From b9193a8d80bf7ea8d768b9521bcd298a03974c9d Mon Sep 17 00:00:00 2001
From: Michael Wallner <mike@php.net>
Date: Fri, 12 Feb 2016 14:32:14 +0100
Subject: [PATCH 1/1] basic callback support

---
 TODO                   |   1 +
 src/context.c          |   6 +++
 src/context_validate.c |  91 +++++++++++++++++++++++---------
 src/engine.c           |  53 ++-----------------
 src/libffi.c           | 117 ++++++++++++++++++++++-------------------
 src/marshal.c          |  36 ++++++++-----
 src/marshal.h          |   9 ++++
 src/parser.h           |  31 ++++++-----
 src/parser_proc.h      | 108 ++++++++++++++++++-------------------
 src/parser_proc.y      |   6 +--
 10 files changed, 247 insertions(+), 211 deletions(-)

diff --git a/TODO b/TODO
index ee63abe..ffda07a 100644
--- a/TODO
+++ b/TODO
@@ -6,3 +6,4 @@
 * pemalloc
 * unions
 * callbacks and function pointers
+* let impl_Var point to impl_arg, just like decl_var?
\ No newline at end of file
diff --git a/src/context.c b/src/context.c
index ed26f82..c86a595 100644
--- a/src/context.c
+++ b/src/context.c
@@ -342,6 +342,12 @@ void PSI_ContextDtor(PSI_Context *C)
 		}
 		free(C->structs);
 	}
+	if (C->unions) {
+		if (C->unions->list) {
+			free(C->unions->list);
+		}
+		free(C->unions);
+	}
 	if (C->enums) {
 		if (C->enums->list) {
 			free(C->enums->list);
diff --git a/src/context_validate.c b/src/context_validate.c
index 56d7b2e..87aba78 100644
--- a/src/context_validate.c
+++ b/src/context_validate.c
@@ -13,6 +13,7 @@
 #include "php_psi_macros.h"
 #include "php_psi_redirs.h"
 
+#include "parser.h"
 #include "calc.h"
 #include "marshal.h"
 #include "engine.h"
@@ -111,6 +112,22 @@ static inline int locate_decl_type_enum(decl_enums *enums, decl_type *type) {
 	return 0;
 }
 
+static inline int locate_decl_type_decl(decls *decls, decl_type *type) {
+	size_t i;
+
+	if (type->func) {
+		return 1;
+	}
+	if (decls) for (i = 0; i < decls->count; ++i) {
+		if (!strcmp(decls->list[i]->func->var->name, type->name)) {
+			type->func = decls->list[i];
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
 static inline int validate_decl_struct(PSI_Data *data, decl_struct *s);
 static inline int validate_decl_union(PSI_Data *data, decl_union *u);
 static inline int validate_decl_enum(PSI_Data *data, decl_enum *e);
@@ -143,6 +160,12 @@ static inline int validate_decl_type(PSI_Data *data, decl_type *type) {
 		if (!locate_decl_type_enum(data->enums, type)) {
 			return 0;
 		}
+		break;
+	case PSI_T_FUNCTION:
+		if (!locate_decl_type_decl(data->decls, type)) {
+			return 0;
+		}
+		break;
 	}
 	return 1;
 }
@@ -781,7 +804,7 @@ static inline int validate_set_value_ex(PSI_Data *data, set_value *set, decl_arg
 		}
 	}
 
-	if (ref_type->type == PSI_T_STRUCT) {
+	if (set->inner && ref_type->type == PSI_T_STRUCT) {
 		/* to_array(struct, to_...) */
 		if (!set->outer.set || set->outer.set->inner->vals != set->inner->vals) {
 			for (i = 0; i < set->inner->count; ++i) {
@@ -877,47 +900,60 @@ static inline int validate_impl_ret_stmt(PSI_Data *data, impl *impl) {
 		return 0;
 	}
 
-	impl->decl->impl = impl;
+	//impl->decl->impl = impl;
 
 	return 1;
 }
 
-static inline int validate_let_func(PSI_Data *data, let_func *func, impl *impl) {
-	int check = 0;
-	size_t j;
+static inline impl_arg *locate_impl_var_arg(impl_var *var, impl_args *args) {
+	size_t i;
 
-	if (impl->func->args) {
-		for (j = 0; j < impl->func->args->count; ++j) {
-			impl_arg *iarg = impl->func->args->args[j];
+	for (i = 0; i < args->count; ++i) {
+		impl_arg *iarg = args->args[i];
 
