1 files changed, 172 insertions, 23 deletions

diff --git a/src/lower.c b/src/lower.c
index 9689928..ee8253a 100644
--- a/src/lower.c
+++ b/src/lower.c
@@ -237,6 +237,23 @@ static int _type_str(FILE *f, struct state *state, struct scope *scope, struct t
 		break;
 	}
 
+	case TYPE_REF: {
+		char *rest = lower_type_str(state, scope, tref_base(type));
+		fprintf(f, "%s*", rest);
+		free(rest);
+		break;
+	}
+
+	case TYPE_BOOL: {
+		fprintf(f, "bool");
+		break;
+	}
+
+	case TYPE_NIL: {
+		fprintf(f, "void*");
+		break;
+	}
+
 	default:
 		internal_error("unhandled type lowering for %s", type_str(type));
 		abort();
@@ -505,6 +522,36 @@ static int lower_expr(struct state *state, struct ast *expr)
 		break;
 	}
 
+	case AST_SIZEOF: {
+		char *type = lower_type_str(state, expr->scope, sizeof_type(expr));
+		fprintf(state->code, "sizeof(%s)", type);
+		free(type);
+		break;
+	}
+
+	case AST_PUT: {
+		fprintf(state->code, "*(");
+		if (lower_expr(state, put_dst(expr)))
+			return -1;
+
+		fprintf(state->code, ")");
+		break;
+	}
+
+	case AST_DEREF: {
+		fprintf(state->code, "*(");
+		if (lower_expr(state, deref_base(expr)))
+			return -1;
+
+		fprintf(state->code, ")");
+		break;
+	}
+
+	case AST_CONST_STR: {
+		fprintf(state->code, "\"%s\"", str_val(expr));
+		break;
+	}
+
 	default:
 		internal_error("unhandled expr lowering: %s", ast_str(expr->k));
 		abort();
@@ -607,6 +654,22 @@ static int lower_if(struct state *state, struct ast *stmt, bool last)
 	return lower_block(state, if_else(stmt), last);
 }
 
+static int lower_nil_check(struct state *state, struct ast *stmt, bool last)
+{
+	indent(state);
+	fprintf(state->code, "if (");
+	if (lower_expr(state, nil_check_expr(stmt)))
+		return -1;
+
+	fprintf(state->code, ")\n");
+	if (lower_block(state, nil_check_body(stmt), last))
+		return -1;
+
+	indent(state);
+	fprintf(state->code, "else\n");
+	return lower_block(state, nil_check_rest(stmt), last);
+}
+
 static int lower_explode(struct state *state, struct ast *stmt, bool last)
 {
 	/* not significant to us */
@@ -665,13 +728,29 @@ static int lower_let(struct state *state, struct ast *stmt, bool last)
 	return 0;
 }
 
+static int lower_write(struct state *state, struct ast *stmt)
+{
+	if (lower_expr(state, write_dst(stmt)))
+		return -1;
+
+	fprintf(state->code, " = ");
+	if (lower_expr(state, write_src(stmt)))
+		return -1;
+
+	fprintf(state->code, ";\n");
+	return 0;
+}
+
 static int lower_stmt(struct state *state, struct ast *stmt, bool last)
 {
 	switch (stmt->k) {
 	case AST_CALL: return lower_call(state, stmt, last);
 	case AST_IF: return lower_if(state, stmt, last);
+	case AST_NIL_CHECK: return lower_nil_check(state, stmt, last);
 	case AST_EXPLODE: return lower_explode(state, stmt, last);
 	case AST_LET: return lower_let(state, stmt, last);
+	case AST_WRITE: return lower_write(state, stmt);
+	case AST_FORGET: break;
 	case AST_EMPTY: break;
 	default:
 		internal_error("unhandled statement kind %s", ast_str(stmt->k));
@@ -728,37 +807,82 @@ static int lower_params(struct state *state, struct ast *params)
 	return 0;
 }
 
-static size_t fwd_typeid(struct type *t)
+static const char *fwd_typeparam(struct type *t)
 {
-	/** @todo this should maybe be cached somewhere earlier? */
 	switch (t->k) {
-	case TYPE_I64: return FWD_I64;
-	case TYPE_PTR: return FWD_PTR;
+	case TYPE_I8:  return "i8";
+	case TYPE_I16: return "i16";
+	case TYPE_I32: return "i32";
+	case TYPE_I64: return "i64";
+	case TYPE_U8:  return "u8";
+	case TYPE_U16: return "u16";
+	case TYPE_U32: return "u32";
+	case TYPE_U64: return "u64";
+	case TYPE_PTR: return "p";
+	case TYPE_NIL: return "p";
+	case TYPE_FUNC_PTR: return "p";
 	default:
 		       abort();
 	}
 
