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-rw-r--r--src/mods/vm.zig532
1 files changed, 532 insertions, 0 deletions
diff --git a/src/mods/vm.zig b/src/mods/vm.zig
new file mode 100644
index 0000000..f8c7db5
--- /dev/null
+++ b/src/mods/vm.zig
@@ -0,0 +1,532 @@
+const std = @import("std");
+const wasm = @import("wasm.zig");
+const Parser = @import("parse.zig");
+const Allocator = std.mem.Allocator;
+const AllocationError = error{OutOfMemory};
+
+fn leb128Decode(comptime T: type, bytes: []u8) Parser.leb128Result(T) {
+ var fbs = std.io.fixedBufferStream(bytes);
+ // TODO: this catch should be unrecheable
+ return Parser.leb128Decode(T, fbs.reader()) catch .{ .len = 0, .val = 0 };
+}
+
+pub fn decodeLittleEndian(comptime T: type, bytes: []u8) T {
+ if (T != i32 and T != i64) {
+ return @as(T, 0);
+ } else {
+ var value = @as(T, 0);
+ for (0..@sizeOf(T)) |b| {
+ value |= ((bytes[b]) << @intCast((@sizeOf(T) - b - 1)));
+ }
+ return value;
+ }
+}
+
+pub fn encodeLittleEndian(comptime T: type, bytes: *[]u8, value: T) void {
+ for (0..@sizeOf(T)) |b| {
+ bytes.*[b] = @intCast(((value >> @intCast((@sizeOf(T) - b - 1))) & 0xff));
+ }
+}
+
+pub const CallFrame = struct {
+ program_counter: usize,
+ code: []u8,
+ locals: []Value,
+};
+
+const ValueType = enum {
+ i32,
+ i64,
+};
+
+pub const Value = union(ValueType) {
+ i32: i32,
+ i64: i64,
+};
+
+pub const Runtime = struct {
+ module: Parser.Module,
+ stack: std.ArrayList(Value),
+ call_stack: std.ArrayList(CallFrame),
+ memory: []u8,
+ global_runtime: *wasm.GlobalRuntime,
+ labels: std.ArrayList(usize),
+
+ pub fn init(allocator: Allocator, module: Parser.Module, global_runtime: *wasm.GlobalRuntime) !Runtime {
+ const memory = try allocator.alloc(u8, module.memory.max);
+ return Runtime{
+ .module = module,
+ .stack = try std.ArrayList(Value).initCapacity(allocator, 10),
+ .call_stack = try std.ArrayList(CallFrame).initCapacity(allocator, 5),
+ .labels = try std.ArrayList(usize).initCapacity(allocator, 2),
+ .memory = memory,
+ .global_runtime = global_runtime,
+ };
+ }
+
+ pub fn deinit(self: *Runtime, allocator: Allocator) void {
+ self.module.deinit(allocator);
+ self.stack.deinit();
+ self.labels.deinit();
+ self.call_stack.deinit();
+ allocator.free(self.memory);
+ }
+
+ pub fn executeFrame(self: *Runtime, allocator: Allocator, frame: *CallFrame) !void {
+ var for_loop = false;
+ loop: while (true) {
+ const byte: u8 = frame.code[frame.program_counter];
+ frame.program_counter += 1;
+ std.debug.print("b: {x}\n", .{byte});
+ switch (byte) {
+ 0x03 => {
+ try self.labels.append(frame.program_counter);
+ frame.program_counter += 1;
+ //const a = frame.code[frame.program_counter];
+ for_loop = true;
+ },
+ 0x0d => {
+ const label = leb128Decode(u32, frame.code[frame.program_counter..]);
+ frame.program_counter += label.len;
+ var address = @as(usize, 0);
+ for (0..(label.val)) |_| {
+ address = self.labels.pop().?;
+ }
+
+ if (self.stack.pop().?.i32 != 0) {
+ frame.program_counter = address;
+ }
+ },
+
+ 0x20 => {
+ const integer = leb128Decode(u32, frame.code[frame.program_counter..]);
+
+ frame.program_counter += integer.len;
+ try self.stack.append(frame.locals[integer.val]);
+ },
+ 0x21 => {
+ const integer = leb128Decode(u32, frame.code[frame.program_counter..]);
