Re: [PATCH v4 02/15] help: move list_config_help to builtin/help

> Starting in 3ac68a93fd2, help.o began to depend on builtin/branch.o,
> builtin/clean.o, and builtin/config.o. This meant that help.o was
> unusable outside of the context of the main Git executable.
>
> To make help.o usable by other commands again, move list_config_help()
> into builtin/help.c (where it makes sense to assume other builtin libraries
> are present).
>
> When command-list.h is included but a member is not used, we start to
> hear a compiler warning. Since the config list is generated in a fairly
> different way than the command list, and since commands and config
> options are semantically different, move the config list into its own
> header and move the generator into its own script and build rule.
>
> Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
> ---

>  .gitignore             |  1 +
>  Makefile               | 16 ++++++--
>  builtin/help.c         | 86 ++++++++++++++++++++++++++++++++++++++++++
>  generate-cmdlist.sh    | 19 ----------
>  generate-configlist.sh | 24 ++++++++++++
>  help.c                 | 85 -----------------------------------------
>  help.h                 |  1 -
>  7 files changed, 123 insertions(+), 109 deletions(-)
>  create mode 100755 generate-configlist.sh
>
> diff --git a/.gitignore b/.gitignore
> index 055a84c4a8..5dde2cc4c8 100644
> --- a/.gitignore
> +++ b/.gitignore
> @@ -189,6 +189,7 @@
>  /gitweb/gitweb.cgi
>  /gitweb/static/gitweb.js
>  /gitweb/static/gitweb.min.*
> +/config-list.h
>  /command-list.h
>  *.tar.gz
>  *.dsc
> diff --git a/Makefile b/Makefile
> index 9dff91436e..c49f55a521 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -815,6 +815,7 @@ LIB_FILE = libgit.a
>  XDIFF_LIB = xdiff/lib.a
>  VCSSVN_LIB = vcs-svn/lib.a
>  
> +GENERATED_H += config-list.h
>  GENERATED_H += command-list.h
>  
>  LIB_H := $(sort $(patsubst ./%,%,$(shell git ls-files '*.h' ':!t/' ':!Documentation/' 2>/dev/null || \
> @@ -2127,7 +2128,7 @@ git$X: git.o GIT-LDFLAGS $(BUILTIN_OBJS) $(GITLIBS)
>  
>  help.sp help.s help.o: command-list.h
>  
> -builtin/help.sp builtin/help.s builtin/help.o: command-list.h GIT-PREFIX
> +builtin/help.sp builtin/help.s builtin/help.o: config-list.h GIT-PREFIX
>  builtin/help.sp builtin/help.s builtin/help.o: EXTRA_CPPFLAGS = \
>  	'-DGIT_HTML_PATH="$(htmldir_relative_SQ)"' \
>  	'-DGIT_MAN_PATH="$(mandir_relative_SQ)"' \
> @@ -2147,6 +2148,12 @@ $(BUILT_INS): git$X
>  	ln -s $< $@ 2>/dev/null || \
>  	cp $< $@
>  
> +config-list.h: generate-configlist.sh
> +
> +config-list.h:
> +	$(QUIET_GEN)$(SHELL_PATH) ./generate-configlist.sh \
> +		>$@+ && mv $@+ $@
> +
>  command-list.h: generate-cmdlist.sh command-list.txt
>  
>  command-list.h: $(wildcard Documentation/git*.txt) Documentation/*config.txt Documentation/config/*.txt
> @@ -2784,7 +2791,7 @@ $(SP_OBJ): %.sp: %.c GIT-CFLAGS FORCE
>  .PHONY: sparse $(SP_OBJ)
>  sparse: $(SP_OBJ)
>  
> -GEN_HDRS := command-list.h unicode-width.h
> +GEN_HDRS := config-list.h command-list.h unicode-width.h
>  EXCEPT_HDRS := $(GEN_HDRS) compat/% xdiff/%
>  ifndef GCRYPT_SHA256
>  	EXCEPT_HDRS += sha256/gcrypt.h
> @@ -2807,7 +2814,7 @@ hdr-check: $(HCO)
>  style:
>  	git clang-format --style file --diff --extensions c,h
>  
> -check: command-list.h
> +check: config-list.h command-list.h
>  	@if sparse; \
>  	then \
>  		echo >&2 "Use 'make sparse' instead"; \
> @@ -3110,7 +3117,8 @@ clean: profile-clean coverage-clean cocciclean
>  	$(RM) $(HCC)
>  	$(RM) -r bin-wrappers $(dep_dirs)
>  	$(RM) -r po/build/
> -	$(RM) *.pyc *.pyo */*.pyc */*.pyo command-list.h $(ETAGS_TARGET) tags cscope*
> +	$(RM) *.pyc *.pyo */*.pyc */*.pyo config-list.h command-list.h
> +	$(RM) $(ETAGS_TARGET) tags cscope*
>  	$(RM) -r $(GIT_TARNAME) .doc-tmp-dir
