For complicated macros, especially macros that are used correctly but have a bug in their implementation somewhere and use 'syntax-case' or 'syntax-rules' multiple times, it can be very convenient to know _which_ syntax-case or syntax-rules raised the syntax-error.
E.g., I'm currently debugging some changes to a (non-Guile) macro, and I don't know what to make of the following -- the '#:getter . datum-type' isn't even present in the original code anywhere: ice-9/boot-9.scm:1685:16: In procedure raise-exception: Syntax error: unknown location: source expression failed to match any pattern in form (#:getter . datum-type) make: *** [Makefile:1333: gnu/gnunet/dht/client.go] Fout 1 As such, partially revert the following commit that does not give a rationale on how backtraces for syntax errors aren't helpful. commit e0c70a8b06db2f6d721556c23280471825c3830a Author: Andy Wingo <wi...@pobox.com> Date: Fri Feb 11 15:16:25 2011 +0100 scm_handle_by_message uses scm_print_exception * libguile/throw.c (handler_message, should_print_backtrace): Use scm_print_exception. Add a helper function to determine when to print a backtrace; don't do so on read or syntax errors. --- libguile/throw.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/libguile/throw.c b/libguile/throw.c index e837abe89..045759a00 100644 --- a/libguile/throw.c +++ b/libguile/throw.c @@ -359,8 +359,7 @@ should_print_backtrace (SCM tag, SCM stack) && scm_initialized_p /* It's generally not useful to print backtraces for errors reading or expanding code in these fallback catch statements. */ - && !scm_is_eq (tag, scm_from_latin1_symbol ("read-error")) - && !scm_is_eq (tag, scm_from_latin1_symbol ("syntax-error")); + && !scm_is_eq (tag, scm_from_latin1_symbol ("read-error")); } static void base-commit: 5b42f8c154906584455a4989038406c88b723cb0 prerequisite-patch-id: ba8a0acaf4d6a80a4e74ec209b127a7f34c84f69 -- 2.39.1