-			if (!strcmp(func->var->name, iarg->var->name)) {
-				func->arg = iarg;
-				check = 1;
-				break;
-			}
+		if (!strcmp(var->name, iarg->var->name)) {
+			return var->arg = iarg;
 		}
 	}
-	if (!check) {
-		data->error(data, func->var->token, PSI_WARNING, "Unknown value '$%s' of `let` statement"
-				" for cast '%s' of implementation '%s'",
-				func->var->name, func->name, impl->func->name);
-		return 0;
+
+	return NULL;
+}
+
+static inline int validate_let_func(PSI_Data *data, let_func *func, impl *impl) {
+	if (impl->func->args) {
+		if (!locate_impl_var_arg(func->var, impl->func->args)) {
+			data->error(data, func->var->token, PSI_WARNING,
+					"Unknown variable '$%s' of `let` statement"
+					" for cast '%s' of implementation '%s'",
+					func->var->name, func->name, impl->func->name);
+			return 0;
+		}
+	}
+	switch (func->type) {
+	case PSI_T_BOOLVAL:		func->handler = psi_let_boolval;	break;
+	case PSI_T_INTVAL:		func->handler = psi_let_intval;		break;
+	case PSI_T_FLOATVAL:	func->handler = psi_let_floatval;	break;
+	case PSI_T_STRVAL:		func->handler = psi_let_strval;		break;
+	case PSI_T_STRLEN:		func->handler = psi_let_strlen;		break;
+	case PSI_T_PATHVAL:		func->handler = psi_let_pathval;	break;
+	case PSI_T_ARRVAL:		func->handler = psi_let_arrval;		break;
+	case PSI_T_OBJVAL:		func->handler = psi_let_objval;		break;
+	EMPTY_SWITCH_DEFAULT_CASE();
 	}
 	return 1;
 }
 
-static inline int validate_let_callback(PSI_Data *data, decl_var *let_var, let_callback *cb, impl *impl) {
-	decl_type *cb_type;
-	decl *cb_func;
+static inline int validate_let_callback(PSI_Data *data, decl_var *cb_var, let_callback *cb, impl *impl) {
 	size_t i;
+	decl *cb_func;
+	decl_type *cb_type = real_decl_type(cb_var->arg->type);
 
 	if (!validate_let_func(data, cb->func, impl)) {
 		return 0;
 	}
 
-	cb_type = real_decl_type(let_var->arg->type);
 	if (cb_type->type != PSI_T_FUNCTION) {
-		data->error(data, let_var->token, PSI_WARNING, "Not a function: %s", let_var->name);
+		data->error(data, cb_var->token, PSI_WARNING, "Not a function: %s", cb_var->name);
 		return 0;
 	}
 	cb_func = cb_type->func;
@@ -926,6 +962,14 @@ static inline int validate_let_callback(PSI_Data *data, decl_var *let_var, let_c
 			return 0;
 		}
 	}
+
+	if (!validate_decl(data, NULL, cb_func)) {
+		return 0;
+	}
+
+	cb->decl = cb_func;
+
+	return 1;
 }
 
 static inline int validate_impl_let_stmts(PSI_Data *data, impl *impl) {
@@ -936,7 +980,6 @@ static inline int validate_impl_let_stmts(PSI_Data *data, impl *impl) {
 	for (i = 0; i < impl->stmts->let.count; ++i) {
 		let_stmt *let = impl->stmts->let.list[i];
 		decl_var *let_var;
-		int check = 0;
 
 		if (let->val && let->val->kind == PSI_LET_TMP) {
 			let_var = let->val->data.var;
diff --git a/src/engine.c b/src/engine.c
index 51f3b28..0c170cb 100644
--- a/src/engine.c
+++ b/src/engine.c
@@ -260,58 +260,18 @@ static inline void *psi_do_calloc(let_calloc *alloc)
 