+
+ frame.program_counter += integer.len;
+ frame.locals[integer.val] = self.stack.pop().?;
+ },
+ 0x22 => {
+ const integer = leb128Decode(u32, frame.code[frame.program_counter..]);
+
+ frame.program_counter += integer.len;
+ frame.locals[integer.val] = self.stack.pop().?;
+ try self.stack.append(Value{ .i32 = @intCast(integer.val) });
+ },
+ 0x28 => {
+ const address = leb128Decode(u32, frame.code[frame.program_counter..]);
+ frame.program_counter += address.len;
+ const offset = leb128Decode(u32, frame.code[frame.program_counter..]);
+ frame.program_counter += offset.len;
+ const start = (address.val + offset.val);
+ const end = start + @sizeOf(u32);
+ try self.stack.append(Value{ .i32 = decodeLittleEndian(i32, self.memory[start..end]) });
+ },
+ 0x29 => {
+ const address = leb128Decode(u32, frame.code[frame.program_counter..]);
+ frame.program_counter += address.len;
+ const offset = leb128Decode(u32, frame.code[frame.program_counter..]);
+ frame.program_counter += offset.len;
+ const start = (address.val + offset.val);
+ const end = start + @sizeOf(u64);
+ try self.stack.append(Value{ .i64 = decodeLittleEndian(i64, self.memory[start..end]) });
+ },
+ 0x36 => {
+ const address = leb128Decode(u32, frame.code[frame.program_counter..]);
+ frame.program_counter += address.len;
+ const offset = leb128Decode(u32, frame.code[frame.program_counter..]);
+ frame.program_counter += offset.len;
+ const start = (address.val + offset.val);
+ const end = start + @sizeOf(u32);
+ try self.stack.append(Value{ .i32 = decodeLittleEndian(i32, self.memory[start..end]) });
+ },
+ 0x37 => {
+ const address = leb128Decode(u32, frame.code[frame.program_counter..]);
+ frame.program_counter += address.len;
+ const offset = leb128Decode(u32, frame.code[frame.program_counter..]);
+ frame.program_counter += offset.len;
+ const start = (address.val + offset.val);
+ const end = start + @sizeOf(u32);
+ encodeLittleEndian(i32, @constCast(&self.memory[start..end]), self.stack.pop().?.i32);
+ },
+ 0x38 => {
+ const address = leb128Decode(u32, frame.code[frame.program_counter..]);
+ frame.program_counter += address.len;
+ const offset = leb128Decode(u32, frame.code[frame.program_counter..]);
+ frame.program_counter += offset.len;
+ const start = (address.val + offset.val);
+ const end = start + @sizeOf(u64);
+ encodeLittleEndian(i64, @constCast(&self.memory[start..end]), self.stack.pop().?.i64);
+ },
+ 0x41 => {
+ const integer = leb128Decode(i32, frame.code[frame.program_counter..]);
+
+ frame.program_counter += integer.len;
+ try self.stack.append(Value{ .i32 = integer.val });
+ },
+ 0x42 => {
+ const integer = leb128Decode(i64, frame.code[frame.program_counter..]);
+
+ frame.program_counter += integer.len;
+ try self.stack.append(Value{ .i64 = integer.val });
+ },
+ 0x45 => {
+ try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(self.stack.pop().?.i32 == 0))) });
+ },
+ 0x46 => {
+ try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(self.stack.pop().?.i32 == self.stack.pop().?.i32))) });
+ },
+ 0x47 => {
+ try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(self.stack.pop().?.i32 != self.stack.pop().?.i32))) });
+ },
+ 0x48 => {
