WIP: Port dmd and druntime to GNU/Hurd by yelninei · Pull Request #22829 · dlang/dmd

yelninei · 2026-03-27T16:06:24Z

Hi,

As announced on https://forum.dlang.org/thread/agrrykgbdsjlbsgjtatq@forum.dlang.org here is my WIP PR for porting druntime and dmd to GNU Hurd.

To be able to build also #22787 is needed.

Things that I know are still a bit of a mess:

Indentation
How to add version(linux) where CRuntime_Glibc is used to mean linux + glibc.
Mix of new and old alias syntax. Some of the parts were originally against gcc-11 to be able to bootrap and I have not revised the patches yet.

I am currently quite happy with the dmd part as all tests pass on 32bit and 64bit except

dmd/compiler/test/dshell/sameenv.d : checks that 2 executables have the same environment variables but they expectedly differ in LD_ORIGIN_PATH
dmd/compiler/test/runnable_cxx/cppa.d : A warning coming from non _GLIBCXX_USE_CXX98_ABI version

For the runtime some tests still crash in pthread_join, I am not entirely sure why as the same test outside of libdruntime_ut works fine.
On x86_64 the test runner gets killed after a while with the gc suspend signal, I dont know yet why the runtime does not handle it.

I am not erntirely sure about the format for the dmd triplet as it differs from both the gnu config and llvm triplet.

I have asked people on the bug-hurd mailing list for help as well
https://lists.gnu.org/archive/html/bug-hurd/2026-03/msg00274.html
https://lists.gnu.org/archive/html/bug-hurd/2026-03/msg00275.html

There are some more things needed to bring this back into gdc,

dlang-bot · 2026-03-27T16:06:27Z

Thanks for your pull request and interest in making D better, @yelninei! We are looking forward to reviewing it, and you should be hearing from a maintainer soon.
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New or modified functions have Ddoc comments (with Params: and Returns:)

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Bugzilla references

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Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "master + dmd#22829"

yelninei · 2026-03-27T16:58:45Z

The error from the circleci is

ERROR: Newly generated header file (/home/circleci/dmd/generated/linux/release/64/frontend.h) doesn't match with the reference header file (/home/circleci/dmd/compiler/src/dmd/frontend.h)

DETAILS:

diff --git a/home/circleci/dmd/compiler/src/dmd/frontend.h b/home/circleci/dmd/generated/linux/release/64/frontend.h
index 8e8e2fe76..479667814 100644
--- a/home/circleci/dmd/compiler/src/dmd/frontend.h
+++ b/home/circleci/dmd/generated/linux/release/64/frontend.h
@@ -7363,8 +7363,9 @@ struct Target final
         FreeBSD = 16u,
         Solaris = 32u,
         DragonFlyBSD = 64u,
-        all = 127u,
-        Posix = 125u,
+        Hurd = 128u,
+        all = 255u,
+        Posix = 253u,
     };
 
     OS os;

===============
The file `src/dmd/frontend.h` seems to be out of sync. This is likely because
changes were made which affect the C++ interface used by GDC and LDC.

I guess this is expected, is there a way to regenerate the header?

pbackus · 2026-03-27T17:30:42Z

Re: regenerating the headers, if you read a few more lines down in that error message, you will see this:

To read more about frontend.h and its usage, see src/README.md#cxx-headers-test

Which refers to https://github.com/dlang/dmd/tree/master/compiler/src#cxx-headers-test

ibuclaw · 2026-03-27T19:41:39Z

I am not erntirely sure about the format for the dmd triplet as it differs from both the gnu config and llvm triplet.

I thought dmd triplet (tuples?) matched ldc.

Historically, I guess gnu/hurd would be i*86-gnu or x86_64-gnu.

compiler/src/dmd/backend/arm/cod1.d

druntime/src/core/internal/elf/dl.d

druntime/src/core/internal/elf/io.d

druntime/src/core/stdc/config.d

druntime/src/core/sys/hurd/dlfcn.d

druntime/src/core/sys/hurd/elf.d

ibuclaw · 2026-03-27T20:00:19Z

druntime/src/core/sys/hurd/execinfo.d

+/**
+ * D header file for GNU Hurd
+ *
+ * Copyright: Copyright Martin Nowak 2012.


