Commit c0685458a2

@@ -77,6 +77,7 @@ pub const testing = @import("testing.zig");
 pub const time = @import("time.zig");
 pub const unicode = @import("unicode.zig");
 pub const valgrind = @import("valgrind.zig");
+pub const wasm = @import("wasm.zig");
 pub const zig = @import("zig.zig");
 pub const start = @import("start.zig");
 

@@ -0,0 +1,266 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2015-2021 Zig Contributors
+// This file is part of [zig](https://ziglang.org/), which is MIT licensed.
+// The MIT license requires this copyright notice to be included in all copies
+// and substantial portions of the software.
+const testing = @import("std.zig").testing;
+
+/// Wasm instruction opcodes
+///
+/// All instructions are defined as per spec:
+/// https://webassembly.github.io/spec/core/appendix/index-instructions.html
+pub const Opcode = enum(u8) {
+    @"unreachable" = 0x00,
+    nop = 0x01,
+    block = 0x02,
+    loop = 0x03,
+    @"if" = 0x04,
+    @"else" = 0x05,
+    end = 0x0B,
+    br = 0x0C,
+    br_if = 0x0D,
+    br_table = 0x0E,
+    @"return" = 0x0F,
+    call = 0x10,
+    call_indirect = 0x11,
+    drop = 0x1A,
+    select = 0x1B,
+    local_get = 0x20,
+    local_set = 0x21,
+    local_tee = 0x22,
+    global_get = 0x23,
+    global_set = 0x24,
+    i32_load = 0x28,
+    i64_load = 0x29,
+    f32_load = 0x2A,
+    f64_load = 0x2B,
+    i32_load8_s = 0x2C,
+    i32_load8_u = 0x2D,
+    i32_load16_s = 0x2E,
+    i32_load16_u = 0x2F,
+    i64_load8_s = 0x30,
+    i64_load8_u = 0x31,
+    i64_load16_s = 0x32,
+    i64_load16_u = 0x33,
+    i64_load32_s = 0x34,
+    i64_load32_u = 0x35,
+    i32_store = 0x36,
+    i64_store = 0x37,
+    f32_store = 0x38,
+    f64_store = 0x39,
+    i32_store8 = 0x3A,
+    i32_store16 = 0x3B,
+    i64_store8 = 0x3C,
+    i64_store16 = 0x3D,
+    i64_store32 = 0x3E,
+    memory_size = 0x3F,
+    memory_grow = 0x40,
+    i32_const = 0x41,
+    i64_const = 0x42,
+    f32_const = 0x43,
+    f64_const = 0x44,
+    i32_eqz = 0x45,
+    i32_eq = 0x46,
+    i32_ne = 0x47,
+    i32_lt_s = 0x48,
+    i32_lt_u = 0x49,
+    i32_gt_s = 0x4A,
+    i32_gt_u = 0x4B,
+    i32_le_s = 0x4C,
+    i32_le_u = 0x4D,
+    i32_ge_s = 0x4E,
+    i32_ge_u = 0x4F,
+    i64_eqz = 0x50,
+    i64_eq = 0x51,
+    i64_ne = 0x52,
+    i64_lt_s = 0x53,
+    i64_lt_u = 0x54,
+    i64_gt_s = 0x55,
+    i64_gt_u = 0x56,
+    i64_le_s = 0x57,
+    i64_le_u = 0x58,
+    i64_ge_s = 0x59,
+    i64_ge_u = 0x5A,
+    f32_eq = 0x5B,
+    f32_ne = 0x5C,
+    f32_lt = 0x5D,
+    f32_gt = 0x5E,
+    f32_le = 0x5F,
+    f32_ge = 0x60,
+    f64_eq = 0x61,
+    f64_ne = 0x62,
+    f64_lt = 0x63,
+    f64_gt = 0x64,
+    f64_le = 0x65,
+    f64_ge = 0x66,
+    i32_clz = 0x67,
+    i32_ctz = 0x68,
+    i32_popcnt = 0x69,
+    i32_add = 0x6A,
+    i32_sub = 0x6B,
+    i32_mul = 0x6C,
+    i32_div_s = 0x6D,
+    i32_div_u = 0x6E,
+    i32_rem_s = 0x6F,
+    i32_rem_u = 0x70,
+    i32_and = 0x71,
+    i32_or = 0x72,
+    i32_xor = 0x73,
+    i32_shl = 0x74,
+    i32_shr_s = 0x75,
+    i32_shr_u = 0x76,
+    i32_rotl = 0x77,
+    i32_rotr = 0x78,
+    i64_clz = 0x79,
+    i64_ctz = 0x7A,
+    i64_popcnt = 0x7B,
+    i64_add = 0x7C,
+    i64_sub = 0x7D,
+    i64_mul = 0x7E,
+    i64_div_s = 0x7F,
+    i64_div_u = 0x80,
+    i64_rem_s = 0x81,
+    i64_rem_u = 0x82,
+    i64_and = 0x83,
+    i64_or = 0x84,
+    i64_xor = 0x85,
+    i64_shl = 0x86,
+    i64_shr_s = 0x87,
+    i64_shr_u = 0x88,
+    i64_rotl = 0x89,
+    i64_rotr = 0x8A,
+    f32_abs = 0x8B,
+    f32_neg = 0x8C,
+    f32_ceil = 0x8D,
