Re: [PATCH 3/3] completion: match ctags symbol names in grep patterns

Jeff King [off-list ref] writes:

A common thing to grep for is the name of a symbol. This
patch teaches the completion for "git grep" to look in
a 'tags' file, if present, to complete a pattern. For
example, in git.git:

  $ make tags
  $ git grep get_sha1<Tab><Tab>
  get_sha1                 get_sha1_oneline
  get_sha1_1               get_sha1_with_context
  get_sha1_basic           get_sha1_with_context_1
  get_sha1_hex             get_sha1_with_mode
  get_sha1_hex_segment     get_sha1_with_mode_1
  get_sha1_mb

Signed-off-by: Jeff King <redacted>
---
It's debatable whether this belongs in the generic completion code, as
it really only works if your project uses ctags. But I find it to be a
huge timesaver for finding callsites of functions, especially when
coupled with "git jump grep" from the previous patch.

Could you elaborate a bit more on how this would help for finding
callsites? You are looking at a function and do not want to break its
callers, so at that point presumably you already know the name of the
function, no?

Ahh, Ok, you do not necessarily want to type the long function name.

By the way, I notice that "make tags" runs "find ." looking for any files
and directories that match "*.[hcS]" (so do $(ETAGS_TARGET) and cscope),
without even excluding .git metadirectory.

Perhaps something like this is in order?

 Makefile |   14 +++++++++++---
 1 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/Makefile b/Makefile
index 17404c4..b38f55b 100644
--- a/Makefile
+++ b/Makefile

@@ -2127,17 +2127,25 @@ po/git.pot: $(LOCALIZED_C)
 
 pot: po/git.pot
 
+git_check = $(shell git ls-files >/dev/null 2>&1; echo $$?)
+ifeq ($(git_check),0)
+FIND_SOURCE_FILES = git ls-files '*.[hcS]'
+else
+FIND_SOURCE_FILES = $(FIND) . \( -name .git -type d -prune \) \
+		-o \( -name '*.[hcS]' -type f -print \)
+endif
+
 $(ETAGS_TARGET): FORCE
 	$(RM) $(ETAGS_TARGET)
-	$(FIND) . -name '*.[hcS]' -print | xargs etags -a -o $(ETAGS_TARGET)
+	$(FIND_SOURCE_FILES) | xargs etags -a -o $(ETAGS_TARGET)
 
 tags: FORCE
 	$(RM) tags
-	$(FIND) . -name '*.[hcS]' -print | xargs ctags -a
+	$(FIND_SOURCE_FILES) | xargs ctags -a
 
 cscope:
 	$(RM) cscope*
-	$(FIND) . -name '*.[hcS]' -print | xargs cscope -b
+	$(FIND_SOURCE_FILES) | xargs cscope -b
 
 ### Detect prefix changes
 TRACK_CFLAGS = $(CC):$(subst ','\'',$(ALL_CFLAGS)):\