+ try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(self.stack.pop().?.i32 < self.stack.pop().?.i32))) });
+ },
+ 0x49 => {
+ try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(@as(u32, @bitCast(self.stack.pop().?.i32)) < @as(u32, @bitCast(self.stack.pop().?.i32))))) });
+ },
+ 0x4a => {
+ try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(self.stack.pop().?.i32 > self.stack.pop().?.i32))) });
+ },
+ 0x4b => {
+ try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(@as(u32, @bitCast(self.stack.pop().?.i32)) > @as(u32, @bitCast(self.stack.pop().?.i32))))) });
+ },
+ 0x4c => {
+ try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(self.stack.pop().?.i32 <= self.stack.pop().?.i32))) });
+ },
+ 0x4d => {
+ try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(@as(u32, @bitCast(self.stack.pop().?.i32)) <= @as(u32, @bitCast(self.stack.pop().?.i32))))) });
+ },
+ 0x4e => {
+ try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(self.stack.pop().?.i32 >= self.stack.pop().?.i32))) });
+ },
+ 0x4f => {
+ try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(@as(u32, @bitCast(self.stack.pop().?.i32)) >= @as(u32, @bitCast(self.stack.pop().?.i32))))) });
+ },
+
+ 0x50 => {
+ try self.stack.append(Value{ .i64 = @intCast(@as(u1, @bitCast(self.stack.pop().?.i64 == 0))) });
+ },
+ 0x51 => {
+ try self.stack.append(Value{ .i64 = @intCast(@as(u1, @bitCast(self.stack.pop().?.i64 == self.stack.pop().?.i64))) });
+ },
+ 0x52 => {
+ try self.stack.append(Value{ .i64 = @intCast(@as(u1, @bitCast(self.stack.pop().?.i64 != self.stack.pop().?.i64))) });
+ },
+ 0x53 => {
+ try self.stack.append(Value{ .i64 = @intCast(@as(u1, @bitCast(self.stack.pop().?.i64 < self.stack.pop().?.i64))) });
+ },
+ 0x54 => {
+ try self.stack.append(Value{ .i64 = @intCast(@as(u1, @bitCast(@as(u64, @bitCast(self.stack.pop().?.i64)) < @as(u64, @bitCast(self.stack.pop().?.i64))))) });
+ },
+ 0x55 => {
+ try self.stack.append(Value{ .i64 = @intCast(@as(u1, @bitCast(self.stack.pop().?.i64 > self.stack.pop().?.i64))) });
+ },
+ 0x56 => {
+ try self.stack.append(Value{ .i64 = @intCast(@as(u1, @bitCast(@as(u64, @bitCast(self.stack.pop().?.i64)) > @as(u64, @bitCast(self.stack.pop().?.i64))))) });
+ },
+ 0x57 => {
+ try self.stack.append(Value{ .i64 = @intCast(@as(u1, @bitCast(self.stack.pop().?.i64 <= self.stack.pop().?.i64))) });
+ },
+ 0x58 => {
+ try self.stack.append(Value{ .i64 = @intCast(@as(u1, @bitCast(@as(u64, @bitCast(self.stack.pop().?.i64)) <= @as(u64, @bitCast(self.stack.pop().?.i64))))) });
+ },
+ 0x59 => {
+ try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(self.stack.pop().?.i64 >= self.stack.pop().?.i64))) });
+ },
+ 0x5a => {
+ try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(@as(u64, @bitCast(self.stack.pop().?.i64)) >= @as(u64, @bitCast(self.stack.pop().?.i64))))) });
+ },
+
+ 0x67 => {
+ var i = @as(i32, 0);
+ const number = self.stack.pop().?.i32;
+ for (0..@sizeOf(i32)) |b| {
+ if (number & (@as(i32, 0x1) << @intCast((@sizeOf(i32) - b - 1))) == 1) {
+ break;
+ }
+ i += 1;
+ }
+ try self.stack.append(Value{ .i32 = i });
+ },
+ 0x68 => {
+ var i = @as(i32, 0);
+ const number = self.stack.pop().?.i32;
+ for (0..@sizeOf(i32)) |b| {
+ if (number & (@as(i32, 0x1) << @intCast(b)) == 1) {
+ break;
+ }
+ i += 1;
+ }
