git-commit-vandalism/trace2/tr2_tgt_event.c
Ævar Arnfjörð Bjarmason d3b2159712 run-command API: remove "argv" member, always use "args"
Remove the "argv" member from the run-command API, ever since "args"
was added in c460c0ecdc (run-command: store an optional argv_array,
2014-05-15) being able to provide either "argv" or "args" has led to
some confusion and bugs.

If we hadn't gone in that direction and only had an "argv" our
problems wouldn't have been solved either, as noted in [1] (and in the
documentation amended here) it comes with inherent memory management
issues: The caller would have to hang on to the "argv" until the
run-command API was finished. If the "argv" was an argument to main()
this wasn't an issue, but if it it was manually constructed using the
API might be painful.

We also have a recent report[2] of a user of the API segfaulting,
which is a direct result of it being complex to use. This commit
addresses the root cause of that bug.

This change is larger than I'd like, but there's no easy way to avoid
it that wouldn't involve even more verbose intermediate steps. We use
the "argv" as the source of truth over the "args", so we need to
change all parts of run-command.[ch] itself, as well as the trace2
logging at the same time.

The resulting Windows-specific code in start_command() is a bit nasty,
as we're now assigning to a strvec's "v" member, instead of to our own
"argv". There was a suggestion of some alternate approaches in reply
to an earlier version of this commit[3], but let's leave larger a
larger and needless refactoring of this code for now.

1. http://lore.kernel.org/git/YT6BnnXeAWn8BycF@coredump.intra.peff.net
2. https://lore.kernel.org/git/20211120194048.12125-1-ematsumiya@suse.de/
3. https://lore.kernel.org/git/patch-5.5-ea1011f7473-20211122T153605Z-avarab@gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-25 22:15:07 -08:00

