[PATCH v4] meson: regenerate config-list.h when Documentation changes

From: D. Ben Knoble <ben.knoble+github@gmail.com>
Date: Feb 16, 2026, 22:28 UTC
Message-ID: <9cdcc9de04f0f8fff657f0474b31c063466ed808.1771280837.git.ben.knoble+github@gmail.com>
In-Reply-To: <0a344f1f3ee4a5d95c6f46df030b9936db4354a1.1770853297.git.ben.knoble+github@gmail.com>

The Meson-based build doesn't know when to rebuild config-list.h, so the header is sometimes stale.

For example, an old build directory might have config-list.h from before 4173df5187 (submodule: introduce extensions.submodulePathConfig, 2026-01-12), which added submodule.<name>.gitdir to the list. Without it, t9902-completion.sh fails. Regenerating the config-list.h artifact from sources fixes the artifact and the test.

Teach the meson build to depend on the Documentation files that generate-configlist.sh reads by having it an additional output as a list of dependency files, since Meson does not have (or want) builtin support for globbing like Make. We assume that if a user adds a new file under Documentation/config then they will also edit one of the existing files to include that new file, and that will trigger a rebuild.

Also mark the generator script as a dependency.

Combining the following commands helps debug dependencies:

    ninja -C <builddir> -t deps config-list.h
    ninja -C <builddir> -t browse config-list.h

The former lists all the dependencies discovered from our output ".d" file (the config documentation) and the latter shows the dependency on the script itself, among other useful edges in the dependency graph.

Helped-by: Patrick Steinhardt <ps@pks.im>
Helped-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: D. Ben Knoble <ben.knoble+github@gmail.com>
---

Notes (benknoble/commits):
    Changes from v3 (<0a344f1f3ee4a5d95c6f46df030b9936db4354a1.1770853297.git.ben.knoble+github@gmail.com>):
    
    • Include the script itself as a dependency via depfile
    • Fix output path escaping (spaces, octothorpes; drop backslashes) for
      Ninja (I've used a loop because I couldn't find a portable construct
      that could escape only the remainder of the lines in the way I
      wanted).
    • Mention our assumptions about Documentation updates triggering
      rebuilds
    • Also include some debugging information in the commit message

 generate-configlist.sh | 12 +++++++++++-
 meson.build            |  5 ++++-
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/generate-configlist.sh b/generate-configlist.sh
index 75c39ade209..63a2e8b6938 100755
--- a/generate-configlist.sh
+++ b/generate-configlist.sh
@@ -2,10 +2,11 @@
 
 SOURCE_DIR="$1"
 OUTPUT="$2"
+DEPFILE="$3"
 
 if test -z "$SOURCE_DIR" || ! test -d "$SOURCE_DIR" || test -z "$OUTPUT"
 then
-	echo >&2 "USAGE: $0 <SOURCE_DIR> <OUTPUT>"
+	echo >&2 "USAGE: $0 <SOURCE_DIR> <OUTPUT> [<DEPFILE>]"
 	exit 1
 fi
 
@@ -36,3 +37,12 @@ print_config_list ()
 	echo
 	print_config_list
 } >"$OUTPUT"
+
+if test -n "$DEPFILE"
+then
+	for doc in "$SOURCE_DIR"/Documentation/*config.adoc \
+		"$SOURCE_DIR"/Documentation/config/*.adoc
+	do
+		printf "$OUTPUT: %s\n" "$(printf '%s\n' "$doc" | sed 's/[# ]/\\&/g')"
+	done >"$DEPFILE"
+fi
diff --git a/meson.build b/meson.build
index 3a1d12caa4b..e4b8f1e33d2 100644
--- a/meson.build
+++ b/meson.build
@@ -720,11 +720,14 @@ endif
 
 builtin_sources += custom_target(
   output: 'config-list.h',
+  depfile: 'config-list.h.d',
+  depend_files: [ 'generate-configlist.sh' ],
   command: [
     shell,
-    meson.current_source_dir() + '/generate-configlist.sh',
+    meson.current_source_dir() / 'generate-configlist.sh',
     meson.current_source_dir(),
     '@OUTPUT@',
+    '@DEPFILE@',
   ],
   env: script_environment,
 )