+ try self.stack.append(Value{ .i32 = i });
+ },
+ 0x69 => {
+ var i = @as(i32, 0);
+ const number = self.stack.pop().?.i32;
+ for (0..@sizeOf(i32)) |b| {
+ if (number & (@as(i32, 0x1) << @intCast(b)) == 1) {
+ i += 1;
+ }
+ }
+ try self.stack.append(Value{ .i32 = i });
+ },
+ 0x6a => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i32 = a.i32 + b.i32 });
+ },
+ 0x6b => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i32 = a.i32 - b.i32 });
+ },
+ 0x6c => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i32 = a.i32 * b.i32 });
+ },
+ 0x6d => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i32 = @divTrunc(a.i32, b.i32) });
+ },
+ 0x6e => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i32 = @as(i32, @bitCast(@as(u32, @bitCast(a.i32)) / @as(u32, @bitCast(b.i32)))) });
+ },
+ 0x6f => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i32 = @rem(a.i32, b.i32) });
+ },
+ 0x70 => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i32 = @as(i32, @bitCast(@as(u32, @bitCast(a.i32)) % @as(u32, @bitCast(b.i32)))) });
+ },
+ 0x71 => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i32 = a.i32 & b.i32 });
+ },
+ 0x72 => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i32 = a.i32 | b.i32 });
+ },
+ 0x73 => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i32 = a.i32 ^ b.i32 });
+ },
+ 0x74 => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i32 = a.i32 << @intCast(b.i32) });
+ },
+ 0x75 => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i32 = a.i32 >> @intCast(b.i32) });
+ },
+ 0x76 => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i32 = @as(i32, @bitCast(@as(u32, @bitCast(a.i32)) >> @intCast(@as(u32, @bitCast(b.i32))))) });
+ },
+ 0x77 => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i32 = (a.i32 << @intCast(@as(u32, @bitCast(b.i32)))) | (a.i32 >> @intCast((@sizeOf(u32) * 8 - b.i32))) });
+ },
+ 0x78 => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i32 = (a.i32 >> @intCast(@as(u32, @bitCast(b.i32)))) | (a.i32 << @intCast((@sizeOf(u32) * 8 - b.i32))) });
+ },
+
+ 0x79 => {
+ var i = @as(i64, 0);
+ const number = self.stack.pop().?.i64;
+ for (0..@sizeOf(i64)) |b| {
+ if (number & (@as(i64, 0x1) << @intCast((@sizeOf(i64) - b - 1))) == 1) {
+ break;
+ }
+ i += 1;
+ }
+ try self.stack.append(Value{ .i64 = i });
+ },
+ 0x7a => {
+ var i = @as(i64, 0);
+ const number = self.stack.pop().?.i64;
+ for (0..@sizeOf(i64)) |b| {
+ if (number & (@as(i64, 0x1) << @intCast(b)) == 1) {
+ break;
+ }
+ i += 1;
+ }
+ try self.stack.append(Value{ .i64 = i });
+ },
+ 0x7b => {
+ var i = @as(i64, 0);
+ const number = self.stack.pop().?.i64;
+ for (0..@sizeOf(i64)) |b| {
+ if (number & (@as(i64, 0x1) << @intCast(b)) == 1) {
+ i += 1;
+ }
+ }
+ try self.stack.append(Value{ .i64 = i });
+ },
+ 0x7c => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i64 = a.i64 + b.i64 });
+ },
+ 0x7d => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i64 = a.i64 - b.i64 });
+ },
+ 0x7e => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i64 = a.i64 * b.i64 });
+ },
+ 0x7f => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i64 = @divTrunc(a.i64, b.i64) });
+ },
+ 0x80 => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i64 = @as(i64, @bitCast(@as(u64, @bitCast(a.i64)) / @as(u64, @bitCast(b.i64)))) });
