- ghc-devs - Haskell.org

[ANNOUNCE] GHC 9.10.1-alpha3 is now available
by Ben Gamari 16 Apr '24

16 Apr '24

The GHC developers are very pleased to announce the availability of the third alpha release of GHC 9.10.1. Binary distributions, source distributions, and documentation are available at https://downloads.haskell.org/ghc/9.10.1-alpha3 We hope to have this release available via ghcup shortly. GHC 9.10 will bring a number of new features and improvements, including: * The introduction of the `GHC2024` language edition, building upon `GHC2021` with the addition of a number of widely-used extensions. * Partial implementation of the [GHC Proposal #281], allowing visible quantification to be used in the types of terms. * [Extension] of LinearTypes to allow linear `let` and `where` bindings ([linear let]) * The implementation of the [exception backtrace proposal], allowing the annotation of exceptions with backtraces, as well as other user-defined context * Further improvements in the info table provenance mechanism, reducing code size to allow IPE information to be enabled more widely * Javascript FFI support in the WebAssembly backend * Improvements in the fragmentation characteristics of the low-latency non-moving garbage collector. * ... and many more A full accounting of changes can be found in the [release notes]. As always, GHC's release status, including planned future releases, can be found on the GHC Wiki [status]. This alpha is the penultimate prerelease leading to 9.10.1. In two weeks we plan to publish a release candidate, followed, if all things go well, by the final release a week later. We would like to thank GitHub, IOG, the Zw3rk stake pool, Well-Typed, Tweag I/O, Serokell, Equinix, SimSpace, the Haskell Foundation, and other anonymous contributors whose on-going financial and in-kind support has facilitated GHC maintenance and release management over the years. Finally, this release would not have been possible without the hundreds of open-source contributors whose work comprise this release. As always, do give this release a try and open a [ticket] if you see anything amiss. Cheers, ~ Ben [release notes]: https://downloads.haskell.org/ghc/9.10.1-alpha3/docs/users_guide/9.10.1-not… [status]: https://gitlab.haskell.org/ghc/ghc/-/wikis/GHC-status [exception backtrace]: https://github.com/ghc-proposals/ghc-proposals/pull/330 [GHC Proposal #281]: https://github.com/ghc-proposals/ghc-proposals/pull/281 [linear let]: https://github.com/ghc-proposals/ghc-proposals/pull/624 [ticket]: https://gitlab.haskell.org/ghc/ghc/-/issues/new

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Request for approval of my GHC GitLab Account
by Hiroki Tokunaga 10 Apr '24

10 Apr '24

Dear GHC administrators, I am Hiroki Tokunaga, and I am interested in joining the development of GHC and other Haskell tools. For this, I would like to get your approval for my GitLab account (username: HirokiTokunaga). Thank you for reading this e-mail. I look forward to your response. Sincerely, Hiroki Tokunaga

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Request for Approval of GHC GitLab Account
by chenxi li 08 Apr '24

08 Apr '24

Dear GHC Administrators, My name is Chenxi Li and I am interested in contributing to the GHC project. I have read through the contributing guidelines and am looking forward to joining the GHC community. My GHC GitLab username is %2Aayanamists(a)gmail.com <ayanamists(a)gmail.com>*. Due to the platform's anti-spam policy, I require your approval to begin contributing. Thank you for your time and consideration. I look forward to your response. Best regards, Chenxi Li

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Missing dependencies
by Simon Peyton Jones 03 Apr '24

03 Apr '24

Friends My work has stalled because of https://gitlab.haskell.org/ghc/ghc/-/issues/24436 E.g. see https://gitlab.haskell.org/ghc/ghc/-/merge_requests/11492 which fails to build. Does anyone know a good workaround? Thanks! Simon

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GitLab Account Approval
by Matthew Wraith 31 Mar '24

31 Mar '24

Hi everyone, I’ve requested to join the gitlab instance with username wraithm Thanks!

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[ANNOUNCE] GHC 9.10.1-alpha2 is now available
by Ben Gamari 30 Mar '24

30 Mar '24

The GHC developers are very pleased to announce the availability of the second alpha release of GHC 9.10.1. Binary distributions, source distributions, and documentation are available at https://downloads.haskell.org/ghc/9.10.1-alpha2 We hope to have this release available via ghcup shortly. GHC 9.10 will bring a number of new features and improvements, including: * The introduction of the `GHC2024` language edition, building upon `GHC2021` with the addition of a number of widely-used extensions. * Partial implementation of the [GHC Proposal #281], allowing visible quantification to be used in the types of terms. * [Extension] of LinearTypes to allow linear `let` and `where` bindings ([linear let]) * The implementation of the [exception backtrace proposal], allowing the annotation of exceptions with backtraces, as well as other user-defined context * Further improvements in the info table provenance mechanism, reducing code size to allow IPE information to be enabled more widely * Javascript FFI support in the WebAssembly backend * Improvements in the fragmentation characteristics of the low-latency non-moving garbage collector. * ... and many more A full accounting of changes can be found in the [release notes]. As always, GHC's release status, including planned future releases, can be found on the GHC Wiki [status]. We would like to thank GitHub, IOG, the Zw3rk stake pool, Well-Typed, Tweag I/O, Serokell, Equinix, SimSpace, the Haskell Foundation, and other anonymous contributors whose on-going financial and in-kind support has facilitated GHC maintenance and release management over the years. Finally, this release would not have been possible without the hundreds of open-source contributors whose work comprise this release. As always, do give this release a try and open a [ticket] if you see anything amiss. [release notes]: https://downloads.haskell.org/ghc/9.10.1-alpha2/docs/users_guide/9.10.1-not… [status]: https://gitlab.haskell.org/ghc/ghc/-/wikis/GHC-status [exception backtrace]: https://github.com/ghc-proposals/ghc-proposals/pull/330 [GHC Proposal #281]: https://github.com/ghc-proposals/ghc-proposals/pull/281 [linear let]: https://github.com/ghc-proposals/ghc-proposals/pull/624 [ticket]: https://gitlab.haskell.org/ghc/ghc/-/issues/new