Wrong year, wrong copyright. :-)

If unsure, please use:

Copyright: Copyright (c) 2026 D Language Foundation

ibuclaw · 2026-03-27T20:01:46Z

druntime/src/core/sys/hurd/execinfo.d

+ *
+ * Copyright: Copyright Martin Nowak 2012.
+ * License:   $(LINK2 http://www.boost.org/LICENSE_1_0.txt, Boost License 1.0)
+ * Authors:   Martin Nowak


I assume Martin didn't author this module.

The file is a copy paste of the linux version with s/linux/hurd/

Is that enough to void the original copyright as it is clearly a derivative?

I'm not qualified to say. In isolation, I don't consider the file big enough to warrant any copyright claim.

Rather, the body of work as a whole (this PR) ought to be considered as authored by the contributor.

ibuclaw · 2026-03-27T20:06:39Z

druntime/src/core/sys/hurd/unistd.d

@@ -0,0 +1,25 @@
+module core.sys.hurd.unistd;


Some modules are missing comment headings/notices entirely. Others have inconsistent styles.

As these are newly introduced sources, I'd err towards not repeating previous bad habits, and pick one format, and use it consistently throughout all new files.

druntime/src/core/sys/linux/stdio.d

ibuclaw · 2026-03-27T20:19:48Z

druntime/src/core/sys/posix/sys/ioctl.d

 }
+else version (Hurd)
+{
+  // What is needed here?


Any part of ioctls.h or ioctl-types.h that would be needed to interact with ioctl().

druntime/src/core/sys/posix/sys/socket.d

druntime/src/core/sys/posix/pthread.d

druntime/src/rt/sections_elf_shared.d

druntime/src/core/time.d

ibuclaw · 2026-04-01T15:53:11Z

I have some patches for gdc-11 and gdc-14 that I currently use to get to dmd, but I have not kept them up to date as maintaining multiple variants of the same changes while it is still quite unstable is a bit to much work for me right now.

More than happy to commit them to a development branch under /users/ibuclaw/ in the gcc git repo.

yelninei · 2026-04-01T18:48:34Z

Fixed importc_compare on x86_64 which also fixes the testrunner getting killed by the gc suspend signal

yelninei · 2026-04-01T20:01:59Z

More than happy to commit them to a development branch under /users/ibuclaw/ in the gcc git repo.

If you want to take a look they are here: https://codeberg.org/Yelninei/dmd/src/branch/version-1.112/patches
they are definitly not ready and are based on an earlier version of the druntime port.
I have just been focusing on dmd as I can more easily run the unittests to find more issues.

Mostly the druntime change with minor gdc specific adjustments and then connecting things in configure and Makefile and regenerating them

yelninei · 2026-04-02T13:06:48Z

I think I found the reason for the crash.

looking at one backtrace I noticed that it started from src/rt/dmain2.d (rt_term) the runtime shutdown.

Through some divine intervention i then tried looking at my pthread_cleanup_push and pthread_cleanup_pop cases which is where I had to convert the c macros to D.

These come from glibc/sysdeps/htl/bits/cancelation.h and is very likely that I incorrectly ported these.

Making these do nothing it stops crashing.

To be continued.

ibuclaw · 2026-04-02T14:44:18Z

druntime/src/core/sys/hurd/sys/types.d

@@ -0,0 +1,52 @@
+module core.sys.hurd.sys.types;


I think this file should be removed, and inline all the values where needed. It just looks odd to have a module with public symbols all starting with __.

ibuclaw · 2026-04-02T14:45:17Z

druntime/src/core/sys/posix/pthread.d

+        PTHREAD_PROCESS_PRIVATE = __pthread_process_shared.__PTHREAD_PROCESS_PRIVATE,
+        PTHREAD_PROCESS_SHARED =  __pthread_process_shared.__PTHREAD_PROCESS_SHARED,


Suggested change

PTHREAD_PROCESS_PRIVATE = __pthread_process_shared.__PTHREAD_PROCESS_PRIVATE,

PTHREAD_PROCESS_SHARED = __pthread_process_shared.__PTHREAD_PROCESS_SHARED,

PTHREAD_PROCESS_PRIVATE = 0,

PTHREAD_PROCESS_SHARED,

ibuclaw · 2026-04-02T14:46:15Z

druntime/src/core/sys/posix/sys/types.d

+
+      struct pthread_condattr_t
+      {
+          __pthread_process_shared __pshared;