+ },
+ 0x81 => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i64 = @rem(a.i64, b.i64) });
+ },
+ 0x82 => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i64 = @as(i64, @bitCast(@as(u64, @bitCast(a.i64)) % @as(u64, @bitCast(b.i64)))) });
+ },
+ 0x83 => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i64 = a.i64 & b.i64 });
+ },
+ 0x84 => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i64 = a.i64 | b.i64 });
+ },
+ 0x85 => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i64 = a.i64 ^ b.i64 });
+ },
+ 0x86 => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i64 = a.i64 << @intCast(b.i64) });
+ },
+ 0x87 => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i64 = a.i64 >> @intCast(b.i64) });
+ },
+ 0x88 => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i64 = @as(i64, @bitCast(@as(u64, @bitCast(a.i64)) >> @intCast(@as(u64, @bitCast(b.i64))))) });
+ },
+ 0x89 => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i64 = (a.i64 << @intCast(@as(u64, @bitCast(b.i64)))) | (a.i64 >> @intCast((@sizeOf(u64) * 8 - b.i64))) });
+ },
+ 0x8a => {
+ const a = self.stack.pop().?;
+ const b = self.stack.pop().?;
+ try self.stack.append(.{ .i64 = (a.i64 >> @intCast(@as(u64, @bitCast(b.i64)))) | (a.i64 << @intCast((@sizeOf(u64) * 8 - b.i64))) });
+ },
+
+ 0x10 => {
+ const integer = leb128Decode(u32, frame.code[frame.program_counter..]);
+ frame.program_counter += integer.len;
+
+ self.call(allocator, integer.val, &[_]usize{}) catch {};
+ },
+ 0xb => {
+ if (for_loop) {
+ frame.program_counter += 1;
+ } else {
+ break :loop;
+ }
+ },
+ else => std.debug.print("instruction {} not implemented\n", .{byte}),
+ }
+ }
+ }
+
+ pub fn callExternal(self: *Runtime, allocator: Allocator, name: []const u8, parameters: []usize) !void {
+ if (self.module.exports.get(name)) |function| {
+ try self.call(allocator, function, parameters);
+ }
+ }
+
+ pub fn call(self: *Runtime, allocator: Allocator, function: usize, parameters: []usize) AllocationError!void {
+ const f = self.module.funcs.items[function];
+ switch (f) {
+ .internal => {
+ const function_type = self.module.types[self.module.functions[f.internal]];
+ var frame = CallFrame{
+ .code = self.module.code[f.internal].code,
+ .program_counter = 0x0,
+ .locals = try allocator.alloc(Value, self.module.code[f.internal].locals.len + function_type.parameters.len),
+ };
+
+ for (parameters, 0..) |p, i| {
+ switch (Parser.parseType(function_type.parameters[i])) {
+ .i32 => {
+ frame.locals[i] = .{ .i32 = @intCast(p) };
+ },
+ .i64 => {
+ frame.locals[i] = .{ .i64 = @intCast(p) };
+ },
+ else => unreachable,
+ }
+ }
+
+ for (self.module.code[f.internal].locals, function_type.parameters.len..) |local, i| {
+ switch (Parser.parseType(local.types[0])) {
+ .i32 => {
+ frame.locals[i] = .{ .i32 = 0 };
+ },
+ .i64 => {
+ frame.locals[i] = .{ .i64 = 0 };
+ },
+ else => unreachable,
+ }
+ }
+
+ try self.executeFrame(allocator, &frame);
+
+ allocator.free(frame.locals);
+ },
+ .external => {
+ const name = self.module.imports.items[f.external].name;
+ if (self.global_runtime.functions.get(name)) |external| {
+ external(&self.stack);
+ }
+ },
+ }
+ }
+};
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-14 12:41:42 +0000