Ambroz Bizjak 9f1067e51a ncd: Implement lazy evaluation in If clause.
The embcall2_multif statement is replaced with embcall, which only takes a template name. The selection of the template name is done using the ifel function, generated during desugaring.
2014-12-09 23:55:46 +01:00

568 lines
19 KiB
C

/**
* @file call2.c
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* @section DESCRIPTION
*
*
* Synopsis:
* call(string template, list args)
*
* Description:
* Calls a process template. The 'template' argument is the name of the process
* template to call, and the 'list' argument is a list of arguments for the
* process template. Calling a process template is roughly equivalent to placing
* the statements within that template into the place of call(), except for the
* points presented next. The 'template' argument can be a special value "<none>",
* which makes call() a no-op.
*
* The process created from the called template will be able to access the arguments
* that were given in the 'args' argument to call() via the '_argN' predefined\
* objects (e.g. _arg0 for the first argumens), and also via '_args' for the entire
* argument list.
*
* The called process also will be able to access objects within the calling
* process as seen by the call() statement. However such any access needs to happen
* via a special '_caller' predefined object. For example, if there is a statement
* 'var("a") x;' somewhere above the call() statement, the called process can access
* it as '_caller.x'.
*
* Note that call() preserves backtracking semantics, i.e. when a statement within
* the called process goes down after having gone up, the behaviour really is as
* if the call() statement was replaced with the statements in the called template,
* (disregarding variable resolution).
*
* Because the template name is an argument, call() can be used for branching.
* For example, if we have an object 'x' with the value "true" or "false", a
* branch can be performed by defining two process templates, 'branch_true'
* and 'branch_false', and branching with the following code:
*
* concat("branch_", x) name;
* call(name, {});
*
*
* Synopsis:
* call_with_caller_target(string template, list args, string caller_target)
*
* Description:
* Like call(), except that the target of the '_caller' predefined object is
* specified by the 'caller_target' argument. This is indented to be used from
* generic code for user-specified callbacks, allowing the user to easily refer to
* his own objects from inside the callback.
*
* The 'caller_target' must be a non-empty string referring to an actual object;
* there is no choice of 'caller_target' that would make call_with_caller_target()
* equivalent to call().
*
*
* Synopsis:
* embcall(string template)
*
* Description:
* Like call, but makes its own scope directly available in the called
* template process, instead of via _caller. Also, doesn not provide any
* arguments to the template process.
*
*
* Synopsis:
* inline_code(string template)
* inline_code::call(list args)
*
* Description:
* The inline_code() acts as a proxy object for calling the specified template.
* The inline_code::call calls the template of the corresponding inline_code
* instance, in a manner similar to a simple "call". The called template will
* have access to the following resources:
* - The arguments will be available in the usual fashion.
* - The scope of the inline_code::call instance will be available as "_caller".
* - The scope of the inline_code instance will be directly available.
* - The scope of the inline_code instance will also be available as "_scope".
* This is useful to access shadowed names, e.g. "_caller" and the arguments
* stuff (_argN, _args).
*/
#include <stdlib.h>
#include <string.h>
#include <misc/debug.h>
#include <misc/offset.h>
#include <structure/LinkedList0.h>
#include <ncd/extra/NCDFastNames.h>
#include <ncd/module_common.h>
#include <generated/blog_channel_ncd_call2.h>
