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* Reorganisation of the source treeSimon Marlow2006-04-0711-5709/+0
| | | | | | | | | | | | | | | Most of the other users of the fptools build system have migrated to Cabal, and with the move to darcs we can now flatten the source tree without losing history, so here goes. The main change is that the ghc/ subdir is gone, and most of what it contained is now at the top level. The build system now makes no pretense at being multi-project, it is just the GHC build system. No doubt this will break many things, and there will be a period of instability while we fix the dependencies. A straightforward build should work, but I haven't yet fixed binary/source distributions. Changes to the Building Guide will follow, too.
* sanity checking: make sure we don't mix registerised and unreg'd codeSimon Marlow2006-03-161-5/+13
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* More work thrown at HscMain.Lemmih2006-03-071-12/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MkIface.writeIfaceFile doesn't check GhcMode anymore. All it does is what the name say: write an interface to disk. I've refactored HscMain so the logic is easier to manage. That means we can avoid running the simplifier when typechecking (: And best of all, HscMain doesn't use GhcMode at all, anymore! The new HscMain intro looks like this: It's the task of the compilation proper to compile Haskell, hs-boot and core files to either byte-code, hard-code (C, asm, Java, ect) or to nothing at all (the module is still parsed and type-checked. This feature is mostly used by IDE's and the likes). Compilation can happen in either 'one-shot', 'batch', 'nothing', or 'interactive' mode. 'One-shot' mode targets hard-code, 'batch' mode targets hard-code, 'nothing' mode targets nothing and 'interactive' mode targets byte-code. The modes are kept separate because of their different types and meanings. In 'one-shot' mode, we're only compiling a single file and can therefore discard the new ModIface and ModDetails. This is also the reason it only targets hard-code; compiling to byte-code or nothing doesn't make sense when we discard the result. 'Batch' mode is like 'one-shot' except that we keep the resulting ModIface and ModDetails. 'Batch' mode doesn't target byte-code since that require us to return the newly compiled byte-code. 'Nothing' mode has exactly the same type as 'batch' mode but they're still kept separate. This is because compiling to nothing is fairly special: We don't output any interface files, we don't run the simplifier and we don't generate any code. 'Interactive' mode is similar to 'batch' mode except that we return the compiled byte-code together with the ModIface and ModDetails.
* Why name a function 'getGhciMode' when it returns GhcMode?Lemmih2006-03-042-3/+3
| | | | | | I've changed the name to 'getGhcMode'. If someone changes it back, please write an explanation above it.
* replace several 'fromJust's with 'expectJust'sSimon Marlow2006-03-021-3/+3
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* Do type refinement in TcIfacesimonpj@microsoft.com2006-02-082-4/+23
| | | | | | | | | | | | | | | | | | | This commit fixes a bug in 6.4.1 and the HEAD. Consider this code, recorded **in an interface file** \(x::a) -> case y of MkT -> case x of { True -> ... } (where MkT forces a=Bool) In the "case x" we need to know x's type, because we use that to find which module to look for "True" in. x's type comes from the envt, so we must refine the envt. The alternative would be to record more info with an IfaceCase, but that would change the interface file format. (This stuff will go away when we have proper coercions.)
* Simon's big boxy-type commitsimonpj@microsoft.com2006-01-253-22/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This very large commit adds impredicativity to GHC, plus numerous other small things. *** WARNING: I have compiled all the libraries, and *** a stage-2 compiler, and everything seems *** fine. But don't grab this patch if you *** can't tolerate a hiccup if something is *** broken. The big picture is this: a) GHC handles impredicative polymorphism, as described in the "Boxy types: type inference for higher-rank types and impredicativity" paper b) GHC handles GADTs in the new simplified (and very sligtly less epxrssive) way described in the "Simple unification-based type inference for GADTs" paper But there are lots of smaller changes, and since it was pre-Darcs they are not individually recorded. Some things to watch out for: c) The story on lexically-scoped type variables has changed, as per my email. I append the story below for completeness, but I am still not happy with it, and it may change again. In particular, the new story does not allow a pattern-bound scoped type variable to be wobbly, so (\(x::[a]) -> ...) is usually rejected. This is more restrictive than before, and we might loosen up again. d) A consequence of adding impredicativity is that GHC is a bit less gung ho about converting automatically