From 8f27b40d702791d7b9ec63efefe7a5fc2a4e804e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fran=C3=A7ois-Ren=C3=A9=20Rideau?= <fare@tunes.org>
Date: Tue, 5 Dec 2023 13:38:30 -0500
Subject: [PATCH] Support version MANIFEST. Update release.md. (#1074)

---
 configure                    | 43 +++++++++++++++++++++++++++----
 doc/reference/dev/release.md | 50 +++++++++++++++++++++++-------------
 manifest.sh                  | 18 +++++++++++++
 src/build/build-version.scm  | 37 ++++++++++++++++----------
 4 files changed, 112 insertions(+), 36 deletions(-)
 create mode 100755 manifest.sh

diff --git a/configure b/configure
index 93b899015..2238dc9a0 100755
--- a/configure
+++ b/configure
@@ -2,6 +2,14 @@
 set -e
 cd $(dirname "$0")
 
+# There are two ways that Gerbil may get version information:
+# 1. a version MANIFEST file, for git-less tarballs and builds (e.g. Nix, Guix)
+# 2. git, for regular development
+#
+# The format of the version MANIFEST file is as generated by ./manifest.sh
+# with quote-less shell definitions var=value for the following variables:
+# gerbil_stamp_version gambit_stamp_version gambit_stamp_ymd gambit_stamp_hms
+
 die() {
   echo "configuration failed"
   exit 1
@@ -57,7 +65,12 @@ package_out_of_tree() {
     echo "It is now available as an external package: github.com/mighty-gerbils/gerbil-${pkg}"
 }
 
-readonly gerbil_version="$(git describe --tags --always)"
+if [ -f MANIFEST ] ; then
+  . ./MANIFEST
+  readonly gerbil_version="$gerbil_stamp_version"
+else
+  readonly gerbil_version="$(git describe --tags --always)"
+fi
 readonly gerbil_targets=""
 readonly default_gambit_tag=8b18ab69504c2d41301f7fec16a5350db717a20e
 readonly default_gambit_config="--enable-targets=${gerbil_targets} --enable-single-host --enable-dynamic-clib --enable-default-runtime-options=tE8,f8,-8 --enable-trust-c-tco"
@@ -213,14 +226,34 @@ else
     fi
 fi
 
-git submodule init || die
-git submodule update --force || die
-
-(cd src/gambit && git fetch origin && git checkout "${gambit_tag}" && touch configure config.status) || die
+if [ ! -f MANIFEST -o ! -f src/gambit/configure ] ; then
+  git submodule init || die
+  git submodule update --force || die
+  (cd src/gambit && git fetch origin && git checkout "${gambit_tag}" && touch configure config.status) || die
+  unset gambit_stamp_version
+fi
 
 gambit_config="--prefix=${gerbil_prefix} --enable-march=${gambit_march} ${gambit_shared} ${gambit_config}"
 (export LDFLAGS="$LDFLAGS"; export CFLAGS="$CFLAGS"; cd src/gambit && ./configure $gambit_config ) || die
 
+if [ -n "$gambit_stamp_version" ] ; then
+  sed -i -e "s/^stamp:/stamp-orig:/" src/gambit/include/makefile
+  echo stamp: >> src/gambit/include/makefile
+  cat >> src/gambit/include/stamp.h <<EOF
+#ifndef ___STAMP_VERSION
+#define ___STAMP_VERSION "${gambit_stamp_version}"
+#endif
+
+#ifndef ___STAMP_YMD
+#define ___STAMP_YMD ${gambit_stamp_ymd}
+#endif
+
+#ifndef ___STAMP_HMS
+#define ___STAMP_HMS ${gambit_stamp_hms}
+#endif
+EOF
+fi
+
 rm -f build-env.sh
 cat > build-env.sh <<EOF
 GERBIL_PREFIX=${gerbil_prefix}
diff --git a/doc/reference/dev/release.md b/doc/reference/dev/release.md
index 1c7daaa54..cd55fbbf0 100644
--- a/doc/reference/dev/release.md
+++ b/doc/reference/dev/release.md
@@ -21,15 +21,26 @@ Linux x86-64, macOS ARM64.
 [Ask for help on gitter](https://app.element.io/#/room/#gerbil-scheme_community:gitter.im)
 regarding platforms you can't support yourself.
 
-## Prepare a PR for the Release
+## Merge Pre-Release PRs
+- Update release scripts and release documentation
+- Update homebrew (macOS) recipe (except exact commit) - ask @drewc for help
+- Update Guix (Linux) recipe (except exact commit) - ask @drewc for help
+- Update to Nix (Linux, macOS) recipe (except exact commit) - ask @fare for help
+  (the recipe is currently in a fork of nixpkgs, not in the gerbil repository)
+
+## Merge a PR for the Release itself
 - Update the version everywhere in documentation
-- Update the version everywhere in in-repo release scripts (homebrew, guix)
-- Generate a `src/gerbil/runtime/version.ss` for the release
-- Temporarily remove `src/gerbil/runtime/version.ss` from the `.gitignore`
 - Include a high-level summary of changes in the
   [CHANGELOG.md](https://github.com/mighty-gerbils/gerbil/blob/master/CHANGELOG.md)
-- Check that the release scripts work on macOS, etc.
-Note that the website will be automatically re-generated from the PR.
+- Generate a `MANIFEST` for the release with the following shell command
+  from the Gerbil repository top directory,
+  where the argument is the desired release name:
+  `./manifest.sh v0.19`
+
+Note that:
+- The release PR should not contain anything but this version bump.
+  Make any other necessary change in the pre-release PRs.
+- The website will be automatically re-generated from the PR. No action needed.
 
