core.ops

/*
** core.ops
*/

BEGIN_OPS_PREAMBLE

#include "parrot/dynext.h"
#include "parrot/runcore_api.h"
#include "parrot/events.h"
#include "pmc/pmc_exception.h"
#include "pmc/pmc_exceptionhandler.h"
#include "pmc/pmc_continuation.h"
#include "pmc/pmc_fixedintegerarray.h"
#include "pmc/pmc_parrotlibrary.h"


END_OPS_PREAMBLE

=head1 NAME

core.ops - Core Opcodes

=cut

=head1 DESCRIPTION

Parrot's core library of ops.

Core operations are primarily flow control and interpreter
introspection.

When making changes to any ops file, run C<make bootstrap-ops> to regenerate
all generated ops files.

=cut

# ' for emacs

###############################################################################

=head2 Basic ops

These are the fundamental operations.
Please note: These opcodes must not be moved; they must have
exactly these opcode numbers. Opcodes ending with underscores are for
internal use only; don't emit these opcodes.

=over 4

=cut

########################################

=item B<end>()

Halts the interpreter. See also B<exit>.

=cut

inline op end()  :check_event :flow {
    UNUSED(interp);
    UNUSED(cur_opcode);
    goto ADDRESS(0);
}


########################################

=item B<noop>()

Does nothing other than waste an iota of time and 32 bits of bytecode space.

=item B<check_events>()

Check the event queue and run event handlers if there are unhandled events.
Note: This opcode is mainly for testing. It should not be necessary to ever
use it explicitly.

=item B<check_events__>()

Check the event queue and run event handlers if there are unhandled events.
Note: Do B<not> use this opcode. It is for internal use only.

=item B<load_bytecode>(in STR)

Load Parrot bytecode from file $1, and search the library path to locate the
file. Automatically triggers :load functions if the file found is a .pbc. If
it is a .pir or a .pasm, the file is compiled first and the :init subs are
triggered instead. Nothing is returned.

=item B<load_bytecode>(out PMC, in STR)

Load Parrot bytecode from file $2, searching the library path to locate the
file. Returns a new PackfileView in $1. Does not perform any automatic
initialization. Use the PackfileView PMC interface to introspect and perform
actions on it.

=cut

inline op noop()  {
    UNUSED(interp)
}

inline op check_events()  :flow {
    opcode_t *next = expr NEXT();
    next = Parrot_cx_check_scheduler(interp, next);
    goto ADDRESS(next);   /* force this being a branch op */
}

inline op check_events__() :internal :flow {
    opcode_t * const _this = CUR_OPCODE;
    opcode_t * const handler = Parrot_ex_throw_from_op_args(interp, _this,
        EXCEPTION_INVALID_OPERATION,
        "check_events__ opcode doesn't do anything useful.");
    goto ADDRESS(handler);
    /* Restore op_func_table. */
    Parrot_runcore_disable_event_checking(interp);
    /* Parrot_cx_handle_tasks(interp, interp->scheduler); */
    goto ADDRESS(_this);   /* force this being a branch op */
}

inline op load_bytecode(in STR) :load_file {
    Parrot_load_bytecode(interp, $1);
}

inline op load_bytecode(out PMC, in STR) :load_file {
    $1 = Parrot_pf_load_bytecode_search(interp, $2);
}

=item B<load_language>(in STR)

Load the compiler libraries for a language $1. Search the library path to
locate the main compiler file in the standard locations.

=cut

inline op load_language(in STR) :load_file {
    Parrot_load_language(interp, $1);
}

=back

=cut

###############################################################################

=head2 Control flow

The control flow opcodes check conditions and manage program flow.

=over 4

=cut

########################################

=item B<branch>(in LABEL)

Branch forward or backward by the amount in $1.

=cut

inline op branch(in LABEL) :base_loop :flow {
    if(Parrot_cx_check_scheduler(interp, cur_opcode + $1) == 0)
        goto ADDRESS(0);
    goto OFFSET($1);
}


########################################

=item B<local_branch>(invar PMC, in LABEL)

Go to the location specified by the label in $2. Push the current location onto
the stack passed in $1 for later returning.

=cut

inline op local_branch(invar PMC, in LABEL)  :check_event :flow {
    INTVAL return_addr;
    opcode_t * const dest = expr NEXT();

    if (PMC_IS_NULL($1) || $1->vtable->base_type != enum_class_ResizableIntegerArray) {
        opcode_t * const handler = Parrot_ex_throw_from_op_args(interp, dest,
            EXCEPTION_INVALID_OPERATION,
            "Must pass a valid integer array to 'local_branch'");
        goto ADDRESS(handler);
    }

    return_addr = PTR2INTVAL(dest);
    VTABLE_push_integer(interp, $1, return_addr);

    goto OFFSET($2);
}

=item B<local_return>(invar PMC)

Pop the location off the top of the call stack and go there.

=cut

inline op local_return(invar PMC) :flow {
    INTVAL return_addr;
    opcode_t *next;
    opcode_t * const dest = expr NEXT();

    if (PMC_IS_NULL($1) || $1->vtable->base_type != enum_class_ResizableIntegerArray) {
        opcode_t * const handler = Parrot_ex_throw_from_op_args(interp, dest,
            EXCEPTION_INVALID_OPERATION,
            "Must pass a valid integer array to 'local_return'");
        goto ADDRESS(handler);
    }

    return_addr = VTABLE_pop_integer(interp, $1);
    next = INTVAL2PTR(opcode_t *, return_addr);

    /* The return address must be within the current code segment. */
    if (! (next >= interp->code->base.data
           && next < (interp->code->base.data + interp->code->base.size))) {
        opcode_t * const handler = Parrot_ex_throw_from_op_args(interp, dest,
            EXCEPTION_INVALID_OPERATION,
            "Address for 'local_return' must be within the current code segment");
        goto ADDRESS(handler);
    }

    goto ADDRESS(next);
}

########################################

=item B<jump>(in LABEL)

Jump to the address held in register $1.