+    f32_floor = 0x8E,
+    f32_trunc = 0x8F,
+    f32_nearest = 0x90,
+    f32_sqrt = 0x91,
+    f32_add = 0x92,
+    f32_sub = 0x93,
+    f32_mul = 0x94,
+    f32_div = 0x95,
+    f32_min = 0x96,
+    f32_max = 0x97,
+    f32_copysign = 0x98,
+    f64_abs = 0x99,
+    f64_neg = 0x9A,
+    f64_ceil = 0x9B,
+    f64_floor = 0x9C,
+    f64_trunc = 0x9D,
+    f64_nearest = 0x9E,
+    f64_sqrt = 0x9F,
+    f64_add = 0xA0,
+    f64_sub = 0xA1,
+    f64_mul = 0xA2,
+    f64_div = 0xA3,
+    f64_min = 0xA4,
+    f64_max = 0xA5,
+    f64_copysign = 0xA6,
+    i32_wrap_i64 = 0xA7,
+    i32_trunc_f32_s = 0xA8,
+    i32_trunc_f32_u = 0xA9,
+    i32_trunc_f64_s = 0xB0,
+    i32_trunc_f64_u = 0xB1,
+    f32_convert_i32_s = 0xB2,
+    f32_convert_i32_u = 0xB3,
+    f32_convert_i64_s = 0xB4,
+    f32_convert_i64_u = 0xB5,
+    f32_demote_f64 = 0xB6,
+    f64_convert_i32_s = 0xB7,
+    f64_convert_i32_u = 0xB8,
+    f64_convert_i64_s = 0xB9,
+    f64_convert_i64_u = 0xBA,
+    f64_promote_f32 = 0xBB,
+    i32_reinterpret_f32 = 0xBC,
+    i64_reinterpret_f64 = 0xBD,
+    f32_reinterpret_i32 = 0xBE,
+    i64_reinterpret_i64 = 0xBF,
+    i32_extend8_s = 0xC0,
+    i32_extend16_s = 0xC1,
+    i64_extend8_s = 0xC2,
+    i64_extend16_s = 0xC3,
+    i64_extend32_s = 0xC4,
+    _,
+};
+
+/// Returns the integer value of an `Opcode`. Used by the Zig compiler
+/// to write instructions to the wasm binary file
+pub fn opcode(op: Opcode) u8 {
+    return @enumToInt(op);
+}
+
+test "Wasm - opcodes" {
+    // Ensure our opcodes values remain intact as certain values are skipped due to them being reserved
+    const i32_const = opcode(.i32_const);
+    const end = opcode(.end);
+    const drop = opcode(.drop);
+    const local_get = opcode(.local_get);
+    const i64_extend32_s = opcode(.i64_extend32_s);
+
+    testing.expectEqual(@as(u16, 0x41), i32_const);
+    testing.expectEqual(@as(u16, 0x0B), end);
+    testing.expectEqual(@as(u16, 0x1A), drop);
+    testing.expectEqual(@as(u16, 0x20), local_get);
+    testing.expectEqual(@as(u16, 0xC4), i64_extend32_s);
+}
+
+/// Enum representing all Wasm value types as per spec:
+/// https://webassembly.github.io/spec/core/binary/types.html
+pub const Valtype = enum(u8) {
+    i32 = 0x7F,
+    i64 = 0x7E,
+    f32 = 0x7D,
+    f64 = 0x7C,
+};
+
+/// Returns the integer value of a `Valtype`
+pub fn valtype(value: Valtype) u8 {
+    return @enumToInt(value);
+}
+
+test "Wasm - valtypes" {
+    const _i32 = valtype(.i32);
+    const _i64 = valtype(.i64);
+    const _f32 = valtype(.f32);
+    const _f64 = valtype(.f64);
+
+    testing.expectEqual(@as(u8, 0x7F), _i32);
+    testing.expectEqual(@as(u8, 0x7E), _i64);
+    testing.expectEqual(@as(u8, 0x7D), _f32);
+    testing.expectEqual(@as(u8, 0x7C), _f64);
+}
+
+/// Wasm module sections as per spec:
+/// https://webassembly.github.io/spec/core/binary/modules.html
+pub const Section = enum(u8) {
+    custom,
+    type,
+    import,
+    function,
+    table,
+    memory,
+    global,
+    @"export",
+    start,
+    element,
+    code,
+    data,
+};
+
+/// Returns the integer value of a given `Section`
+pub fn section(val: Section) u8 {
+    return @enumToInt(val);
+}
+
+// types
+pub const element_type: u8 = 0x70;
+pub const function_type: u8 = 0x60;
+pub const result_type: u8 = 0x40;
+
+/// Represents a block which will not return a value
+pub const block_empty: u8 = 0x40;
+
+// binary constants
+pub const magic = [_]u8{ 0x00, 0x61, 0x73, 0x6D }; // \0asm
+pub const version = [_]u8{ 0x01, 0x00, 0x00, 0x00 }; // version 1