647 lines
18 KiB
C

#include "cache.h"
#include "config.h"
#include "json-writer.h"
#include "run-command.h"
#include "version.h"
#include "trace2/tr2_dst.h"
#include "trace2/tr2_tbuf.h"
#include "trace2/tr2_sid.h"
#include "trace2/tr2_sysenv.h"
#include "trace2/tr2_tgt.h"
#include "trace2/tr2_tls.h"
static struct tr2_dst tr2dst_event = { TR2_SYSENV_EVENT, 0, 0, 0, 0 };
/*
* The version number of the JSON data generated by the EVENT target in this
* source file. The version should be incremented if new event types are added,
* if existing fields are removed, or if there are significant changes in
* interpretation of existing events or fields. Smaller changes, such as adding
* a new field to an existing event, do not require an increment to the EVENT
* format version.
*/
#define TR2_EVENT_VERSION "3"
/*
* Region nesting limit for messages written to the event target.
*
* The "region_enter" and "region_leave" messages (especially recursive
* messages such as those produced while diving the worktree or index)
* are primarily intended for the performance target during debugging.
*
* Some of the outer-most messages, however, may be of interest to the
* event target. Use the TR2_SYSENV_EVENT_NESTING setting to increase
* region details in the event target.
*/
static int tr2env_event_max_nesting_levels = 2;
/*
* Use the TR2_SYSENV_EVENT_BRIEF to omit the <time>, <file>, and
* <line> fields from most events.
*/
static int tr2env_event_be_brief;
static int fn_init(void)
{
int want = tr2_dst_trace_want(&tr2dst_event);
int max_nesting;
int want_brief;
const char *nesting;
const char *brief;
if (!want)
return want;
nesting = tr2_sysenv_get(TR2_SYSENV_EVENT_NESTING);
if (nesting && *nesting && ((max_nesting = atoi(nesting)) > 0))
tr2env_event_max_nesting_levels = max_nesting;
brief = tr2_sysenv_get(TR2_SYSENV_EVENT_BRIEF);
if (brief && *brief &&
((want_brief = git_parse_maybe_bool(brief)) != -1))
tr2env_event_be_brief = want_brief;
return want;
}
static void fn_term(void)
{
tr2_dst_trace_disable(&tr2dst_event);
}
/*
* Append common key-value pairs to the currently open JSON object.
* "event:"<event_name>"
* "sid":"<sid>"
* "thread":"<thread_name>"
* "time":"<time>"
* "file":"<filename>"
* "line":<line_number>
* "repo":<repo_id>
*/
static void event_fmt_prepare(const char *event_name, const char *file,
int line, const struct repository *repo,
struct json_writer *jw)
{
struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
struct tr2_tbuf tb_now;
jw_object_string(jw, "event", event_name);
jw_object_string(jw, "sid", tr2_sid_get());
jw_object_string(jw, "thread", ctx->thread_name.buf);
/*
* In brief mode, only emit <time> on these 2 event types.
*/
if (!tr2env_event_be_brief || !strcmp(event_name, "version") ||
!strcmp(event_name, "atexit")) {
tr2_tbuf_utc_datetime_extended(&tb_now);
jw_object_string(jw, "time", tb_now.buf);
}
if (!tr2env_event_be_brief && file && *file) {
jw_object_string(jw, "file", file);
jw_object_intmax(jw, "line", line);
}
if (repo)
jw_object_intmax(jw, "repo", repo->trace2_repo_id);
}
static void fn_too_many_files_fl(const char *file, int line)
{
const char *event_name = "too_many_files";
struct json_writer jw = JSON_WRITER_INIT;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, NULL, &jw);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void fn_version_fl(const char *file, int line)
{
const char *event_name = "version";
struct json_writer jw = JSON_WRITER_INIT;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, NULL, &jw);
jw_object_string(&jw, "evt", TR2_EVENT_VERSION);
jw_object_string(&jw, "exe", git_version_string);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
if (tr2dst_event.too_many_files)
fn_too_many_files_fl(file, line);
}
static void fn_start_fl(const char *file, int line,
uint64_t us_elapsed_absolute, const char **argv)
{
const char *event_name = "start";
struct json_writer jw = JSON_WRITER_INIT;
double t_abs = (double)us_elapsed_absolute / 1000000.0;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, NULL, &jw);
jw_object_double(&jw, "t_abs", 6, t_abs);
jw_object_inline_begin_array(&jw, "argv");
jw_array_argv(&jw, argv);
jw_end(&jw);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void fn_exit_fl(const char *file, int line, uint64_t us_elapsed_absolute,
int code)
{
const char *event_name = "exit";
struct json_writer jw = JSON_WRITER_INIT;
double t_abs = (double)us_elapsed_absolute / 1000000.0;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, NULL, &jw);
jw_object_double(&jw, "t_abs", 6, t_abs);
jw_object_intmax(&jw, "code", code);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void fn_signal(uint64_t us_elapsed_absolute, int signo)
{
const char *event_name = "signal";
struct json_writer jw = JSON_WRITER_INIT;
double t_abs = (double)us_elapsed_absolute / 1000000.0;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, __FILE__, __LINE__, NULL, &jw);
jw_object_double(&jw, "t_abs", 6, t_abs);
jw_object_intmax(&jw, "signo", signo);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void fn_atexit(uint64_t us_elapsed_absolute, int code)
{
const char *event_name = "atexit";
struct json_writer jw = JSON_WRITER_INIT;
double t_abs = (double)us_elapsed_absolute / 1000000.0;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, __FILE__, __LINE__, NULL, &jw);
jw_object_double(&jw, "t_abs", 6, t_abs);