>  	$(RM) $(GIT_TARNAME).tar.gz git-core_$(GIT_VERSION)-*.tar.gz
>  	$(RM) $(htmldocs).tar.gz $(manpages).tar.gz
> diff --git a/builtin/help.c b/builtin/help.c
> index e5590d7787..1c5f2b9255 100644
> --- a/builtin/help.c
> +++ b/builtin/help.c
> @@ -8,6 +8,7 @@
>  #include "parse-options.h"
>  #include "run-command.h"
>  #include "column.h"
> +#include "config-list.h"
>  #include "help.h"
>  #include "alias.h"
>  
> @@ -62,6 +63,91 @@ static const char * const builtin_help_usage[] = {
>  	NULL
>  };
>  
> +struct slot_expansion {
> +	const char *prefix;
> +	const char *placeholder;
> +	void (*fn)(struct string_list *list, const char *prefix);
> +	int found;
> +};
> +
> +static void list_config_help(int for_human)
> +{
> +	struct slot_expansion slot_expansions[] = {
> +		{ "advice", "*", list_config_advices },
> +		{ "color.branch", "<slot>", list_config_color_branch_slots },
> +		{ "color.decorate", "<slot>", list_config_color_decorate_slots },
> +		{ "color.diff", "<slot>", list_config_color_diff_slots },
> +		{ "color.grep", "<slot>", list_config_color_grep_slots },
> +		{ "color.interactive", "<slot>", list_config_color_interactive_slots },
> +		{ "color.remote", "<slot>", list_config_color_sideband_slots },
> +		{ "color.status", "<slot>", list_config_color_status_slots },
> +		{ "fsck", "<msg-id>", list_config_fsck_msg_ids },
> +		{ "receive.fsck", "<msg-id>", list_config_fsck_msg_ids },
> +		{ NULL, NULL, NULL }
> +	};
> +	const char **p;
> +	struct slot_expansion *e;
> +	struct string_list keys = STRING_LIST_INIT_DUP;
> +	int i;
> +
> +	for (p = config_name_list; *p; p++) {
> +		const char *var = *p;
> +		struct strbuf sb = STRBUF_INIT;
> +
> +		for (e = slot_expansions; e->prefix; e++) {
> +
> +			strbuf_reset(&sb);
> +			strbuf_addf(&sb, "%s.%s", e->prefix, e->placeholder);
> +			if (!strcasecmp(var, sb.buf)) {
> +				e->fn(&keys, e->prefix);
> +				e->found++;
> +				break;
> +			}
> +		}
> +		strbuf_release(&sb);
> +		if (!e->prefix)
> +			string_list_append(&keys, var);
> +	}
> +
> +	for (e = slot_expansions; e->prefix; e++)
> +		if (!e->found)
> +			BUG("slot_expansion %s.%s is not used",
> +			    e->prefix, e->placeholder);
> +
> +	string_list_sort(&keys);
> +	for (i = 0; i < keys.nr; i++) {
> +		const char *var = keys.items[i].string;
> +		const char *wildcard, *tag, *cut;
> +
> +		if (for_human) {
> +			puts(var);
> +			continue;
> +		}
> +
> +		wildcard = strchr(var, '*');
> +		tag = strchr(var, '<');
> +
> +		if (!wildcard && !tag) {
> +			puts(var);
> +			continue;
> +		}
> +
> +		if (wildcard && !tag)
> +			cut = wildcard;
> +		else if (!wildcard && tag)
> +			cut = tag;
> +		else
> +			cut = wildcard < tag ? wildcard : tag;
> +
> +		/*
> +		 * We may produce duplicates, but that's up to
> +		 * git-completion.bash to handle
> +		 */
> +		printf("%.*s\n", (int)(cut - var), var);
> +	}
> +	string_list_clear(&keys, 0);
> +}
> +
>  static enum help_format parse_help_format(const char *format)
>  {
>  	if (!strcmp(format, "man"))
> diff --git a/generate-cmdlist.sh b/generate-cmdlist.sh
> index 71158f7d8b..45fecf8bdf 100755
> --- a/generate-cmdlist.sh
> +++ b/generate-cmdlist.sh
> @@ -76,23 +76,6 @@ print_command_list () {
>  	echo "};"
>  }
>  
> -print_config_list () {
> -	cat <<EOF
> -static const char *config_name_list[] = {
> -EOF
> -	grep -h '^[a-zA-Z].*\..*::$' Documentation/*config.txt Documentation/config/*.txt |
> -	sed '/deprecated/d; s/::$//; s/,  */\n/g' |
> -	sort |
> -	while read line
> -	do
> -		echo "	\"$line\","
> -	done
> -	cat <<EOF
> -	NULL,
> -};
> -EOF
> -}
> -
>  exclude_programs=
>  while test "--exclude-program" = "$1"
>  do
> @@ -113,5 +96,3 @@ echo
>  define_category_names "$1"
>  echo
>  print_command_list "$1"
> -echo
> -print_config_list