@@ -7,6 +7,7 @@ const assert = std.debug.assert;
 const fs = std.fs;
 const leb = std.leb;
 const log = std.log.scoped(.link);
+const wasm = std.wasm;
 
 const Module = @import("../Module.zig");
 const Compilation = @import("../Compilation.zig");
@@ -16,25 +17,6 @@ const trace = @import("../tracy.zig").trace;
 const build_options = @import("build_options");
 const Cache = @import("../Cache.zig");
 
-/// Various magic numbers defined by the wasm spec
-const spec = struct {
-    const magic = [_]u8{ 0x00, 0x61, 0x73, 0x6D }; // \0asm
-    const version = [_]u8{ 0x01, 0x00, 0x00, 0x00 }; // version 1
-
-    const custom_id = 0;
-    const types_id = 1;
-    const imports_id = 2;
-    const funcs_id = 3;
-    const tables_id = 4;
-    const memories_id = 5;
-    const globals_id = 6;
-    const exports_id = 7;
-    const start_id = 8;
-    const elements_id = 9;
-    const code_id = 10;
-    const data_id = 11;
-};
-
 pub const base_tag = link.File.Tag.wasm;
 
 pub const FnData = struct {
@@ -65,19 +47,19 @@ pub fn openPath(allocator: *Allocator, sub_path: []const u8, options: link.Optio
     const file = try options.emit.?.directory.handle.createFile(sub_path, .{ .truncate = true, .read = true });
     errdefer file.close();
 
