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Basic "Hello world" working

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This commit is contained in:
Luuk de Gram
2021-03-27 23:26:20 +01:00
parent 9f744f19e7
commit 00b2e31589
2 changed files with 185 additions and 64 deletions
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128
src/codegen/wasm.zig
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@@ -163,25 +163,23 @@ fn buildOpcode(args: OpcodeBuildArguments) wasm.Opcode {
.global_get => return .global_get,
.global_set => return .global_set,
.load => if (args.width) |width|
switch (width) {
8 => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_load8_s else return .i32_load8_u,
.i64 => if (args.signedness.? == .signed) return .i64_load8_s else return .i64_load8_u,
.f32, .f64 => unreachable,
},
16 => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_load16_s else return .i32_load16_u,
.i64 => if (args.signedness.? == .signed) return .i64_load16_s else return .i64_load16_u,
.f32, .f64 => unreachable,
},
32 => switch (args.valtype1.?) {
.i64 => if (args.signedness.? == .signed) return .i64_load32_s else return .i64_load32_u,
.i32, .f32, .f64 => unreachable,
},
else => unreachable,
}
else switch (args.valtype1.?) {
.load => if (args.width) |width| switch (width) {
8 => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_load8_s else return .i32_load8_u,
.i64 => if (args.signedness.? == .signed) return .i64_load8_s else return .i64_load8_u,
.f32, .f64 => unreachable,
},
16 => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_load16_s else return .i32_load16_u,
.i64 => if (args.signedness.? == .signed) return .i64_load16_s else return .i64_load16_u,
.f32, .f64 => unreachable,
},
32 => switch (args.valtype1.?) {
.i64 => if (args.signedness.? == .signed) return .i64_load32_s else return .i64_load32_u,
.i32, .f32, .f64 => unreachable,
},
else => unreachable,
} else switch (args.valtype1.?) {
.i32 => return .i32_load,
.i64 => return .i64_load,
.f32 => return .f32_load,
@@ -469,6 +467,13 @@ test "Wasm - buildOpcode" {
testing.expectEqual(@as(wasm.Opcode, .f64_reinterpret_i64), f64_reinterpret_i64);
}
pub const Result = union(enum) {
/// The codegen bytes have been appended to `Context.code`
appended: void,
/// The data is managed externally and are part of the `Result`
externally_managed: []const u8,
};
/// Hashmap to store generated `WValue` for each `Inst`
pub const ValueTable = std.AutoHashMapUnmanaged(*Inst, WValue);
@@ -504,6 +509,8 @@ pub const Context = struct {
const InnerError = error{
OutOfMemory,
CodegenFail,
/// Can occur when dereferencing a pointer that points to a `Decl` of which the analysis has failed
AnalysisFail,
};
pub fn deinit(self: *Context) void {
@@ -604,48 +611,65 @@ pub const Context = struct {
}
/// Generates the wasm bytecode for the function declaration belonging to `Context`
pub fn gen(self: *Context) InnerError!void {
pub fn gen(self: *Context) InnerError!Result {
assert(self.code.items.len == 0);
try self.genFunctype();
// Write instructions
// TODO: check for and handle death of instructions
const tv = self.decl.typed_value.most_recent.typed_value;
const mod_fn = blk: {
if (tv.val.castTag(.function)) |func| break :blk func.data;
if (tv.val.castTag(.extern_fn)) |ext_fn| return; // don't need codegen for extern functions
return self.fail(.{ .node_offset = 0 }, "TODO: Wasm codegen for decl type '{s}'", .{tv.ty.tag()});
};
switch (tv.ty.zigTypeTag()) {
.Fn => {
try self.genFunctype();
// Reserve space to write the size after generating the code as well as space for locals count
try self.code.resize(10);
// Write instructions
// TODO: check for and handle death of instructions
const mod_fn = blk: {
if (tv.val.castTag(.function)) |func| break :blk func.data;
if (tv.val.castTag(.extern_fn)) |ext_fn| return Result.appended; // don't need code body for extern functions
return self.fail(.{ .node_offset = 0 }, "TODO: Wasm codegen for decl type '{s}'", .{tv.ty.tag()});
};
try self.genBody(mod_fn.body);
// Reserve space to write the size after generating the code as well as space for locals count
try self.code.resize(10);
// finally, write our local types at the 'offset' position
{
leb.writeUnsignedFixed(5, self.code.items[5..10], @intCast(u32, self.locals.items.len));
try self.genBody(mod_fn.body);
// offset into 'code' section where we will put our locals types
var local_offset: usize = 10;
// finally, write our local types at the 'offset' position
{
leb.writeUnsignedFixed(5, self.code.items[5..10], @intCast(u32, self.locals.items.len));
// emit the actual locals amount
for (self.locals.items) |local| {
var buf: [6]u8 = undefined;
leb.writeUnsignedFixed(5, buf[0..5], @as(u32, 1));
buf[5] = local;
try self.code.insertSlice(local_offset, &buf);
local_offset += 6;
}
// offset into 'code' section where we will put our locals types
var local_offset: usize = 10;
// emit the actual locals amount
for (self.locals.items) |local| {
var buf: [6]u8 = undefined;
leb.writeUnsignedFixed(5, buf[0..5], @as(u32, 1));
buf[5] = local;
try self.code.insertSlice(local_offset, &buf);
local_offset += 6;
}
}
const writer = self.code.writer();
try writer.writeByte(wasm.opcode(.end));
// Fill in the size of the generated code to the reserved space at the
// beginning of the buffer.
const size = self.code.items.len - 5 + self.decl.fn_link.wasm.?.idx_refs.items.len * 5;
leb.writeUnsignedFixed(5, self.code.items[0..5], @intCast(u32, size));
// codegen data has been appended to `code`
return Result.appended;
},
.Array => {
if (tv.val.castTag(.bytes)) |payload| {
if (tv.ty.sentinel()) |sentinel| {
// TODO, handle sentinel correctly
}
return Result{ .externally_managed = payload.data };
} else return self.fail(.{ .node_offset = 0 }, "TODO implement gen for more kinds of arrays", .{});
},
else => |tag| return self.fail(.{ .node_offset = 0 }, "TODO: Implement zig type codegen for type: '{s}'", .{tag}),
}
const writer = self.code.writer();
try writer.writeByte(wasm.opcode(.end));
// Fill in the size of the generated code to the reserved space at the
// beginning of the buffer.
const size = self.code.items.len - 5 + self.decl.fn_link.wasm.?.idx_refs.items.len * 5;
leb.writeUnsignedFixed(5, self.code.items[0..5], @intCast(u32, size));
}
fn genInst(self: *Context, inst: *Inst) InnerError!WValue {