 static inline impl_val *psi_let_val(token_t let_func, impl_arg *iarg, impl_val *arg_val, decl_struct *strct, void **to_free)
 {
-	switch (let_func) {
-	case PSI_T_BOOLVAL:
-		break;
-	case PSI_T_INTVAL:
-		break;
-	case PSI_T_FLOATVAL:
-		break;
-	case PSI_T_PATHVAL:
-	case PSI_T_STRVAL:
-		if (PSI_T_PATHVAL == let_func) {
-
-		}
-		break;
-	case PSI_T_STRLEN:
-		break;
-	case PSI_T_ARRVAL:
-		if (iarg->type->type == PSI_T_ARRAY) {
-			arg_val = psi_array_to_struct(strct, HASH_OF(iarg->_zv));
-			*to_free = arg_val;
-		}
-		break;
-	case PSI_T_OBJVAL:
-		if (iarg->type->type == PSI_T_OBJECT) {
-			psi_object *obj;
-
-			if (!instanceof_function(Z_OBJCE_P(iarg->_zv), psi_object_get_class_entry())) {
-				return NULL;
-			}
-
-			obj = PSI_OBJ(iarg->_zv, NULL);
-			arg_val->ptr = obj->data;
-		}
-		break;
-	case PSI_T_CALLBACK:
-		if (iarg->type->type == PSI_T_CALLABLE) {
-			
-		}
-		break;
-	EMPTY_SWITCH_DEFAULT_CASE();
-	}
+	abort();
 	return arg_val;
 }
 
 static inline impl_val *psi_let_func(let_func *func, decl_arg *darg) {
-	return darg->ptr = func->handler(darg->ptr, darg->type, func->arg, &darg->mem);
+	return darg->ptr = func->handler(darg->ptr, darg->type, func->var->arg, &darg->mem);
 }
 
 static inline void *psi_do_let(let_stmt *let)
 {
 	decl_arg *darg = let->var->arg;
 	impl_val *arg_val = darg->ptr;
-	impl_arg *iarg;
 
 	switch (let->val ? let->val->kind : PSI_LET_NULL) {
 	case PSI_LET_TMP:
@@ -335,7 +295,7 @@ static inline void *psi_do_let(let_stmt *let)
 		darg->mem = arg_val->ptr;
 		break;
 	case PSI_LET_CALLBACK:
-		arg_val->ptr = 0 /* callback closure */;
+		arg_val->ptr = let->val->data.callback->decl->call.sym;
 		break;
 	case PSI_LET_NUMEXP:
 		arg_val->zend.lval = psi_long_num_exp(let->val->data.num, NULL);
@@ -344,12 +304,7 @@ static inline void *psi_do_let(let_stmt *let)
 		if (!psi_let_func(let->val->data.func, darg)) {
 			return NULL;
 		}
-
-		iarg = let->val->data.func->arg;
-
-		if (!(darg->ptr = psi_let_val(let->val->data.func->type, iarg, darg->ptr, real_decl_type(darg->type)->strct, &darg->mem))) {
-			return NULL;
-		}
+		break;
 	}
 
 	if (let->val && let->val->flags.one.is_reference) {
diff --git a/src/libffi.c b/src/libffi.c
index 221e2c2..0e948a8 100644
--- a/src/libffi.c
+++ b/src/libffi.c
@@ -78,49 +78,44 @@ static void psi_ffi_handler(ffi_cif *_sig, void *_result, void **_args, void *_d
 
 static void psi_ffi_callback(ffi_cif *_sig, void *_result, void **_args, void *_data)
 {
+	size_t i;
 	unsigned argc = _sig->nargs;
 	void **argv = _args;
-	ffi_arg *res = _result;
-	let_stmt *let;
-	decl_arg *darg = let->var->arg;
-	decl *decl_cb = darg->type->func;
-	let_callback *cb = let->val->data.callback;
-	impl_arg *iarg = cb->func->arg;
-	size_t i, argc = cb->args->count;
-	zval return_value, *argv = calloc(argc, sizeof(*argv));
-
-	// prepare args for the userland call
-	for (i = 0; i < decl_cb->args->count; ++i) {
+	let_callback *cb = _data;
+	decl *decl_cb = cb->decl;
+	impl_arg *iarg = cb->func->var->arg;
+	zval return_value, *zargv = calloc(argc, sizeof(*zargv));
+	void *result, *to_free = NULL;
+
+	ZEND_ASSERT(argc == cb->decl->args->count);
 
