unreachable .addrspacecast in Builder.zig:castConstAssumeCapacity is reachable

[MasterQ32]

Zig Version

0.11.0

Steps to Reproduce and Observed Behavior

Observed behaviour: Compiler crash when compiling ZigEmbeddedGroup/microchip-atmega@081683a

Stack trace

thread 310581 panic: reached unreachable code
/home/felix/projects/forks/zig/src/codegen/llvm/Builder.zig:9038:21: 0x13622df in castConstAssumeCapacity (zig)
            else => unreachable,
                    ^
/home/felix/projects/forks/zig/src/codegen/llvm/Builder.zig:8996:40: 0x136249d in convConstAssumeCapacity (zig)
    return self.castConstAssumeCapacity(self.convTag(Constant.Tag, signedness, val_ty, ty), val, ty);
                                       ^
/home/felix/projects/forks/zig/src/codegen/llvm/Builder.zig:6992:40: 0xf79ce4 in convConst (zig)
    return self.convConstAssumeCapacity(signedness, val, ty);
                                       ^
/home/felix/projects/forks/zig/src/codegen/llvm.zig:4450:49: 0xf74619 in lowerDeclRefValue (zig)
        const llvm_val = try o.builder.convConst(
                                                ^
/home/felix/projects/forks/zig/src/codegen/llvm.zig:3858:60: 0xcfbdbc in lowerValue (zig)
                    .decl => |decl| try o.lowerDeclRefValue(ptr_ty, decl),
                                                           ^
/home/felix/projects/forks/zig/src/codegen/llvm.zig:4215:53: 0xd03337 in lowerValue (zig)
                    const payload = try o.lowerValue(un.val);
                                                    ^
/home/felix/projects/forks/zig/src/codegen/llvm.zig:4732:51: 0xcf5979 in genDecl (zig)
                const llvm_init = try o.lowerValue(init_val);
                                                  ^
/home/felix/projects/forks/zig/src/codegen/llvm.zig:1676:19: 0xd084d5 in updateDecl (zig)
        dg.genDecl() catch |err| switch (err) {
                  ^
/home/felix/projects/forks/zig/src/link/Elf.zig:2641:74: 0xd4ab35 in updateDecl (zig)
        if (self.llvm_object) |llvm_object| return llvm_object.updateDecl(mod, decl_index);
                                                                         ^
/home/felix/projects/forks/zig/src/link.zig:579:77: 0xaa0f77 in updateDecl (zig)
            .elf   => return @fieldParentPtr(Elf,   "base", base).updateDecl(module, decl_index),
                                                                            ^
/home/felix/projects/forks/zig/src/Module.zig:6284:29: 0xaa0b71 in linkerUpdateDecl (zig)
    comp.bin_file.updateDecl(mod, decl_index) catch |err| switch (err) {
                            ^
/home/felix/projects/forks/zig/src/Compilation.zig:3181:52: 0xc8fc27 in processOneJob (zig)
                        try module.linkerUpdateDecl(decl_index);
                                                   ^
/home/felix/projects/forks/zig/src/Compilation.zig:3134:30: 0xaeb81d in performAllTheWork (zig)
            try processOneJob(comp, work_item, main_progress_node);
                             ^
/home/felix/projects/forks/zig/src/Compilation.zig:2058:31: 0xae71f5 in update (zig)
    try comp.performAllTheWork(main_progress_node);
                              ^
/home/felix/projects/forks/zig/src/main.zig:4030:24: 0xb19d60 in updateModule (zig)
        try comp.update(main_progress_node);
                       ^
/home/felix/projects/forks/zig/src/main.zig:3451:17: 0xb3f7dd in buildOutputType (zig)
    updateModule(comp) catch |err| switch (err) {
                ^
/home/felix/projects/forks/zig/src/main.zig:270:31: 0x98cee2 in mainArgs (zig)
        return buildOutputType(gpa, arena, args, .{ .build = .Exe });
                              ^
/home/felix/projects/forks/zig/src/main.zig:214:20: 0x989b95 in main (zig)
    return mainArgs(gpa, arena, args);
                   ^
/home/felix/projects/forks/zig/lib/std/start.zig:574:37: 0x9894d2 in main (zig)
            const result = root.main() catch |err| {

