Function append_stacktrace

src/backend/utils/error/elog.c:3781–3984

* Append the backtrace to the given PipeProtoChunk or the syslogger file or stderr. * * We can not use the default backtrace_symbols since it calls malloc, which * is not async-safe, to allocate space for symbols. Even though we don't * really support async-safe error logging yet, the malloc has caused several * deadlock issues in the past, we should avoid using them in our error handler. *

 * Otherwise, write to stderr.
 */
static void
append_stacktrace(PipeProtoChunk *buffer, StringInfo append, void *const *stackarray,
				  int stacksize, bool amsyslogger)
{
#if !defined(WIN32) && !defined(_AIX)
	int stack_no;
	char symbol[SYMBOL_SIZE]; /* a reasonable size for a symbol */
	Dl_info dli;
	int symbol_len;


	FILE * fd;
	bool fd_ok = false;
	char cmd[CMD_BUFFER_SIZE];
	char cmdresult[STACK_DEPTH_MAX][SYMBOL_SIZE];
	char addrtxt[ADDRESS_SIZE];

#if defined(__darwin__)
	const char * prog = "atos -o";
#else
	const char * prog = "addr2line -s -e";
#endif

	static bool in_translate_stacktrace = false;
	bool addr2line_ok = gp_log_stack_trace_lines;

	if (stacksize == 0)
		return;


	if (!in_translate_stacktrace && addr2line_ok)
	{
		/*
		 * Keep a record that we are doing this work, so if we crash during it, we don't
		 * try to do it again when we recurse back here,
		 */
		in_translate_stacktrace = true;

		snprintf(cmd,sizeof(cmd),"%s %s ",prog,my_exec_path);

		for (stack_no = 0; stack_no < stacksize && stack_no < 100; stack_no++)
		{
			cmdresult[stack_no][0] = '\0';   /* clear this array for later */
			snprintf(addrtxt, sizeof(addrtxt),"%p ",stackarray[stack_no]);
			
			Assert(sizeof(cmd) > strlen(cmd));
			strncat(cmd, addrtxt, sizeof(cmd) - strlen(cmd) - 1);
		}

		cmdresult[0][0] = '\0';
		fd = popen(cmd,"r");
		if (fd != NULL)
			fd_ok = true;

		if (fd_ok)
		{
			for (stack_no = 0; stack_no < stacksize && stack_no < STACK_DEPTH_MAX; stack_no++)
			{