=cut

inline op jump(in LABEL) :base_loop :flow {
    opcode_t * const loc = INTVAL2PTR(opcode_t *, $1);
    UNUSED(interp);
    UNUSED(cur_opcode);
    goto ADDRESS(loc);
}

=back

=cut

###############################################################################

=head2 Conditional branch operations

These operations perform a conditional relative branch. If the condition is
met, the branch happens.  Otherwise control falls to the next operation.

=over 4

=cut

########################################

=item B<if>(invar INT, inconst LABEL)

=item B<if>(invar NUM, inconst LABEL)

=item B<if>(invar PMC, inconst LABEL)

=item B<if>(invar STR, inconst LABEL)

Check register $1. If true, branch by $2.

=cut

inline op if (invar INT, inconst LABEL) {
    if ($1 != 0)
        goto OFFSET($2);
}

inline op if (invar NUM, inconst LABEL) {
    if (!FLOAT_IS_ZERO($1))
        goto OFFSET($2);
}

op if (invar STR, inconst LABEL) {
    if (Parrot_str_boolean(interp, $1))
        goto OFFSET($2);
}

op if (invar PMC, inconst LABEL) {
    if (VTABLE_get_bool(interp, $1))
        goto OFFSET($2);
}

########################################

=item B<unless>(invar INT, inconst LABEL)

=item B<unless>(invar NUM, inconst LABEL)

=item B<unless>(invar PMC, inconst LABEL)

=item B<unless>(invar STR, inconst LABEL)

Check register $1. If false, branch by $2.

=cut

inline op unless(invar INT, inconst LABEL) {
    if ($1 == 0)
        goto OFFSET($2);
}

inline op unless(invar NUM, inconst LABEL) {
    if (FLOAT_IS_ZERO($1))
        goto OFFSET($2);
}

op unless(invar STR, inconst LABEL) {
    if (!Parrot_str_boolean(interp, $1))
        goto OFFSET($2);
}

op unless(invar PMC, inconst LABEL) {
    if (!VTABLE_get_bool(interp, $1))
        goto OFFSET($2);
}

=back

=cut

###############################################################################

=head2 Subroutine operations

These operations are used to generate and call subroutines and
continuations.

=over 4

=cut

########################################

=item B<invokecc>(invar PMC)

Call the subroutine in $1 and generate a new return continuation, if needed.
For example, a NCI subroutine which executes code in some C library will not
create a continuation, nor will anything but the first call to a coroutine.

=item B<invoke>(invar PMC, invar PMC)

Call the subroutine in $1 and use continuation $2.

=item B<yield>()

Yield results from a coroutine.

=item B<tailcall>(invar PMC)

Call the subroutine in $1 and use the current continuation as the subs
continuation.

=item B<returncc>()

Return from the sub or method via the current continuation.

=item B<capture_lex>(invar PMC)

Capture the current lexical state of the inner subroutine PMC.

=item B<newclosure>(out PMC, invar PMC)

Create a closure of the given subroutine PMC by cloning the sub's state.

=cut

inline op invokecc(invar PMC) :flow {
    PMC      * const p     = $1;
    opcode_t *dest         = expr NEXT();
    PMC      * const ctx   = CURRENT_CONTEXT(interp);
    PMC      * const signature = Parrot_pcc_get_signature(interp, ctx);

    Parrot_pcc_set_pc(interp, ctx, dest);
    Parrot_pcc_reuse_continuation(interp, ctx, dest);
    dest                   = VTABLE_invoke(interp, p, dest);
    goto ADDRESS(dest);
}

inline op invoke(invar PMC, invar PMC) :flow {
    opcode_t   *dest       = expr NEXT();
    PMC * const p          = $1;
    PMC * const ctx        = CURRENT_CONTEXT(interp);
    PMC * const signature  = Parrot_pcc_get_signature(interp, ctx);

    Parrot_pcc_set_pc(interp, ctx, dest);
    interp->current_cont   = $2;
    dest = VTABLE_invoke(interp, p, dest);
    goto ADDRESS(dest);
}

inline op yield() :flow {
    opcode_t   *dest = expr NEXT();
    PMC * const p    = Parrot_pcc_get_sub(interp, CURRENT_CONTEXT(interp));

    VTABLE_increment(interp, p);
    dest = VTABLE_invoke(interp, p, dest);
    goto ADDRESS(dest);
}

inline op tailcall(invar PMC) :flow {
    PMC * const p               = $1;
    opcode_t   *dest            = expr NEXT();
    PMC * const ctx             = CURRENT_CONTEXT(interp);
    PMC * const parent_ctx      = Parrot_pcc_get_caller_ctx(interp, ctx);
    PMC * const this_call_sig   = Parrot_pcc_get_signature(interp, ctx);
    PMC * const parent_call_sig = Parrot_pcc_get_signature(interp, parent_ctx);
    interp->current_cont        = Parrot_pcc_get_continuation(interp, ctx);

