- Jul 29, 2021
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Noticed build failures like ``` ghc-stage1: panic! (the 'impossible' happened) GHC version 9.3.20210721: pprCallishMachOp_for_C: MO_x64_Ne not supported! ``` on `--tagget=hppa2.0-unknown-linux-gnu`. The change does not fix all 32-bit unreg target problems, but at least allows linking final ghc binaries. Signed-off-by:Sergei Trofimovich <slyfox@gentoo.org>
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Previously `GHC.Types.Id.Make.newLocal` would name all locals `dt`, making it unnecessarily difficult to determine their origin. Noticed while looking at #19557.
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Running the test suite with asserts enabled is somewhat tricky at the moment as running it with a GHC compiled the DEBUG way has some hundred failures from the start. These seem to be unrelated to assertions though. So this provides a toggle to make it easier to debug failing assertions using the test suite.
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We have a couple of places where the conditions in asserts depend on code ifdefed out when DEBUG is off. I'd like to allow compiling assertions into non-DEBUG RTSen so that won't do. Currently if we remove the conditional around the definition of ASSERT() the build will not actually work due to a deadlock caused by initMutex not initializing mutexes with PTHREAD_MUTEX_ERRORCHECK because DEBUG is off.
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On big-endian systems a narrow after a load cannot be replaced with a narrow load.
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- Jul 28, 2021
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In order: * Introduce the `PsErrUnknownOptionsPragma` diagnostic message This commit changes the diagnostic emitted inside `GHC.Parser.Header.checkProcessArgsResult` from an (erroneous) and unstructured `DriverUnknownMessage` to a `PsErrUnknownOPtionsPragma`, i.e. a new data constructor of a `PsHeaderMessage`. * Add the `DriverUserDefinedRuleIgnored` diagnostic message * Add `DriverUserDefinedRuleIgnored` data constructor This commit adds (and use) a new data constructor to the `DriverMessage` type, replacing a `DriverUnknownMessage` with it. * Add and use `DriverCannotLoadInterfaceFile` constructor This commit introduces the DriverCannotLoadInterfaceFile constructor for the `DriverMessage` type and it uses it to replace and occurrence of `DriverUnknownMessage`. * Add and use the `DriverInferredSafeImport` constructor This commit adds a new `DriverInferredSafeImport` constructor to the `DriverMessage` type, and uses it in `GHC.Driver.Main` to replace one occurrence of `DriverUnknownMessage`. * Add and use `DriverCannotImportUnsafeModule` constructor This commit adds the `DriverCannotImportUnsafeModule` constructor to the `DriverMessage` type, and later using it to replace one usage of `DriverUnknownMessage` in the `GHC.Driver.Main` module. * Add and use `DriverMissingSafeHaskellMode` constructor * Add and use `DriverPackageNotTrusted` constructor * Introduce and use `DriverInferredSafeModule` constructor * Add and use `DriverMarkedTrustworthyButInferredSafe` constructor * Add and use `DriverCannotImportFromUntrustedPackage`
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In the call to prepareBinding (in simplLazyBind), I had failed to extend the in-scope set with the binders from body_floats1. As as result, when eta-expanding deep inside prepareBinding we made up an eta-binder that shadowed a variable free in body1. Yikes. It's hard to trigger this bug. It showed up when I was working on !5658, and I started using the in-scope set for eta-expansion, rather than taking free variables afresh. But even then it only showed up when compiling a module in Haddock utils/haddock/haddock-api/src/Haddock/Interface/Rename.hs Sadly Haddock is compiled without Core Lint, so we ultimately got a seg-fault. Lint nailed it fast once I realised that it was off. There is some other tiny refactoring in this patch.
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Eta expansion was taking ages on T18223. This patch * Aggressively squash reflexive casts in etaInfoApp. See Note [Check for reflexive casts in eta expansion] These changes decreased compile-time allocation by 80%! * Passes the Simplifier's in-scope set to etaExpandAT, so we don't need to recompute it. (This alone saved 10% of compile time.) Annoyingly several functions in the Simplifier (namely makeTrivialBinding and friends) need to get SimplEnv, rather than SimplMode, but that is no big deal. Lots of small changes in compile-time allocation, less than 1% and in both directions. A couple of bigger changes, including the rather delicate T18223 T12425(optasm) ghc/alloc 98448216.0 97121224.0 -1.3% GOOD T18223(normal) ghc/alloc 5454689676.0 1138238008.0 -79.1% GOOD Metric Decrease: T12425 T18223 -
Previously the eta-expansion would return lambdas interspersed with casts; now the cast is just pushed to the outside: #20153. This actually simplifies the code. I also improved mkNthCo to account for SymCo, so that mkNthCo n (SymCo (TyConAppCo tc cos)) would work well.