#define STATE_WORKING 1
#define STATE_UP 2
#define STATE_WAITING 3
#define STATE_TERMINATING 4
#define STATE_NONE 5
struct instance;
typedef void (*call_extra_free_cb) (struct instance *o);
struct instance {
NCDModuleInst *i;
call_extra_free_cb extra_free_cb;
NCDModuleProcess process;
int state;
};
struct instance_with_caller_target {
struct instance base;
NCDFastNames names;
};
struct inline_code {
NCDModuleInst *i;
NCDValRef template_name;
LinkedList0 calls_list;
};
struct inline_code_call {
struct instance base;
struct inline_code *ic;
LinkedList0Node ic_node;
};
static void process_handler_event (NCDModuleProcess *process, int event);
static int process_func_getspecialobj_embed (NCDModuleProcess *process, NCD_string_id_t name, NCDObject *out_object);
static int process_func_getspecialobj_noembed (NCDModuleProcess *process, NCD_string_id_t name, NCDObject *out_object);
static int process_func_getspecialobj_with_caller_target (NCDModuleProcess *process, NCD_string_id_t name, NCDObject *out_object);
static int caller_obj_func_getobj (const NCDObject *obj, NCD_string_id_t name, NCDObject *out_object);
static int caller_obj_func_getobj_with_caller_target (const NCDObject *obj, NCD_string_id_t name, NCDObject *out_object);
static void func_new_templ (void *vo, NCDModuleInst *i, NCDValRef template_name, NCDValRef args, NCDModuleProcess_func_getspecialobj func_getspecialobj, call_extra_free_cb extra_free_cb);
static void instance_free (struct instance *o);
static void call_with_caller_target_extra_free (struct instance *bo);
static void inline_code_extra_free (struct instance *bo);
static int inline_code_call_process_getspecialobj (NCDModuleProcess *process, NCD_string_id_t name, NCDObject *out_object);
static int inline_code_scope_obj_getobj (const NCDObject *obj, NCD_string_id_t name, NCDObject *out_object);
static void process_handler_event (NCDModuleProcess *process, int event)
{
struct instance *o = UPPER_OBJECT(process, struct instance, process);
switch (event) {
case NCDMODULEPROCESS_EVENT_UP: {
ASSERT(o->state == STATE_WORKING)
// signal up
NCDModuleInst_Backend_Up(o->i);
// set state up
o->state = STATE_UP;
} break;
case NCDMODULEPROCESS_EVENT_DOWN: {
ASSERT(o->state == STATE_UP)
// signal down
NCDModuleInst_Backend_Down(o->i);
// set state waiting
o->state = STATE_WAITING;
} break;
case NCDMODULEPROCESS_EVENT_TERMINATED: {
ASSERT(o->state == STATE_TERMINATING)
// die finally
instance_free(o);
return;
} break;
default: ASSERT(0);
}
}
static int process_func_getspecialobj_embed (NCDModuleProcess *process, NCD_string_id_t name, NCDObject *out_object)
{
struct instance *o = UPPER_OBJECT(process, struct instance, process);
return NCDModuleInst_Backend_GetObj(o->i, name, out_object);
}
static int process_func_getspecialobj_noembed (NCDModuleProcess *process, NCD_string_id_t name, NCDObject *out_object)
{
struct instance *o = UPPER_OBJECT(process, struct instance, process);
if (name == NCD_STRING_CALLER) {
*out_object = NCDObject_Build(-1, o, NCDObject_no_getvar, caller_obj_func_getobj);
return 1;
}
return 0;
}
static int process_func_getspecialobj_with_caller_target (NCDModuleProcess *process, NCD_string_id_t name, NCDObject *out_object)
{
struct instance *o = UPPER_OBJECT(process, struct instance, process);
if (name == NCD_STRING_CALLER) {
*out_object = NCDObject_Build(-1, o, NCDObject_no_getvar, caller_obj_func_getobj_with_caller_target);
return 1;
}
return 0;
}
static int caller_obj_func_getobj (const NCDObject *obj, NCD_string_id_t name, NCDObject *out_object)
{
struct instance *o = NCDObject_DataPtr(obj);
return NCDModuleInst_Backend_GetObj(o->i, name, out_object);
}
static int caller_obj_func_getobj_with_caller_target (const NCDObject *obj, NCD_string_id_t name, NCDObject *out_object)
{
struct instance_with_caller_target *o_ch = NCDObject_DataPtr(obj);
NCD_string_id_t *names = NCDFastNames_GetNames(&o_ch->names);
NCDObject object;