    Parrot_pcc_merge_signature_for_tailcall(interp, parent_call_sig, this_call_sig);
    SUB_FLAG_TAILCALL_SET(interp->current_cont);
    dest = VTABLE_invoke(interp, p, dest);
    goto ADDRESS(dest);
}

inline op returncc() :flow {
    PMC * const p = Parrot_pcc_get_continuation(interp, CURRENT_CONTEXT(interp));
    opcode_t * const dest = VTABLE_invoke(interp, p, expr NEXT());
    goto ADDRESS(dest);
}

inline op capture_lex(invar PMC) {
    Parrot_sub_capture_lex(interp, $1);
}

inline op newclosure(out PMC, invar PMC) {
    $1 = Parrot_sub_new_closure(interp, $2);
}

=back

=head2 Function argument opcode

Implementations of function argument and params handling

=over 4

=item B<set_args>(inconst PMC /* , ... */)

Define arguments for the next function call.

=item B<get_results>(inconst PMC /* , ... */)

Define return values for the next function call.

=item B<get_params>(inconst PMC /* , ... */)

Define function parameters for this subroutine.

=item B<set_returns>(inconst PMC /* , ... */)

Define return results for the subroutine return statement.

For all of these opcodes the passed invar PMC constant is the string
representation of a FixedIntegerArray with one flag word per argument.
The flags are documented currently in F<include/parrot/enums.h> only.

After this argument a variable amount of arguments must follow according
to the elements of the signature array.

=cut


op set_args(inconst PMC) :flow {
    opcode_t * const raw_args = CUR_OPCODE;
    PMC * const signature = $1;
    PMC * const call_sig = Parrot_pcc_build_sig_object_from_op(interp,
            PMCNULL, signature, raw_args);
    INTVAL argc;
    GETATTR_FixedIntegerArray_size(interp, signature, argc);
    Parrot_pcc_set_signature(interp, CURRENT_CONTEXT(interp), call_sig);
    goto OFFSET(argc + 2);
}

op get_params(inconst PMC) :flow {
    opcode_t * const raw_params  = CUR_OPCODE;
    PMC      * const signature   = $1;
    PMC      * const ctx         = CURRENT_CONTEXT(interp);
    PMC      * const ccont       = Parrot_pcc_get_continuation(interp, ctx);
    PMC      * const caller_ctx  = Parrot_pcc_get_caller_ctx(interp, ctx);
    PMC      * const call_object = Parrot_pcc_get_signature(interp, caller_ctx);
    INTVAL argc;

    Parrot_pcc_fill_params_from_op(interp, call_object, signature, raw_params,
            PARROT_ERRORS_PARAM_COUNT_FLAG);

    /* TODO Factor out with Sub.invoke */
    if (PObj_get_FLAGS(ccont) & SUB_FLAG_TAILCALL) {
        PObj_get_FLAGS(ccont) &= ~SUB_FLAG_TAILCALL;
        Parrot_pcc_dec_recursion_depth(interp, ctx);
        Parrot_pcc_set_caller_ctx(interp, ctx, Parrot_pcc_get_caller_ctx(interp, caller_ctx));
    }
    GETATTR_FixedIntegerArray_size(interp, signature, argc);
    goto OFFSET(argc + 2);
}

op set_returns(inconst PMC) :flow {
    opcode_t * const raw_args   = CUR_OPCODE;
    PMC      * const signature  = $1;
    PMC      * ctx              = CURRENT_CONTEXT(interp);
    PMC      * const caller_ctx = Parrot_pcc_get_caller_ctx(interp, ctx);
    PMC      * const call_sig   = Parrot_pcc_build_sig_object_from_op(interp,
                Parrot_pcc_get_signature(interp, caller_ctx), signature, raw_args);
    INTVAL argc;

    Parrot_pcc_set_signature(interp, ctx, call_sig);
    GETATTR_FixedIntegerArray_size(interp, signature, argc);
    goto OFFSET(argc + 2);
}

op get_results(inconst PMC) :flow {
    opcode_t * const raw_params  = CUR_OPCODE;
    PMC      * const signature   = $1;
    PMC      * const ctx         = CURRENT_CONTEXT(interp);
    PMC      * const call_object = Parrot_pcc_get_signature(interp, ctx);
    INTVAL argc;

    Parrot_pcc_fill_params_from_op(interp, call_object, signature, raw_params,
            PARROT_ERRORS_RESULT_COUNT_FLAG);
    GETATTR_FixedIntegerArray_size(interp, signature, argc);
    Parrot_pcc_set_signature(interp, ctx, PMCNULL);
    goto OFFSET(argc + 2);
}

=item B<set_result_info>(in PMC)

Set result_info. See also C<result_info>.

=cut

inline op set_result_info(in PMC) {
    PMC * const ctx = CURRENT_CONTEXT(interp);

    VTABLE_set_attr_str(interp, ctx,
            Parrot_str_new_constant(interp, "return_flags"),
            $1);
}

=item B<result_info>(out PMC)

Returns the get_results signature PMC of the caller. This PMC is a
FixedIntegerPMCArray. The number of elements of this PMC is equal to the number
of return values that are expected.  The individual bits per entry are
specified in F<docs/pdds/pdd03_calling_conventions.pod>.

