microscript: add c functions

6 files changed, 107 insertions, 15 deletions

diff --git a/uscript/uscript.c b/uscript/uscript.c
index 2b32110..ee02f15 100644
--- a/uscript/uscript.c
+++ b/uscript/uscript.c
@@ -37,3 +37,10 @@ int us_declare_global(const char *name)
 {
         return declare_global(copy_str(name, -1));
 }
+
+void us_set_cfunc(const char *c_name, us_cfunc_sig c, int argc)
+{
+        struct us_str *name = copy_str(c_name, -1);
+        int global = declare_global(name);
+        set_global(global, wrap_cfunc(create_cfunc(name, c, argc)));
+}
diff --git a/uscript/uscript.h b/uscript/uscript.h
index 74958e5..a7efced 100644
--- a/uscript/uscript.h
+++ b/uscript/uscript.h
@@ -3,6 +3,8 @@
 
 struct us_func;
 
+typedef void (*us_cfunc_sig)(int argc);
+
 void us_init(void);
 void us_deinit(void);
 
@@ -11,4 +13,6 @@ void us_load_src(const char *src);
 
 void us_exec(struct us_func *func);
 
+void us_set_cfunc(const char *c_name, us_cfunc_sig c, int argc);
+
 #endif // __USCRIPT_LANG_H__
diff --git a/uscript/val.c b/uscript/val.c
index 77f7753..f204e20 100644
--- a/uscript/val.c
+++ b/uscript/val.c
@@ -68,6 +68,16 @@ struct us_func *create_func(struct us_proto *proto)
         return func;
 }
 
+struct us_cfunc *create_cfunc(struct us_str *name, us_cfunc_sig func, int argc)
+{
+        struct us_cfunc *cfunc = mem_alloc(sizeof(struct us_cfunc));
+        cfunc->name = name;
+        cfunc->c = func;
+        cfunc->argc = argc;
+        init_obj(wrap_cfunc(cfunc), &cfunc->header);
+        return cfunc;
+}
+
 struct us_upval *create_upval(struct us_val *val)
 {
         struct us_upval *upval = mem_alloc(sizeof(struct us_upval));
@@ -106,6 +116,7 @@ void free_val(struct us_val v)
                 mem_free(func);
                 break;
         }
+        case VAL_CFUNC:
         case VAL_UPVAL:
                 mem_free(get_obj(v));
                 break;
@@ -140,6 +151,7 @@ bool vals_eql(struct us_val a, struct us_val b)
         }
         case VAL_ARR:
         case VAL_FUNC:
+        case VAL_CFUNC:
         case VAL_UPVAL:
         case VAL_PROTO: return get_obj(a) == get_obj(b);
         }
@@ -219,6 +231,27 @@ char *val_to_str(struct us_val v, int *len_out)
         }
         case VAL_FUNC:
                 return val_to_str(wrap_proto(get_func(v)->proto), len_out);
+        case VAL_CFUNC: {
+                const struct us_cfunc *cfunc = get_cfunc(v);
+                int len = snprintf(
+                        NULL,
+                        0,
+                        STR_FUNC_FMT,
+                        cfunc->name->chars,
+                        (void*)cfunc
+                );
+                char *str = mem_alloc(sizeof(char) * (len + 1));
+                snprintf(
+                        str,
+                        len + 1,
+                        STR_FUNC_FMT,
+                        cfunc->name->chars,
+                        (void*)cfunc
+                );
+                if (len_out)
+                        *len_out = len;
+                return str;
+        }
         case VAL_UPVAL:
                 return val_to_str(*get_upval(v)->loc, len_out);
         }
diff --git a/uscript/val.h b/uscript/val.h
index 4789973..5140fc2 100644
--- a/uscript/val.h
+++ b/uscript/val.h
@@ -2,6 +2,7 @@
 #define __USCRIPT_VAL_H__
 
 #include "common.h"
+#include "uscript.h"
 
 #define create_num(n)  ((struct us_val){.type=VAL_NUM,   .dat={.number=(n)}})
 #define create_bool(b) ((struct us_val){.type=VAL_BOOL,  .dat={.boolean=(b)}})
@@ -10,6 +11,7 @@
 #define wrap_arr(o)    ((struct us_val){.type=VAL_ARR,   .dat={.arr=(o)}})
 #define wrap_proto(o)  ((struct us_val){.type=VAL_PROTO, .dat={.proto=(o)}})
 #define wrap_func(o)   ((struct us_val){.type=VAL_FUNC,  .dat={.func=(o)}})
+#define wrap_cfunc(o)  ((struct us_val){.type=VAL_CFUNC, .dat={.cfunc=(o)}})
 #define wrap_upval(o)  ((struct us_val){.type=VAL_UPVAL, .dat={.upval=(o)}})
 
