Re: Printing backtrace of postgres processes

On 2022-Jan-27, vignesh C wrote:

> diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
> index 0ee6974f1c..855ccc8902 100644
> --- a/doc/src/sgml/func.sgml
> +++ b/doc/src/sgml/func.sgml

> + You can get the file name and line number from the logged details by using
> + gdb/addr2line in linux platforms (users must ensure gdb/addr2line is
> + already installed).

This doesn't read great. I mean, what is gdb/addr2line? I think you
mean either GDB or addr2line; this could be clearer.

> diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
> index 7402696986..522a525741 100644
> --- a/src/backend/utils/error/elog.c
> +++ b/src/backend/utils/error/elog.c
> @@ -944,9 +943,10 @@ errbacktrace(void)
> * Compute backtrace data and add it to the supplied ErrorData. num_skip
> * specifies how many inner frames to skip. Use this to avoid showing the
> * internal backtrace support functions in the backtrace. This requires that
> - * this and related functions are not inlined.
> + * this and related functions are not inlined. If the edata pointer is valid,
> + * backtrace information will be set in edata.
> */
> -static void
> +void
> set_backtrace(ErrorData *edata, int num_skip)
> {
> StringInfoData errtrace;

This seems like a terrible API choice, and the comment change is no
good. I suggest you need to create a function that deals only with a
StringInfo, maybe
append_backtrace(StringInfo buf, int num_skip)
which is used by set_backtrace to print the backtrace in
edata->backtrace, and a new function log_backtrace() that does the
ereport(LOG_SERVER_ONLY) thing.

--
Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/
"Before you were born your parents weren't as boring as they are now. They
got that way paying your bills, cleaning up your room and listening to you
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