+	/* prepare args for the userland call */
+	for (i = 0; i < argc; ++i) {
+		cb->decl->args->args[i]->ptr = argv[i];
 	}
 	for (i = 0; i < cb->args->count; ++i) {
-		psi_do_set(&argv[i], cb->args->vals[i]);
+		psi_do_set(&zargv[i], cb->args->vals[i]);
 	}
-	zend_fcall_info_argp(iarg->val.zend.cb->fci, argc, argv);
-	zend_fcall_info_call(&iarg->val.zend.cb->fci, &iarg->val.zend.cb->fcc,
-			&return_value, NULL);
-	// marshal return value of the userland call
-	switch (cb->func->type) {
-	case PSI_T_BOOLVAL:
-		break;
-	case PSI_T_INTVAL:
-		break;
-	case PSI_T_FLOATVAL:
-		break;
-	case PSI_T_PATHVAL:
-	case PSI_T_STRVAL:
-		break;
-	case PSI_T_STRLEN:
-		break;
-	case PSI_T_ARRVAL:
-		break;
-	case PSI_T_OBJVAL:
-		break;
-	case PSI_T_CALLBACK:
-		break;
-	EMPTY_SWITCH_DEFAULT_CASE();
+	zend_fcall_info_argp(&iarg->val.zend.cb->fci, cb->args->count, zargv);
+
+	/* callback into userland */
+	ZVAL_UNDEF(&return_value);
+	iarg->_zv = &return_value;
+	zend_fcall_info_call(&iarg->val.zend.cb->fci, &iarg->val.zend.cb->fcc, iarg->_zv, NULL);
+
+	/* marshal return value of the userland call */
+	switch (iarg->type->type) {
+	case PSI_T_BOOL:	zend_parse_arg_bool(iarg->_zv, &iarg->val.zend.bval, NULL, 0);		break;
+	case PSI_T_LONG:	zend_parse_arg_long(iarg->_zv, &iarg->val.zend.lval, NULL, 0, 1);	break;
+	case PSI_T_FLOAT:
+	case PSI_T_DOUBLE:	zend_parse_arg_double(iarg->_zv, &iarg->val.dval, NULL, 0);			break;
+	case PSI_T_STRING:	zend_parse_arg_str(iarg->_zv, &iarg->val.zend.str, 0);				break;
+	}
+	result = cb->func->handler(_result, decl_cb->func->type, iarg, &to_free);
+
+	if (result != _result) {
+		*(void **)_result = result;
 	}
-	darg->ptr = psi_let_val(cb->func->type, iarg, darg->ptr, real_decl_type(darg->type)->strct, &darg->mem);
 }
 
 static inline ffi_type *psi_ffi_decl_arg_type(decl_arg *darg);
@@ -163,12 +158,14 @@ static inline PSI_LibffiCall *PSI_LibffiCallAlloc(PSI_Context *C, decl *decl) {
 	return call;
 }
 
-static inline void PSI_LibffiCallInitClosure(PSI_Context *C, PSI_LibffiCall *call, impl *impl) {
+static inline ffi_status PSI_LibffiCallInitClosure(PSI_Context *C, PSI_LibffiCall *call, impl *impl) {
 	PSI_LibffiContext *context = C->context;
-	ffi_status rc;
 
-	rc = psi_ffi_prep_closure(&call->closure, &call->code, &context->signature, psi_ffi_handler, impl);
-	ZEND_ASSERT(FFI_OK == rc);
+	return psi_ffi_prep_closure(&call->closure, &call->code, &context->signature, psi_ffi_handler, impl);
+}
+
+static inline ffi_status PSI_LibffiCallInitCallbackClosure(PSI_Context *C, PSI_LibffiCall *call, let_callback *cb) {
+	return psi_ffi_prep_closure(&call->closure, &call->code, &call->signature, psi_ffi_callback, cb);
 }
 
 static inline void PSI_LibffiCallFree(PSI_LibffiCall *call) {
@@ -311,18 +308,6 @@ static inline ffi_type *psi_ffi_decl_type(decl_type *type) {
 
 	switch (real->type) {
 	case PSI_T_FUNCTION:
-		if (!real->func->call.sym) {
-			PSI_LibffiCall *call = PSI_LibffiCallAlloc(&PSI_G(context), real->func);
-			ffi_status rc;
-
-			rc = psi_ffi_prep_closure(
-					(void *) &real->func->call.closure.data,
-					&real->func->call.sym, &call->signature, psi_ffi_handler, NULL);
-			if (FFI_OK == rc) {
-				real->func->call.info = call;
-				real->func->call.closure.dtor = psi_ffi_closure_free;
-			}
-		}
 		return &ffi_type_pointer;
 
 	case PSI_T_STRUCT:
@@ -394,7 +379,7 @@ static void psi_ffi_dtor(PSI_Context *C)
 
 static zend_function_entry *psi_ffi_compile(PSI_Context *C)
 {
-	size_t i, j = 0;
+	size_t c, i, j = 0;
 	zend_function_entry *zfe;
 
 	if (!C->impls) {
@@ -412,19 +397,41 @@ static zend_function_entry *psi_ffi_compile(PSI_Context *C)
 		}
 
