- Jul 10, 2019
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The code, including the generated module with the version, is now in ghc-boot. Config.hs reexports stuff as needed, ghc-pkg doesn't need any tricks at all.
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These prevent multi-target builds. They were gotten rid of in 3 ways: 1. In the compiler itself, replacing `#if` with runtime `if`. In these cases, we care about the target platform still, but the target platform is dynamic so we must delay the elimination to run time. 2. In the compiler itself, replacing `TARGET` with `HOST`. There was just one bit of this, in some code splitting strings representing lists of paths. These paths are used by GHC itself, and not by the compiled binary. (They are compiler lookup paths, rather than RPATHS or something that does matter to the compiled binary, and thus would legitamentally be target-sensative.) As such, the path-splitting method only depends on where GHC runs and not where code it produces runs. This should have been `HOST` all along. 3. Changing the RTS. The RTS doesn't care about the target platform, full stop. 4. `includes/stg/HaskellMachRegs.h` This file is also included in the genapply executable. This is tricky because the RTS's host platform really is that utility's target platform. so that utility really really isn't multi-target either. But at least it isn't an installed part of GHC, but just a one-off tool when building the RTS. Lying with the `HOST` to a one-off program (genapply) that isn't installed doesn't seem so bad. It's certainly better than the other way around of lying to the RTS though not to genapply. The RTS is more important, and it is installed, *and* this header is installed as part of the RTS.
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If the union of dependencies of imported modules change, the `mi_deps` field of the interface files should change as well. Because of that, we need to check for changes in this in recompilation checker which we are not doing right now. This adds a checks for that.
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- Jul 09, 2019
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Ryan Scott authored
To avoid having to `panic` any time a TTG extension constructor is consumed, this MR introduces an uninhabited 'NoExtCon' type and uses that in every extension constructor's type family instance where it is appropriate. This also introduces a 'noExtCon' function which eliminates a 'NoExtCon', much like 'Data.Void.absurd' eliminates a 'Void'. I also renamed the existing `NoExt` type to `NoExtField` to better distinguish it from `NoExtCon`. Unsurprisingly, there is a lot of code churn resulting from this. Bumps the Haddock submodule. Fixes #15247.
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- Jul 08, 2019
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This is important as in hard link mode shake makes all such files read only to avoid accidentally modifying cache files via the hard link. It turns out, many Hadrian rules attempt read access to such files and hence fail in the hard link mode. These rules could be refactored to avoid write access, but using copy instead of hard link a much simpler solution.
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- Jul 05, 2019
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Attach the `SrcSpan` of the first pattern synonym binding involved in the recursive group when throwing the corresponding error message, similarly to how it is done for type synonyms. Fixes #16900.
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The relative URLs were a workaround to let most contributors fork from Github due to a weakness in the haskell.org server. This workaround is no longer needed. And relative submodule URLs are an impediment to forking which makes contributions harder than they should be. The URLs are chosen to clone from https, because this makes sure that anybody, even not a registered Gitlab user, can clone a fork recursively.
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Adds stripStgTicksTopE which only returns the stripped expression. So far we also allocated a list for the stripped ticks which was never used. Allocation difference is as expected very small but present. About 0.02% difference when compiling with -O.
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Ticket #16247 showed that we were discarding an implication constraint that had empty ic_wanted, when we still needed to keep it so we could check whether it had a bad telescope. Happily it's a one line fix. All the rest is comments!
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In dumpCensus we switch/case on doHeapProfile twice. The second switch tries to barf on unknown doHeapProfile modes but HEAP_BY_CLOSURE_TYPE is checked by the first switch and not included in the second. So when trying to pass -hT to the profiling rts it barfs. This commit simply merges the two switches into one which fixes this problem.
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In the eager unifier, when unifying (tv1 ~ tv2), when we decide to swap them over, to unify (tv2 ~ tv1), I'd forgotten to ensure that tv1's kind was fully zonked, which is an invariant of uUnfilledTyVar2. That could lead us to build an infinite kind, or (in the case of #16902) update the same unification variable twice. Yikes. Now we get an error message rather than non-termination, which is much better. The error message is not great, but it's a very strange program, and I can't see an easy way to improve it, so for now I'm just committing this fix. Here's the decl data F (a :: k) :: (a ~~ k) => Type where MkF :: F a and the rather error message of which I am not proud T16902.hs:11:10: error: • Expected a type, but found something with kind ‘a1’ • In the type ‘F a’ -
Before this refactoring: * DerivInfo for data family instances was returned from tcTyAndClassDecls * DerivInfo for data declarations was generated with mkDerivInfos and added at a later stage of the pipeline in tcInstDeclsDeriv After this refactoring: * DerivInfo for both data family instances and data declarations is returned from tcTyAndClassDecls in a single list. This uniform treatment results in a more convenient arrangement to fix #16731.