Suggested change

__pthread_process_shared __pshared;

int __pshared;

ibuclaw · 2026-04-02T14:46:42Z

druntime/src/core/sys/posix/sys/types.d

+
+      struct pthread_rwlockattr_t
+      {
+          __pthread_process_shared __pshared;


Suggested change

__pthread_process_shared __pshared;

int __pshared;

ibuclaw · 2026-04-02T14:46:53Z

druntime/src/core/sys/posix/sys/types.d

+
+      struct pthread_barrierattr_t
+      {
+          __pthread_process_shared __pshared;


Suggested change

__pthread_process_shared __pshared;

int __pshared;

ibuclaw · 2026-04-02T14:47:46Z

druntime/src/core/sys/posix/pthread.d

+        PTHREAD_EXPLICIT_SCHED = __pthread_inheritsched.__PTHREAD_EXPLICIT_SCHED,
+        PTHREAD_INHERIT_SCHED = __pthread_inheritsched.__PTHREAD_INHERIT_SCHED,


Suggested change

PTHREAD_EXPLICIT_SCHED = __pthread_inheritsched.__PTHREAD_EXPLICIT_SCHED,

PTHREAD_INHERIT_SCHED = __pthread_inheritsched.__PTHREAD_INHERIT_SCHED,

PTHREAD_EXPLICIT_SCHED = 0,

PTHREAD_INHERIT_SCHED,

ibuclaw · 2026-04-02T14:49:09Z

druntime/src/core/sys/posix/pthread.d

+        PTHREAD_CREATE_JOINABLE = __pthread_detachstate.__PTHREAD_CREATE_JOINABLE,
+        PTHREAD_CREATE_DETACHED = __pthread_detachstate.__PTHREAD_CREATE_DETACHED,


Suggested change

PTHREAD_CREATE_JOINABLE = __pthread_detachstate.__PTHREAD_CREATE_JOINABLE,

PTHREAD_CREATE_DETACHED = __pthread_detachstate.__PTHREAD_CREATE_DETACHED,

PTHREAD_CREATE_JOINABLE = 0,

PTHREAD_CREATE_DETACHED,

ibuclaw · 2026-04-02T14:49:50Z

druntime/src/core/sys/posix/pthread.d

+        enum PTHREAD_MUTEX_NORMAL       = __pthread_mutex_type.__PTHREAD_MUTEX_TIMED;
+        enum PTHREAD_MUTEX_ERRORCHECK   = __pthread_mutex_type.__PTHREAD_MUTEX_ERRORCHECK;
+        enum PTHREAD_MUTEX_RECURSIVE    = __pthread_mutex_type.__PTHREAD_MUTEX_RECURSIVE;


Suggested change

enum PTHREAD_MUTEX_NORMAL = __pthread_mutex_type.__PTHREAD_MUTEX_TIMED;

enum PTHREAD_MUTEX_ERRORCHECK = __pthread_mutex_type.__PTHREAD_MUTEX_ERRORCHECK;

enum PTHREAD_MUTEX_RECURSIVE = __pthread_mutex_type.__PTHREAD_MUTEX_RECURSIVE;

enum PTHREAD_MUTEX_NORMAL = 0;

enum PTHREAD_MUTEX_ERRORCHECK = 1;

enum PTHREAD_MUTEX_RECURSIVE = 2;

ibuclaw · 2026-04-02T14:50:32Z

druntime/src/core/sys/posix/sys/types.d

+          __pthread_mutex_protocol __protocol;
+          __pthread_process_shared __pshared;
+          __pthread_mutex_type __mutex_type;


Suggested change

__pthread_mutex_protocol __protocol;

__pthread_process_shared __pshared;

__pthread_mutex_type __mutex_type;

int __protocol;

int __pshared;

int __mutex_type;

ibuclaw · 2026-04-02T14:51:03Z

druntime/src/core/sys/posix/pthread.d

+      PTHREAD_PRIO_NONE =__pthread_mutex_protocol.__PTHREAD_PRIO_NONE,
+      PTHREAD_PRIO_INHERIT =__pthread_mutex_protocol.__PTHREAD_PRIO_INHERIT,
+      PTHREAD_PRIO_PROTECT =__pthread_mutex_protocol.__PTHREAD_PRIO_PROTECT,