-    const wasm = try createEmpty(allocator, options);
-    errdefer wasm.base.destroy();
+    const wasm_bin = try createEmpty(allocator, options);
+    errdefer wasm_bin.base.destroy();
 
-    wasm.base.file = file;
+    wasm_bin.base.file = file;
 
-    try file.writeAll(&(spec.magic ++ spec.version));
+    try file.writeAll(&(wasm.magic ++ wasm.version));
 
-    return wasm;
+    return wasm_bin;
 }
 
 pub fn createEmpty(gpa: *Allocator, options: link.Options) !*Wasm {
-    const wasm = try gpa.create(Wasm);
-    wasm.* = .{
+    const wasm_bin = try gpa.create(Wasm);
+    wasm_bin.* = .{
         .base = .{
             .tag = .wasm,
             .options = options,
@@ -85,7 +67,7 @@ pub fn createEmpty(gpa: *Allocator, options: link.Options) !*Wasm {
             .allocator = gpa,
         },
     };
-    return wasm;
+    return wasm_bin;
 }
 
 pub fn deinit(self: *Wasm) void {
@@ -176,8 +158,8 @@ pub fn flushModule(self: *Wasm, comp: *Compilation) !void {
     const header_size = 5 + 1;
 
     // No need to rewrite the magic/version header
-    try file.setEndPos(@sizeOf(@TypeOf(spec.magic ++ spec.version)));
-    try file.seekTo(@sizeOf(@TypeOf(spec.magic ++ spec.version)));
+    try file.setEndPos(@sizeOf(@TypeOf(wasm.magic ++ wasm.version)));
+    try file.seekTo(@sizeOf(@TypeOf(wasm.magic ++ wasm.version)));
 
     // Type section
     {
@@ -188,7 +170,7 @@ pub fn flushModule(self: *Wasm, comp: *Compilation) !void {
         try writeVecSectionHeader(
             file,
             header_offset,
-            spec.types_id,
+            .type,
             @intCast(u32, (try file.getPos()) - header_offset - header_size),
             @intCast(u32, self.funcs.items.len),
         );
@@ -202,7 +184,7 @@ pub fn flushModule(self: *Wasm, comp: *Compilation) !void {
         try writeVecSectionHeader(
             file,
             header_offset,
-            spec.funcs_id,
+            .function,
             @intCast(u32, (try file.getPos()) - header_offset - header_size),
             @intCast(u32, self.funcs.items.len),
         );
@@ -235,7 +217,7 @@ pub fn flushModule(self: *Wasm, comp: *Compilation) !void {
         try writeVecSectionHeader(
             file,
             header_offset,
-            spec.exports_id,
+            .@"export",
             @intCast(u32, (try file.getPos()) - header_offset - header_size),
             count,
         );
@@ -266,7 +248,7 @@ pub fn flushModule(self: *Wasm, comp: *Compilation) !void {
         try writeVecSectionHeader(
             file,
             header_offset,
-            spec.code_id,
+            .code,
             @intCast(u32, (try file.getPos()) - header_offset - header_size),
             @intCast(u32, self.funcs.items.len),
         );
@@ -549,9 +531,9 @@ fn reserveVecSectionHeader(file: fs.File) !u64 {
     return (try file.getPos()) - header_size;
 }
 
-fn writeVecSectionHeader(file: fs.File, offset: u64, section: u8, size: u32, items: u32) !void {
+fn writeVecSectionHeader(file: fs.File, offset: u64, section: wasm.Section, size: u32, items: u32) !void {
     var buf: [1 + 5 + 5]u8 = undefined;
-    buf[0] = section;
+    buf[0] = @enumToInt(section);
     leb.writeUnsignedFixed(5, buf[1..6], size);
     leb.writeUnsignedFixed(5, buf[6..], items);
     try file.pwriteAll(&buf, offset);