Re: [PATCH 2/7] help -a: do not list commands that are excluded from the build
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Apr 15, 2019, 07:08 UTC
- Message-ID
- <xmqqo957sq2g.fsf@gitster-ct.c.googlers.com>
- In-Reply-To
- <7dc5293e9e0f8997674b1273393f22954e72c4cd.1555070430.git.gitgitgadget@gmail.com>
"Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com> writes:
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> From: Johannes Schindelin <johannes.schindelin@gmx.de> > > When built with NO_CURL or with NO_UNIX_SOCKETS, some commands are > skipped from the build. It does not make sense to list them in the > output of `git help -a`, so let's just not.
The objective makes sense quite a lot.
> command-list.h: $(wildcard Documentation/git*.txt) Documentation/*config.txt Documentation/config/*.txt > - $(QUIET_GEN)$(SHELL_PATH) ./generate-cmdlist.sh command-list.txt >$@+ && mv $@+ $@ > + $(QUIET_GEN)$(SHELL_PATH) ./generate-cmdlist.sh \ > + $(patsubst %,--exclude-program %,$(EXCLUDED_PROGRAMS)) \
Each whitespace separated token on $(EXCLUDED_PROGRAMS) is the name of a program to be excluded and we know there is no funny characters in it, hence quoing in "^$1 " (without protecting us against funnies) is sufficient.
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> + command-list.txt >$@+ && mv $@+ $@
>
> SCRIPT_DEFINES = $(SHELL_PATH_SQ):$(DIFF_SQ):$(GIT_VERSION):\
> $(localedir_SQ):$(NO_CURL):$(USE_GETTEXT_SCHEME):$(SANE_TOOL_PATH_SQ):\
> diff --git a/generate-cmdlist.sh b/generate-cmdlist.sh
> index 709d67405b..7867b99d19 100755
> --- a/generate-cmdlist.sh
> +++ b/generate-cmdlist.sh
> @@ -6,7 +6,7 @@ die () {
> }
>
> command_list () {
> - grep -v '^#' "$1"
> + eval grep -ve '^#' $exclude_programs "$1"The original protects against $IFS in the filename given as $1, but with the eval that is no longer true. We have been feeding the constant "command-list.txt" to the program since its inception, and I do not expect it to change, so this regression in defensiveness does not matter in practice. Also because # is prefixed with ^, the unintended loss of quotes around it when the eval makes the shell re-parse the generated command line would not make the remainder into a comment.
But it does look brittle, and smells like a trap for less experienced shell programmers to blindly copy & paste & tweak without understanding what is going on, leading to bugs.
eval "grep -v -e '^#' $exclude_programs" <"$1"
or something like that, perhaps?
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> @@ -93,6 +93,14 @@ EOF > EOF > } > > +exclude_programs= > +while test "a$1" = "a--exclude-program"
s/a/z/g; if you want to pretend to be old-fashioned, but s/a//g; should be sufficient in the modern world.
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> +do > + shift > + exclude_programs="$exclude_programs -e \"^$1 \"" > + shift > +done
As I said, this part looks good enough given the things we feed as parameters to --exclude-program option.
Thanks.