Suggested change

PTHREAD_PRIO_NONE =__pthread_mutex_protocol.__PTHREAD_PRIO_NONE,

PTHREAD_PRIO_INHERIT =__pthread_mutex_protocol.__PTHREAD_PRIO_INHERIT,

PTHREAD_PRIO_PROTECT =__pthread_mutex_protocol.__PTHREAD_PRIO_PROTECT,

PTHREAD_PRIO_NONE = 0,

PTHREAD_PRIO_INHERIT,

PTHREAD_PRIO_PROTECT,

ibuclaw · 2026-04-02T14:52:32Z

druntime/src/core/sys/posix/sys/types.d

+      struct pthread_attr_t
+      {
+          __sched_param schedparam;


Suggested change

struct pthread_attr_t

{

__sched_param schedparam;

private struct __sched_param

{

int __sched_priority;

}

private struct __pthread;

struct pthread_attr_t

{

__sched_param schedparam;

druntime/src/core/sys/posix/pthread.d

yelninei · 2026-04-02T16:58:14Z

druntime/test/importc_compare/src/importc_compare.d

+    ErrorFilter("core.stdc.math.double_t", "", "Hurd", 0, ""),
+    ErrorFilter("core.stdc.math.float_t", "", "Hurd", 0, ""),
    ErrorFilter("core.stdc.signal.sig_atomic_t", "", "FreeBSD", 0, ""),
    ErrorFilter("core.stdc.stdio.FILE", "", "FreeBSD", 0, ""),
    ErrorFilter("core.stdc.stdio.FILE", "", "linux", 0, ""),
    ErrorFilter("core.stdc.stdio._IO_FILE", "", "linux", 0, ""),
+    ErrorFilter("core.stdc.stdio.FILE", "", "Hurd", 0, ""),
+    ErrorFilter("core.stdc.stdio._IO_FILE", "", "Hurd", 0, ""),


these failures are inherited from CRuntime_Glibc

yelninei · 2026-04-02T17:00:24Z

druntime/test/profile/myprofilegc.log.hurd.32.exp

@@ -0,0 +1,18 @@
+bytes allocated, allocations, type, function, file:line
+            128	              1	float profilegc.main src/profilegc.d:18


this is a copy pase of the linux/freebsd one as the the test fails if the file is not present.

having duplicate files for different oses seems a bit weird to me.

yelninei · 2026-04-02T17:10:21Z

The remaining test failures in druntime (phobos has some more, but i have not looked yet whether this is because of druntime or phobos)

core/thread/osthread : this fails because we hit stubs in libc failing with ENOSYS for pthread_setschedprio, sched_get_priority_max and sched_get_priority_min . Not that big of a deal for now.
druntime/test/shared: loadDR and host test segfault

all dmd compiler tests also pass.

ibuclaw · 2026-04-02T17:32:03Z

druntime/src/core/sys/posix/sys/ipc.d

+    version (X86)
+   {


Our old friend, indentation. :-)

ibuclaw · 2026-04-02T17:33:56Z

druntime/src/core/sys/posix/sys/ipc.d

+           ushort  __seq;
+       }
+   }
+    else


To be on the safe side, guard with (X86_64), then add

else static assert(false, "Unsupported platform");

Just in case someone decides to do aarch64-gnu or riscv-gnu.

Suggested change

else

else version (X86_64)

ibuclaw · 2026-04-02T17:36:50Z

druntime/src/core/sys/posix/sys/msg.d

+    struct msg;
+    struct __wait_queue;


Suggested change

struct msg;

struct __wait_queue;

private struct msg;

private struct __wait_queue;

No need to make these opaque types public.