 		call = PSI_LibffiCallAlloc(C, impl->decl);
-		PSI_LibffiCallInitClosure(C, call, impl);
+		if (FFI_OK != PSI_LibffiCallInitClosure(C, call, impl)) {
+			PSI_LibffiCallFree(call);
+			continue;
+		}
 
 		zf->fname = impl->func->name + (impl->func->name[0] == '\\');
 		zf->num_args = impl->func->args->count;
 		zf->handler = call->code;
 		zf->arg_info = psi_internal_arginfo(impl);
 		++j;
+
+		for (c = 0; c < impl->stmts->let.count; ++c) {
+			let_stmt *let = impl->stmts->let.list[c];
+
+			if (let->val->kind == PSI_LET_CALLBACK) {
+				let_callback *cb = let->val->data.callback;
+
+				call = PSI_LibffiCallAlloc(C, cb->decl);
+				if (FFI_OK != PSI_LibffiCallInitCallbackClosure(C, call, cb)) {
+					PSI_LibffiCallFree(call);
+					continue;
+				}
+
+				cb->decl->call.sym = call->code;
+			}
+		}
 	}
 
 	for (i = 0; i < C->decls->count; ++i) {
 		decl *decl = C->decls->list[i];
 
-		if (decl->impl) {
+//		if (decl->impl) {
+//			continue;
+//		}
+		if (decl->call.info) {
 			continue;
 		}
 
diff --git a/src/marshal.c b/src/marshal.c
index 23042a4..31ff9ba 100644
--- a/src/marshal.c
+++ b/src/marshal.c
@@ -88,7 +88,7 @@ void psi_to_int(zval *return_value, set_value *set, impl_val *ret_val)
 }
 
 static inline impl_val *psi_val_intval(impl_val *tmp, token_t real_type, zend_long intval) {
-	switch (real_decl_type(type)->type) {
+	switch (real_type) {
 	case PSI_T_INT8:		tmp->i8 = intval;		break;
 	case PSI_T_UINT8:		tmp->u8 = intval;		break;
 	case PSI_T_INT16:		tmp->i16 = intval;		break;
@@ -148,7 +148,7 @@ void psi_to_double(zval *return_value, set_value *set, impl_val *ret_val)
 }
 
 static inline impl_val *psi_val_floatval(impl_val *tmp, token_t real_type, double floatval) {
-	switch (real_decl_type(type)->type) {
+	switch (real_type) {
 	case PSI_T_INT8:		tmp->i8 = floatval;		break;
 	case PSI_T_UINT8:		tmp->u8 = floatval;		break;
 	case PSI_T_INT16:		tmp->i16 = floatval;	break;
@@ -171,7 +171,7 @@ static inline impl_val *psi_val_floatval(impl_val *tmp, token_t real_type, doubl
 impl_val *psi_let_floatval(impl_val *tmp, decl_type *type, impl_arg *iarg, void **to_free)
 {
 	double floatval;
-	token_t real_type = type ? real_decl_type(type)->real : PSI_T_DOUBLE;
+	token_t real_type = type ? real_decl_type(type)->type : PSI_T_DOUBLE;
 
 	if (iarg->type->type == PSI_T_FLOAT || iarg->type->type == PSI_T_DOUBLE) {
 		floatval = iarg->val.dval;
@@ -476,13 +476,25 @@ void psi_to_array(zval *return_value, set_value *set, impl_val *r_val)
 	}
 }
 
-impl_val *psi_arrval(impl_val *tmp, decl_type *type, void *val, void **to_free)
+impl_val *psi_let_arrval(impl_val *tmp, decl_type *type, impl_arg *iarg, void **to_free)
 {
-	HashTable *arr = (HashTable *) val;
-	decl_type *real = type ? real_decl_type(type) : NULL;
+	decl_type *real = real_decl_type(type);
+	HashTable *arr;
+
+	if (iarg->type->type != PSI_T_ARRAY) {
+		SEPARATE_ARG_IF_REF(iarg->_zv);
+		convert_to_array(iarg->_zv);
+	}
+	arr = HASH_OF(iarg->_zv);
 
-	ZEND_ASSERT(real && real->type == PSI_T_STRUCT);
-	return *to_free = psi_array_to_struct(real->strct, arr);
+	switch (real->type) {
+	case PSI_T_STRUCT:
+		*to_free = tmp = psi_array_to_struct(real->strct, arr);
+		break;
+	EMPTY_SWITCH_DEFAULT_CASE();
+	}
+
+	return tmp;
 }
 
 void psi_to_object(zval *return_value, set_value *set, impl_val *r_val)
@@ -500,16 +512,16 @@ void psi_to_object(zval *return_value, set_value *set, impl_val *r_val)
 	}
 }
 