jw_object_intmax(&jw, "code", code);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void maybe_add_string_va(struct json_writer *jw, const char *field_name,
const char *fmt, va_list ap)
{
if (fmt && *fmt) {
va_list copy_ap;
struct strbuf buf = STRBUF_INIT;
va_copy(copy_ap, ap);
strbuf_vaddf(&buf, fmt, copy_ap);
va_end(copy_ap);
jw_object_string(jw, field_name, buf.buf);
strbuf_release(&buf);
return;
}
}
static void fn_error_va_fl(const char *file, int line, const char *fmt,
va_list ap)
{
const char *event_name = "error";
struct json_writer jw = JSON_WRITER_INIT;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, NULL, &jw);
maybe_add_string_va(&jw, "msg", fmt, ap);
/*
* Also emit the format string as a field in case
* post-processors want to aggregate common error
* messages by type without argument fields (such
* as pathnames or branch names) cluttering it up.
*/
if (fmt && *fmt)
jw_object_string(&jw, "fmt", fmt);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void fn_command_path_fl(const char *file, int line, const char *pathname)
{
const char *event_name = "cmd_path";
struct json_writer jw = JSON_WRITER_INIT;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, NULL, &jw);
jw_object_string(&jw, "path", pathname);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void fn_command_ancestry_fl(const char *file, int line, const char **parent_names)
{
const char *event_name = "cmd_ancestry";
const char *parent_name = NULL;
struct json_writer jw = JSON_WRITER_INIT;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, NULL, &jw);
jw_object_inline_begin_array(&jw, "ancestry");
while ((parent_name = *parent_names++))
jw_array_string(&jw, parent_name);
jw_end(&jw); /* 'ancestry' array */
jw_end(&jw); /* event object */
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void fn_command_name_fl(const char *file, int line, const char *name,
const char *hierarchy)
{
const char *event_name = "cmd_name";
struct json_writer jw = JSON_WRITER_INIT;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, NULL, &jw);
jw_object_string(&jw, "name", name);
if (hierarchy && *hierarchy)
jw_object_string(&jw, "hierarchy", hierarchy);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void fn_command_mode_fl(const char *file, int line, const char *mode)
{
const char *event_name = "cmd_mode";
struct json_writer jw = JSON_WRITER_INIT;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, NULL, &jw);
jw_object_string(&jw, "name", mode);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void fn_alias_fl(const char *file, int line, const char *alias,
const char **argv)
{
const char *event_name = "alias";
struct json_writer jw = JSON_WRITER_INIT;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, NULL, &jw);
jw_object_string(&jw, "alias", alias);
jw_object_inline_begin_array(&jw, "argv");
jw_array_argv(&jw, argv);
jw_end(&jw);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void fn_child_start_fl(const char *file, int line,
uint64_t us_elapsed_absolute,
const struct child_process *cmd)
{
const char *event_name = "child_start";
struct json_writer jw = JSON_WRITER_INIT;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, NULL, &jw);
jw_object_intmax(&jw, "child_id", cmd->trace2_child_id);
if (cmd->trace2_hook_name) {
jw_object_string(&jw, "child_class", "hook");
jw_object_string(&jw, "hook_name", cmd->trace2_hook_name);
} else {
const char *child_class =
cmd->trace2_child_class ? cmd->trace2_child_class : "?";
jw_object_string(&jw, "child_class", child_class);
}
if (cmd->dir)
jw_object_string(&jw, "cd", cmd->dir);
jw_object_bool(&jw, "use_shell", cmd->use_shell);
jw_object_inline_begin_array(&jw, "argv");
if (cmd->git_cmd)
jw_array_string(&jw, "git");
jw_array_argv(&jw, cmd->args.v);
jw_end(&jw);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void fn_child_exit_fl(const char *file, int line,
uint64_t us_elapsed_absolute, int cid, int pid,
int code, uint64_t us_elapsed_child)
{
const char *event_name = "child_exit";
struct json_writer jw = JSON_WRITER_INIT;
double t_rel = (double)us_elapsed_child / 1000000.0;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, NULL, &jw);
jw_object_intmax(&jw, "child_id", cid);
jw_object_intmax(&jw, "pid", pid);
jw_object_intmax(&jw, "code", code);
jw_object_double(&jw, "t_rel", 6, t_rel);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void fn_child_ready_fl(const char *file, int line,
uint64_t us_elapsed_absolute, int cid, int pid,
const char *ready, uint64_t us_elapsed_child)
{
const char *event_name = "child_ready";
struct json_writer jw = JSON_WRITER_INIT;
double t_rel = (double)us_elapsed_child / 1000000.0;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, NULL, &jw);
jw_object_intmax(&jw, "child_id", cid);
jw_object_intmax(&jw, "pid", pid);
jw_object_string(&jw, "ready", ready);
jw_object_double(&jw, "t_rel", 6, t_rel);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void fn_thread_start_fl(const char *file, int line,
uint64_t us_elapsed_absolute)
{
const char *event_name = "thread_start";
struct json_writer jw = JSON_WRITER_INIT;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, NULL, &jw);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void fn_thread_exit_fl(const char *file, int line,
uint64_t us_elapsed_absolute,
uint64_t us_elapsed_thread)
{
const char *event_name = "thread_exit";
struct json_writer jw = JSON_WRITER_INIT;