between (ty1 -> forall a. ty2) and (forall a. ty1 -> ty2) In particular, you may need to eta-expand some functions to make typechecking work again. Furthermore, functions are now invariant in their argument types, rather than being contravariant. Again, the main consequence is that you may occasionally need to eta-expand function arguments when using higher-rank polymorphism. Please test, and let me know of any hiccups Scoped type variables in GHC ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ January 2006 0) Terminology. A *pattern binding* is of the form pat = rhs A *function binding* is of the form f pat1 .. patn = rhs A binding of the formm var = rhs is treated as a (degenerate) *function binding*. A *declaration type signature* is a separate type signature for a let-bound or where-bound variable: f :: Int -> Int A *pattern type signature* is a signature in a pattern: \(x::a) -> x f (x::a) = x A *result type signature* is a signature on the result of a function definition: f :: forall a. [a] -> a head (x:xs) :: a = x The form x :: a = rhs is treated as a (degnerate) function binding with a result type signature, not as a pattern binding. 1) The main invariants: A) A lexically-scoped type variable always names a (rigid) type variable (not an arbitrary type). THIS IS A CHANGE. Previously, a scoped type variable named an arbitrary *type*. B) A type signature always describes a rigid type (since its free (scoped) type variables name rigid type variables). This is also a change, a consequence of (A). C) Distinct lexically-scoped type variables name distinct rigid type variables. This choice is open; 2) Scoping 2(a) If a declaration type signature has an explicit forall, those type variables are brought into scope in the right hand side of the corresponding binding (plus, for function bindings, the patterns on the LHS). f :: forall a. a -> [a] f (x::a) = [x :: a, x] Both occurences of 'a' in the second line are bound by the 'forall a' in the first line A declaration type signature *without* an explicit top-level forall is implicitly quantified over all the type variables that are mentioned in the type but not already in scope. GHC's current rule is that this implicit quantification does *not* bring into scope any new scoped type variables. f :: a -> a f x = ...('a' is not in scope here)... This gives compatibility with Haskell 98 2(b) A pattern type signature implicitly brings into scope any type variables mentioned in the type that are not already into scope. These are called *pattern-bound type variables*. g :: a -> a -> [a] g (x::a) (y::a) = [y :: a, x] The pattern type signature (x::a) brings 'a' into scope. The 'a' in the pattern (y::a) is bound, as is the occurrence on the RHS. A pattern type siganture is the only way you can bring existentials into scope. data T where MkT :: forall a. a -> (a->Int) -> T f x = case x of MkT (x::a) f -> f (x::a) 2a) QUESTION class C a where op :: forall b. b->a->a instance C (T p q) where op = <rhs> Clearly p,q are in scope in <rhs>, but is 'b'? Not at the moment. Nor can you add a type signature for op in the instance decl. You'd have to say this: instance C (T p q) where op = let op' :: forall b. ... op' = <rhs> in op' 3) A pattern-bound type variable is allowed only if the pattern's expected type is rigid. Otherwise we don't know exactly *which* skolem the scoped type variable should be bound to, and that means we can't do GADT refinement. This is invariant (A), and it is a big change from the current situation. f (x::a) = x -- NO; pattern type is wobbly g1 :: b -> b g1 (x::b) = x -- YES, because the pattern type is rigid g2 :: b -> b g2 (x::c) = x -- YES, same reason h :: forall b. b -> b h (x::b) = x -- YES, but the inner b is bound k :: forall b. b -> b k (x::c) = x -- NO, it can't be both b and c 3a) You cannot give different names for the same type variable in the same scope (Invariant (C)): f1 :: p -> p -> p -- NO; because 'a' and 'b' would be f1 (x::a) (y::b) = (x::a) -- bound to the same type variable f2 :: p -> p -> p -- OK; 'a' is bound to the type variable f2 (x::a) (y::a) = (x::a) -- over which f2 is quantified -- NB: 'p' is not lexically scoped f3 :: forall p. p -> p -> p -- NO: 'p' is now scoped, and is bound to f3 (x::a) (y::a) = (x::a) -- to the same type varialble as 'a' f4 :: forall p. p -> p -> p -- OK: 'p' is now scoped, and its occurences f4 (x::p) (y::p) = (x::p) -- in the patterns are bound by the forall 3b) You can give a different name to the same type variable in different disjoint scopes, just as you can (if you want) give diferent names to the same value parameter g :: a -> Bool -> Maybe a g (x::p) True = Just x :: Maybe p g (y::q) False = Nothing :: Maybe q 3c) Scoped type variables respect alpha renaming. For example, function f2 from (3a) above could also be written: f2' :: p -> p -> p f2' (x::b) (y::b) = x::b where the scoped type variable is called 'b' instead of 'a'. 