=cut

inline op result_info(out PMC) {
    PMC * const caller_ctx = Parrot_pcc_get_caller_ctx(interp, CURRENT_CONTEXT(interp));
    PMC * const sig        = VTABLE_get_attr_str(interp, caller_ctx,
            Parrot_str_new_constant(interp, "return_flags"));

    /* If no elements, hand back empty array; otherwise PMC. */
    if (PMC_IS_NULL(sig))
        $1 = Parrot_pmc_new(interp, enum_class_FixedIntegerArray);
    else
        $1 = sig;
}

=back

=head2 Address manipulation

=for clarity

=cut

=over 4

=item B<set_addr>(out INT, inconst LABEL)

Sets register $1 to the current address plus the offset $2.

=item B<set_addr>(invar PMC, inconst LABEL)

Sets PMC in register $1 to the current address plus the offset $2.

=item B<set_addr>(invar PMC, invar LABEL)

Sets PMC in register $1 to the absolute address $2 obtained from B<get_addr>.

=item B<get_addr>(out INT, invar PMC)

Sets $1 to the absolute address of the Sub PMC $2.

=cut

inline op set_addr(out INT, inconst LABEL) {
    $1 = PTR2INTVAL(CUR_OPCODE + $2);
}

inline op set_addr(invar PMC, inconst LABEL) {
    VTABLE_set_pointer(interp, $1, (CUR_OPCODE + $2));
}

inline op set_addr(invar PMC, invar LABEL) {
    VTABLE_set_pointer(interp, $1, (void*)$2);
}

inline op get_addr(out INT, invar PMC) {
    void * const ptr = VTABLE_get_pointer(interp, $2);
    $1 = (INTVAL)ptr;
}

=back

=cut

########################################

=head2 Concurrency operations

=over 4

=item B<schedule>(invar PMC)

Register a task with the concurrency scheduler. Details about the task are
stored within the task PMC.

=cut

inline op schedule(invar PMC) {
    Parrot_cx_schedule_task(interp, $1);
}

=item B<schedule_local>(invar PMC)

Like schedule but execute it on the current thread.

=cut

inline op schedule_local(invar PMC) {
    Parrot_cx_schedule_immediate(interp, $1);
}

=item B<addhandler>(invar PMC)

Add an event or exception handler to the concurrency scheduler. Details about
the handler are stored within the handler PMC.

=cut

inline op addhandler(invar PMC) {
    Parrot_cx_add_handler(interp, $1);
}

=back

=cut

########################################

=head2 Exception handling

=over 4

=item B<push_eh>(inconst LABEL)

Create an exception handler for the given catch label and push it onto
the exception handler stack.

=item B<push_eh>(invar PMC)

Push an invokable PMC onto the exception handler stack.

=item B<pop_eh>()

Pop the most recently placed exception off the handler stack.

=item B<throw>(invar PMC)

Throw the exception in $1 with current continuation.

=item B<throw>(invar PMC, invar PMC)

Throw the exception in $1 with continuation from $2.

=item B<rethrow>(invar PMC)

Only valid inside an exception handler. Rethrow the exception $1.

=item B<count_eh>(out INT)

Get a count of currently active exception handlers on the stack.

=item B<die>(in STR)

=item B<die>(in PMC)

Die with message $1

=item B<die>(in INT, in INT)

Die with severity $1 and error $2. If severity is .EXCEPT_DOOMED,
call _exit($2). The latter isn't catchable.

=item B<exit>(in INT)

Exit the interpreter with exit_status $1. If you want to communicate an
extended exit status, create an exception with severity B<EXCEPT_exit>
and throw it.

=item B<finalize>(in PMC)

Finalize exception handling, freeing any information needed to resume
the handled exception, like inner runloops.
$1 is the Exception handled or the ExceptionHandler that is handling it.

=item B<pop_upto_eh>(in PMC)

Pops all exception handlers upto the one indicated by $1. Like with the
finalize op, $1 can either be the handled Exception or the ExceptionHandler
handling it. Also, you should not resume Exceptions after pop_upto_eh
or finalize has been called. This limitation may be fixed in a future
version of parrot. Also note that the specified exception handler
is not popped.

=item B<peek_exception>(out PMC)

Returns the caught exception without clearing the call object. This is
currently needed because HLL authors use get_params to fetch the exception,
but get_params clears the call object. So we can't use get_params in PCT
to get the exception object without disturbing the HLL code.
This op will be removed again when PCT offers another mechansim to get
the exception and the HLLs switched to it.

=cut

inline op push_eh(inconst LABEL) {
    PMC * const eh = Parrot_pmc_new(interp, enum_class_ExceptionHandler);
    VTABLE_set_pointer(interp, eh, CUR_OPCODE + $1);
    Parrot_cx_add_handler_local(interp, eh);
}

inline op push_eh(invar PMC) {
    Parrot_cx_add_handler_local(interp, $1);
}

inline op pop_eh() {
    Parrot_cx_delete_handler_local(interp);
}

inline op throw(invar PMC) :flow {
    PMC * except = $1;
    opcode_t *dest;
    opcode_t * const ret    = expr NEXT();
    PMC      * const resume = Parrot_pmc_new(interp, enum_class_Continuation);
    STRING * const exception_str = Parrot_str_new_constant(interp, "Exception");

    VTABLE_set_pointer(interp, resume, ret);

    if (PMC_IS_NULL(except) || !VTABLE_does(interp, except, exception_str))
        except = Parrot_ex_build_exception(interp, EXCEPT_fatal,
                EXCEPTION_UNIMPLEMENTED,
                Parrot_str_new_constant(interp, "Not a throwable object"));