-	return 0;
+	return NULL;
 }
 
-static const char *fwd_typeparam(struct type *t)
+static const char *fwd_ctypestr(struct type *t)
 {
 	switch (t->k) {
-	case TYPE_I64: return "i64";
-	case TYPE_PTR: return "p";
+	case TYPE_I8: return "FWD_I8";
+	case TYPE_I16: return "FWD_I16";
+	case TYPE_I32: return "FWD_I32";
+	case TYPE_I64: return "FWD_I64";
+	case TYPE_U8: return "FWD_U8";
+	case TYPE_U16: return "FWD_U16";
+	case TYPE_U32: return "FWD_U32";
+	case TYPE_U64: return "FWD_U64";
+	case TYPE_PTR: return "FWD_PTR";
+	case TYPE_NIL: return "FWD_PTR"; /* void ptr */
+	case TYPE_FUNC_PTR: return "FWD_PTR";
 	default:
-		       abort();
+			abort();
 	}
 
+	return NULL;
+}
+
+static int lower_extern_closure_call(struct state *state, struct type *rtype, size_t idx)
+{
+	char *q = buildstr("%s_call%zu", state->prefix, uniq(state));
+
+	char *ctx_buf = NULL; size_t ctx_size = 0;
+	FILE *ctx = open_memstream(&ctx_buf, &ctx_size);
+	fprintf(ctx, "struct %s {\n fwd_start_t start;\n fwd_call_t closure;\n};\n", q);
+	fclose(ctx);
+	assert(ctx_buf);
+
+	add_type(state, ctx_buf);
+
+	indent(state);
+	fprintf(state->code, "fwd_call_t call = ctx->a%zu.call;\n", idx);
+
+	indent(state);
+	fprintf(state->code, "struct %s *call_ctx = ctx->a%zu.args;\n", q, idx);
+
+	indent(state);
+	fprintf(state->code, "call_ctx->a0 = extern_args[0].%s;\n",
+			fwd_typeparam(rtype));
+
+	indent(state);
+	fprintf(state->code, "fwd_stack_free(&stack, extern_args);\n");
+
+	indent(state);
+	fprintf(state->code, "FWD_MUSTTAIL return call(stack, call_ctx);\n");
+
+	free(q);
 	return 0;
 }
 
 static int lower_extern_proc(struct state *state, struct ast *proc)
 {
-	/* only void external functions supported atm */
-	struct type *rtype = proc_rtype(proc);
-	assert(rtype->k == TYPE_VOID);
-
 	add_proc(state, proc);
 	char *name = mangle2(proc);
 	char *proto = buildstr("static fwd_stack_t %s(fwd_stack_t stack, fwd_args_t args)",
@@ -796,17 +920,26 @@ static int lower_extern_proc(struct state *state, struct ast *proc)
 	fprintf(new_state.code, "struct fwd_arg *extern_args = fwd_stack_alloc(&stack);\n");
 
 	size_t idx = 0;
+	struct type *rtype = NULL;
 	foreach_node(p, proc_params(proc)) {
+		/* lower arg */
+		char *type_str = lower_type_str(state, p->scope, p->t);
+		fprintf(new_state.ctx, "  %s a%zu;\n", type_str, idx);
+		free(type_str);
+
+		/* don't lower last parameter as an extern arg if it's a
+		 * closure, since that's our return type  */
+		if (!p->n && is_closure_type(p->t->k)) {
+			rtype = p->t;
+			break;
+		}
+
 		indent(&new_state);
 		/* leave place for return value */
-		fprintf(new_state.code, "extern_args[%zu] = (fwd_arg_t){%zu, "
+		fprintf(new_state.code, "extern_args[%zu] = (fwd_arg_t){%s, "
 				"{.%s = ctx->a%zu}};\n",
-				idx + 1, fwd_typeid(p->t), fwd_typeparam(p->t), idx);
-
+				idx + 1, fwd_ctypestr(p->t), fwd_typeparam(p->t), idx);
 
-		char *type_str = lower_type_str(state, p->scope, p->t);
-		fprintf(new_state.ctx, "  %s a%zu;\n", type_str, idx);
-		free(type_str);
 		idx++;
 	}
 
@@ -815,11 +948,27 @@ static int lower_extern_proc(struct state *state, struct ast *proc)
 			proc_id(proc), idx);
 
 
-	indent(&new_state);
-	fprintf(new_state.code, "fwd_stack_free(&stack, extern_args);\n");
+	if (rtype) {
+		struct type *ctype = rtype->k == TYPE_PURE_CLOSURE
+			? tpure_closure_args(rtype)
+			: tclosure_args(rtype)
+			;
 
-	indent(&new_state);
-	fprintf(new_state.code, "return stack;\n");
+		indent(&new_state);
+		fprintf(new_state.code, "assert(extern_args[0].type == %s);\n",
+				fwd_ctypestr(ctype));
+
+		if (lower_extern_closure_call(&new_state, ctype, idx))
+			return -1;
+
+	} else {
+		/* void func */
+		indent(&new_state);
+		fprintf(new_state.code, "fwd_stack_free(&stack, extern_args);\n");
+
+		indent(&new_state);
+		fprintf(new_state.code, "return stack;\n");
+	}
 
 	fprintf(new_state.code, "}\n\n");
 	fprintf(new_state.ctx, "};\n\n");