Merge branch 'js/enhanced-version-info'

"git version --build-options" learned to report the host CPU and
the exact commit object name the binary was built from.

* js/enhanced-version-info:
  version --build-options: report commit, too, if possible
  version --build-options: also report host CPU

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
@@ -1099,6 +1102,12 @@ 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=$(INLINE)
 endif
@@ -1897,7 +1906,9 @@ builtin/help.sp builtin/help.s builtin/help.o: EXTRA_CPPFLAGS = \
 version.sp version.s version.o: GIT-VERSION-FILE GIT-USER-AGENT
 version.sp version.s version.o: EXTRA_CPPFLAGS = \
 	'-DGIT_VERSION="$(GIT_VERSION)"' \
-	'-DGIT_USER_AGENT=$(GIT_USER_AGENT_CQ_SQ)'
+	'-DGIT_USER_AGENT=$(GIT_USER_AGENT_CQ_SQ)' \
+	'-DGIT_BUILT_FROM_COMMIT="$(shell GIT_CEILING_DIRECTORIES=\"$(CURDIR)/..\" \
+		git rev-parse -q --verify HEAD || :)"'
 
 $(BUILT_INS): git$X
 	$(QUIET_BUILT_IN)$(RM) $@ && \

help.c

@@ -412,6 +412,12 @@ int cmd_version(int argc, const char **argv, const char *prefix)
 	printf("git version %s\n", git_version_string);
 
 	if (build_options) {
+		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));
 		/* NEEDSWORK: also save and output GIT-BUILD_OPTIONS? */
 	}

version.c

@@ -3,6 +3,7 @@
 #include "strbuf.h"
 
 const char git_version_string[] = GIT_VERSION;
+const char git_built_from_commit_string[] = GIT_BUILT_FROM_COMMIT;
 
 const char *git_user_agent(void)
 {

version.h

@@ -2,6 +2,7 @@
 #define VERSION_H
 
 extern const char git_version_string[];
+extern const char git_built_from_commit_string[];
 
 const char *git_user_agent(void);
 const char *git_user_agent_sanitized(void);