    VTABLE_set_attr_str(interp, except, Parrot_str_new_constant(interp, "resume"), resume);
    dest = Parrot_ex_throw_from_op(interp, except, ret);
    goto ADDRESS(dest);
}

inline op throw(invar PMC, invar PMC) :flow {
    opcode_t * dest;
    PMC * except = $1;
    STRING * const exception_str = Parrot_str_new_constant(interp, "Exception");

    if (PMC_IS_NULL(except) || !VTABLE_does(interp, except, exception_str))
        except = Parrot_ex_build_exception(interp, EXCEPT_fatal,
                EXCEPTION_UNIMPLEMENTED,
                Parrot_str_new_constant(interp, "Not a throwable object"));
    dest = Parrot_ex_throw_from_op(interp, $1,
                                VTABLE_get_pointer(interp, $2));
    goto ADDRESS(dest);
}

inline op rethrow(invar PMC) :flow {
    opcode_t * dest;
    PMC * except = $1;
    STRING * const exception_str = Parrot_str_new_constant(interp, "Exception");

    if (PMC_IS_NULL(except) || !VTABLE_does(interp, except, exception_str)) {
        opcode_t * const ret    = expr NEXT();
        except = Parrot_ex_build_exception(interp, EXCEPT_fatal,
                EXCEPTION_UNIMPLEMENTED,
                Parrot_str_new_constant(interp, "Not a throwable object"));
        dest = Parrot_ex_throw_from_op(interp, except, ret);
        goto ADDRESS(dest);
    }
    dest = Parrot_ex_rethrow_from_op(interp, except);
    goto ADDRESS(dest);
}

inline op count_eh(out INT) {
    $1 = Parrot_cx_count_handlers_local(interp);
}

inline op die(in STR) :flow {
    opcode_t        *dest;
    opcode_t * const ret       = expr NEXT();
    PMC      * const resume    = Parrot_pmc_new(interp, enum_class_Continuation);
    PMC      * const exception = Parrot_ex_build_exception(interp, EXCEPT_error,
                                    EXCEPTION_DIE, $1);

    VTABLE_set_pointer(interp, resume, ret);

    VTABLE_set_attr_str(interp, exception,
                        Parrot_str_new_constant(interp, "resume"), resume);
    dest = Parrot_ex_throw_from_op(interp, exception, ret);
    goto ADDRESS(dest);
}

inline op die(in PMC) :flow {
    opcode_t        *dest;
    opcode_t * const ret       = expr NEXT();
    PMC      * const resume    = Parrot_pmc_new(interp, enum_class_Continuation);
    STRING   * const msg       = PMC_IS_NULL($1) ? NULL : VTABLE_get_string(interp, $1);
    PMC      * const exception =
        Parrot_ex_build_exception(interp, EXCEPT_error, EXCEPTION_DIE, msg);

    VTABLE_set_pointer(interp, resume, ret);

    VTABLE_set_attr_str(interp, exception,
                        Parrot_str_new_constant(interp, "resume"), resume);
    dest = Parrot_ex_throw_from_op(interp, exception, ret);
    goto ADDRESS(dest);
}

inline op die(in INT, in INT) :flow {
    if ($1 == EXCEPT_doomed)
        Parrot_x_jump_out(interp, $2);
    else {
        opcode_t        *dest;
        opcode_t * const ret       = expr NEXT();
        PMC      * const resume    = Parrot_pmc_new(interp, enum_class_Continuation);
        PMC      * const exception = Parrot_ex_build_exception(interp, $1, $2, NULL);

        VTABLE_set_pointer(interp, resume, ret);

        VTABLE_set_attr_str(interp, exception,
                Parrot_str_new_constant(interp, "resume"), resume);
        dest = Parrot_ex_throw_from_op(interp, exception, ret);
        goto ADDRESS(dest);
    }
}

inline op exit(in INT) :flow {
    opcode_t        *dest;
    opcode_t * const ret       = expr NEXT();
    PMC      * const resume    = Parrot_pmc_new(interp, enum_class_Continuation);
    PMC      * const exception = Parrot_ex_build_exception(interp, EXCEPT_exit,
                                                           CONTROL_EXIT, NULL);

    VTABLE_set_pointer(interp, resume, ret);

    VTABLE_set_attr_str(interp, exception,
                        Parrot_str_new_constant(interp, "resume"), resume);
    VTABLE_set_integer_keyed_str(interp, exception,
        Parrot_str_new_constant(interp, "exit_code"), $1);
    dest = Parrot_ex_throw_from_op(interp, exception, ret);
    goto ADDRESS(dest);
}

op finalize(in PMC) {
    /* Go to the next op after loop unrolling */
    opcode_t * const dest = expr NEXT();
    PMC *eh = Parrot_ex_get_current_handler(interp, $1);
    if (!PMC_IS_NULL(eh)) {
        /* Get the runloop_id from the continuation and jump to it. */
        Parrot_runloop *rl = interp->current_runloop;
        INTVAL rid;
        if (eh->vtable->base_type == enum_class_ExceptionHandler)
            GETATTR_ExceptionHandler_runloop_id(interp, eh, rid);
        else
            Parrot_pcc_invoke_method_from_c_args(interp,
                    eh, Parrot_str_new_constant(interp, "rid"), "->I", &rid);
        while (rl && rl->id != rid)
            rl = rl->prev;
        if (rl) {
            if (rl != interp->current_runloop) {
                rl->handler_start = dest;
                longjmp(rl->resume, PARROT_JMP_EXCEPTION_FINALIZED);
            }
        }
        else
            Parrot_ex_throw_from_c_args(interp, NULL,
                    EXCEPTION_INVALID_OPERATION, "missing runloop");
    }
}

op pop_upto_eh(in PMC) {
    PMC *eh = Parrot_ex_get_current_handler(interp, $1);
    if (!PMC_IS_NULL(eh))
        Parrot_cx_delete_upto_handler_local(interp, eh);
}

op peek_exception(out PMC) {
    PMC      * const ctx         = CURRENT_CONTEXT(interp);
    PMC      * const call_object = Parrot_pcc_get_signature(interp, ctx);
    $1 = VTABLE_get_pmc_keyed_int(interp, call_object, 0);
}

=back

=cut

###############################################################################

=head2 Interpreter operations

These operations inspect or modify the interpreter itself, possibly
affecting its subsequent operation.