> diff --git a/generate-configlist.sh b/generate-configlist.sh
> new file mode 100755
> index 0000000000..eca6a00c30
> --- /dev/null
> +++ b/generate-configlist.sh
> @@ -0,0 +1,24 @@
> +#!/bin/sh
> +
> +echo "/* Automatically generated by generate-configlist.sh */"
> +echo
> +
> +print_config_list () {
> +	cat <<EOF
> +static const char *config_name_list[] = {
> +EOF
> +	grep -h '^[a-zA-Z].*\..*::$' Documentation/*config.txt Documentation/config/*.txt |
> +	sed '/deprecated/d; s/::$//; s/,  */\n/g' |
> +	sort |
> +	while read line
> +	do
> +		echo "	\"$line\","
> +	done
> +	cat <<EOF
> +	NULL,
> +};
> +EOF
> +}
> +
> +echo
> +print_config_list
> diff --git a/help.c b/help.c
> index cf67624a94..a21487db77 100644
> --- a/help.c
> +++ b/help.c
> @@ -407,91 +407,6 @@ void list_common_guides_help(void)
>  	putchar('\n');
>  }
>  
> -struct slot_expansion {
> -	const char *prefix;
> -	const char *placeholder;
> -	void (*fn)(struct string_list *list, const char *prefix);
> -	int found;
> -};
> -
> -void list_config_help(int for_human)
> -{
> -	struct slot_expansion slot_expansions[] = {
> -		{ "advice", "*", list_config_advices },
> -		{ "color.branch", "<slot>", list_config_color_branch_slots },
> -		{ "color.decorate", "<slot>", list_config_color_decorate_slots },
> -		{ "color.diff", "<slot>", list_config_color_diff_slots },
> -		{ "color.grep", "<slot>", list_config_color_grep_slots },
> -		{ "color.interactive", "<slot>", list_config_color_interactive_slots },
> -		{ "color.remote", "<slot>", list_config_color_sideband_slots },
> -		{ "color.status", "<slot>", list_config_color_status_slots },
> -		{ "fsck", "<msg-id>", list_config_fsck_msg_ids },
> -		{ "receive.fsck", "<msg-id>", list_config_fsck_msg_ids },
> -		{ NULL, NULL, NULL }
> -	};
> -	const char **p;
> -	struct slot_expansion *e;
> -	struct string_list keys = STRING_LIST_INIT_DUP;
> -	int i;
> -
> -	for (p = config_name_list; *p; p++) {
> -		const char *var = *p;
> -		struct strbuf sb = STRBUF_INIT;
> -
> -		for (e = slot_expansions; e->prefix; e++) {
> -
> -			strbuf_reset(&sb);
> -			strbuf_addf(&sb, "%s.%s", e->prefix, e->placeholder);
> -			if (!strcasecmp(var, sb.buf)) {
> -				e->fn(&keys, e->prefix);
> -				e->found++;
> -				break;
> -			}
> -		}
> -		strbuf_release(&sb);
> -		if (!e->prefix)
> -			string_list_append(&keys, var);
> -	}
> -
> -	for (e = slot_expansions; e->prefix; e++)
> -		if (!e->found)
> -			BUG("slot_expansion %s.%s is not used",
> -			    e->prefix, e->placeholder);
> -
> -	string_list_sort(&keys);
> -	for (i = 0; i < keys.nr; i++) {
> -		const char *var = keys.items[i].string;
> -		const char *wildcard, *tag, *cut;
> -
> -		if (for_human) {
> -			puts(var);
> -			continue;
> -		}
> -
> -		wildcard = strchr(var, '*');
> -		tag = strchr(var, '<');
> -
> -		if (!wildcard && !tag) {
> -			puts(var);
> -			continue;
> -		}
> -
> -		if (wildcard && !tag)
> -			cut = wildcard;
> -		else if (!wildcard && tag)
> -			cut = tag;
> -		else
> -			cut = wildcard < tag ? wildcard : tag;
> -
> -		/*
> -		 * We may produce duplicates, but that's up to
> -		 * git-completion.bash to handle
> -		 */
> -		printf("%.*s\n", (int)(cut - var), var);
> -	}
> -	string_list_clear(&keys, 0);
> -}
> -
>  static int get_alias(const char *var, const char *value, void *data)
>  {
>  	struct string_list *list = data;
> diff --git a/help.h b/help.h
> index 7a455beeb7..9071894e8c 100644
> --- a/help.h
> +++ b/help.h
> @@ -22,7 +22,6 @@ static inline void mput_char(char c, unsigned int num)
>  void list_common_cmds_help(void);
>  void list_all_cmds_help(void);
>  void list_common_guides_help(void);
> -void list_config_help(int for_human);
>  
>  void list_all_main_cmds(struct string_list *list);
>  void list_all_other_cmds(struct string_list *list);