Files
pv/src/main/debug.c
T

120 lines
2.9 KiB
C

/*
* Output debugging information.
*
* Copyright 2002-2008, 2010, 2012-2015, 2017, 2021, 2023-2026 Andrew Wood
*
* License GPLv3+: GNU GPL version 3 or later; see `docs/COPYING'.
*/
#include "config.h"
#include "pv.h"
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <time.h>
#include <sys/types.h>
#include <unistd.h>
#ifdef ENABLE_DEBUGGING
/*@null@*/ static const char *debug_filename = NULL;
/*
* Set the destination for debugging information.
*/
void debugging_output_destination(const char *filename)
{
debug_filename = filename;
}
/*
* Output debugging information to the file specified earlier by a call to
* debugging_output_destination(), if any.
*/
void debugging_output(const char *function, const char *file, int line, const char *format, ...)
{
static bool tried_open = false;
static FILE *debugfptr = NULL;
va_list ap;
time_t t;
const struct tm *tm;
char tbuf[128]; /* flawfinder: ignore */
/*
* flawfinder note: tbuf is only written to by strftime() which
* takes its size, and string termination is enforced.
*/
if (false == tried_open) {
if (NULL != debug_filename) {
debugfptr = fopen(debug_filename, "a"); /* flawfinder: ignore */
/*
* flawfinder note: the caller directly controls the
* filename, so using append mode is the safest
* option.
*/
}
tried_open = true;
}
if (NULL == debugfptr) {
return;
}
/*
* Note gmtime() is used rather than localtime(). Testing with
* "strace" showed many cases where "pv </dev/zero | cat >/dev/null"
* being paused and backgrounded would cause pv to be stuck in
* futex_wait() inside a pv_sig_alrm() inside a pv_sig_cont(). The
* backtrace mentioned many time zone conversion steps, and all of
* that goes away with gmtime().
*/
(void) time(&t);
tm = gmtime(&t);
tbuf[0] = '\0';
if (0 == strftime(tbuf, sizeof(tbuf), "%Y-%m-%d %H:%M:%S", tm)) {
tbuf[0] = '\0';
}
tbuf[sizeof(tbuf) - 1] = '\0'; /* enforce termination. */
(void) fprintf(debugfptr, "[%s] (%d) %s (%s:%d): ", tbuf, getpid(), function, file, line);
va_start(ap, format);
(void) vfprintf(debugfptr, format, ap); /* flawfinder: ignore */
va_end(ap);
/*
* flawfinder note: vfprintf format is explicitly controlled by the
* caller of this function - no mitigation is possible or desirable.
*/
(void) fprintf(debugfptr, "\n");
(void) fflush(debugfptr);
}
#else /* ! ENABLE_DEBUGGING */
/*
* Stub debugging destination function.
*/
void debugging_output_destination( /*@unused@ */ __attribute__((unused))
const char *filename)
{
}
/*
* Stub debugging output function.
*/
void debugging_output( /*@unused@ */ __attribute__((unused))
const char *function, /*@unused@ */ __attribute__((unused))
const char *file, /*@unused@ */ __attribute__((unused))
int line, /*@unused@ */ __attribute__((unused))
const char *format, ...)
{
}
#endif /* ENABLE_DEBUGGING */