 ## Create Official Announcements
 Once the release PR is merged:
@@ -43,22 +54,25 @@ Once the release PR is merged:
   Use that as the basis for the GitHub release note page.
   See e.g. [this previous release](https://github.com/mighty-gerbils/gerbil/releases/tag/v0.18).
 
+Note that creating the release on GitHub should create a git tag,
+that you can pull in your local repository with: `git pull --tags`
+
 ## Update Tarballs
-- Generate tarball for the source code, including Gambit module
-- Generate binary tarball for Linux x86-64. - ask @ober for help
+- Generate tarball for the Gerbil source code,
+  *including the Gambit submodule at the correct version* in `src/gambit`.
+  Mind that the tarball autogenerated by GitHub does not include Gambit.
+- Generate a binary tarball for Linux x86-64. - ask @fare or @ober for help
+- Generate a binary tarball for the shared objects that the above uses (e.g. `sqlite.so`),
+  so that e.g. the previous tarball can be deployed on Heroku. - ask @fare for help
 - Generate rpm and deb packages for Linux x86-64. - ask @ober for help
-- Publish the tarballs as artifacts on GitHub on the
+- Publish each of these tarballs as artifacts on GitHub on the
   [release page](https://github.com/mighty-gerbils/gerbil/releases/)
 
-## Update Other Build Recipes
-- Update Homebrew (macOS) — ask @drewc for help
-- Update Nixpkgs (Linux, macOS) - ask @fare for help
-- Update Guix (Linux) — ask @drewc for help
-
-## Clean up PR after the Release
-Assuming the release happened on the `master` branch, undo it:
-- Remove the `src/gerbil/runtime/version.ss`
-- Add it back to `.gitignore`
+## Merge Post-Release PRs
+- Remove the `MANIFEST` file.
+- Update to homebrew (macOS) recipe - ask @drewc for help
+- Update to Guix (Linux) recipe - ask @drewc for help
+- Update to Nixpkgs (Linux, macOS) recipe - ask @fare for help
 
 ## Announce the Release to the World
 Point to the announcement page on GitHub.
diff --git a/manifest.sh b/manifest.sh
new file mode 100755
index 000000000..d439686ce
--- /dev/null
+++ b/manifest.sh
@@ -0,0 +1,18 @@
+#!/bin/sh
+# Create a version MANIFEST so you can build a git-less tarball of Gerbil.
+#
+# Given an argument $1, use it as the gerbil_stamp_version, e.g. for a release.
+# Otherwise, extract the gerbil_stamp_version from git.
+#
+# Commit the MANIFEST to git for a release and a release only.
+# Delete it from git immediately after release.
+# See doc/reference/dev/release.md for instructions.
+#
+# git grep MANIFEST will tell you which files care about the MANIFEST
+
+cat > MANIFEST <<EOF
+gerbil_stamp_version=${1:-$(git describe --tags --always)}
+gambit_stamp_version=$(cd src/gambit ; git describe --tags --always)
+gambit_stamp_ymd=$(cd src/gambit ; TZ=UTC git show --quiet --date='format-local:%Y%m%d' --format=%cd)
+gambit_stamp_hms=$(cd src/gambit ; TZ=UTC git show --quiet --date='format-local:%H%M%S' --format=%cd)
+EOF
diff --git a/src/build/build-version.scm b/src/build/build-version.scm
index e48b98e22..9e0a8f67f 100644
--- a/src/build/build-version.scm
+++ b/src/build/build-version.scm
@@ -1,19 +1,30 @@
 (let* ((gerbil-version-path
         (path-expand "gerbil/runtime/version.ss" (getenv "GERBIL_SOURCE")))
        (git-version
-        (with-exception-catcher
-         (lambda (e) (display-exception e) #f)
-         (lambda ()
-           (let* ((proc (open-process
-                         '(path: "git"
-                                 arguments: ("describe" "--tags" "--always")
-                                 show-console: #f)))
-                  (version (read-line proc))
-                  (status (process-status proc)))
-             (close-port proc)
-             (and (zero? status)
-                  (string? version) ;; (not (eof-object? version))
-                  version)))))
+        (if (file-exists? "../MANIFEST")
+          (call-with-input-file "../MANIFEST"
+            (lambda (port)
+              (let loop ()
+                (let ((line (read-line port))
+                      (prefix "gerbil_stamp_version="))
+                  (cond
+                   ((eof-object? line) #f)
+                   ((string-prefix? prefix line)
+                    (substring line (string-length prefix) (string-length line)))
+                   (else (loop)))))))
+          (with-exception-catcher
+           (lambda (e) (display-exception e) #f)
+           (lambda ()
+             (let* ((proc (open-process
+                           '(path: "git"
+                                   arguments: ("describe" "--tags" "--always")
+                                   show-console: #f)))
+                    (version (read-line proc))
+                    (status (process-status proc)))
+               (close-port proc)
+               (and (zero? status)
+                    (string? version) ;; (not (eof-object? version))
+                    version))))))
        (gerbil-version-text
         (and git-version
              (string-append "(def (gerbil-version-string) \"" git-version "\")\n"))))