=over 4

=cut

########################################

=item B<debug>(in INT)

If $1 is zero, turn off debugging. Otherwise turn debug flag $1 on.

=cut

inline op debug(in INT) :flow {
    if ($1 != 0) { Interp_debug_SET(interp,   $1); }
    else         { Interp_debug_CLEAR(interp, PARROT_ALL_DEBUG_FLAGS); }
    restart NEXT();
}


########################################

=item B<bounds>(in INT)

If $1 is zero, turn off byte code bounds checking. Otherwise turn it on.

=cut

inline op bounds(in INT) :flow {
    if ($1 != 0) { Parrot_interp_set_flag(interp,   PARROT_BOUNDS_FLAG); }
    else         { Interp_flags_CLEAR(interp, PARROT_BOUNDS_FLAG); }
    restart NEXT();
}


########################################

=item B<profile>(in INT)

If $1 is zero, turn off profiling. Otherwise turn it on.

=cut

inline op profile(in INT) :flow {
    if ($1 != 0) { Parrot_interp_set_flag(interp,   PARROT_PROFILE_FLAG); }
    else         { Interp_flags_CLEAR(interp, PARROT_PROFILE_FLAG); }
    restart NEXT();
}


########################################

=item B<trace>(in INT)

If $1 is zero, turn off tracing. Otherwise turn trace flag $1 on.

=cut

inline op trace(in INT) :flow {
    if ($1 != 0) { Parrot_interp_set_trace(interp,   $1); }
    else         { Parrot_interp_clear_trace(interp, PARROT_ALL_TRACE_FLAGS); }
    restart NEXT();
}

########################################

=item B<gc_debug>(in INT)

If $1 is zero, turn off GC_DEBUG. Otherwise turn it on.

=cut

inline op gc_debug(in INT) {
    if ($1 != 0) { Interp_flags_SET(interp,   PARROT_GC_DEBUG_FLAG); }
    else         { Interp_flags_CLEAR(interp, PARROT_GC_DEBUG_FLAG); }
}

########################################

=item B<interpinfo>

Fetch some piece of information about the interpreter and put it in $1.
Possible values for $2 are defined in F<runtime/parrot/include/interpinfo.pasm>.
The valid constants for each return value are (excluding the .INTERPINFO_
prefix):

=over 4

=item B<interpinfo>(out INT, in INT)

TOTAL_MEM_ALLOC, TOTAL_MEM_USED, GC_MARK_RUNS, GC_COLLECT_RUNS, ACTIVE_PMCS,
ACTIVE_BUFFERS, TOTAL_PMCS, TOTAL_BUFFERS, HEADER_ALLOCS_SINCE_COLLECT,
MEM_ALLOCS_SINCE_COLLECT, TOTAL_COPIED, IMPATIENT_PMCS, GC_LAZY_MARK_RUNS,
EXTENDED_PMCS, CURRENT_RUNCORE, PARROT_INTSIZE, PARROT_FLOATSIZE, PARROT_POINTERSIZE,
PARROT_INTMAX, PARROT_INTMIN

=item B<interpinfo>(out PMC, in INT)

CURRENT_SUB, CURRENT_CONT, CURRENT_OBJECT, CURRENT_LEXPAD

=item B<interpinfo>(out STR, in INT)

EXECUTABLE_FULLNAME, EXECUTABLE_BASENAME, RUNTIME_PREFIX, CURRENT_RUNCORE, PARROT_OS,
PARROT_OS_VERSION, PARROT_OS_VERSION_NUMBER, CPU_ARCH, CPU_TYPE

=back

=cut

op interpinfo(out INT, in INT) {
    $1 = Parrot_interp_info(interp, $2);
}

op interpinfo(out PMC, in INT) {
    $1 = Parrot_interp_info_p(interp, $2);
}

op interpinfo(out STR, in INT) {
    STRING * const s = Parrot_interp_info_s(interp, $2);
    $1 = s;
}

=item B<warningson>(in INT)

Turns on warnings categories. Categories already turned on will stay on.
Initial setting is currently all warnings off.  Include F<warnings.pasm> to
access the categories. Refer to that file for the current list of warnings
available.

=over 4

=back

To turn on multiple categories, OR the category numbers together.

=cut

inline op warningson(in INT) {
    PARROT_WARNINGS_on(interp, $1);
}

=item B<warningsoff>(in INT)

Turns off warnings categories.  Categories already turned off will
stay off.  See the documentation for B<warningson> for category
numbers.

=cut

inline op warningsoff(in INT) {
    PARROT_WARNINGS_off(interp, $1);
}

=item B<errorson>(in INT)

Turns on error categories. Categories already turned on will stay on.  To
access these from PASM, include F<errors.pasm>.  The current categories are:

=over 4

=item .PARROT_ERRORS_OVERFLOW_FLAG

When performing arithmetic on Integer PMCs, throw a math overflow exception
instead of promoting to BigInt. This flag does not pertain to native integers,
which are never promoted. Default: off.