-impl_val *psi_objval(impl_val *tmp, decl_type *type, void *val, void **to_free)
+impl_val *psi_let_objval(impl_val *tmp, decl_type *type, impl_arg *iarg, void **to_free)
 {
-	zval *zv = (zval *) val;
 	psi_object *obj;
 
-	if (!instanceof_function(Z_OBJCE_P(zv), psi_object_get_class_entry())) {
+	if (Z_TYPE_P(iarg->_zv) != IS_OBJECT
+	||	!instanceof_function(Z_OBJCE_P(iarg->_zv), psi_object_get_class_entry())) {
 		return NULL;
 	}
 
-	obj = PSI_OBJ(zv, NULL);
+	obj = PSI_OBJ(iarg->_zv, NULL);
 	tmp->ptr = obj->data;
 
 	return tmp;
diff --git a/src/marshal.h b/src/marshal.h
index 6b2d7fa..a6028dc 100644
--- a/src/marshal.h
+++ b/src/marshal.h
@@ -13,4 +13,13 @@ void psi_to_object(zval *return_value, set_value *set, impl_val *ret_val);
 void *psi_array_to_struct(decl_struct *s, HashTable *arr);
 void psi_from_zval(impl_val *mem, decl_arg *spec, zval *zv, void **tmp);
 
+impl_val *psi_let_boolval(impl_val *tmp, decl_type *type, impl_arg *iarg, void **to_free);
+impl_val *psi_let_intval(impl_val *tmp, decl_type *type, impl_arg *iarg, void **to_free);
+impl_val *psi_let_floatval(impl_val *tmp, decl_type *type, impl_arg *iarg, void **to_free);
+impl_val *psi_let_strval(impl_val *tmp, decl_type *type, impl_arg *iarg, void **to_free);
+impl_val *psi_let_pathval(impl_val *tmp, decl_type *type, impl_arg *iarg, void **to_free);
+impl_val *psi_let_strlen(impl_val *tmp, decl_type *type, impl_arg *iarg, void **to_free);
+impl_val *psi_let_arrval(impl_val *tmp, decl_type *type, impl_arg *iarg, void **to_free);
+impl_val *psi_let_objval(impl_val *tmp, decl_type *type, impl_arg *iarg, void **to_free);
+
 #endif
diff --git a/src/parser.h b/src/parser.h
index 30388ad..0041155 100644
--- a/src/parser.h
+++ b/src/parser.h
@@ -157,7 +157,7 @@ typedef struct decl_arg {
 	decl_type *type;
 	decl_var *var;
 	decl_struct_layout *layout;
-	struct let_stmt *let;
+	struct let_stmt *let; /* FIXME: decls must not point to impls !!! */
 	impl_val val;
 	void *ptr;
 	void *mem;
@@ -297,10 +297,6 @@ typedef struct decl_callinfo {
 	size_t argc;
 	void **args;
 	void **rval;
-	struct {
-		void *data;
-		void (*dtor)(void *data);
-	} closure;
 } decl_callinfo;
 
 typedef struct decl {
@@ -481,6 +477,7 @@ static inline void free_impl_type(impl_type *type) {
 typedef struct impl_var {
 	PSI_Token *token;
 	char *name;
+	struct impl_arg *arg;
 	unsigned reference:1;
 } impl_var;
 
@@ -601,6 +598,7 @@ static inline impl_arg *init_impl_arg(impl_type *type, impl_var *var, impl_def_v
 	impl_arg *arg = calloc(1, sizeof(*arg));
 	arg->type = type;
 	arg->var = var;
+	arg->var->arg = arg;
 	arg->def = def;
 	return arg;
 }
@@ -902,6 +900,7 @@ static inline void free_let_calloc(let_calloc *alloc) {
 typedef struct let_callback {
 	struct let_func *func;
 	struct set_values *args;
+	decl *decl;
 } let_callback;
 
 static inline void free_let_func(struct let_func *func);
@@ -924,8 +923,7 @@ typedef struct let_func {
 	token_t type;
 	char *name;
 	impl_var *var;
-	impl_arg *arg;
-	impl_val *(*handler)(impl_val *tmp, decl_type *type, void *val, void **to_free);
+	impl_val *(*handler)(impl_val *tmp, decl_type *type, impl_arg *iarg, void **to_free);
 } let_func;
 