4) Result type signatures obey the same rules as pattern types signatures. In particular, they can bind a type variable only if the result type is rigid f x :: a = x -- NO g :: b -> b g x :: b = x -- YES; binds b in rhs 5) A *pattern type signature* in a *pattern binding* cannot bind a scoped type variable (x::a, y) = ... -- Legal only if 'a' is already in scope Reason: in type checking, the "expected type" of the LHS pattern is always wobbly, so we can't bind a rigid type variable. (The exception would be for an existential type variable, but existentials are not allowed in pattern bindings either.) Even this is illegal f :: forall a. a -> a f x = let ((y::b)::a, z) = ... in Here it looks as if 'b' might get a rigid binding; but you can't bind it to the same skolem as a. 6) Explicitly-forall'd type variables in the *declaration type signature(s)* for a *pattern binding* do not scope AT ALL. x :: forall a. a->a -- NO; the forall a does Just (x::a->a) = Just id -- not scope at all y :: forall a. a->a Just y = Just (id :: a->a) -- NO; same reason THIS IS A CHANGE, but one I bet that very few people will notice. Here's why: strange :: forall b. (b->b,b->b) strange = (id,id) x1 :: forall a. a->a y1 :: forall b. b->b (x1,y1) = strange This is legal Haskell 98 (modulo the forall). If both 'a' and 'b' both scoped over the RHS, they'd get unified and so cannot stand for distinct type variables. One could *imagine* allowing this: x2 :: forall a. a->a y2 :: forall a. a->a (x2,y2) = strange using the very same type variable 'a' in both signatures, so that a single 'a' scopes over the RHS. That seems defensible, but odd, because though there are two type signatures, they introduce just *one* scoped type variable, a. 7) Possible extension. We might consider allowing \(x :: [ _ ]) -> <expr> where "_" is a wild card, to mean "x has type list of something", without naming the something.
* [project @ 2006-01-06 16:30:17 by simonmar]simonmar2006-01-062-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support for UTF-8 source files GHC finally has support for full Unicode in source files. Source files are now assumed to be UTF-8 encoded, and the full range of Unicode characters can be used, with classifications recognised using the implementation from Data.Char. This incedentally means that only the stage2 compiler will recognise Unicode in source files, because I was too lazy to port the unicode classifier code into libcompat. Additionally, the following synonyms for keywords are now recognised: forall symbol (U+2200) forall right arrow (U+2192) -> left arrow (U+2190) <- horizontal ellipsis (U+22EF) .. there are probably more things we could add here. This will break some source files if Latin-1 characters are being used. In most cases this should result in a UTF-8 decoding error. Later on if we want to support more encodings (perhaps with a pragma to specify the encoding), I plan to do it by recoding into UTF-8 before parsing. Internally, there were some pretty big changes: - FastStrings are now stored in UTF-8 - Z-encoding has been moved right to the back end. Previously we used to Z-encode every identifier on the way in for simplicity, and only decode when we needed to show something to the user. Instead, we now keep every string in its UTF-8 encoding, and Z-encode right before printing it out. To avoid Z-encoding the same string multiple times, the Z-encoding is cached inside the FastString the first time it is requested. This speeds up the compiler - I've measured some definite improvement in parsing at least, and I expect compilations overall to be faster too. It also cleans up a lot of cruft from the OccName interface. Z-encoding is nicely hidden inside the Outputable instance for Names & OccNames now. - StringBuffers are UTF-8 too, and are now represented as ForeignPtrs. - I've put together some test cases, not by any means exhaustive, but there are some interesting UTF-8 decoding error cases that aren't obvious. Also, take a look at unicode001.hs for a demo.
* [project @ 2005-11-16 12:55:58 by simonpj]simonpj2005-11-164-30/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Two significant changes to the representation of types 1. Change the representation of type synonyms Up to now, type synonym applications have been held in *both* expanded *and* un-expanded form. Unfortunately, this has exponential (!) behaviour when type synonyms are deeply nested. E.g. type P a b = (a,b) f :: P a (P b (P c (P d e))) This showed up in a program of Joel Reymont, now immortalised as typecheck/should_compile/syn-perf.hs So now synonyms are held as ordinary TyConApps, and expanded only on demand. SynNote has disappeared altogether, so the only remaining TyNote is a FTVNote. I'm not sure if it's even useful. 2. Eta-reduce newtypes See the Note [Newtype eta] in TyCon.lhs If we have newtype T a b = MkT (S a b) then, in Core land, we would like S = T, even though the application of T is then not saturated. This commit eta-reduces T's RHS, and keeps that inside the TyCon (in nt_etad_rhs). Result is that coreEqType can be simpler, and has less need of expanding newtypes.
