From: Ben Knoble <ben.knoble@gmail.com>
Date: Tue, 17 Feb 2026 00:33:19 GMT
Subject: Re: [PATCH v4] meson: regenerate config-list.h when Documentation changes
Message-ID: <286624E8-94CD-4C65-BB91-BF8338B8A79A@gmail.com>
In-Reply-To: <9cdcc9de04f0f8fff657f0474b31c063466ed808.1771280837.git.ben.knoble+github@gmail.com>


> Le 16 févr. 2026 à 17:29, D. Ben Knoble <ben.knoble+github@gmail.com> a écrit :
> 
> 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

Hmm. I’m pretty sure this worked locally but I’m seeing some CI failures on GitHub. Will investigate.