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- Jul 04, 2019
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Ben Gamari authored
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- Jul 03, 2019
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Commit cef80c0b debuted a breaking change to `template-haskell`, so in order to guard against it properly with CPP, we need to bump the `template-haskell` version number accordingly.
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Previously we used the deb9-debug job which used the `validate` build flavour which disabled `BUILD_SPHINX_PDF`. Fix this. Fixes #16890.
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This adds support for constructing vector types from Float#, Double# etc and performing arithmetic operations on them Cleaned-Up-By:Ben Gamari <ben@well-typed.com>
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- Jul 02, 2019
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As such the internal linker will fail for them. The alternative would be to implement them as stubs in the linker and have them barf when called. > Not all operations are supported by all target processors. If a particular operation cannot be implemented on the target processor, a warning is generated and a call an external function is generated. The external function carries the same name as the built-in version, with an additional suffix ‘_n’ where n is the size of the data type. (https://gcc.gnu.org/onlinedocs/gcc/_005f_005fsync-Builtins.html)
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This adds lookup logic for _GLOBAL_OFFSET_TABLE_ as well as relocation logic for R_ARM_BASE_PREL and R_ARM_GOT_BREL which the gnu toolchain (gas, gcc, ...) prefers to produce. Apparently recent llvm toolchains will produce those as well.
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- Jun 28, 2019
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Ben Gamari authored
I'm not entirely sure we are careful about ensuring this; this is a last-ditch check.
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Here the following changes are introduced: - A read barrier machine op is added to Cmm. - The order in which a closure's fields are read and written is changed. - Memory barriers are added to RTS code to ensure correctness on out-or-order machines with weak memory ordering. Cmm has a new CallishMachOp called MO_ReadBarrier. On weak memory machines, this is lowered to an instruction that ensures memory reads that occur after said instruction in program order are not performed before reads coming before said instruction in program order. On machines with strong memory ordering properties (e.g. X86, SPARC in TSO mode) no such instruction is necessary, so MO_ReadBarrier is simply erased. However, such an instruction is necessary on weakly ordered machines, e.g. ARM and PowerPC. Weam memory ordering has consequences for how closures are observed and mutated. For example, consider a closure that needs to be updated to an indirection. In order for the indirection to be safe for concurrent observers to enter, said observers must read the indirection's info table before they read the indirectee. Furthermore, the entering observer makes assumptions about the closure based on its info table contents, e.g. an INFO_TYPE of IND imples the closure has an indirectee pointer that is safe to follow. When a closure is updated with an indirection, both its info table and its indirectee must be written. With weak memory ordering, these two writes can be arbitrarily reordered, and perhaps even interleaved with other threads' reads and writes (in the absence of memory barrier instructions). Consider this example of a bad reordering: - An updater writes to a closure's info table (INFO_TYPE is now IND). - A concurrent observer branches upon reading the closure's INFO_TYPE as IND. - A concurrent observer reads the closure's indirectee and enters it. (!!!) - An updater writes the closure's indirectee. Here the update to the indirectee comes too late and the concurrent observer has jumped off into the abyss. Speculative execution can also cause us issues, consider: - An observer is about to case on a value in closure's info table. - The observer speculatively reads one or more of closure's fields. - An updater writes to closure's info table. - The observer takes a branch based on the new info table value, but with the old closure fields! - The updater writes to the closure's other fields, but its too late. Because of these effects, reads and writes to a closure's info table must be ordered carefully with respect to reads and writes to the closure's other fields, and memory barriers must be placed to ensure that reads and writes occur in program order. Specifically, updates to a closure must follow the following pattern: - Update the closure's (non-info table) fields. - Write barrier. - Update the closure's info table. Observing a closure's fields must follow the following pattern: - Read the closure's info pointer. - Read barrier. - Read the closure's (non-info table) fields. This patch updates RTS code to obey this pattern. This should fix long-standing SMP bugs on ARM (specifically newer aarch64 microarchitectures supporting out-of-order execution) and PowerPC. This fixes issue #15449. Co-Authored-By: -
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- Jun 27, 2019
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