 #define get_num(v)   (v.dat.number)
@@ -19,6 +21,7 @@
 #define get_arr(v)   (v.dat.arr)
 #define get_proto(v) (v.dat.proto)
 #define get_func(v)  (v.dat.func)
+#define get_cfunc(v) (v.dat.cfunc)
 #define get_upval(v) (v.dat.upval)
 
 #define val_is_obj(v) (v.type >= VAL_STR)
@@ -35,6 +38,7 @@ enum val_type {
         VAL_ARR,
         VAL_PROTO,
         VAL_FUNC,
+        VAL_CFUNC,
         VAL_UPVAL,
 };
 
@@ -48,6 +52,7 @@ struct us_val {
                 struct us_arr *arr;
                 struct us_proto *proto;
                 struct us_func *func;
+                struct us_cfunc *cfunc;
                 struct us_upval *upval;
         } dat;
 };
@@ -81,6 +86,13 @@ struct us_proto {
         u8 nconstants;
 };
 
+struct us_cfunc {
+        struct us_obj header;
+        us_cfunc_sig c;
+        const struct us_str *name;
+        int argc;
+};
+
 struct us_func {
         struct us_obj header;
         struct us_proto *proto;
@@ -99,6 +111,7 @@ struct us_str *copy_str(const char *chars, int len);
 struct us_arr *create_arr(void);
 struct us_proto *create_proto(struct us_str *name);
 struct us_func *create_func(struct us_proto *proto);
+struct us_cfunc *create_cfunc(struct us_str *name, us_cfunc_sig func, int argc);
 struct us_upval *create_upval(struct us_val *val);
 
 void free_val(struct us_val v);
diff --git a/uscript/vm.c b/uscript/vm.c
index 363912a..c01bb0f 100644
--- a/uscript/vm.c
+++ b/uscript/vm.c
@@ -76,12 +76,59 @@ void close_upvals(struct us_val *to)
         vm.open_upvals = upval;
 }
 
+
+static
+void call_val(struct us_val callee, int argc) 
+{
+        switch (callee.type) {
+        case VAL_FUNC: {
+                struct us_func *func = get_func(callee);
+                if (argc != func->proto->argc) {
+                        log_fatal(
+                                1,
+                                "wrong number of arguments to '%s()' (%d/%d)",
+                                func->proto->name->chars,
+                                argc,
+                                func->proto->argc
+                        );
+                }
+                us_exec(func);
+                break;
+        }
+        case VAL_CFUNC: {
+                struct us_cfunc *cfunc = get_cfunc(callee);
+                if (argc != cfunc->argc) {
+                        log_fatal(
+                                1,
+                                "wrong number of arguments to '%s()' (%d/%d)",
+                                cfunc->name->chars,
+                                argc,
+                                cfunc->argc
+                        );
+                }
+
+                vm.cf++;
+                vm.cf->func = wrap_cfunc(cfunc);
+                vm.cf->stackbot = vm.stacktop - argc;
+                cfunc->c(argc);
+                struct us_val ret_val = vm_pop();
+                vm.stacktop = vm.cf->stackbot - 1;
+                vm.cf--;
+                vm_push(ret_val);
+                break;
+        }
+        default:
+                log_fatal(1, "cannot call that value");
+                break;
+        }
+}
+
 void us_exec(struct us_func *func)
 {
 #define read_byte() (func->proto->bytecode[++i])
 #define read_const() (func->proto->constants[read_byte()])
         vm.cf++;
-        vm.cf->func = func;
+        vm.cf->func = wrap_func(func);
         vm.cf->stackbot = vm.stacktop - func->proto->argc;
         
         for (int i = 0; i < da_len(func->proto->bytecode); i++) {
@@ -344,19 +391,7 @@ void us_exec(struct us_func *func)
                 case BC_CALL: {
                         int argc = read_byte();
                         struct us_val callee = vm.stacktop[-argc - 1];
-                        if (callee.type != VAL_FUNC)
-                                log_fatal(1, "can only call functions");
-                        struct us_func *func = get_func(callee);
-                        if (argc != func->proto->argc) {
-                                log_fatal(
-                                        1,
-                                        "wrong number of arguments to '%s()' (%d/%d)",
-                                        func->proto->name->chars,
-                                        argc,
-                                        func->proto->argc
-                                );
-                        }
-                        us_exec(func);
+                        call_val(callee, argc);
                         break;
                 }
                 case BC_RET: {
diff --git a/uscript/vm.h b/uscript/vm.h
index 2911d01..cf9aa60 100644
--- a/uscript/vm.h
+++ b/uscript/vm.h
@@ -20,7 +20,7 @@ enum bytecode {
 };
 
 struct call_frame {
-        struct us_func *func;
+        struct us_val func;
         struct us_val *stackbot;
 };