=item .PARROT_ERRORS_PARAM_COUNT_FLAG

Throw an exception on an argument versus parameter count mismatch. Default: on.

=item .PARROT_ERRORS_RESULT_COUNT_FLAG

Throw an exception on a return versus result count mismatch. Default: off.

=item .PARROT_ERRORS_ALL_FLAG

=back

To turn on multiple categories, OR the category numbers together.

=cut

inline op errorson(in INT) {
    PARROT_ERRORS_on(interp, $1);
}

=item B<errorsoff>(in INT)

Turns off errors categories.  Categories already turned off will
stay off.  See the documentation for B<errorson> for category
numbers.

=cut

inline op errorsoff(in INT) {
    PARROT_ERRORS_off(interp, $1);
}

=item B<set_runcore>(in STR)

Switch the current runcore to the one with the specified name.
Needs to be an op, as we need to restart the runops() call.
You can get the name of the current runcore with the interpinfo op.

=cut

inline op set_runcore(in STR) {
    Parrot_runcore_switch(interp, $1);
    restart NEXT();
}

########################################

=item B<runinterp>(invar PMC, in LABEL)

Run the code starting at offset $2 within interpreter $1.

=item B<getinterp>(out PMC)

Get the current ParrotInterpreter.

=cut

op runinterp(invar PMC, in LABEL) {
    Interp * const new_interp = (Interp *)VTABLE_get_pointer(interp, $1);
    Interp_flags_SET(new_interp, PARROT_EXTERN_CODE_FLAG);
    Parrot_switch_to_cs(new_interp, interp->code, 1);
    runops(new_interp, REL_PC + $2);
}

op getinterp(out PMC) {
    $1 = VTABLE_get_pmc_keyed_int(interp, interp->iglobals,
           IGLOBALS_INTERPRETER);
}

#######################################



=back

=cut

###############################################################################

=head2 Garbage Collection

Opcodes that interact with the GC subsystem.

=over 4

=cut

########################################

=item B<sweep>(inconst INT)

Triggers a GC run, based on the value of $1, where:

=over

=item * 0

Trigger a GC run only if there are things that have flagged themselves as
really needing to be collected.

=item * 1

Trigger a GC run unconditionally.

=back

=cut

op sweep(inconst INT) {
    if ($1)
        Parrot_gc_mark_and_sweep(interp, GC_trace_normal_FLAG);
    else
        if (Parrot_gc_impatient_pmcs(interp))
            Parrot_gc_mark_and_sweep(interp, GC_lazy_FLAG);
}

=item B<collect>()

Trigger a garbage collection.

=cut

op collect() {
    Parrot_gc_compact_memory_pool(interp);
}

=item B<sweepoff>()

Disable GC runs. (Nestable)

=cut

op sweepoff() {
    Parrot_block_GC_mark(interp);
}

=item B<sweepon>()

Re-enable GC runs.

=cut

op sweepon() {
    Parrot_unblock_GC_mark(interp);
}

=item B<collectoff>()

Disable GC runs (nestable).

=cut

op collectoff() {
    Parrot_block_GC_sweep(interp);
}

=item B<collecton>()

Re-enable GC.

=cut

op collecton() {
    Parrot_unblock_GC_sweep(interp);
}

=item B<needs_destroy>(invar PMC)

Mark the PMC wanting destruction as soon as possible, for example
when unused during the lazy sweep, triggered by C<sweep 0>.

=cut

op needs_destroy(invar PMC) {
    Parrot_gc_pmc_needs_early_collection(interp, $1);
}

=back

=head2 Native Call Interface

Opcodes for interfacing with C functions in shared libraries.

=over 4

=cut

########################################

=item B<loadlib>(out PMC, in STR)

=item B<loadlib>(out PMC, in STR, in PMC)

Load a dynamic link library named $2 and store it in $1. $3, if
provided, controls library loading and initialization; currently,
we expect a bitmask accessible as an integer.  Bit definitions are
accessible from PASM if F<dlopenflags.pasm> is included.  The current
bits are:

=over 4

=item PARROT_DLOPEN_GLOBAL

Make any symbols in the library accessible to other libraries loaded.

=back

=item B<dlfunc>(out PMC, invar PMC, in STR, in STR)

=item B<dlfunc>(out PMC, invar PMC, in STR, invar PMC)

Look up symbol $3 in library $2 with signature $4, and put the
corresponding sub object in $1. Note that you need the signature so we
can build or find an appropriate thunking function.

=item B<dlvar>(out PMC, invar PMC, in STR)

Look up symbol $3 in library $2. We assume that this is actually a
variable address rather than a function address, and build an
UnManagedStruct PMC and stick the address into its data pointer.

=item B<compreg>(out PMC, in STR)

Get the compiler object for source type $2.  The returned compiler
object should provide a C<compile> method for translating code
in the source type.  However, some Parrot compilers such as
C<PIR> and C<PASM> currently return a sub that is to be
invoked directly on the source.

=item B<compreg>(in STR, invar PMC)

Register $2 as the compiler object for source type $1.

=item B<new_callback>(out PMC, invar PMC, invar PMC, in STR)

Create a callback stub $1 for PASM subroutine $2 with userdata $3 and
callback function signature $4. Only 2 argument signatures with
signature chars I<U[1iscpt]> or I<[1iscpt]U>  are handled currently.
But these cover a lot of callback signatures. Please note that the
userdata PMC I<U> has to be handled transparently by the caller of
the callback function.