* [project @ 2005-11-02 17:39:57 by simonpj]simonpj2005-11-021-1/+1
| | | | Trace output only
* [project @ 2005-10-14 11:22:41 by simonpj]simonpj2005-10-142-22/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add record syntax for GADTs ~~~~~~~~~~~~~~~~~~~~~~~~~~~ Atrijus Tang wanted to add record syntax for GADTs and existential types, so he and I worked on it a bit at ICFP. This commit is the result. Now you can say data T a where T1 { x :: a } :: T [a] T2 { x :: a, y :: Int } :: T [a] forall b. Show b => T3 { naughty :: b, ok :: Int } :: T Int T4 :: Eq a => a -> b -> T (a,b) Here the constructors are declared using record syntax. Still to come after this commit: - User manual documentation - More regression tests - Some missing cases in the parser (e.g. T3 won't parse) Autrijus is going to do these. Here's a quick summary of the rules. (Atrijus is going to write proper documentation shortly.) Defnition: a 'vanilla' constructor has a type of the form forall a1..an. t1 -> ... -> tm -> T a1 ... an No existentials, no context, nothing. A constructor declared with Haskell-98 syntax is vanilla by construction. A constructor declared with GADT-style syntax is vanilla iff its type looks like the above. (In the latter case, the order of the type variables does not matter.) * You can mix record syntax and non-record syntax in a single decl * All constructors that share a common field 'x' must have the same result type (T [a] in the example). * You can use field names without restriction in record construction and record pattern matching. * Record *update* only works for data types that only have 'vanilla' constructors. * Consider the field 'naughty', which uses a type variable that does not appear in the result type ('b' in the example). You can use the field 'naughty' in pattern matching and construction, but NO SELECTOR function is generated for 'naughty'. [An attempt to use 'naughty' as a selector function will elicit a helpful error message.] * Data types declared in GADT syntax cannot have a context. So this is illegal: data (Monad m) => T a where .... * Constructors in GADT syntax can have a context (t.g. T3, T4 above) and that context is stored in the constructor and made available when the constructor is pattern-matched on. WARNING: not competely implemented yet, but that's the plan. Implementation notes ~~~~~~~~~~~~~~~~~~~~ - Data constructors (even vanilla ones) no longer share the type variables of their parent type constructor. - HsDecls.ConDecl has changed quite a bit - TyCons don't record the field labels and type any more (doesn't make sense for existential fields) - GlobalIdDetails records which selectors are 'naughty', and hence don't have real code.
* [project @ 2005-08-18 10:02:54 by simonpj]simonpj2005-08-181-1/+1
| | | | | | | | | | | | | | | Make the forkM failure fail more tidily. Interface-file inconsistencies give rise to failures in the IfM monad. An error message is printed, but up to now we've also said "The impossible happened, must be a GHC bug". That's not true, though, it could just be messed up interface files. So this commit still makes the compiler halt, but in a tidier, less self-accusatory way. Still to come: when original names in interface files mention the package Id too, the error will become clearer still. MERGE to STABLE
* [project @ 2005-08-09 16:58:39 by simonpj]simonpj2005-08-091-3/+9
| | | | Wibble to loadHomeInterface for TH quoting; MERGE to STABLE
* [project @ 2005-07-25 11:42:24 by simonpj]simonpj2005-07-251-2/+2
| | | | Comments
* [project @ 2005-07-22 14:00:34 by simonpj]simonpj2005-07-221-9/+7
| | | | | | | | | | | | | | | | | MERGE TO STABLE Fix a long-standing bug in dependency tracking. If you have import M( x ) then you must recompile if M's export list changes, because it might no longer export x. Until now we have only done that if the import was import M I can't think why this bug has lasted so long. Thanks to Ian Lynagh for pointing it out.
* [project @ 2005-07-19 16:44:50 by simonpj]simonpj2005-07-193-15/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | WARNING: this is a big commit. You might want to wait a few days before updating, in case I've broken something. However, if any of the changes are what you wanted, please check it out and test! This commit does three main things: 1. A re-organisation of the way that GHC handles bindings in HsSyn. This has been a bit of a mess for quite a while. The key new types are -- Bindings for a let or where clause data HsLocalBinds id = HsValBinds (HsValBinds id) | HsIPBinds (HsIPBinds id) | EmptyLocalBinds -- Value bindings (not implicit parameters) data HsValBinds id = ValBindsIn -- Before typechecking (LHsBinds id) [LSig id] -- Not dependency analysed -- Recursive by default | ValBindsOut -- After typechecking [(RecFlag, LHsBinds id)]-- Dependency analysed 2. Implement Mark Jones's idea of increasing polymoprhism by using type signatures to cut the strongly-connected components of a recursive group. As a consequence, GHC no longer insists on the contexts of the type signatures of a recursive group being identical. This drove a significant change: the renamer no longer does dependency analysis. Instead, it attaches a free-variable set to each binding, so that the type checker can do the dep anal. Reason: the typechecker needs to do *two* analyses: one to find the true mutually-recursive groups (which we need so we can build the right CoreSyn) one to find the groups in which to typecheck, taking account of type signatures 3. Implement non-ground SPECIALISE pragmas, as promised, and as requested by Remi and Ross. Certainly, this should fix the current problem with GHC, namely that if you have g :: Eq a => a -> b -> b then you can now specialise thus SPECIALISE g :: Int -> b -> b (This didn't use to work.) However, it goes further than that. For example: f :: (Eq a, Ix b) => a -> b -> b then you can make a partial specialisation SPECIALISE f :: (Eq a) => a -> Int -> Int In principle, you can specialise f to *any* type that is "less polymorphic" (in the sense of subsumption) than f's actual type. Such as SPECIALISE f :: Eq a => [a] -> Int -> Int But I haven't tested that. I implemented this by doing the specialisation in the typechecker and desugarer, rather than leaving around the strange SpecPragmaIds, for the specialiser to find. Indeed, SpecPragmaIds have vanished altogether (hooray). Pragmas in general are handled more tidily. There's a new data type HsBinds.Prag, which lives in an AbsBinds, and carries pragma info from the typechecker to the desugarer. Smaller things - The loop in the renamer goes via RnExpr, instead of RnSource. (That makes it more like the type checker.) - I fixed the thing that was causing 'check_tc' warnings to be emitted.
