[PATCH v2 0/2] Offer more information in `git version --build-options`'s output

In Git for Windows, we ask users to paste the output of said command into their bug reports, with the idea that this frequently helps identify where the problems are coming from.

There are some obvious missing bits of information in said output, though, and this patch series tries to fill the gaps at least a little.

Changes since v1:

- replaced 1/2 by Eric's proposed alternative patch

- when no commit can be determined, it now says

	no commit associated with this build
  instead of

	built from commit: (unknown)

- the code is now careful not to look further than Git's top-level
  directory for a Git repository from which to determine the current
  commit. As Junio pointed out, some developer may extract Git's source
  code from a tarball into a worktree of a completely different project.

Eric Sunshine (1):
  version --build-options: also report host CPU

Johannes Schindelin (1):
  version --build-options: report commit, too, if possible

 Makefile  | 13 ++++++++++++-
 help.c    |  6 ++++++
 version.c |  1 +
 version.h |  1 +
 4 files changed, 20 insertions(+), 1 deletion(-)

base-commit: 95ec6b1b3393eb6e26da40c565520a8db9796e9f
Published-As: https://github.com/dscho/git/releases/tag/built-from-commit-v2
Fetch-It-Via: git fetch https://github.com/dscho/git built-from-commit-v2

Interdiff vs v1:
 diff --git a/Makefile b/Makefile
 index 92a0ae3d8e3..2ce70d205d9 100644
 --- a/Makefile
 +++ b/Makefile
 @@ -425,6 +425,9 @@ all::
  #
  # to say "export LESS=FRX (and LV=-c) if the environment variable
  # LESS (and LV) is not set, respectively".
 +#
 +# When cross-compiling, define HOST_CPU as the canonical name of the CPU on
 +# which the built Git will run (for instance "x86_64").
  
  GIT-VERSION-FILE: FORCE
  	@$(SHELL_PATH) ./GIT-VERSION-GEN
 @@ -1095,6 +1098,12 @@ else
  BROKEN_PATH_FIX = '/^\# @@BROKEN_PATH_FIX@@$$/d'
  endif
  
 +ifeq (,$(HOST_CPU))
 +	BASIC_CFLAGS += -DGIT_HOST_CPU="\"$(firstword $(subst -, ,$(uname_M)))\""
 +else
 +	BASIC_CFLAGS += -DGIT_HOST_CPU="\"$(HOST_CPU)\""
 +endif
 +
  ifneq (,$(INLINE))
  	BASIC_CFLAGS += -Dinline=$(INLINE)
  endif
 @@ -1894,8 +1903,8 @@ version.sp version.s version.o: GIT-VERSION-FILE GIT-USER-AGENT
  version.sp version.s version.o: EXTRA_CPPFLAGS = \
  	'-DGIT_VERSION="$(GIT_VERSION)"' \
  	'-DGIT_USER_AGENT=$(GIT_USER_AGENT_CQ_SQ)' \
 -	'-DGIT_BUILT_FROM_COMMIT="$(shell git rev-parse -q --verify HEAD || \
 -		echo "(unknown)")"'
 +	'-DGIT_BUILT_FROM_COMMIT="$(shell GIT_CEILING_DIRECTORIES=\"$(CURDIR)/..\" \
 +		git rev-parse -q --verify HEAD || :)"'
  
  $(BUILT_INS): git$X
  	$(QUIET_BUILT_IN)$(RM) $@ && \
 diff --git a/help.c b/help.c
 index 6ebea665780..60071a9beaa 100644
 --- a/help.c
 +++ b/help.c
 @@ -390,7 +390,6 @@ const char *help_unknown_cmd(const char *cmd)
  
  int cmd_version(int argc, const char **argv, const char *prefix)
  {
 -	static char build_platform[] = GIT_BUILD_PLATFORM;
  	int build_options = 0;
  	const char * const usage[] = {
  		N_("git version [<options>]"),
 @@ -413,10 +412,13 @@ int cmd_version(int argc, const char **argv, const char *prefix)
  	printf("git version %s\n", git_version_string);
  
  	if (build_options) {
 -		printf("built from commit: %s\n",
 -		       git_built_from_commit_string);
 +		printf("cpu: %s\n", GIT_HOST_CPU);
 +		if (git_built_from_commit_string[0])
 +			printf("built from commit: %s\n",
 +			       git_built_from_commit_string);
 +		else
 +			printf("no commit associated with this build\n");
  		printf("sizeof-long: %d\n", (int)sizeof(long));
 -		printf("machine: %s\n", build_platform);
  		/* NEEDSWORK: also save and output GIT-BUILD_OPTIONS? */
  	}
  	return 0;
 diff --git a/help.h b/help.h
 index 42dd9852194..b21d7c94e8c 100644
 --- a/help.h
 +++ b/help.h
 @@ -33,16 +33,3 @@ extern void list_commands(unsigned int colopts, struct cmdnames *main_cmds, stru
   */
  extern void help_unknown_ref(const char *ref, const char *cmd, const char *error);
  #endif /* HELP_H */
 -
 -/*
 - * identify build platform
 - */
 -#ifndef GIT_BUILD_PLATFORM
 -	#if defined __x86__ || defined __i386__ || defined __i586__ || defined __i686__
 -		#define GIT_BUILD_PLATFORM "x86"
 -	#elif defined __x86_64__
 -		#define GIT_BUILD_PLATFORM "x86_64"
 -	#else
 -		#define GIT_BUILD_PLATFORM "unknown"
 -	#endif
 -#endif