stage2 regression in beginComptimePtrMutation

[slimsag]

This issue prevents us from building Mach's Entity Component System with the new self-hosted compiler. hexops/mach#180

Zig Version

0.10.0-dev.3891+6a62a15ec (aarch64-macos)

Steps to Reproduce

main.zig:

const std = @import("std");

fn NamespacedComponents(comptime modules: anytype) type {
    return @Type(.{
        .Struct = .{
            .layout = .Auto,
            .is_tuple = false,
            .fields = &.{.{
                .name = "components",
                .field_type = @TypeOf(modules.components),
                .default_value = null,
                .is_comptime = false,
                .alignment = @alignOf(@TypeOf(modules.components)),
            }},
            .decls = &[_]std.builtin.Type.Declaration{},
        },
    });
}

fn namespacedComponents(comptime modules: anytype) NamespacedComponents(modules) {
    var x: NamespacedComponents(modules) = undefined;
    x.components = modules.components;
    return x;
}

pub fn World(comptime modules: anytype) type {
    const all_components = namespacedComponents(modules);
    _ = all_components;
    return struct {};
}

pub fn main() !void {
    _ = World(.{
        .components = .{
            .location = struct {},
        },
    });
}

Expected Behavior

Program compiles

Actual Behavior

% zig build-exe main.zig
thread 603970 panic: reached unreachable code
/Users/slimsag/Desktop/zig/src/Sema.zig:24753:29: 0x1010b2127 in beginComptimePtrMutation (zig)
                    else => unreachable,
                            ^
/Users/slimsag/Desktop/zig/src/Sema.zig:24312:47: 0x1010af2d7 in storePtrVal (zig)
    var mut_kit = try beginComptimePtrMutation(sema, block, src, ptr_val, operand_ty);
                                              ^
/Users/slimsag/Desktop/zig/src/Sema.zig:24238:33: 0x100e6837b in storePtr2 (zig)
            try sema.storePtrVal(block, src, ptr_val, operand_val, elem_ty);
                                ^
/Users/slimsag/Desktop/zig/src/Sema.zig:4476:67: 0x1010995eb in zirStoreNode (zig)
    return sema.storePtr2(block, src, ptr, src, operand, src, if (is_ret) .ret_ptr else .store);
                                                                  ^
/Users/slimsag/Desktop/zig/src/Sema.zig:1049:38: 0x100e5e13f in analyzeBodyInner (zig)
                try sema.zirStoreNode(block, inst);
                                     ^
/Users/slimsag/Desktop/zig/src/Sema.zig:609:30: 0x100e5062f in analyzeBody (zig)
    _ = sema.analyzeBodyInner(block, body) catch |err| switch (err) {
                             ^
/Users/slimsag/Desktop/zig/src/Sema.zig:6057:33: 0x10128ff17 in analyzeCall (zig)
                sema.analyzeBody(&child_block, fn_info.body) catch |err| switch (err) {
                                ^
/Users/slimsag/Desktop/zig/src/Sema.zig:5595:28: 0x1010117e3 in zirCall (zig)
    return sema.analyzeCall(block, func, func_src, call_src, modifier, ensure_result_used, resolved_args, bound_arg_src);
                           ^
/Users/slimsag/Desktop/zig/src/Sema.zig:725:62: 0x100e51eab in analyzeBodyInner (zig)
            .call                         => try sema.zirCall(block, inst),
                                                             ^
/Users/slimsag/Desktop/zig/src/Sema.zig:609:30: 0x100e5062f in analyzeBody (zig)
    _ = sema.analyzeBodyInner(block, body) catch |err| switch (err) {
                             ^
/Users/slimsag/Desktop/zig/src/Sema.zig:6057:33: 0x10128ff17 in analyzeCall (zig)
                sema.analyzeBody(&child_block, fn_info.body) catch |err| switch (err) {
                                ^
/Users/slimsag/Desktop/zig/src/Sema.zig:5595:28: 0x1010117e3 in zirCall (zig)
    return sema.analyzeCall(block, func, func_src, call_src, modifier, ensure_result_used, resolved_args, bound_arg_src);
                           ^
/Users/slimsag/Desktop/zig/src/Sema.zig:725:62: 0x100e51eab in analyzeBodyInner (zig)
            .call                         => try sema.zirCall(block, inst),
                                                             ^
/Users/slimsag/Desktop/zig/src/Sema.zig:609:30: 0x100e5062f in analyzeBody (zig)
    _ = sema.analyzeBodyInner(block, body) catch |err| switch (err) {
                             ^
/Users/slimsag/Desktop/zig/src/Module.zig:5570:21: 0x100cb871b in analyzeFnBody (zig)
    sema.analyzeBody(&inner_block, fn_info.body) catch |err| switch (err) {
                    ^
/Users/slimsag/Desktop/zig/src/Module.zig:4271:40: 0x100aeee6f in ensureFuncBodyAnalyzed (zig)
            var air = mod.analyzeFnBody(func, sema_arena) catch |err| switch (err) {
                                       ^
/Users/slimsag/Desktop/zig/src/Compilation.zig:2976:42: 0x100aed5eb in processOneJob (zig)
            module.ensureFuncBodyAnalyzed(func) catch |err| switch (err) {
                                         ^
/Users/slimsag/Desktop/zig/src/Compilation.zig:2914:30: 0x100a0441f in performAllTheWork (zig)
            try processOneJob(comp, work_item);
                             ^
/Users/slimsag/Desktop/zig/src/Compilation.zig:2254:31: 0x100a01353 in update (zig)
    try comp.performAllTheWork(main_progress_node);
                              ^
/Users/slimsag/Desktop/zig/src/main.zig:3348:20: 0x100a27183 in updateModule (zig)
    try comp.update();
                   ^
/Users/slimsag/Desktop/zig/src/main.zig:3022:17: 0x1007f64ff in buildOutputType (zig)
    updateModule(gpa, comp, hook) catch |err| switch (err) {
                ^
/Users/slimsag/Desktop/zig/src/main.zig:230:31: 0x100784dff in mainArgs (zig)
        return buildOutputType(gpa, arena, args, .{ .build = .Exe });
                              ^
/Users/slimsag/Desktop/zig/src/stage1.zig:48:24: 0x100784547 in main (zig)
        stage2.mainArgs(gpa, arena, args) catch unreachable;
                       ^
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