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When eyeballing calls of GHC.Core.Opt.Simplify.Monad.traceSmpl, I saw that lots of cold-path logging code was getting inlined into the main Simplifier module. So in GHC.Utils.Logger I added a NOINLINE on logDumpFile'. For logging, the "hot" path, up to and including the conditional, should be inlined, but after that we should inline as little as possible, to reduce code size in the caller.
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occAnalArgs and occAnalApp are very heavily used functions, so it pays to make them rather strict: fewer thunks constructed. All these thunks are ultimately evaluated anyway. This patch gives a welcome reduction compile time allocation of around 0.5% across the board. For T9961 it's a 2.2% reduction. Metric Decrease: T9961 -
No change in behaviour
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substExpr warns if it finds a LocalId that isn't in the in-scope set. This patch extends the in-scope set to silence the warnings. (It has no effect on behaviour.)
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See Note [Use occ-anald RHS in postInlineUnconditionally]. This explains how to eliminate an extra round of simplification, which can happen if postInlineUnconditionally uses a RHS that is no occurrence-analysed. This opportunity has been there for ages; I discovered it when looking at a compile-time perf regression that happened because the opportunity wasn't exploited.
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I noticed that smallEnoughToInline said "no" to UnfWhen guidance, which seems quite wrong -- those functions are particularly small.
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The make build system doesn't source config.mk when CLEANING=YES, consequently we previously failed to identify an appropriate adjustor implementation to use during cleaning. Fixes #20166.
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Hadrian uses the RTS ways to determine which iserv programs to embed into bindist. But profiled iserv program (and any other code) can't be built without profiling libs and Hadrian fails. So we disable the profiling RTS way with the no_profiled_libs flavour transformer.
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This is reverting a change introduced in linear types commit 40fa237e. Previously, we had to abort early, but thanks to later changes, this is no longer needed. There's no test, but the behavior should be better. The plan is to remove levity polymorphism checking in the desugarer anyway.
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The comment about 'parError' was obsolete.
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- Jul 27, 2021
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Ack. @monoidal
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Added :since: fields to users_guide on warning, for warnings introduced starting GHC 6.0. The data was extracted from the HTML docs on warnings, see ghc/ghc#18087 and partially verified by consulting the change logs.
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New warnings are only released in major versions, it seems. One way or the other, a .1 minor version can always be dropped.
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This patch addresses #20143, which wants to discard unused calls to unsafeEqualityProof. There are two parts: * In exprOkForSideEffects, we want to know that unsafeEqualityProof indeed terminates, without any exceptions etc * But we can only discard the case if we know that the coercion variable is not used, which means we have to gather accurate occurrence info for CoVars. Previously OccurAnal only did a half hearted job of doing so; this patch finishes the job. See Note [Gather occurrences of coercion variables] in OccurAnal. Because the occurrence analyser does more work, there is a small compile-time cost but it's pretty small. The compiler perf tests are usually 0.0% but occasionally up to 0.3% increase. I'm just going to accept this -- gathering accurate occurrence information really seems like the Right Thing to do. There is an increase in `compile_time/peak_megabytes_allocated`, for T11545, or around 14%; but I can't reproduce it on my machine (it's the same before and after), and the peak-usage stats are vulnerable to when exactly the GC takes place, so I'm just going to accept it. Metric Increase: T11545
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This patch fixes #20103, by treating HasCallStack constraints as cheap when eta-expanding. See Note [Eta expanding through CallStacks] in GHC.Core.Opt.Arity
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As #19918 pointed out, the CallStack mechanism didn't work well with RebindableSyntax. This patch improves matters. See GHC.Tc.Types.Evidence Note [Overview of implicit CallStacks] * New predicate isPushCallStackOrigin distinguishes when a CallStack constraint should be solved "directly" or by pushing an item on the stack. * The constructor EvCsPushCall now has a FastString, which can describe not only a function call site, but also things like "the literal 42" or "an if-then-else expression". * I also fixed #20126 thus: exprCtOrigin (HsIf {}) = IfThenElseOrigin (Previously it was "can't happen".)
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The package.cache needs to have a later mod-time than all of the .conf files. This invariant can be destroyed by `cp -r` and so we run `ghc-pkg recache` to ensure the package database which is distributed is consistent. If you are installing a relocatable bindist, for example, on windows, you should preserve mtimes by using cp -a or run ghc-pkg recache after installing.
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