 static inline let_func *init_let_func(token_t type, const char *name, impl_var *var) {
@@ -1088,9 +1086,10 @@ static inline set_value *init_set_value(set_func *func, decl_vars *vars) {
 	val->vars = vars;
 	return val;
 }
+
+static inline set_values *add_set_value(set_values *vals, set_value *val);
 static inline set_value *add_inner_set_value(set_value *val, set_value *inner) {
-	val->inner->vals = realloc(val->inner->vals, ++val->inner->count * sizeof(*val->inner->vals));
-	val->inner->vals[val->inner->count-1] = inner;
+	val->inner = add_set_value(val->inner, inner);
 	inner->outer.set = val;
 	return val;
 }
@@ -1103,11 +1102,7 @@ static inline void free_set_value(set_value *val) {
 		free_decl_vars(val->vars);
 	}
 	if (val->inner && (!val->outer.set || val->outer.set->inner != val->inner)) {
-		size_t i;
-		for (i = 0; i < val->inner->count; ++i) {
-			free_set_value(val->inner->vals[i]);
-		}
-		free(val->inner->vals);
+		free_set_values(val->inner);
 	}
 	if (val->num) {
 		free_num_exp(val->num);
@@ -1126,6 +1121,9 @@ static inline set_values *init_set_values(set_value *val) {
 }
 
 static inline set_values *add_set_value(set_values *vals, set_value *val) {
+	if (!vals) {
+		vals = calloc(1, sizeof(*vals));
+	}
 	vals->vals = realloc(vals->vals, ++vals->count * sizeof(val));
 	vals->vals[vals->count-1] = val;
 	return vals;
@@ -1133,6 +1131,11 @@ static inline set_values *add_set_value(set_values *vals, set_value *val) {
 
