way to properly add Jitter to bootstrap?

I reckon it's good enough, since it should match with what autopull
decides by default (and the default is use_git=true).

WDYT?

Thanks, have a great day.

 ChangeLog                | 11 +++++++++++
 build-aux/bootstrap      | 13 ++++++++-----
 top/autogen.sh           |  4 ++++
 top/autopull.sh          |  4 ++++
 top/bootstrap            |  3 +++
 top/bootstrap-funclib.sh |  7 +++++++
 6 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 36825874d..58be71b45 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2022-11-27  Arsen Arsenović  <arsen@aarsen.me>
+
+       bootstrap: Provide a hook for submodule _SRCDIR setup
+       * top/bootstrap-funclib.sh (bootstrap_srcdirs_hook): Define a hook
+       for user-specified submodule directory paths.
+       * top/bootstrap: Call bootstrap_srcdirs_hook after setting up
+       GNULIB_SRCDIR.
+       * top/autogen.sh: Likewise.
+       * top/autopull.sh: Likewise.
+       * build-aux/bootstrap: Regenerate.
+
 2022-11-26  Paul Eggert  <eggert@cs.ucla.edu>
 
        Prefer "kill -INT" to killing with a number
diff --git a/build-aux/bootstrap b/build-aux/bootstrap
index 341d05d57..31ded443d 100755
--- a/build-aux/bootstrap
+++ b/build-aux/bootstrap
@@ -30,7 +30,7 @@
 
 # Please report bugs or propose patches to bug-gnulib@gnu.org.
 
-scriptversion=2022-07-24.15; # UTC
+scriptversion=2022-07-29.23; # UTC
 
 me="$0"
 medir=`dirname "$me"`
@@ -147,6 +147,10 @@ bootstrap_post_import_hook() { :; }
 # Override it via your own definition in bootstrap.conf.
 bootstrap_epilogue() { :; }
 
+# A function to be called after setting GNULIB_SRCDIR, but before anything
+# else, so that they user may define their own *_SRCDIR variables.
+bootstrap_srcdirs_hook() { :; }
+
 # The command to download all .po files for a specified domain into a
 # specified directory.  Fill in the first %s with the destination
 # directory and the second with the domain name.
@@ -657,10 +661,6 @@ Options:
                            and history on your machine, and do not want
                            to waste your bandwidth downloading them again.
                            Defaults to \$GNULIB_REFDIR
-  --bootstrap-sync         if this bootstrap script is not identical to
-                           the version in the local gnulib sources,
-                           update this script, and then restart it with
-
   --bootstrap-sync         if this bootstrap script is not identical to
                            the version in the local gnulib sources,
                            update this script, and then restart it with
@@ -768,6 +768,9 @@ if test -n "$checkout_only_file" && test ! -r 
"$checkout_only_file"; then
   die "Bootstrapping from a non-checked-out distribution is risky."
 fi
 
+# Now, call the users _SRCDIR setups.
+bootstrap_srcdirs_hook
+
 check_build_prerequisites $use_git
 
 if ! test -f "$medir"/bootstrap-funclib.sh; then
diff --git a/top/autogen.sh b/top/autogen.sh
index 81db3fe03..49417c5bd 100755
--- a/top/autogen.sh
+++ b/top/autogen.sh
@@ -126,6 +126,10 @@ if $use_gnulib; then
   fi
 fi
 
+# Let the user set up their own _SRCDIRs, in case they weren't passed down from
+# bootstrap itself.
+bootstrap_srcdirs_hook
+
 version_controlled_file() {
   parent=$1
   file=$2
diff --git a/top/autopull.sh b/top/autopull.sh
index ffb4ba7cb..6df8613b6 100755
--- a/top/autopull.sh
+++ b/top/autopull.sh
@@ -151,6 +151,10 @@ $use_git || test -n "$GNULIB_SRCDIR" \
 test -z "$GNULIB_SRCDIR" || test -d "$GNULIB_SRCDIR" \
   || die "Error: \$GNULIB_SRCDIR environment variable or --gnulib-srcdir 
option is specified, but does not denote a directory"
 
+# Let the user set up their own _SRCDIRs, in case they weren't passed down from
+# bootstrap itself.
+bootstrap_srcdirs_hook
+
 if test -n "$checkout_only_file" && test ! -r "$checkout_only_file"; then
   die "Running this script from a non-checked-out distribution is risky."
 fi
diff --git a/top/bootstrap b/top/bootstrap
index cf8d007f6..747565cb3 100755
--- a/top/bootstrap
+++ b/top/bootstrap
@@ -166,6 +166,9 @@ if test -n "$checkout_only_file" && test ! -r 
"$checkout_only_file"; then
   die "Bootstrapping from a non-checked-out distribution is risky."
 fi
 
+# Now, call the users _SRCDIR setups.
+bootstrap_srcdirs_hook
+
 check_build_prerequisites $use_git
 
 if ! test -f "$medir"/bootstrap-funclib.sh; then
diff --git a/top/bootstrap-funclib.sh b/top/bootstrap-funclib.sh
index cfad85a31..b5d85100e 100644
--- a/top/bootstrap-funclib.sh
+++ b/top/bootstrap-funclib.sh
@@ -108,6 +108,13 @@ bootstrap_post_import_hook() { :; }
 # Override it via your own definition in bootstrap.conf.
 bootstrap_epilogue() { :; }
 
+# A function to be called after setting GNULIB_SRCDIR, but before anything
+# else, so that they user may define their own *_SRCDIR variables.  This hook
+# should only bother with setting up your _SRCDIR variables and exporting them,
+# *not pulling them*.  The latter should be handled by
+# bootstrap_post_pull_hook.
+bootstrap_srcdirs_hook() { :; }
+
 # The command to download all .po files for a specified domain into a
 # specified directory.  Fill in the first %s with the destination
 # directory and the second with the domain name.
-- 
2.38.1