-
26dbcf61
by fendor at 2025-08-30T05:10:08-04:00
Move stack decoding logic from ghc-heap to ghc-internal
The stack decoding logic in `ghc-heap` is more sophisticated than the one
currently employed in `CloneStack`. We want to use the stack decoding
implementation from `ghc-heap` in `base`.
We cannot simply depend on `ghc-heap` in `base` due do bootstrapping
issues.
Thus, we move the code that is necessary to implement stack decoding to
`ghc-internal`. This is the right location, as we don't want to add a
new API to `base`.
Moving the stack decoding logic and re-exposing it in ghc-heap is
insufficient, though, as we have a dependency cycle between.
* ghc-heap depends on stage1:ghc-internal
* stage0:ghc depends on stage0:ghc-heap
To fix this, we remove ghc-heap from the set of `stage0` dependencies.
This is not entirely straight-forward, as a couple of boot dependencies,
such as `ghci` depend on `ghc-heap`.
Luckily, the boot compiler of GHC is now >=9.10, so we can migrate `ghci`
to use `ghc-internal` instead of `ghc-heap`, which already exports the
relevant modules.
However, we cannot 100% remove ghc's dependency on `ghc-heap`, since
when we compile `stage0:ghc`, `stage1:ghc-internal` is not yet
available.
Thus, when we compile with the boot-compiler, we still depend on an
older version of `ghc-heap`, and only use the modules from `ghc-internal`,
if the `ghc-internal` version is recent enough.
-------------------------
Metric Increase:
T24602_perf_size
T25046_perf_size_gzip
T25046_perf_size_unicode
T25046_perf_size_unicode_gzip
size_hello_artifact
size_hello_artifact_gzip
size_hello_unicode
size_hello_unicode_gzip
-------------------------
These metric increases are unfortunate, they are most likely caused by
the larger (literally in terms of lines of code) stack decoder implementation
that are now linked into hello-word binaries.
On linux, it is almost a 10% increase, which is considerable.
-
bd80bb70
by fendor at 2025-08-30T05:10:08-04:00
Implement `decode` in terms of `decodeStackWithIpe`
Uses the more efficient stack decoder implementation.
-
24441165
by fendor at 2025-08-30T05:10:08-04:00
Remove stg_decodeStackzh
-
fb9cc882
by Simon Peyton Jones at 2025-08-30T05:10:51-04:00
Fix a long standing bug in the coercion optimiser
We were mis-optimising ForAllCo, leading to #26345
Part of the poblem was the tricky tower of abstractions leading to
the dreadful
GHC.Core.TyCo.Subst.substForAllCoTyVarBndrUsing
This function was serving two masters: regular substitution, but also
coercion optimsation. So tricky was it that it did so wrong.
In this MR I locate all the fancy footwork for coercion optimisation
in GHC.Core.Coercion.Opt, where it belongs. That leaves substitution
free to be much simpler.
-
3e5b9839
by Sylvain Henry at 2025-09-01T04:55:47-04:00
Driver: substitute virtual Prim module in --make mode too
When we build ghc-internal with --make (e.g. with cabal-install), we
need to be careful to substitute the virtual interface file for
GHC.Internal.Prim:
- after code generation (we generate code for an empty module, so we get
an empty interface)
- when we try to reload its .hi file
-
4c6c5795
by fendor at 2025-09-01T04:55:48-04:00
Expose Stack Annotation frames in IPE backtraces by default
When decoding the Haskell-native call stack and displaying the IPE information
for the stack frames, we print the `StackAnnotation` of the `AnnFrame` by default.
This means, when an exception is thrown, any intermediate stack annotations will
be displayed in the `IPE Backtrace`.
Example backtrace:
```
Exception: ghc-internal:GHC.Internal.Exception.ErrorCall:
Oh no!
IPE backtrace:
annotateCallStackIO, called at app/Main.hs:48:10 in backtrace-0.1.0.0-inplace-server:Main
annotateCallStackIO, called at app/Main.hs:46:13 in backtrace-0.1.0.0-inplace-server:Main
Main.handler (app/Main.hs:(46,1)-(49,30))
Main.liftIO (src/Servant/Server/Internal/Handler.hs:30:36-42)
Servant.Server.Internal.Delayed.runHandler' (src/Servant/Server/Internal/Handler.hs:27:31-41)
Control.Monad.Trans.Resource.runResourceT (./Control/Monad/Trans/Resource.hs:(192,14)-(197,18))
Network.Wai.Handler.Warp.HTTP1.processRequest (./Network/Wai/Handler/Warp/HTTP1.hs:195:20-22)
Network.Wai.Handler.Warp.HTTP1.processRequest (./Network/Wai/Handler/Warp/HTTP1.hs:(195,5)-(203,31))
Network.Wai.Handler.Warp.HTTP1.http1server.loop (./Network/Wai/Handler/Warp/HTTP1.hs:(141,9)-(157,42))
HasCallStack backtrace:
error, called at app/Main.hs:48:32 in backtrace-0.1.0.0-inplace-server:Main
```
The first two entries have been added by `annotateCallStackIO`, defined in `annotateCallStackIO`.