The addresses for packed inline symbols reference `mrb->symbuf` that
could be overridden by the later call of `mrb_sym2name_len`. Since
file names in call stack information are kept as symbols, keeping the
address in the C structures could cause problems like #4342.
This changes small incompatible changes in function prototypes:
* `mrb_parser_get_filename`: return value changed to `mrb_sym`.
* `mrb_debug_get_filename`: add `mrb_state*` as a first argument.
* `mrb_debug_get_line`: ditto.
I believe above functions are almost internal, and no third-party
mrbgem use them.
Instead of preserving a backtrace in `mrb_state`, `mrb_exc_set`
keeps packed backtrace in an exception object. `#backtrace` unpacks
it to an array of strings.
GitHub: fix#3122
It reverts #3126. #3126 fixes the segmentation fault but generates
broken backtrace.
This change fixes the segmentation fault and generates correct
backtrace. The strategy of this change is "generating backtrace while
irep is alive".
/tmp/test.rb:
def gen
e0 = nil
begin
1.times {
raise 'foobar'
}
rescue => e
e0 = e
end
e0
end
e = gen
GC.start
gen
GC.start
puts e.backtrace.join("\n")
Run:
% bin/mruby /tmp/test.rb
/tmp/test.rb:5:in Object.gen
/home/kou/work/ruby/mruby.kou/mrblib/numeric.rb:77:in Integral#times
/tmp/test.rb:4:in Object.gen
/tmp/test.rb:13
FYI:
% ruby -v /tmp/test.rb
ruby 2.3.0p0 (2015-12-25) [x86_64-linux-gnu]
/tmp/test.rb:5:in `block in gen'
/tmp/test.rb:4:in `times'
/tmp/test.rb:4:in `gen'
/tmp/test.rb:13:in `<main>'
GitHub: fix#2902, #2917
The current implementation traverses stack to retrieve backtrace. But
stack will be changed when some operations are occurred. It means that
backtrace may be broken after some operations.
This change (1) saves the minimum information to retrieve backtrace when
exception is raised and (2) restores backtrace from the minimum
information when backtrace is needed. It reduces overhead for creating
backtrace Ruby objects.
The space for the minimum information is reused by multiple
exceptions. So memory allocation isn't occurred for each exception.
If the argument is always a string, then mrb_str_cat_str() can be
directly called instead of indirectly by mrb_str_append().
mrb_any_to_s(), mrb_obj_as_string(), mrb_inspect() always return a
string.
KOBAYASHI Shuji