git/usage.c
Jeff Hostetler ee4512ed48 trace2: create new combined trace facility
Create a new unified tracing facility for git.  The eventual intent is to
replace the current trace_printf* and trace_performance* routines with a
unified set of git_trace2* routines.

In addition to the usual printf-style API, trace2 provides higer-level
event verbs with fixed-fields allowing structured data to be written.
This makes post-processing and analysis easier for external tools.

Trace2 defines 3 output targets.  These are set using the environment
variables "GIT_TR2", "GIT_TR2_PERF", and "GIT_TR2_EVENT".  These may be
set to "1" or to an absolute pathname (just like the current GIT_TRACE).

* GIT_TR2 is intended to be a replacement for GIT_TRACE and logs command
  summary data.

* GIT_TR2_PERF is intended as a replacement for GIT_TRACE_PERFORMANCE.
  It extends the output with columns for the command process, thread,
  repo, absolute and relative elapsed times.  It reports events for
  child process start/stop, thread start/stop, and per-thread function
  nesting.

* GIT_TR2_EVENT is a new structured format. It writes event data as a
  series of JSON records.

Calls to trace2 functions log to any of the 3 output targets enabled
without the need to call different trace_printf* or trace_performance*
routines.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-22 15:27:59 -08:00

296 lines
6.4 KiB
C

/*
* GIT - The information manager from hell
*
* Copyright (C) Linus Torvalds, 2005
*/
#include "git-compat-util.h"
#include "cache.h"
void vreportf(const char *prefix, const char *err, va_list params)
{
char msg[4096];
char *p;
vsnprintf(msg, sizeof(msg), err, params);
for (p = msg; *p; p++) {
if (iscntrl(*p) && *p != '\t' && *p != '\n')
*p = '?';
}
fprintf(stderr, "%s%s\n", prefix, msg);
}
static NORETURN void usage_builtin(const char *err, va_list params)
{
vreportf("usage: ", err, params);
/*
* When we detect a usage error *before* the command dispatch in
* cmd_main(), we don't know what verb to report. Force it to this
* to facilitate post-processing.
*/
trace2_cmd_name("_usage_");
/*
* Currently, the (err, params) are usually just the static usage
* string which isn't very useful here. Usually, the call site
* manually calls fprintf(stderr,...) with the actual detailed
* syntax error before calling usage().
*
* TODO It would be nice to update the call sites to pass both
* the static usage string and the detailed error message.
*/
exit(129);
}
static NORETURN void die_builtin(const char *err, va_list params)
{
/*
* We call this trace2 function first and expect it to va_copy 'params'
* before using it (because an 'ap' can only be walked once).
*/
trace2_cmd_error_va(err, params);
vreportf("fatal: ", err, params);
exit(128);
}
static void error_builtin(const char *err, va_list params)
{
/*
* We call this trace2 function first and expect it to va_copy 'params'
* before using it (because an 'ap' can only be walked once).
*/
trace2_cmd_error_va(err, params);
vreportf("error: ", err, params);
}
static void warn_builtin(const char *warn, va_list params)
{
vreportf("warning: ", warn, params);
}
static int die_is_recursing_builtin(void)
{
static int dying;
/*
* Just an arbitrary number X where "a < x < b" where "a" is
* "maximum number of pthreads we'll ever plausibly spawn" and
* "b" is "something less than Inf", since the point is to
* prevent infinite recursion.
*/
static const int recursion_limit = 1024;
dying++;
if (dying > recursion_limit) {
return 1;
} else if (dying == 2) {
warning("die() called many times. Recursion error or racy threaded death!");
return 0;
} else {
return 0;
}
}
/* If we are in a dlopen()ed .so write to a global variable would segfault
* (ugh), so keep things static. */
static NORETURN_PTR void (*usage_routine)(const char *err, va_list params) = usage_builtin;