* [project @ 2005-06-21 10:44:37 by simonmar]simonmar2005-06-211-9/+11
| | | | | | | | | | | | | | | | | | | | | | | Relax the restrictions on conflicting packages. This should address many of the traps that people have been falling into with the current package story. Now, a local module can shadow a module in an exposed package, as long as the package is not otherwise required by the program. GHC checks for conflicts when it knows the dependencies of the module being compiled. Also, we now check for module conflicts in exposed packages only when importing a module: if an import can be satisfied from multiple packages, that's an error. It's not possible to prevent GHC from starting by installing packages now (unless you install another base package). It seems to be possible to confuse GHCi by having a local module shadowing a package module that goes away and comes back again. I think it's nearly right, but strange happenings have been observed. I'll try to merge this into the STABLE branch.
* [project @ 2005-05-24 14:18:34 by simonmar]simonmar2005-05-241-3/+5
| | | | Don't write the interface in JustTypecheck mode
* [project @ 2005-05-19 11:15:40 by simonpj]simonpj2005-05-192-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Tune up the reporting of unused imports Merge to STABLE (I think the earlier change made it across) (PS: the commit also does some trimming of redundant imports. If they don't merge, just discard them.) My earlier fixes to the reporting of unused imports still missed some obscure cases, some of which are now fixed by this commit. I had to make the import-provenance data type yet richer, but in fact it has more sharing now, so it may be cheaper on space. There's still one infelicity. Consider import M( x ) imoprt N( x ) where the same underlying 'x' is involved in both cases. Currently we don't report a redundant import, because dropping either import would change the qualified names in scope (M.x, N.x). But if the qualified names aren't used, the import is indeed redundant. Sadly we don't know that, because we only know what Names are used. Left for the future! There's a comment in RnNames.warnDuplicateImports This commit also trims quite a few redundant imports disovered by the new setup.
* [project @ 2005-05-16 12:38:38 by simonpj]simonpj2005-05-161-3/+5
| | | | | | | | | | | Newtype representation Merge to STABLE This commit fixes a long-standing bug (simple clerical error) in mkNewTyConRep, which for some reason had gone un-discovered for years. tc183 tests it.
* [project @ 2005-05-05 12:39:19 by simonpj]simonpj2005-05-051-2/+11
| | | | Only compare hi-boot iface with mother module if there *is* an hi-boot iface
* [project @ 2005-05-04 15:46:39 by simonmar]simonmar2005-05-041-9/+25
| | | | Fix instance-matching issue (affects nofib/real/prolog).
* [project @ 2005-05-02 13:08:38 by simonpj]simonpj2005-05-021-2/+2
| | | | | | | | In the :i command for ghci, load the interface files for the home module of every in-scope type or class. That way we are sure to see all their instance declarations. MERGE TO STABLE branch
* [project @ 2005-04-28 23:09:24 by simonpj]simonpj2005-04-281-1/+5
| | | | A couple of hs-boot files
* [project @ 2005-04-28 16:05:54 by simonpj]simonpj2005-04-281-8/+10
| | | | | | | | | Re-plumb the connections between TidyPgm and the various code generators. There's a new type, CgGuts, to mediate this, which has the happy effect that ModGuts can die earlier. The non-O route still isn't quite right, because default methods are being lost. I'm working on it.