 static inline void free_set_values(set_values *vals) {
 	if (vals->vals) {
+		size_t i;
+
+		for (i = 0; i < vals->count; ++i) {
+			free_set_value(vals->vals[i]);
+		}
 		free(vals->vals);
 	}
 	free(vals);
diff --git a/src/parser_proc.h b/src/parser_proc.h
index 344fdb9..d7f28a2 100644
--- a/src/parser_proc.h
+++ b/src/parser_proc.h
@@ -9,60 +9,60 @@
 #define PSI_T_LET                              9
 #define PSI_T_RETURN                          10
 #define PSI_T_CALLOC                          11
-#define PSI_T_LIB                             12
-#define PSI_T_STRING                          13
-#define PSI_T_EOF                             14
-#define PSI_T_EOS                             15
-#define PSI_T_QUOTED_STRING                   16
-#define PSI_T_ENUM                            17
-#define PSI_T_LBRACE                          18
-#define PSI_T_RBRACE                          19
-#define PSI_T_COMMA                           20
-#define PSI_T_EQUALS                          21
-#define PSI_T_UNION                           22
-#define PSI_T_STRUCT                          23
-#define PSI_T_COLON                           24
-#define PSI_T_LPAREN                          25
-#define PSI_T_NUMBER                          26
-#define PSI_T_RPAREN                          27
-#define PSI_T_BOOL                            28
-#define PSI_T_INT                             29
-#define PSI_T_FLOAT                           30
-#define PSI_T_CONST                           31
-#define PSI_T_NSNAME                          32
-#define PSI_T_TYPEDEF                         33
-#define PSI_T_VOID                            34
-#define PSI_T_LBRACKET                        35
-#define PSI_T_RBRACKET                        36
-#define PSI_T_ELLIPSIS                        37
-#define PSI_T_CHAR                            38
-#define PSI_T_SHORT                           39
-#define PSI_T_LONG                            40
-#define PSI_T_DOUBLE                          41
-#define PSI_T_UNSIGNED                        42
-#define PSI_T_SIGNED                          43
-#define PSI_T_INT8                            44
-#define PSI_T_UINT8                           45
-#define PSI_T_INT16                           46
-#define PSI_T_UINT16                          47
-#define PSI_T_INT32                           48
-#define PSI_T_UINT32                          49
-#define PSI_T_INT64                           50
-#define PSI_T_UINT64                          51
-#define PSI_T_FUNCTION                        52
-#define PSI_T_NULL                            53
-#define PSI_T_TRUE                            54
-#define PSI_T_FALSE                           55
-#define PSI_T_DOLLAR_NAME                     56
-#define PSI_T_OBJVAL                          57
-#define PSI_T_ARRVAL                          58
-#define PSI_T_PATHVAL                         59
-#define PSI_T_STRLEN                          60
-#define PSI_T_STRVAL                          61
-#define PSI_T_FLOATVAL                        62
-#define PSI_T_INTVAL                          63
-#define PSI_T_BOOLVAL                         64
-#define PSI_T_CALLBACK                        65
+#define PSI_T_CALLBACK                        12
+#define PSI_T_LIB                             13
+#define PSI_T_STRING                          14
+#define PSI_T_EOF                             15
+#define PSI_T_EOS                             16
+#define PSI_T_QUOTED_STRING                   17
+#define PSI_T_ENUM                            18
+#define PSI_T_LBRACE                          19
+#define PSI_T_RBRACE                          20
+#define PSI_T_COMMA                           21
+#define PSI_T_EQUALS                          22
+#define PSI_T_UNION                           23
+#define PSI_T_STRUCT                          24
+#define PSI_T_COLON                           25
+#define PSI_T_LPAREN                          26
+#define PSI_T_NUMBER                          27
+#define PSI_T_RPAREN                          28
+#define PSI_T_BOOL                            29
+#define PSI_T_INT                             30
+#define PSI_T_FLOAT                           31
+#define PSI_T_CONST                           32
+#define PSI_T_NSNAME                          33
+#define PSI_T_TYPEDEF                         34
+#define PSI_T_VOID                            35
+#define PSI_T_LBRACKET                        36
+#define PSI_T_RBRACKET                        37
+#define PSI_T_ELLIPSIS                        38
+#define PSI_T_CHAR                            39
+#define PSI_T_SHORT                           40
+#define PSI_T_LONG                            41
+#define PSI_T_DOUBLE                          42
+#define PSI_T_UNSIGNED                        43
+#define PSI_T_SIGNED                          44
+#define PSI_T_INT8                            45
+#define PSI_T_UINT8                           46
+#define PSI_T_INT16                           47
+#define PSI_T_UINT16                          48
+#define PSI_T_INT32                           49
+#define PSI_T_UINT32                          50
+#define PSI_T_INT64                           51
+#define PSI_T_UINT64                          52
+#define PSI_T_FUNCTION                        53
+#define PSI_T_NULL                            54
+#define PSI_T_TRUE                            55
+#define PSI_T_FALSE                           56
+#define PSI_T_DOLLAR_NAME                     57
+#define PSI_T_OBJVAL                          58
+#define PSI_T_ARRVAL                          59
+#define PSI_T_PATHVAL                         60
+#define PSI_T_STRLEN                          61
+#define PSI_T_STRVAL                          62
+#define PSI_T_FLOATVAL                        63
+#define PSI_T_INTVAL                          64
+#define PSI_T_BOOLVAL                         65
 #define PSI_T_TO_OBJECT                       66
 #define PSI_T_TO_ARRAY                        67
 #define PSI_T_TO_STRING                       68
diff --git a/src/parser_proc.y b/src/parser_proc.y
index 57fc968..50d54da 100644
--- a/src/parser_proc.y
+++ b/src/parser_proc.y
@@ -29,7 +29,7 @@ void psi_error(int, const char *, int, const char *, ...);
 %nonassoc NAME.
 %left PLUS MINUS.
 %left SLASH ASTERISK.
-%fallback NAME TEMP FREE SET LET RETURN CALLOC LIB STRING.
+%fallback NAME TEMP FREE SET LET RETURN CALLOC CALLBACK LIB STRING.
 
 file ::= blocks.
 
@@ -716,7 +716,7 @@ let_func(func) ::= let_func_token(T) LPAREN impl_var(var) RPAREN. {
 %type callback_arg_list {set_values *}
 %destructor callback_arg_list {free_set_values($$);}
 callback_arg_list ::= .
-callback_arg_list(args) ::= COMMA callback_args(args_). {
+callback_arg_list(args) ::= callback_args(args_). {
 	args = args_;
 }
 
@@ -743,7 +743,7 @@ let_val(val) ::= CALLOC LPAREN let_calloc(alloc) RPAREN. {
 let_val(val) ::= let_func(func). {
 	val = init_let_val(PSI_LET_FUNC, func);
 }
-let_val(val) ::= CALLBACK let_func_token(F) LPAREN impl_var(var) callback_arg_list(args_) RPAREN. {
+let_val(val) ::= CALLBACK let_func_token(F) LPAREN impl_var(var) LPAREN callback_arg_list(args_) RPAREN RPAREN. {
 	val = init_let_val(PSI_LET_CALLBACK, init_let_callback(
 		init_let_func(F->type, F->text, var), args_));
 	free(F);
-- 
2.30.2