static NORETURN_PTR void (*die_routine)(const char *err, va_list params) = die_builtin;
static void (*error_routine)(const char *err, va_list params) = error_builtin;
static void (*warn_routine)(const char *err, va_list params) = warn_builtin;
static int (*die_is_recursing)(void) = die_is_recursing_builtin;
void set_die_routine(NORETURN_PTR void (*routine)(const char *err, va_list params))
{
die_routine = routine;
}
void set_error_routine(void (*routine)(const char *err, va_list params))
{
error_routine = routine;
}
void (*get_error_routine(void))(const char *err, va_list params)
{
return error_routine;
}
void set_warn_routine(void (*routine)(const char *warn, va_list params))
{
warn_routine = routine;
}
void (*get_warn_routine(void))(const char *warn, va_list params)
{
return warn_routine;
}
void set_die_is_recursing_routine(int (*routine)(void))
{
die_is_recursing = routine;
}
void NORETURN usagef(const char *err, ...)
{
va_list params;
va_start(params, err);
usage_routine(err, params);
va_end(params);
}
void NORETURN usage(const char *err)
{
usagef("%s", err);
}
void NORETURN die(const char *err, ...)
{
va_list params;
if (die_is_recursing()) {
fputs("fatal: recursion detected in die handler\n", stderr);
exit(128);
}
va_start(params, err);
die_routine(err, params);
va_end(params);
}
static const char *fmt_with_err(char *buf, int n, const char *fmt)
{
char str_error[256], *err;
int i, j;
err = strerror(errno);
for (i = j = 0; err[i] && j < sizeof(str_error) - 1; ) {
if ((str_error[j++] = err[i++]) != '%')
continue;
if (j < sizeof(str_error) - 1) {
str_error[j++] = '%';
} else {
/* No room to double the '%', so we overwrite it with
* '\0' below */
j--;
break;
}
}
str_error[j] = 0;
/* Truncation is acceptable here */
snprintf(buf, n, "%s: %s", fmt, str_error);
return buf;
}
void NORETURN die_errno(const char *fmt, ...)
{
char buf[1024];
va_list params;
if (die_is_recursing()) {
fputs("fatal: recursion detected in die_errno handler\n",
stderr);
exit(128);
}
va_start(params, fmt);
die_routine(fmt_with_err(buf, sizeof(buf), fmt), params);
va_end(params);
}
#undef error_errno
int error_errno(const char *fmt, ...)
{
char buf[1024];
va_list params;
va_start(params, fmt);
error_routine(fmt_with_err(buf, sizeof(buf), fmt), params);
va_end(params);
return -1;
}
#undef error
int error(const char *err, ...)
{
va_list params;
va_start(params, err);
error_routine(err, params);
va_end(params);
return -1;
}
void warning_errno(const char *warn, ...)
{
char buf[1024];
va_list params;
va_start(params, warn);
warn_routine(fmt_with_err(buf, sizeof(buf), warn), params);
va_end(params);
}
void warning(const char *warn, ...)
{
va_list params;
va_start(params, warn);
warn_routine(warn, params);
va_end(params);
}
/* Only set this, ever, from t/helper/, when verifying that bugs are caught. */
int BUG_exit_code;
static NORETURN void BUG_vfl(const char *file, int line, const char *fmt, va_list params)
{
char prefix[256];
/* truncation via snprintf is OK here */
if (file)
snprintf(prefix, sizeof(prefix), "BUG: %s:%d: ", file, line);
else
snprintf(prefix, sizeof(prefix), "BUG: ");
vreportf(prefix, fmt, params);
if (BUG_exit_code)
exit(BUG_exit_code);
abort();
}
#ifdef HAVE_VARIADIC_MACROS
NORETURN void BUG_fl(const char *file, int line, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
BUG_vfl(file, line, fmt, ap);
va_end(ap);
}
#else
NORETURN void BUG(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
BUG_vfl(NULL, 0, fmt, ap);
va_end(ap);
}
#endif
#ifdef SUPPRESS_ANNOTATED_LEAKS
void unleak_memory(const void *ptr, size_t len)
{
static struct suppressed_leak_root {
struct suppressed_leak_root *next;
char data[FLEX_ARRAY];
} *suppressed_leaks;
struct suppressed_leak_root *root;
FLEX_ALLOC_MEM(root, data, ptr, len);
root->next = suppressed_leaks;
suppressed_leaks = root;
}
#endif