GDB log

(gdb) bt
#0  0x00007fffeb0a1adc in __pthread_kill_implementation () from /nix/store/46m4xx889wlhsdj72j38fnlyyvvvvbyb-glibc-2.37-8/lib/libc.so.6
#1  0x00007fffeb052cb6 in raise () from /nix/store/46m4xx889wlhsdj72j38fnlyyvvvvbyb-glibc-2.37-8/lib/libc.so.6
#2  0x00007fffeb03c8ba in abort () from /nix/store/46m4xx889wlhsdj72j38fnlyyvvvvbyb-glibc-2.37-8/lib/libc.so.6
#3  0x0000000000bc6399 in os.abort () at /home/felix/projects/forks/zig/lib/std/os.zig:601
#4  0x00000000009bfa89 in crash_report.PanicSwitch.abort () at crash_report.zig:501
#5  0x0000000000bc635f in crash_report.PanicSwitch.goTo () at crash_report.zig:509
#6  crash_report.PanicSwitch.releaseRefCount (state=0x7ffff3f1b788) at crash_report.zig:483
#7  0x0000000000bc5e69 in crash_report.PanicSwitch.goTo () at crash_report.zig:509
#8  crash_report.PanicSwitch.releaseMutex (state=0x7ffff3f1b788) at crash_report.zig:455
#9  0x0000000000bc5f3e in crash_report.PanicSwitch.goTo () at crash_report.zig:509
#10 crash_report.PanicSwitch.reportStack (state=0x7ffff3f1b788) at crash_report.zig:437
#11 0x00000000009bf732 in crash_report.PanicSwitch.goTo () at crash_report.zig:509
#12 crash_report.PanicSwitch.goTo () at crash_report.zig:541
#13 crash_report.PanicSwitch.initPanic (state=, trace=, stack=..., msg=...) at crash_report.zig:533
#14 crash_report.PanicSwitch.initPanic (state=0x7ffff3f1b788, trace=0x0, stack=..., msg=...) at crash_report.zig:402
#15 0x000000000098a0f6 in crash_report.PanicSwitch.goTo () at crash_report.zig:509
#16 crash_report.PanicSwitch.dispatch (trace=0x0, stack_ctx=..., msg=...) at crash_report.zig:366
#17 0x0000000000989693 in crash_report.compilerPanic (msg=..., error_return_trace=0x0, maybe_ret_addr=...) at crash_report.zig:161
#18 0x00000000013622e0 in codegen.llvm.Builder.castConstAssumeCapacity (self=0x337cf50, tag=addrspacecast, val=(none | unknown: 0x4000000c), ty=53)
    at /home/felix/projects/forks/zig/src/codegen/llvm/Builder.zig:9038
#19 0x000000000136249e in codegen.llvm.Builder.convConstAssumeCapacity (self=0x337cf50, signedness=unneeded, val=(none | unknown: 0x4000000c), ty=53)
    at /home/felix/projects/forks/zig/src/codegen/llvm/Builder.zig:8996
#20 0x0000000000f79ce5 in codegen.llvm.Builder.convConst (self=0x337cf50, signedness=unneeded, val=(none | unknown: 0x4000000c), ty=53)
    at /home/felix/projects/forks/zig/src/codegen/llvm/Builder.zig:6992
#21 0x0000000000f7461a in codegen.llvm.Object.lowerDeclRefValue (o=0x337cf40, ty=..., decl_index=(unknown: 0x64d))
    at /home/felix/projects/forks/zig/src/codegen/llvm.zig:4450
#22 0x0000000000cfbdbd in codegen.llvm.Object.lowerValue (o=0x337cf40, arg_val=999) at /home/felix/projects/forks/zig/src/codegen/llvm.zig:3858
#23 0x0000000000d03338 in codegen.llvm.Object.lowerValue (o=0x337cf40, arg_val=1001) at /home/felix/projects/forks/zig/src/codegen/llvm.zig:4215
#24 0x0000000000cf597a in codegen.llvm.DeclGen.genDecl (dg=0x7ffffffebcc8) at /home/felix/projects/forks/zig/src/codegen/llvm.zig:4732
#25 0x0000000000d084d6 in codegen.llvm.Object.updateDecl (self=0x337cf40, module=0x337b240, decl_index=(unknown: 0x649))
    at /home/felix/projects/forks/zig/src/codegen/llvm.zig:1676
#26 0x0000000000d4ab36 in link.Elf.updateDecl (self=0x337c5b0, mod=0x337b240, decl_index=(unknown: 0x649)) at /home/felix/projects/forks/zig/src/link/Elf.zig:2641
#27 0x0000000000aa0f78 in link.File.updateDecl (base=0x337c5b0, module=0x337b240, decl_index=(unknown: 0x649)) at link.zig:579
#28 0x0000000000aa0b72 in Module.linkerUpdateDecl (mod=0x337b240, decl_index=(unknown: 0x649)) at Module.zig:6284
#29 0x0000000000c8fc28 in Compilation.processOneJob (comp=0x337a860, job=..., prog_node=0x7ffffffeed18) at Compilation.zig:3181
#30 0x0000000000aeb81e in Compilation.performAllTheWork (comp=0x337a860, main_progress_node=0x7ffffffeed18) at Compilation.zig:3134
#31 0x0000000000ae71f6 in Compilation.update (comp=0x337a860, main_progress_node=0x7ffffffeed18) at Compilation.zig:2058
#32 0x0000000000b19d61 in main.updateModule (comp=0x337a860) at main.zig:4030
#33 0x0000000000b3f7de in main.buildOutputType (gpa=..., arena=..., all_args=..., arg_mode=...) at main.zig:3451
#34 0x000000000098cee3 in main.mainArgs (gpa=..., arena=..., args=...) at main.zig:270
#35 0x0000000000989b96 in main.main () at main.zig:214
(gdb) selec t18
No symbol "t18" in current context.
(gdb) select 18
(gdb) info locals 
data = {cast = {val = (none | unknown: 0x4000000c), type = 53}, tag = addrspacecast}
gop = {key_ptr = 0xaaaaaaaaaaaaaaaa, value_ptr = 0xaaaaaaaaaaaaaaaa, index = 34, found_existing = false}

Expected Behavior

Code should compile (obviously) 👅

[Snektron]

This was already fixed in #16684