double t_rel = (double)us_elapsed_thread / 1000000.0;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, NULL, &jw);
jw_object_double(&jw, "t_rel", 6, t_rel);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void fn_exec_fl(const char *file, int line, uint64_t us_elapsed_absolute,
int exec_id, const char *exe, const char **argv)
{
const char *event_name = "exec";
struct json_writer jw = JSON_WRITER_INIT;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, NULL, &jw);
jw_object_intmax(&jw, "exec_id", exec_id);
if (exe)
jw_object_string(&jw, "exe", exe);
jw_object_inline_begin_array(&jw, "argv");
jw_array_argv(&jw, argv);
jw_end(&jw);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void fn_exec_result_fl(const char *file, int line,
uint64_t us_elapsed_absolute, int exec_id,
int code)
{
const char *event_name = "exec_result";
struct json_writer jw = JSON_WRITER_INIT;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, NULL, &jw);
jw_object_intmax(&jw, "exec_id", exec_id);
jw_object_intmax(&jw, "code", code);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void fn_param_fl(const char *file, int line, const char *param,
const char *value)
{
const char *event_name = "def_param";
struct json_writer jw = JSON_WRITER_INIT;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, NULL, &jw);
jw_object_string(&jw, "param", param);
jw_object_string(&jw, "value", value);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void fn_repo_fl(const char *file, int line,
const struct repository *repo)
{
const char *event_name = "def_repo";
struct json_writer jw = JSON_WRITER_INIT;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, repo, &jw);
jw_object_string(&jw, "worktree", repo->worktree);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
static void fn_region_enter_printf_va_fl(const char *file, int line,
uint64_t us_elapsed_absolute,
const char *category,
const char *label,
const struct repository *repo,
const char *fmt, va_list ap)
{
const char *event_name = "region_enter";
struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
struct json_writer jw = JSON_WRITER_INIT;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, repo, &jw);
jw_object_intmax(&jw, "nesting", ctx->nr_open_regions);
if (category)
jw_object_string(&jw, "category", category);
if (label)
jw_object_string(&jw, "label", label);
maybe_add_string_va(&jw, "msg", fmt, ap);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
}
static void fn_region_leave_printf_va_fl(
const char *file, int line, uint64_t us_elapsed_absolute,
uint64_t us_elapsed_region, const char *category, const char *label,
const struct repository *repo, const char *fmt, va_list ap)
{
const char *event_name = "region_leave";
struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
struct json_writer jw = JSON_WRITER_INIT;
double t_rel = (double)us_elapsed_region / 1000000.0;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, repo, &jw);
jw_object_double(&jw, "t_rel", 6, t_rel);
jw_object_intmax(&jw, "nesting", ctx->nr_open_regions);
if (category)
jw_object_string(&jw, "category", category);
if (label)
jw_object_string(&jw, "label", label);
maybe_add_string_va(&jw, "msg", fmt, ap);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
}
static void fn_data_fl(const char *file, int line, uint64_t us_elapsed_absolute,
uint64_t us_elapsed_region, const char *category,
const struct repository *repo, const char *key,
const char *value)
{
const char *event_name = "data";
struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
struct json_writer jw = JSON_WRITER_INIT;
double t_abs = (double)us_elapsed_absolute / 1000000.0;
double t_rel = (double)us_elapsed_region / 1000000.0;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, repo, &jw);
jw_object_double(&jw, "t_abs", 6, t_abs);
jw_object_double(&jw, "t_rel", 6, t_rel);
jw_object_intmax(&jw, "nesting", ctx->nr_open_regions);
jw_object_string(&jw, "category", category);
jw_object_string(&jw, "key", key);
jw_object_string(&jw, "value", value);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
}
static void fn_data_json_fl(const char *file, int line,
uint64_t us_elapsed_absolute,
uint64_t us_elapsed_region, const char *category,
const struct repository *repo, const char *key,
const struct json_writer *value)
{
const char *event_name = "data_json";
struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
struct json_writer jw = JSON_WRITER_INIT;
double t_abs = (double)us_elapsed_absolute / 1000000.0;
double t_rel = (double)us_elapsed_region / 1000000.0;
jw_object_begin(&jw, 0);
event_fmt_prepare(event_name, file, line, repo, &jw);
jw_object_double(&jw, "t_abs", 6, t_abs);
jw_object_double(&jw, "t_rel", 6, t_rel);
jw_object_intmax(&jw, "nesting", ctx->nr_open_regions);
jw_object_string(&jw, "category", category);
jw_object_string(&jw, "key", key);
jw_object_sub_jw(&jw, "value", value);
jw_end(&jw);
tr2_dst_write_line(&tr2dst_event, &jw.json);
jw_release(&jw);
}
}
struct tr2_tgt tr2_tgt_event = {
&tr2dst_event,
fn_init,
fn_term,
fn_version_fl,
fn_start_fl,
fn_exit_fl,
fn_signal,
fn_atexit,
fn_error_va_fl,
fn_command_path_fl,
fn_command_ancestry_fl,
fn_command_name_fl,
fn_command_mode_fl,
fn_alias_fl,
fn_child_start_fl,
fn_child_exit_fl,
fn_child_ready_fl,
fn_thread_start_fl,
fn_thread_exit_fl,
fn_exec_fl,
fn_exec_result_fl,
fn_param_fl,
fn_repo_fl,
fn_region_enter_printf_va_fl,
fn_region_leave_printf_va_fl,
fn_data_fl,
fn_data_json_fl,
NULL, /* printf */
};