=cut

inline op loadlib(out PMC, in STR) {
    $1 = Parrot_dyn_load_lib(interp, $2, NULL);
}

inline op loadlib(out PMC, in STR, in PMC) {
    $1 = Parrot_dyn_load_lib(interp, $2, $3);
}

op dlfunc(out PMC, invar PMC, in STR, in STR) {
    void         *dl_handle = NULL;
    void         *ptr;
    funcptr_t     p;

    if (!PMC_IS_NULL($2)
    && $2->vtable->base_type == enum_class_ParrotLibrary
    && VTABLE_defined(interp, $2)) {
        dl_handle = ((Parrot_ParrotLibrary_attributes*)PMC_data($2))->dl_handle;
    }

    ptr = Parrot_dyn_dlsym_str(interp, dl_handle, $3);
    p = D2FPTR(ptr);

    if (p == NULLfunc) {
        const char * const err = Parrot_dlerror();
        Parrot_warn(interp, PARROT_WARNINGS_UNDEF_FLAG,
                "Symbol '%Ss' not found: %s\n", $3, err ? err : "unknown reason");
        $1 = Parrot_pmc_new(interp, enum_class_Undef);
    }
    else {
        $1 = Parrot_pmc_new(interp, enum_class_NCI);
        VTABLE_set_pointer_keyed_str(interp, $1, $4, F2DPTR(p));
    }
}

op dlfunc(out PMC, invar PMC, in STR, invar PMC) {
    void         *dl_handle = NULL;
    void         *ptr;
    funcptr_t     p;

    if (!PMC_IS_NULL($2)
    && $2->vtable->base_type == enum_class_ParrotLibrary
    && VTABLE_defined(interp, $2)) {
        dl_handle = ((Parrot_ParrotLibrary_attributes*)PMC_data($2))->dl_handle;
    }

    ptr = Parrot_dyn_dlsym_str(interp, dl_handle, $3);
    p = D2FPTR(ptr);

    if (p == NULLfunc) {
        const char * const err = Parrot_dlerror();
        Parrot_warn(interp, PARROT_WARNINGS_UNDEF_FLAG,
                "Symbol '%Ss' not found: %s\n", $3, err ? err : "unknown reason");
        $1 = Parrot_pmc_new(interp, enum_class_Undef);
    }
    else {
        $1 = Parrot_pmc_new(interp, enum_class_NCI);
        VTABLE_set_pointer_keyed(interp, $1, $4, F2DPTR(p));
    }
}

op dlvar(out PMC, invar PMC, in STR) {
    void *        dl_handle = NULL;
    void *        p;

    if (!PMC_IS_NULL($2)
    && $2->vtable->base_type == enum_class_ParrotLibrary
    && VTABLE_defined(interp, $2)) {
        dl_handle = ((Parrot_ParrotLibrary_attributes*)PMC_data($2))->dl_handle;
    }

    p = Parrot_dyn_dlsym_str(interp, dl_handle, $3);

    if (p == NULL) {
        const char * const err = Parrot_dlerror();
        Parrot_warn(interp, PARROT_WARNINGS_UNDEF_FLAG,
                "Symbol '%Ss' not found: %s\n", $3, err ? err : "unknown reason");
        $1 = Parrot_pmc_new(interp, enum_class_Undef);
    }
    else {
        /* At this point we have the symbol's address. We just need to build
           a PMC with it so we can get and set the value */
        $1 = Parrot_pmc_new(interp, enum_class_UnManagedStruct);
        VTABLE_set_pointer(interp, $1, p);
    }
}

inline op compreg(in STR, invar PMC) {
    Parrot_interp_set_compiler(interp, $1, $2);
}

inline op compreg(out PMC, in STR) {
    $1 = Parrot_interp_get_compiler(interp, $2);
}

op new_callback(out PMC, invar PMC, invar PMC, in STR) {
    $1 = Parrot_make_cb(interp, $2, $3, $4);
}

=back

=cut

###############################################################################

=head2 Annotations operations

These operations relate to bytecode annotations.

=over 4

=cut

########################################

=item B<annotations>(out PMC)

Gets all bytecode annotations in effect at the current point, in a Hash.
If there are none, returns an empty Hash.

=cut

inline op annotations(out PMC) {
    if (interp->code->annotations) {
        const opcode_t cur_pos = (expr NEXT()) - interp->code->base.data;
        $1 = PackFile_Annotations_lookup(interp, interp->code->annotations,
                cur_pos, NULL);
    }
    else {
        $1 = Parrot_pmc_new(interp, enum_class_Hash);
    }
}

=item B<annotations>(out PMC, in STR)

Gets the bytecode annotation with the given name that is in effect at the
current point. Returns PMCNULL if there is none.

=cut

inline op annotations(out PMC, in STR) {
    if (interp->code->annotations) {
        const opcode_t cur_pos = (expr NEXT()) - interp->code->base.data;
        $1 = PackFile_Annotations_lookup(interp, interp->code->annotations,
                cur_pos, $2);
    }
    else {
        $1 = PMCNULL;
    }
}

=back

=cut

###############################################################################

=head1 COPYRIGHT

Copyright (C) 2001-2012, Parrot Foundation.

=head1 LICENSE

This program is free software. It is subject to the same license
as the Parrot interpreter itself.

=cut

/*
 * Local variables:
 *   c-file-style: "parrot"
 * End:
 * vim: expandtab shiftwidth=4 cinoptions='\:2=2' :
 */