if (!NCDModuleInst_Backend_GetObj(o_ch->base.i, names[0], &object)) {
return 0;
}
NCDObject obj2;
if (!NCDObject_ResolveObjExprCompact(&object, names + 1, NCDFastNames_GetNumNames(&o_ch->names) - 1, &obj2)) {
return 0;
}
if (name == NCD_STRING_EMPTY) {
*out_object = obj2;
return 1;
}
return NCDObject_GetObj(&obj2, name, out_object);
}
static void func_new_templ (void *vo, NCDModuleInst *i, NCDValRef template_name, NCDValRef args, NCDModuleProcess_func_getspecialobj func_getspecialobj, call_extra_free_cb extra_free_cb)
{
ASSERT(NCDVal_IsInvalid(template_name) || NCDVal_IsString(template_name))
ASSERT(NCDVal_IsInvalid(args) || NCDVal_IsList(args))
ASSERT(func_getspecialobj)
struct instance *o = vo;
o->i = i;
o->extra_free_cb = extra_free_cb;
if (NCDVal_IsInvalid(template_name) || ncd_is_none(template_name)) {
// signal up
NCDModuleInst_Backend_Up(o->i);
// set state none
o->state = STATE_NONE;
} else {
// create process
if (!NCDModuleProcess_InitValue(&o->process, o->i, template_name, args, process_handler_event)) {
ModuleLog(o->i, BLOG_ERROR, "NCDModuleProcess_Init failed");
goto fail1;
}
// set special functions
NCDModuleProcess_SetSpecialFuncs(&o->process, func_getspecialobj);
// set state working
o->state = STATE_WORKING;
}
return;
fail1:
if (o->extra_free_cb) {
o->extra_free_cb(o);
}
NCDModuleInst_Backend_DeadError(i);
}
static void instance_free (struct instance *o)
{
if (o->extra_free_cb) {
o->extra_free_cb(o);
}
// free process
if (o->state != STATE_NONE) {
NCDModuleProcess_Free(&o->process);
}
NCDModuleInst_Backend_Dead(o->i);
}
static void func_new_call (void *vo, NCDModuleInst *i, const struct NCDModuleInst_new_params *params)
{
NCDValRef template_arg;
NCDValRef args_arg;
if (!NCDVal_ListRead(params->args, 2, &template_arg, &args_arg)) {
ModuleLog(i, BLOG_ERROR, "wrong arity");
goto fail0;
}
if (!NCDVal_IsString(template_arg) || !NCDVal_IsList(args_arg)) {
ModuleLog(i, BLOG_ERROR, "wrong type");
goto fail0;
}
func_new_templ(vo, i, template_arg, args_arg, process_func_getspecialobj_noembed, NULL);
return;
fail0:
NCDModuleInst_Backend_DeadError(i);
}
static void func_new_call_with_caller_target (void *vo, NCDModuleInst *i, const struct NCDModuleInst_new_params *params)
{
NCDValRef template_arg;
NCDValRef args_arg;
NCDValRef caller_target_arg;
if (!NCDVal_ListRead(params->args, 3, &template_arg, &args_arg, &caller_target_arg)) {
ModuleLog(i, BLOG_ERROR, "wrong arity");
goto fail0;
}
if (!NCDVal_IsString(template_arg) || !NCDVal_IsList(args_arg) || !NCDVal_IsString(caller_target_arg)) {
ModuleLog(i, BLOG_ERROR, "wrong type");
goto fail0;
}
struct instance_with_caller_target *o = vo;
int res = NCDFastNames_Init(&o->names, i->params->iparams->string_index, NCDVal_StringMemRef(caller_target_arg));
if (!res) {
ModuleLog(i, BLOG_ERROR, "NCDFastNames_Init failed");
goto fail0;
}
func_new_templ(vo, i, template_arg, args_arg, process_func_getspecialobj_with_caller_target, call_with_caller_target_extra_free);
return;
fail0:
NCDModuleInst_Backend_DeadError(i);
}
static void call_with_caller_target_extra_free (struct instance *bo)
{
struct instance_with_caller_target *o = (void *)bo;
NCDFastNames_Free(&o->names);
}
static void func_new_embcall (void *vo, NCDModuleInst *i, const struct NCDModuleInst_new_params *params)
{
NCDValRef template_arg;
if (!NCDVal_ListRead(params->args, 1, &template_arg)) {
ModuleLog(i, BLOG_ERROR, "wrong arity");
goto fail0;
}
if (!NCDVal_IsString(template_arg)) {
ModuleLog(i, BLOG_ERROR, "wrong type");
goto fail0;
}
func_new_templ(vo, i, template_arg, NCDVal_NewInvalid(), process_func_getspecialobj_embed, NULL);
return;
fail0:
NCDModuleInst_Backend_DeadError(i);
}
static void func_die (void *vo)
{
struct instance *o = vo;
ASSERT(o->state != STATE_TERMINATING)
// if none, die now
if (o->state == STATE_NONE) {
instance_free(o);
return;
}
// request process to terminate
NCDModuleProcess_Terminate(&o->process);
// set state terminating