* [project @ 2005-04-28 13:13:27 by simonpj]simonpj2005-04-282-25/+32
| | | | Instance for wired-in tycons wibble
* [project @ 2005-04-28 10:09:41 by simonpj]simonpj2005-04-289-665/+372
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This big commit does several things at once (aeroplane hacking) which change the format of interface files. So you'll need to recompile your libraries! 1. The "stupid theta" of a newtype declaration ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Retain the "stupid theta" in a newtype declaration. For some reason this was being discarded, and putting it back in meant changing TyCon and IfaceSyn slightly. 2. Overlap flags travel with the instance ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Arrange that the ability to support overlap and incoherence is a property of the *instance declaration* rather than the module that imports the instance decl. This allows a library writer to define overlapping instance decls without the library client having to know. The implementation is that in an Instance we store the overlap flag, and preseve that across interface files 3. Nuke the "instnce pool" and "rule pool" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A major tidy-up and simplification of the way that instances and rules are sucked in from interface files. Up till now an instance decl has been held in a "pool" until its "gates" (a set of Names) are in play, when the instance is typechecked and added to the InstEnv in the ExternalPackageState. This is complicated and error-prone; it's easy to suck in too few (and miss an instance) or too many (and thereby be forced to suck in its type constructors, etc). Now, as we load an instance from an interface files, we put it straight in the InstEnv... but the Instance we put in the InstEnv has some Names (the "rough-match" names) that can be used on lookup to say "this Instance can't match". The detailed dfun is only read lazily, and the rough-match thing meansn it is'nt poked on until it has a chance of being needed. This simply continues the successful idea for Ids, whereby they are loaded straightaway into the TypeEnv, but their TyThing is a lazy thunk, not poked on until the thing is looked up. Just the same idea applies to Rules. On the way, I made CoreRule and Instance into full-blown records with lots of info, with the same kind of key status as TyCon or DataCon or Class. And got rid of IdCoreRule altogether. It's all much more solid and uniform, but it meant touching a *lot* of modules. 4. Allow instance decls in hs-boot files ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Allowing instance decls in hs-boot files is jolly useful, becuase in a big mutually-recursive bunch of data types, you want to give the instances with the data type declarations. To achieve this * The hs-boot file makes a provisional name for the dict-fun, something like $fx9. * When checking the "mother module", we check that the instance declarations line up (by type) and generate bindings for the boot dfuns, such as $fx9 = $f2 where $f2 is the dfun generated by the mother module * In doing this I decided that it's cleaner to have DFunIds get their final External Name at birth. To do that they need a stable OccName, so I have an integer-valued dfun-name-supply in the TcM monad. That keeps it simple. This feature is hardly tested yet. 5. Tidy up tidying, and Iface file generation ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main/TidyPgm now has two entry points: simpleTidyPgm is for hi-boot files, when typechecking only (not yet implemented), and potentially when compiling without -O. It ignores the bindings, and generates a nice small TypeEnv. optTidyPgm is the normal case: compiling with -O. It generates a TypeEnv rich in IdInfo MkIface.mkIface now only generates a ModIface. A separate procedure, MkIface.writeIfaceFile, writes the file out to disk.
* [project @ 2005-04-22 02:10:10 by simonpj]simonpj2005-04-221-6/+18
| | | | Fix hi-boot interface-finding code
* [project @ 2005-04-16 22:47:23 by simonpj]simonpj2005-04-163-59/+90
| | | | | | | | | | | | | | | Significant clean-up of the handling of hi-boot files. Previously, when compling A.hs, we loaded A.hi-boot, and it went into the External Package Table. It was strange but it worked. This tidy up stops it going anywhere; it's just read in, and typechecked into a ModDetails. All this was on the way to improving the handling of instances in hs-boot files, something Chris Ryder wanted. I think they work quite sensibly now. If I've got all this right (have not had a chance to fully test it) we can merge it into STABLE.
* [project @ 2005-04-14 04:32:29 by dons]dons2005-04-141-1/+1
| | | | Typo in comment only.
* [project @ 2005-03-31 10:16:33 by simonmar]simonmar2005-03-311-1/+1
| | | | | | | Tweaks to get the GHC sources through Haddock. Doesn't quite work yet, because Haddock complains about the recursive modules. Haddock needs to understand SOURCE imports (it can probably just ignore them as a first attempt).
* [project @ 2005-03-22 17:13:12 by simonmar]simonmar2005-03-221-7/+8
| | | | | | | | | | | | | | | A start on the GHC API: Flesh out the GHC module so that it can replace CompManager. Now, the clients that used CompManager consume the GHC API instead (namely Main, DriverMkDepend, and InteractiveUI). Main is significantly cleaner as a result. The interface needs more work: in particular, getInfo returns results in the form of IfaceDecls but we want to use full HsSyn and Id/DataCon/Class across the boundary instead. The interfaces for inspecting loaded modules are not yet implemented.