Diff-intervalle contre v3 :
1:  0a344f1f3ee ! 1:  9cdcc9de04f meson: regenerate config-list.h when Documentation changes
    @@ Commit message
         Teach the meson build to depend on the Documentation files that
         generate-configlist.sh reads by having it an additional output as a list
         of dependency files, since Meson does not have (or want) builtin support
    -    for globbing like Make.
    +    for globbing like Make. We assume that if a user adds a new file under
    +    Documentation/config then they will also edit one of the existing files
    +    to include that new file, and that will trigger a rebuild.
    +
    +    Also mark the generator script as a dependency.
    +
    +    Combining the following commands helps debug dependencies:
    +
    +        ninja -C <builddir> -t deps config-list.h
    +        ninja -C <builddir> -t browse config-list.h
    +
    +    The former lists all the dependencies discovered from our output ".d"
    +    file (the config documentation) and the latter shows the dependency on
    +    the script itself, among other useful edges in the dependency graph.
     
         Helped-by: Patrick Steinhardt <ps@pks.im>
    +    Helped-by: Phillip Wood <phillip.wood@dunelm.org.uk>
     
     
      ## Notes (benknoble/commits) ##
    -    Changes from v2 (<c9ae171eed6bd5b0fa6671b10a5ad0da024f36d0.1770649805.git.ben.knoble+github@gmail.com>):
    +    Changes from v3 (<0a344f1f3ee4a5d95c6f46df030b9936db4354a1.1770853297.git.ben.knoble+github@gmail.com>):
     
    -    • Pick up (and tweak) Patrick's depfile proposal
    -    • Include the script itself as a dependency
    -    • Escape output paths (spaces, octothorpes, and backslashes) for Ninja
    -
    -    I'm not 100% sure I've actually done the escaping correctly, though,
    -    since Ninja's source says that a space preceded by 2N backslashes
    -    represents 2N backslashes at the end of a filename, and
    -
    -        λ printf '%s\n' 'foo\' | sed 's/[# \\]/\\&/g' | xxd
    -        00000000: 666f 6f5c 5c0a                           foo\\.
    -
    -    So would they interpret that as the filename 'foo\\' instead of 'foo\' ?
    -    (Or, no because the 2N slashes aren't followed by a SP, but a NL?)
    +    • Include the script itself as a dependency via depfile
    +    • Fix output path escaping (spaces, octothorpes; drop backslashes) for
    +      Ninja (I've used a loop because I couldn't find a portable construct
    +      that could escape only the remainder of the lines in the way I
    +      wanted).
    +    • Mention our assumptions about Documentation updates triggering
    +      rebuilds
    +    • Also include some debugging information in the commit message
     
      ## generate-configlist.sh ##
     @@
    @@ generate-configlist.sh: print_config_list ()
     +
     +if test -n "$DEPFILE"
     +then
    -+	printf "$OUTPUT: %s\n" "$0" "$SOURCE_DIR"/Documentation/*config.adoc \
    -+	    "$SOURCE_DIR"/Documentation/config/*.adoc |
    -+	    sed 's/[# \\]/\\&/g' >"$DEPFILE"
    ++	for doc in "$SOURCE_DIR"/Documentation/*config.adoc \
    ++		"$SOURCE_DIR"/Documentation/config/*.adoc
    ++	do
    ++		printf "$OUTPUT: %s\n" "$(printf '%s\n' "$doc" | sed 's/[# ]/\\&/g')"
    ++	done >"$DEPFILE"
     +fi
     
      ## meson.build ##
    @@ meson.build: endif
      builtin_sources += custom_target(
        output: 'config-list.h',
     +  depfile: 'config-list.h.d',
    ++  depend_files: [ 'generate-configlist.sh' ],
        command: [
          shell,
     -    meson.current_source_dir() + '/generate-configlist.sh',

base-commit: 19a08e0c02faf1c5b4efd1add85598cf8390ff7e
prerequisite-patch-id: 364ba1899740b93be5957262d3583348d030e8fa

-- 
2.48.1