[PATCH] Makefile: add a prerequisite to the coverage-report target

[PATCH] Makefile: add a prerequisite to the coverage-report target

[Elia Pinto]

Directly invoking make coverage-report as a target results in an error because
its prerequisites are missing,

The patch adds the necessary prerequisite.

Signed-off-by: Elia Pinto <gitter.spiros@gmail.com>
---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index e8aba291d7..d9e8dd331e 100644
--- a/Makefile
+++ b/Makefile
@@ -3409,7 +3409,7 @@ coverage-prove: coverage-clean-results coverage-compile
 		DEFAULT_TEST_TARGET=prove GIT_PROVE_OPTS="$(GIT_PROVE_OPTS) -j1" \
 		-j1 test
 
-coverage-report:
+coverage-report: coverage-test
 	$(QUIET_GCOV)for dir in $(object_dirs); do \
 		$(GCOV) $(GCOVFLAGS) --object-directory=$$dir $$dir*.c || exit; \
 	done
-- 
2.35.1

Re: [PATCH] Makefile: add a prerequisite to the coverage-report target

[Junio C Hamano]

Elia Pinto <gitter.spiros@gmail.com> writes:

> @@ -3409,7 +3409,7 @@ coverage-prove: coverage-clean-results coverage-compile
>  		DEFAULT_TEST_TARGET=prove GIT_PROVE_OPTS="$(GIT_PROVE_OPTS) -j1" \
>  		-j1 test
>  
> -coverage-report:
> +coverage-report: coverage-test
>  	$(QUIET_GCOV)for dir in $(object_dirs); do \
>  		$(GCOV) $(GCOVFLAGS) --object-directory=$$dir $$dir*.c || exit; \
>  	done

I am not sure if this alone makes it a good change.

With the current set-up, you can run coverage-test or coverage-prove
once, view coverage-report, shift your attention to elsewhere to
address issues you saw in the report, and then decide to view the
report again to remind yourself what you saw and what motivated you
to work on your changes.  Most likely this sequence would be
followed by another run of coverage-test followed by coverage-report
to compare what you saw before you made these changes with the
covernage report after your changes.

If this were conditional, i.e. "ah, I see you haven't run any
coverage test yet, so let me run it for you before showing the
result" combined with "ok, I see you did run coverage test, so let
me just show the result without running tests anew", then it would
be a strict improvement from the status quo.

But with the patch as posted, wouldn't we unconditonally wipe the
earlier result out?  If so that may negatively affect established
workflow of some people, I am afraid.

Thanks.

[PATCH v2 1/1] Makefile: add a prerequisite to the coverage-report target

[Elia Pinto]

Directly invoking make coverage-report as a target results in an error because
its prerequisites are missing,

This patch adds the compile-test prerequisite, which is run only once each time
the compile-report target is invoked. In practice, the developer may decide to
review the coverage-report results without necessarily rerunning for this
coverage-test, if it has already been run.

Signed-off-by: Elia Pinto <gitter.spiros@gmail.com>
---
This is the second version of the patch.

With respect to the first version, we tried to eliminate the inefficient
coverage-test invocation if the target is coverage-report, introducing a more
useful invocation order

 Makefile | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index e8aba291d7..eacdffd748 100644
--- a/Makefile
+++ b/Makefile
@@ -3378,6 +3378,8 @@ check-builtins::
 .PHONY: coverage-untested-functions cover_db cover_db_html
 .PHONY: coverage-clean-results
 
+coverage-test.file?=coverage-test.file
+
 coverage:
 	$(MAKE) coverage-test
 	$(MAKE) coverage-untested-functions
@@ -3389,6 +3391,7 @@ coverage-clean-results:
 	$(RM) coverage-untested-functions
 	$(RM) -r cover_db/
 	$(RM) -r cover_db_html/
+	$(RM) -f $(coverage-test.file)
 
 coverage-clean: coverage-clean-results
 	$(RM) $(addsuffix *.gcno,$(object_dirs))
@@ -3404,12 +3407,16 @@ coverage-test: coverage-clean-results coverage-compile
 	$(MAKE) CFLAGS="$(COVERAGE_CFLAGS)" LDFLAGS="$(COVERAGE_LDFLAGS)" \
 		DEFAULT_TEST_TARGET=test -j1 test
 
+$(coverage-test.file):
+	@make coverage-test
+	touch $(coverage-test.file)
+
 coverage-prove: coverage-clean-results coverage-compile
 	$(MAKE) CFLAGS="$(COVERAGE_CFLAGS)" LDFLAGS="$(COVERAGE_LDFLAGS)" \
 		DEFAULT_TEST_TARGET=prove GIT_PROVE_OPTS="$(GIT_PROVE_OPTS) -j1" \
 		-j1 test
 
-coverage-report:
+coverage-report: $(coverage-test.file)
 	$(QUIET_GCOV)for dir in $(object_dirs); do \
 		$(GCOV) $(GCOVFLAGS) --object-directory=$$dir $$dir*.c || exit; \
 	done
-- 
2.35.1