* [project @ 2005-03-18 13:37:27 by simonmar]simonmar2005-03-184-12/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Flags cleanup. Basically the purpose of this commit is to move more of the compiler's global state into DynFlags, which is moving in the direction we need to go for the GHC API which can have multiple active sessions supported by a single GHC instance. Before: $ grep 'global_var' */*hs | wc -l 78 After: $ grep 'global_var' */*hs | wc -l 27 Well, it's an improvement. Most of what's left won't really affect our ability to host multiple sessions. Lots of static flags have become dynamic flags (yay!). Notably lots of flags that we used to think of as "driver" flags, like -I and -L, are now dynamic. The most notable static flags left behind are the "way" flags, eg. -prof. It would be nice to fix this, but it isn't urgent. On the way, lots of cleanup has happened. Everything related to static and dynamic flags lives in StaticFlags and DynFlags respectively, and they share a common command-line parser library in CmdLineParser. The flags related to modes (--makde, --interactive etc.) are now private to the front end: in fact private to Main itself, for now.
* [project @ 2005-03-09 10:36:38 by simonmar]simonmar2005-03-091-12/+2
| | | | revert previous change, it didn't work
* [project @ 2005-03-08 10:14:32 by simonpj]simonpj2005-03-082-15/+46
| | | | Avoid losing location info for ghci; please merge
* [project @ 2005-03-08 09:45:45 by simonpj]simonpj2005-03-081-4/+7
| | | | Better printing of types; merge please
* [project @ 2005-03-07 15:59:27 by simonmar]simonmar2005-03-071-2/+12
| | | | | | | Include WORD_SIZE_IN_BITS in the interface header, and test it when reading. Fixes a problem whereby GHC on a 64-bit platform will crash if it tries to read an interface file generated by the same version of GHC on a 32-bit platform.
* [project @ 2005-02-28 16:04:54 by simonpj]simonpj2005-02-282-10/+19
| | | | | | | | | Add forall-hoisting to TcIface; see comments with mkIfTcAPp Fixes Sourceforge bug 1146068 tc191 tests This fix is temporary, until we get rid of forall-hoisting altogether
* [project @ 2005-02-25 13:06:31 by simonpj]simonpj2005-02-252-6/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | --------------------------------------------- Type signatures are no longer instantiated with skolem constants --------------------------------------------- Merge to STABLE Consider p :: a q :: b (p,q,r) = (r,r,p) Here, 'a' and 'b' end up being the same, because they are both bound to the type for 'r', which is just a meta type variable. So 'a' and 'b' can't be skolems. Sigh. This commit goes back to an earlier way of doing things, by arranging that type signatures get instantiated with *meta* type variables; then at the end we must check that they have not been unified with types, nor with each other. This is a real bore. I had to do quite a bit of related fiddling around to make error messages come out right. Improved one or two. Also a small unrelated fix to make :i (:+) print with parens in ghci. Sorry this got mixed up in the same commit.
* [project @ 2005-02-21 14:07:07 by simonmar]simonmar2005-02-212-30/+33
| | | | | | Fix a recompilation bug caused by the fact that typecheckIface wasn't going via loadDecl to create the binders properly. The fix actually results in slightly cleaner code.
* [project @ 2005-02-14 13:27:52 by simonmar]simonmar2005-02-142-1/+4
| | | | | Put the GlobalRdrEnv back into the ModIface, so it gets preserved when we reload a module without recompiling it.
* [project @ 2005-01-28 17:44:55 by simonpj]simonpj2005-01-285-51/+59
| | | | | | | | | | | | | | Arrange that when seeking instance decls in GHCi, in response to a :info command, we only print ones whose types are in scope unqualified. This eliminates an alarmingly long list when simply typing ':info Show', say. On the way, I reorganised a bit. GHCi printing happens by converting a TyThing to an IfaceDecl, and printing that. I now arrange to generate unqualifed IfaceExtNames directly during this conversion, based on what is in scope. Previously it was done during the pretty-printing part via the UserStyle. But this is nicer.