I'd be almost inclined to actually use void* as the field type instead in the msqid_ds definition.

ibuclaw · 2026-04-02T17:37:11Z

druntime/src/core/sys/posix/sys/shm.d

+    else
+        alias ipc_pid_t = int;
+
+    struct __vm_area_struct;


Suggested change

struct __vm_area_struct;

private struct __vm_area_struct;

ibuclaw · 2026-04-02T17:39:01Z

druntime/src/core/sys/posix/sys/shm.d

+        ushort      __shm_npages;
+        c_ulong*    __shm_pages;
+        __vm_area_struct* __attaches;


Suggested change

ushort __shm_npages;

c_ulong* __shm_pages;

__vm_area_struct* __attaches;

private ushort __shm_npages;

private c_ulong* __shm_pages;

private __vm_area_struct* __attaches;

Fields not present in the POSIX standard should be private to the user.

https://pubs.opengroup.org/onlinepubs/007904875/basedefs/sys/shm.h.html

ibuclaw · 2026-04-02T17:42:51Z

druntime/src/core/sys/posix/semaphore.d

-      _pthread_fastlock __sem_lock;
-      int               __sem_value;
-      void*             __sem_waiting;
+        enum __SIZEOF_SEM_T = 20;


Suggested change

enum __SIZEOF_SEM_T = 20;

private enum __SIZEOF_SEM_T = 20;

ibuclaw · 2026-04-02T17:43:51Z

druntime/src/core/sys/posix/spawn.d

+        int __policy;
+        int[16] __pad;
+    }
+    struct __spawn_action;


Suggested change

struct __spawn_action;

private struct __spawn_action;

ibuclaw · 2026-04-02T18:09:46Z

druntime/src/core/sys/posix/signal.d

+    // This exists but always return 32
+    // private extern (C) nothrow @nogc
+    //   {
+    //     int __libc_current_sigrtmin();
+    //     int __libc_current_sigrtmax();
+    //   }
+
+    // @property int SIGRTMIN()() nothrow @nogc {
+    //   __gshared int sig = -1;
+    //   if (sig == -1) {
+    //  sig = __libc_current_sigrtmin();
+    //   }
+    //   return sig;
+    // }
+
+    // @property int SIGRTMAX()() nothrow @nogc {
+    //   __gshared int sig = -1;
+    //   if (sig == -1) {
+    //  sig = __libc_current_sigrtmax();
+    //   }
+    //   return sig;
+    // }


My guess is this should be identical to the version (linux) path? Or just don't include this at all - same as OpenBSD.

yes, but i think this is the gcc-11 version of the linux code.

this is how SIGRTMIN/SIGRTMAX are defined but currently SIGRTMIN == SIGRTMAX == 32 always so it is not useful.

This then caused problem for the gc as the default is using SIGRTMIN and SIGRTMIN + 1 for the suspend/resume signals which is an invalid signo.

I guess removing makes more sense and make it someone elses problem in the future.

ibuclaw · 2026-04-02T18:20:10Z

I think I've managed to get through the entire lot. Just the open comments to address.

ibuclaw · 2026-04-02T18:23:14Z

@yelninei oh - and thanks for this herculean effort, and the patience. 🙇

yelninei · 2026-04-02T18:47:27Z

I fixed struct flock which incorrectly uses int vs short on 32 bit.

This was pointed out on the bug-hurd thread.

The importc_compare test does not seem to catch this.

yelninei · 2026-04-02T18:48:40Z

@ibuclaw thanks a lot for the very helpful feedback and dealing with my mess of whitespace issues :)

Followup to 90772c4.

yelninei · 2026-04-03T20:39:44Z

i fixed a few things that were noticed by the probos tests. I went over all tests again to see if the failure is bercause of druntime:

std/file: rename(NULL, "") and remove(NULL) crash in libc
std/socket: lots of unimplemented things in libc, setsockopt with SO_RCVTIMEO, getpeername, ...
std/net/curl: A test timeouts after a while
core/thread/osthread and std/parallelism : The tests using pthread_setschedprio fail. Currently only the libc stub is availanble which always fails and raises warnings during linking.

druntime/test/shared: loadDR and host : fail somewhere in pthread .

A flaky std/process test but not sure about that.

The rest just works (with the linked minimal phobos patch).

There are some things that could be done i.e. faking priority on the D side as is already done for netbsd but Ill leave that to someone in the future.

This feels like a good place for the initial support to me and should make future updates and bugfixes a lot easier.

I hope I can address your comments soon.

yelninei force-pushed the dmd-hurd branch from e08d353 to 90c7a07 Compare March 27, 2026 16:10

yelninei mentioned this pull request Mar 27, 2026

WIP: phobos: Fixes for GNU/Hurd. dlang/phobos#10980

Draft

yelninei force-pushed the dmd-hurd branch from 90c7a07 to 0843c6b Compare March 27, 2026 17:55