Merge pull request #3 from Rexicon226/function-frames

Basic Function Frames

demo/test.py

@@ -1,2 +1,7 @@
-a = 1
-print(a)
+a = 10
+def b(x): 
+    # c = "test"
+    print(x)
+
+
+b(a)

src/compiler/CodeObject.zig

@@ -4,6 +4,7 @@ const std = @import("std");
 const Marshal = @import("Marshal.zig");
 const Instruction = @import("Instruction.zig");
 const OpCode = @import("opcodes.zig").OpCode;
+const Object = @import("../vm/Object.zig");
 const Result = Marshal.Result;
 const Reference = Marshal.Reference;
 const FlagRef = Marshal.FlagRef;
@@ -31,6 +32,8 @@ stack_size: u32,
 /// ByteCode
 code: []const u8,
 
+varnames: []Object,
+
 // Interal reference table.
 flag_refs: []const ?FlagRef,
 

src/compiler/Marshal.zig

@@ -3,6 +3,8 @@
 const std = @import("std");
 const ObjType = @import("objtype.zig").ObjType;
 const CodeObject = @import("CodeObject.zig");
+const Object = @import("../vm/Object.zig");
+const Vm = @import("../vm/Vm.zig");
 const tracer = @import("tracer");
 
 const Marshal = @This();
@@ -198,6 +200,13 @@ fn read_codeobject(marshal: *Marshal) Result {
     const filename = dict.get("filename").?;
     co.filename = filename.String;
 
+    const varname_tuple = dict.get("varnames").?.Tuple;
+    const varnames = marshal.allocator.alloc(Object, varname_tuple.len) catch @panic("OOM");
+    for (varname_tuple, 0..) |elem, i| {
+        varnames[i] = Vm.loadConst(marshal.allocator, elem) catch @panic("OOM");
+    }
+    co.varnames = varnames;
+
     co.consts = dict.get("consts").?.Tuple;
     co.stack_size = @intCast(dict.get("stacksize").?.Int);
     co.code = dict.get("code").?.String;

src/vm/Object.zig

@@ -1,6 +1,7 @@
 const std = @import("std");
 const Vm = @import("Vm.zig");
 const builtins = @import("../builtins.zig");
+const Co = @import("../compiler/CodeObject.zig");
 
 const BigIntConst = std.math.big.int.Const;
 const BigIntMutable = std.math.big.int.Mutable;
@@ -43,6 +44,9 @@ pub const Tag = enum(usize) {
     /// A builtin Zig defined function.
     zig_function,
 
+    codeobject,
+    function,
+
     pub fn PayloadType(comptime t: Tag) type {
         assert(@intFromEnum(t) >= Tag.first_payload);
 
@@ -57,6 +61,8 @@ pub const Tag = enum(usize) {
             .list => Payload.List,
 
             .zig_function => Payload.ZigFunc,
+            .codeobject => Payload.CodeObject,
+            .function => Payload.PythonFunction,
 
             .none => unreachable,
             else => @compileError("TODO: PayloadType " ++ @tagName(t)),
@@ -111,6 +117,8 @@ pub const Payload = union(enum) {
     zig_func: ZigFunc,
     tuple: Tuple,
     list: List,
+    codeobject: CodeObject,
+    function: PythonFunction,
 
     pub const Value = union(enum) {
         int: BigIntManaged,
@@ -119,7 +127,9 @@ pub const Payload = union(enum) {
     };
 
     pub const ZigFunc = *const builtins.func_proto;
+
     pub const Tuple = []const Object;
+
     pub const List = struct {
         list: std.ArrayListUnmanaged(Object),
 
@@ -140,6 +150,15 @@ pub const Payload = union(enum) {
             try vm.stack.append(vm.allocator, return_val);
         }
     };
+
+    pub const CodeObject = struct {
+        co: *Co,
+    };
+
+    pub const PythonFunction = struct {
+        name: []const u8,
+        co: *Co,
+    };
 };
 
 pub fn format(
@@ -191,6 +210,7 @@ pub fn format(
 
             try writer.writeAll(")");
         },
+
         else => try writer.print("TODO: Object.format '{s}'", .{@tagName(object.tag)}),
     }
 }