* [project @ 2005-01-27 15:53:38 by simonpj]simonpj2005-01-271-2/+4
| | | | Comments
* [project @ 2005-01-27 10:44:00 by simonpj]simonpj2005-01-275-85/+64
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | -------------------------------------------- Replace hi-boot files with hs-boot files -------------------------------------------- This major commit completely re-organises the way that recursive modules are dealt with. * It should have NO EFFECT if you do not use recursive modules * It is a BREAKING CHANGE if you do ====== Warning: .hi-file format has changed, so if you are ====== updating into an existing HEAD build, you'll ====== need to make clean and re-make The details: [documentation still to be done] * Recursive loops are now broken with Foo.hs-boot (or Foo.lhs-boot), not Foo.hi-boot * An hs-boot files is a proper source file. It is compiled just like a regular Haskell source file: ghc Foo.hs generates Foo.hi, Foo.o ghc Foo.hs-boot generates Foo.hi-boot, Foo.o-boot * hs-boot files are precisely a subset of Haskell. In particular: - they have the same import, export, and scoping rules - errors (such as kind errors) in hs-boot files are checked You do *not* need to mention the "original" name of something in an hs-boot file, any more than you do in any other Haskell module. * The Foo.hi-boot file generated by compiling Foo.hs-boot is a machine- generated interface file, in precisely the same format as Foo.hi * When compiling Foo.hs, its exports are checked for compatibility with Foo.hi-boot (previously generated by compiling Foo.hs-boot) * The dependency analyser (ghc -M) knows about Foo.hs-boot files, and generates appropriate dependencies. For regular source files it generates Foo.o : Foo.hs Foo.o : Baz.hi -- Foo.hs imports Baz Foo.o : Bog.hi-boot -- Foo.hs source-imports Bog For a hs-boot file it generates similar dependencies Bog.o-boot : Bog.hs-boot Bog.o-boot : Nib.hi -- Bog.hs-boto imports Nib * ghc -M is also enhanced to use the compilation manager dependency chasing, so that ghc -M Main will usually do the job. No need to enumerate all the source files. * The -c flag is no longer a "compiler mode". It simply means "omit the link step", and synonymous with -no-link.
* [project @ 2005-01-20 12:02:06 by simonpj]simonpj2005-01-201-3/+3
| | | | Fix syntax error
* [project @ 2005-01-18 12:18:11 by simonpj]simonpj2005-01-185-161/+176
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------ Reorganisation of hi-boot files ------------------------ The main point of this commit is to arrange that in the Compilation Manager's dependendency graph, hi-boot files are proper nodes. This is important to make sure that we compile everything in the right order. It's a step towards hs-boot files. * The fundamental change is that CompManager.ModSummary has a new field, ms_boot :: IsBootInterface I also tided up CompManager a bit. No change to the Basic Plan. ModSummary is now exported abstractly from CompManager (was concrete) * Hi-boot files now have import declarations. The idea is they are compulsory, so that the dependency analyser can find them * I changed an invariant: the Compilation Manager used to ensure that hscMain was given a HomePackageTable only for the modules 'below' the one being compiled. This was really only important for instances and rules, and it was a bit inconvenient. So I moved the filter to the compiler itself: see HscTypes.hptInstances and hptRules. * Module Packages.hs now defines data PackageIdH = HomePackage -- The "home" package is the package -- curently being compiled | ExtPackage PackageId -- An "external" package is any other package It was just a Maybe type before, so this makes it a bit clearer. * I tried to add a bit better location info to the IfM monad, so that errors in interfaces come with a slightly more helpful error message. See the if_loc field in TcRnTypes --- and follow-on consequences * Changed Either to Maybes.MaybeErr in a couple of places (more perspicuous)
* [project @ 2004-12-22 16:58:34 by simonpj]simonpj2004-12-221-2/+2
| | | | | | | | | | | | | | | | | ---------------------------------------- Add more scoped type variables ---------------------------------------- Now the top-level forall'd variables of a type signature scope over the right hand side of that function. f :: a -> a f x = .... The type variable 'a' is in scope in the RHS, and in f's patterns. It's implied by -fglasgow-exts, but can also be switched off independently using -fscoped-type-variables (and the -fno variant)
* [project @ 2004-12-22 12:06:13 by simonpj]simonpj2004-12-221-1/+0
| | | | | | | | | | | | | | | | | | | ---------------------------------------- New Core invariant: keep case alternatives in sorted order ---------------------------------------- We now keep the alternatives of a Case in the Core language in sorted order. Sorted, that is, by constructor tag for DataAlt by literal for LitAlt The main reason is that it makes matching and equality testing more robust. But in fact some lines of code vanished from SimplUtils.mkAlts. WARNING: no change to interface file formats, but you'll need to recompile your libraries so that they generate interface files that respect the invariant.
* [project @ 2004-12-22 12:04:14 by simonpj]simonpj2004-12-221-12/+21
| | | | | | | | | | | | | -------------------------- Add -fwarn-orphans flag -------------------------- This gives a decent report for modules that contain 'orphan' instance and rule declarations. These are to be avoided, because GHC has to proactively read the interface file every single time, just in case the instance/rule is needed. The flag just gives a convenient way of identifying the culprits.
* [project @ 2004-12-21 12:11:37 by simonpj]simonpj2004-12-211-2/+1
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