Commit e24f635c758242b9c8d8aacac668d31dead7623e | zig | Meg's Mirrors

author	Andrew Kelley <andrew@ziglang.org> 2024-12-06 23:50:30-08:00
committer	Andrew Kelley <andrew@ziglang.org> 2025-01-15 15:11:35-08:00
log	e24f635c758242b9c8d8aacac668d31dead7623e
tree	6c6261da339a1710f83290531d1ea5137e924b5e
parent	bffa14860078fe466e9f005dfc56869e195281b5

wasm: implement errors_len as a MIR opcode with no linker involvement

3 files changed, 16 insertions(+), 4 deletions(-)

src
- arch
  - wasm
    CodeGen.zig
    Emit.zig
    Mir.zig

src/arch/wasm/CodeGen.zig+2-4

...	...	@@ -3634,14 +3634,12 @@ fn airCmpVector(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
3634	3634	fn airCmpLtErrorsLen(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
3635	3635	const un_op = func.air.instructions.items(.data)[@intFromEnum(inst)].un_op;
3636	3636	const operand = try func.resolveInst(un_op);
3637		const sym_index = try func.wasm.getGlobalSymbol("__zig_errors_len", null);
3638		const errors_len: WValue = .{ .memory = @intFromEnum(sym_index) };
3639	3637
3640	3638	try func.emitWValue(operand);
3641	3639	const pt = func.pt;
3642	3640	const err_int_ty = try pt.errorIntType();
3643		const errors_len_val = try func.load(errors_len, err_int_ty, 0);
3644		const result = try func.cmp(.stack, errors_len_val, err_int_ty, .lt);
	3641	try func.addTag(.errors_len);
	3642	const result = try func.cmp(.stack, .stack, err_int_ty, .lt);
3645	3643
3646	3644	return func.finishAir(inst, result, &.{un_op});
3647	3645	}

src/arch/wasm/Emit.zig+10

...	...	@@ -70,6 +70,16 @@ pub fn lowerToCode(emit: *Emit) Error!void {
70	70	inst += 1;
71	71	continue :loop tags[inst];
72	72	},
	73	.errors_len => {
	74	try code.ensureUnusedCapacity(gpa, 6);
	75	code.appendAssumeCapacity(@intFromEnum(std.wasm.Opcode.i32_const));
	76	// MIR is lowered during flush, so there is indeed only one thread at this time.
	77	const errors_len = 1 + comp.zcu.?.intern_pool.global_error_set.getNamesFromMainThread().len;
	78	leb.writeIleb128(code.fixedWriter(), errors_len) catch unreachable;
	79
	80	inst += 1;
	81	continue :loop tags[inst];
	82	},
73	83	.br_if, .br, .memory_grow, .memory_size => {
74	84	try code.ensureUnusedCapacity(gpa, 11);
75	85	code.appendAssumeCapacity(@intFromEnum(tags[inst]));

src/arch/wasm/Mir.zig+4

...	...	@@ -84,6 +84,10 @@ pub const Inst = struct {
84	84	///
85	85	/// Uses `payload` of which the payload type is `DbgLineColumn`
86	86	dbg_line,
	87	/// Lowers to an i32_const containing the number of unique Zig error
	88	/// names.
	89	/// Uses `tag`.
	90	errors_len,
87	91	/// Represents the end of a function body or an initialization expression
88	92	///
89	93	/// Uses `tag` (no additional data).