-
58009c14
by Apoorv Ingle at 2026-04-02T09:51:24+01:00
Streamline expansions using HsExpansion (#25001)
Notes added [Error Context Stack] [Typechecking by expansion: overview]
Notes updated Note [Expanding HsDo with XXExprGhcRn] [tcApp: typechecking applications]
-------------------------
Metric Decrease:
T9020
-------------------------
There are 2 key changes:
1. `HsExpand` datatype mediates between expansions
2. Replace `ErrCtxtM` to a simpler `HsCtxt` that does not depend on a `TidyEnv`
This has some consequences detailed below:
1. `HsExpand` datatype mediates between expansions
* Simplifies the implementations of `tcExpr` to work on `XExpr`
* Removes `VACtxt` (and its associated `VAExpansion` and `VACall`) datatype, it is subsumed by simply a `SrcSpan`.
* Removes the function `addHeadCtxt` as it is now mearly setting a location
* The function `tcValArgs` does its own argument number management
* move `splitHsTypes` out of `tcApp`
* Removes special case of tcBody from `tcLambdaMatches`
* Removes special case of `dsExpr` for `ExpandedThingTc`
* Renames `tcMonoExpr` -> `tcMonoLExpr`, `tcMonoExprNC` -> `tcMonoLExpr`
* Renames `EValArg`, `EValArgQL` fields: `ea_ctxt` -> `ea_loc_span` and `eaql_ctx` -> `eaql_loc_span`
* Remove `PopErrCtxt` from `XXExprGhcRn`
* `fun_orig` in tcInstFun depends on the SrcSpan of the head of the application chain (similar to addArgCtxt)
- it references the application chain head if it is user located, or
uses the error context stack as a fallback if it's a generated
location
* Make a new variant `GeneratedSrcSpan` in `SrcSpan` for HIEAst Nodes
- Expressions wrapped around `GeneratedSrcSpan` are ignored and never added to the error context stack
- In Explicit list expansion `fromListN` is wrapped with a `GeneratedSrcSpan` with `GeneratedSrcSpanDetails` field to store the original srcspan
2. Replace `ErrCtxtM` to a simpler `HsCtxt` that does not depend on a `TidyEnv`
* Merge `HsThingRn` to `HsCtxt`
* Landmark Error messages are now just computed on the fly
* Make HsExpandedRn and HsExpandedTc payload a located HsExpr GhcRn
* `HsCtxt` are tidied and zonked at the end right before printing
Co-authored-by: simonpj <simon.peytonjones@gmail.com>
-
9d964ec9
by Zubin Duggal at 2026-04-02T16:15:51-04:00
driver: recognise .dyn_o as a valid object file to link if passed on the command line.
This allows plugins compiled with this suffix to run.
Fixes #24486
-
117f299b
by Simon Jakobi at 2026-04-02T16:15:54-04:00
Add regression test for #16145
Closes #16145.
-
87807fc2
by Matthew Pickering at 2026-04-02T16:15:55-04:00
bytecode: Add magic header/version to bytecode files
In order to avoid confusing errors when using stale interface files (ie
from an older compiler version), we add a simple header/version check
like the one for interface files.
Fixes #27068
-
2d653e6a
by fendor at 2026-04-02T16:15:55-04:00
Add constants for bytecode in-memory buffer size
Introduce a common constant for the default size of the .gbc and
.bytecodelib binary buffer.
The buffer is by default set to 1 MB.
-
e28fd7fc
by Duncan Coutts at 2026-04-02T16:15:56-04:00
Add a rts posix FdWakup utility module
This will be used to implement wakeupIOManager for in-RTS I/O managers.
It provides a notification/wakeup mechanism using FDs, suitable for
situations when a thread is blocked on a set of fds anyway. It uses the
classic self-pipe trick, or equivalently eventfd on supported platforms.
This will initially be used to implement prompt interrupt or shutdown of
the posix ticker thread.
-
85199690
by Duncan Coutts at 2026-04-02T16:15:56-04:00
Add prompt shutdown to the pthread ticker implementation.
The Linux timerfd ticker monitors a pipe which is used by exitTicker to
ensure a prompt wakeup and shutdown. The pthread ticker lacked this and
so would only exit at the next ticker wakeup (10ms by default).
This patch adds the same mechanism to the pthread ticker.
This changes the pthread ticker from waiting by using nanosleep() to
waiting using either ppoll() or select(), so that it can wait on both
a time and a file descriptor. On Linux at least, a test program to
compare the timing jitter of these APIs shows that using nanpsleep,
ppoll or select makes no statistical difference to the maximum or
average jitter.
This is a step towards unifying the posix ticker implementations, so
that we can have just one portable one (albeit with some limited cpp).
It is also a step towards using the ticker as part of a more general
implementation of wakeUpRts, since this will require a method to wake
the rts from a signal handler context (ctl-c handler).
-
bd6e5d21
by Duncan Coutts at 2026-04-02T16:15:56-04:00
Update ticker header commentary
It was antique and didn't apply even to the previous implementation, and
certainly not to the updated one.
-
4286c294
by Duncan Coutts at 2026-04-02T16:15:56-04:00
Remove the timerfd-based ticker implementation
There does not appear to be any remaining advantage on Linux to using
the timerfd ticker implementation over the portable one (using ppoll on
Linux for precise timing).
The eventfd implementation was originally added at a time when Linux was
still using a signal based implementation. So it made sense at the time.
See (closed) issue #10840.
-
6bf4326a
by Duncan Coutts at 2026-04-02T16:15:56-04:00
Consolidate to a single posix ticker implementation
Previously we had four implementations, two using signals and two using
threads. Having just one should make behaviour more consistent between
platforms, and should make maintenance easier.
-
93344577
by mangoiv at 2026-04-02T16:15:57-04:00
issue template: fix add bug label
-
5c57fa5f
by Sylvain Henry at 2026-04-02T16:16:28-04:00
Add more canned GC functions for common register patterns (#27142)
Based on analysis of heap-check sites across the GHC compiler and Cabal,
the following patterns were not covered by existing canned GC functions
but occurred frequently enough to warrant specialisation:
stg_gc_ppppp -- 5 GC pointers
stg_gc_ip -- unboxed word + GC pointer
stg_gc_pi -- GC pointer + unboxed word
stg_gc_ii -- two unboxed words
stg_gc_bpp -- byte (I8) + two GC pointers
Adding these reduces the fraction of heap-check sites falling back to
the generic GC path from ~1.4% to ~0.4% when compiling GHC itself.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>