bugreport: gather git version and build info

Knowing which version of Git a user has and how it was built allows us
to more precisely pin down the circumstances when a certain issue
occurs, so teach bugreport how to tell us the same output as 'git
version --build-options'.

It's not ideal to directly call 'git version --build-options' because
that output goes to stdout. Instead, wrap the version string in a helper
within help.[ch] library, and call that helper from within the bugreport
library.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-bugreport.txt

@@ -23,6 +23,10 @@ The following information is requested from the user:
  - Expected behavior
  - Actual behavior
 
+The following information is captured automatically:
+
+ - 'git version --build-options'
+
 This tool is invoked via the typical Git setup process, which means that in some
 cases, it might not be able to launch - for example, if a relevant config file
 is unreadable. In this kind of scenario, it may be helpful to manually gather

bugreport.c

@@ -1,8 +1,17 @@
-#include "builtin.h"
+#include "cache.h"
 #include "parse-options.h"
 #include "stdio.h"
 #include "strbuf.h"
 #include "time.h"
+#include "help.h"
+
+static void get_system_info(struct strbuf *sys_info)
+{
+	/* get git version from native cmd */
+	strbuf_addstr(sys_info, _("git version:\n"));
+	get_version_info(sys_info, 1);
+	strbuf_complete_line(sys_info);
+}
 
 static const char * const bugreport_usage[] = {
 	N_("git bugreport [-o|--output-directory <file>] [-s|--suffix <format>]"),
@@ -32,6 +41,11 @@ static int get_bug_template(struct strbuf *template)
 	return 0;
 }
 
+static void get_header(struct strbuf *buf, const char *title)
+{
+	strbuf_addf(buf, "\n\n[%s]\n", title);
+}
+
 int cmd_main(int argc, const char **argv)
 {
 	struct strbuf buffer = STRBUF_INIT;
@@ -79,6 +93,9 @@ int cmd_main(int argc, const char **argv)
 	/* Prepare the report contents */
 	get_bug_template(&buffer);
 
+	get_header(&buffer, _("System Info"));
+	get_system_info(&buffer);
+
 	/* fopen doesn't offer us an O_EXCL alternative, except with glibc. */
 	report = open(report_path.buf, O_CREAT | O_EXCL | O_WRONLY, 0666);
 

help.c

@@ -622,8 +622,32 @@ const char *help_unknown_cmd(const char *cmd)
 	exit(1);
 }
 
+void get_version_info(struct strbuf *buf, int show_build_options)
+{
+	/*
+	 * The format of this string should be kept stable for compatibility
+	 * with external projects that rely on the output of "git version".
+	 *
+	 * Always show the version, even if other options are given.
+	 */
+	strbuf_addf(buf, "git version %s\n", git_version_string);
+
+	if (show_build_options) {
+		strbuf_addf(buf, "cpu: %s\n", GIT_HOST_CPU);
+		if (git_built_from_commit_string[0])
+			strbuf_addf(buf, "built from commit: %s\n",
+			       git_built_from_commit_string);
+		else
+			strbuf_addstr(buf, "no commit associated with this build\n");
+		strbuf_addf(buf, "sizeof-long: %d\n", (int)sizeof(long));
+		strbuf_addf(buf, "sizeof-size_t: %d\n", (int)sizeof(size_t));
+		/* NEEDSWORK: also save and output GIT-BUILD_OPTIONS? */
+	}
+}
+
 int cmd_version(int argc, const char **argv, const char *prefix)
 {
+	struct strbuf buf = STRBUF_INIT;
 	int build_options = 0;
 	const char * const usage[] = {
 		N_("git version [<options>]"),
@@ -637,25 +661,11 @@ int cmd_version(int argc, const char **argv, const char *prefix)
 
 	argc = parse_options(argc, argv, prefix, options, usage, 0);
 
-	/*
-	 * The format of this string should be kept stable for compatibility
-	 * with external projects that rely on the output of "git version".
-	 *
-	 * Always show the version, even if other options are given.
-	 */
-	printf("git version %s\n", git_version_string);
+	get_version_info(&buf, build_options);
+	printf("%s", buf.buf);
+
+	strbuf_release(&buf);
 
-	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));
-		printf("sizeof-size_t: %d\n", (int)sizeof(size_t));
-		/* NEEDSWORK: also save and output GIT-BUILD_OPTIONS? */
-	}
 	return 0;
 }
 

help.h

@@ -37,6 +37,7 @@ void add_cmdname(struct cmdnames *cmds, const char *name, int len);
 void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes);
 int is_in_cmdlist(struct cmdnames *cmds, const char *name);
 void list_commands(unsigned int colopts, struct cmdnames *main_cmds, struct cmdnames *other_cmds);
+void get_version_info(struct strbuf *buf, int show_build_options);
 
 /*
  * call this to die(), when it is suspected that the user mistyped a