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GitLab planned outage
by Ben Gamari 26 Mar '24

26 Mar '24

Hi all, On Wednesday evening EST I will bring down gitlab.haskell.org for some scheduled maintenance. I expect that the outage will likely start at 19:00 EST and last for up to two hours. Cheers, - Ben

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GHC proposals not rendering
by Simon Peyton Jones 23 Mar '24

23 Mar '24

If you go to https://github.com/ghc-proposals/ghc-proposals/pull/448, and click on the "rendered" link, namely https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0448-t…, Github is now displaying the .rst source, not the rendered proposal. This has started happening (consistently across other proposals) today. Does anyone know why? How can I fix this? Simon

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GitLab account approval
by Vo Minh Thu 22 Mar '24

22 Mar '24

Hi, I've signed up with the username "noteed" on gitlab.haskell.org and would like to be approved. To give you an idea of what changes I'd like to see, and possibly already hear some feedback, here are some notes I had (all about GHCi): - Add a `:version` command. This would show either the same as `ghc --version`, or the (beginning of the) first output line of GHCi, which is "GHCi, version 9.11.20240322: https://www.haskell.org/ghc/ :? for help". This seems like a very simple addition, and could help me learn to hack GHC, and would make sense for the next point. - Have a flag to make GHCi not output the string "Loaded GHCi configuration from path/to/ghci.conf". This would let the `ghci.conf` file be in complete charge of what is displayed, instead of being necessarily followed by that string. I guess it would make sense to also hide the version string (see above). - Make it possible to start/stop and observe running threads. So maybe a `:threads` (or `:set threads`, `:show threads` ?) command. Those could be user-defined, or provided by GHCi. - Have GHCi watch files for changes (or be easily notified of changes) so it reloads them automatically (à la ghcid). I guess the main difference with ghcid is that after reloading the files, there is still an interactive prompt available (and running threads should be restarted (when using `:reload` too)). - One of the running thread, instead of being user-supplied, could be a builtin feature of GHCi: the ability to listen for commands, just like the regular interactive prompt. - Have GHCi be running as a background daemon, with no text interface beside a listening thread (or more than one). (This is related to https://gitlab.haskell.org/ghc/ghc/-/issues/15461.)

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Follow up: Modifying the "StgHeader" struct
by Adithya Kumar 18 Mar '24

18 Mar '24

Hey folks, I'm adding a field to "StgHeader" under a flag. ``` typedef struct { const StgInfoTable* info; #if defined(NEW_WAY) StgWord new_field; #endif #if defined(PROFILING) StgProfHeader prof; #endif } StgHeader; typedef struct { const StgInfoTable* info; #if defined(NEW_WAY) StgWord new_field; #endif #if defined(PROFILING) StgProfHeader prof; #endif StgSMPThunkHeader smp; } StgThunkHeader; ``` Follow-up changes: ================== The following are the additional changes I've made following the `PROFILING` flag: Similar to `PROF_HDR_FIELDS` macro, I've added `NEW_HDR_FIELDS` macro: ``` #if defined(NEW_WAY) #define NEW_HDR_FIELDS(w_,hdr) w_ hdr, #else #define NEW_HDR_FIELDS(w_,hdr) /* Nothing */ #endif ``` and updated the required stg code accordingly following the changes from `PROF_HDR_FIELDS`. I've also updated `GHC.Exts.Heap.ClosureTypes.closureTypeHeaderSize` accordingly. Error: ====== I'm greeted with the following error, ``` ASSERTION FAILED: file rts/StgStartup.cmm, line 100 ``` Basically, the following assert fails ``` #define CHECK_SENSIBLE_REGS() \ ASSERT(Hp != 0); \ ASSERT(HpAlloc == 0); \ ASSERT(Sp != 0); \ ASSERT(SpLim != 0); \ ASSERT(SpLim - WDS(RESERVED_STACK_WORDS) <= Sp); ``` More context for the error: =========================== Values for the correct version: ``` Hp 283468906488 HpAlloc 0 Sp 283468911440 SpLim 283468910784 SpLim - WDS(RESERVED_STACK_WORDS) 1069080 ``` Values with the changes: ``` Hp 283468906488 HpAlloc 0 Sp 7532120 SpLim 9301536 SpLim - WDS(RESERVED_STACK_WORDS) 9301368 ``` I recorded these values by calling a C print from the Cmm code. Clearly, my changes messed up a lot of things. How do I go about this now? The past 2 weeks I've only been looking at a lot of ghc code. If any more additional context is required I can provide it. Best, Adithya

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