o->state = STATE_TERMINATING;
}
static void func_clean (void *vo)
{
struct instance *o = vo;
if (o->state != STATE_WAITING) {
return;
}
// allow process to continue
NCDModuleProcess_Continue(&o->process);
// set state working
o->state = STATE_WORKING;
}
static int func_getobj (void *vo, NCD_string_id_t name, NCDObject *out_object)
{
struct instance *o = vo;
if (o->state == STATE_NONE) {
return 0;
}
return NCDModuleProcess_GetObj(&o->process, name, out_object);
}
static void inline_code_new (void *vo, NCDModuleInst *i, const struct NCDModuleInst_new_params *params)
{
NCDValRef template_arg;
if (!NCDVal_ListRead(params->args, 1, &template_arg)) {
ModuleLog(i, BLOG_ERROR, "wrong arity");
goto fail0;
}
if (!NCDVal_IsString(template_arg)) {
ModuleLog(i, BLOG_ERROR, "wrong type");
goto fail0;
}
struct inline_code *o = vo;
o->i = i;
o->template_name = template_arg;
LinkedList0_Init(&o->calls_list);
NCDModuleInst_Backend_Up(i);
return;
fail0:
NCDModuleInst_Backend_DeadError(i);
}
static void inline_code_die (void *vo)
{
struct inline_code *o = vo;
for (LinkedList0Node *ln = LinkedList0_GetFirst(&o->calls_list); ln; ln = LinkedList0Node_Next(ln)) {
struct inline_code_call *call = UPPER_OBJECT(ln, struct inline_code_call, ic_node);
ASSERT(call->ic == o)
call->ic = NULL;
}
NCDModuleInst_Backend_Dead(o->i);
}
static void inline_code_call_new (void *vo, NCDModuleInst *i, const struct NCDModuleInst_new_params *params)
{
struct inline_code_call *o = vo;
o->ic = NCDModuleInst_Backend_GetUser((NCDModuleInst *)params->method_user);
LinkedList0_Prepend(&o->ic->calls_list, &o->ic_node);
func_new_templ(vo, i, o->ic->template_name, params->args, inline_code_call_process_getspecialobj, inline_code_extra_free);
}
static void inline_code_extra_free (struct instance *bo)
{
struct inline_code_call *o = (void *)bo;
if (o->ic) {
LinkedList0_Remove(&o->ic->calls_list, &o->ic_node);
}
}
static int inline_code_call_process_getspecialobj (NCDModuleProcess *process, NCD_string_id_t name, NCDObject *out_object)
{
struct inline_code_call *o = UPPER_OBJECT(process, struct inline_code_call, base.process);
if (name == NCD_STRING_CALLER) {
*out_object = NCDObject_Build(-1, o, NCDObject_no_getvar, caller_obj_func_getobj);
return 1;
}
if (!o->ic) {
ModuleLog(o->base.i, BLOG_ERROR, "inline_code object is gone");
return 0;
}
if (name == NCD_STRING_SCOPE) {
*out_object = NCDObject_Build(-1, o->ic, NCDObject_no_getvar, inline_code_scope_obj_getobj);
return 1;
}
return NCDModuleInst_Backend_GetObj(o->ic->i, name, out_object);
}
static int inline_code_scope_obj_getobj (const NCDObject *obj, NCD_string_id_t name, NCDObject *out_object)
{
struct inline_code *ic = NCDObject_DataPtr(obj);
return NCDModuleInst_Backend_GetObj(ic->i, name, out_object);
}
static struct NCDModule modules[] = {
{
.type = "call",
.func_new2 = func_new_call,
.func_die = func_die,
.func_clean = func_clean,
.func_getobj = func_getobj,
.flags = NCDMODULE_FLAG_CAN_RESOLVE_WHEN_DOWN,
.alloc_size = sizeof(struct instance)
}, {
.type = "call_with_caller_target",
.func_new2 = func_new_call_with_caller_target,
.func_die = func_die,
.func_clean = func_clean,
.func_getobj = func_getobj,
.flags = NCDMODULE_FLAG_CAN_RESOLVE_WHEN_DOWN,
.alloc_size = sizeof(struct instance_with_caller_target)
}, {
.type = "embcall",
.func_new2 = func_new_embcall,
.func_die = func_die,
.func_clean = func_clean,
.func_getobj = func_getobj,
.flags = NCDMODULE_FLAG_CAN_RESOLVE_WHEN_DOWN,
.alloc_size = sizeof(struct instance)
}, {
.type = "inline_code",
.func_new2 = inline_code_new,
.func_die = inline_code_die,
.alloc_size = sizeof(struct inline_code)
}, {
.type = "inline_code::call",
.func_new2 = inline_code_call_new,
.func_die = func_die,
.func_clean = func_clean,
.func_getobj = func_getobj,
.flags = NCDMODULE_FLAG_CAN_RESOLVE_WHEN_DOWN,
.alloc_size = sizeof(struct inline_code_call)
}, {
.type = NULL
}
};
const struct NCDModuleGroup ncdmodule_call2 = {
.modules = modules
};