Feature #7424
closed
an embedded Ruby interpreter doesn't get the full Ruby environment unless it calls ruby_process_options() (which is not documented)
Description
The documented way to embed a Ruby interpreter is to call:
RUBY_INIT_STACK;
ruby_init();
ruby_init_loadpath();
However, this leaves the Ruby environment incomplete. As an example, the following program:
#include <ruby.h>
int
main(int argc, char *argv[])
{
RUBY_INIT_STACK;
ruby_init();
ruby_init_loadpath();
rb_eval_string("p Mutex.new.methods");
return 0;
}
prints:
[:locked?, :try_lock, :lock, :unlock, :sleep, :nil?, :===, :=~, :!~, :eql?, :hash, :<=>, :class, :singleton_class, :clone, :dup, :initialize_dup, :initialize_clone, :taint, :tainted?, :untaint, :untrust, :untrusted?, :trust, :freeze, :frozen?, :to_s, :inspect, :methods, :singleton_methods, :protected_methods, :private_methods, :public_methods, :instance_variables, :instance_variable_get, :instance_variable_set, :instance_variable_defined?, :instance_of?, :kind_of?, :is_a?, :tap, :send, :public_send, :respond_to?, :respond_to_missing?, :extend, :display, :method, :public_method, :define_singleton_method, :object_id, :to_enum, :enum_for,
:==, :equal?, :!, :!=, :instance_eval, :instance_exec, :send, :id]
Whereas running "ruby -e 'p Mutex.new.methods'" produces:
[:locked?, :try_lock, :lock, :unlock, :sleep, :synchronize, :nil?, :===, :=~, :!~, :eql?, :hash, :<=>, :class, :singleton_class, :clone, :dup, :initialize_dup, :initialize_clone, :taint, :tainted?, :untaint, :untrust, :untrusted?, :trust, :freeze, :frozen?, :to_s, :inspect, :methods, :singleton_methods, :protected_methods, :private_methods, :public_methods, :instance_variables, :instance_variable_get, :instance_variable_set, :instance_variable_defined?, :instance_of?, :kind_of?, :is_a?, :tap, :send, :public_send, :respond_to?, :respond_to_missing?, :extend, :display, :method, :public_method, :define_singleton_method, :object_id, :to_enum, :enum_for, :==, :equal?, :!, :!=, :instance_eval, :instance_exec, :send, :id]
Note that ":synchronize" is missing from the former. This is because ruby_init_prelude() has not been called - that's what adds synchronize() to Mutex.
A workwaround is to call ruby_process_options() as in the following:
#include <ruby.h>
int
main(int argc, char argv[])
{
RUBY_INIT_STACK;
ruby_init();
ruby_init_loadpath();
static char args[] = { "ruby", "/dev/null" };
ruby_process_options(2, args);
rb_eval_string("p Mutex.new.methods");
return 0;
}
This seems very clumsy!
Some possible solutions are:
- call ruby_init_prelude() from ruby_init()
- change the linkage of ruby_init_prelude() to be non-static and have the Ruby embedded program call it explicitly (requires a documentation change).
Updated by 
Updated by