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Commits (7)
  • Adam Sandberg Eriksson's avatar
    docs: fix formatting and add some links · f31b1311
    Adam Sandberg Eriksson authored
    [skip ci]
    f31b1311
  • Andrew Martin's avatar
    Implement cstringLength# and FinalPtr · 7699a7ab
    Andrew Martin authored
    This function and its accompanying rule resolve issue #5218.
    A future PR to the bytestring library will make the internal
    Data.ByteString.Internal.unsafePackAddress compute string length
    with cstringLength#. This will improve the status quo because it is
    eligible for constant folding.
    
    Additionally, introduce a new data constructor to ForeignPtrContents
    named FinalPtr. This additional data constructor, when used in the
    IsString instance for ByteString, leads to more Core-to-Core
    optimization opportunities, fewer runtime allocations, and smaller
    binaries.
    
    Also, this commit re-exports all the functions from GHC.CString
    (including cstringLength#) in GHC.Exts. It also adds a new test
    driver. This test driver is used to perform substring matches on Core
    that is dumped after all the simplifier passes. In this commit, it is
    used to check that constant folding of cstringLength# works.
    7699a7ab
  • Ben Gamari's avatar
    simplCore: Ignore ticks in rule templates · f9d20958
    Ben Gamari authored
    This fixes #17619, where a tick snuck in to the template of a rule,
    resulting in a panic during rule matching. The tick in question was
    introduced via post-inlining, as discussed in `Note [Simplifying
    rules]`. The solution we decided upon was to simply ignore ticks in the
    rule template, as discussed in `Note [Tick annotations in RULE
    matching]`.
    
    Fixes #18162.
    Fixes #17619.
    f9d20958
  • John Ericson's avatar
    Fix #18145 and also avoid needless work with implicit vars · f8f18a40
    John Ericson authored
     - `forAllOrNothing` now is monadic, so we can trace whether we bind
       an explicit `forall` or not.
    
     - #18145 arose because the free vars calculation was needlessly
       complex. It is now greatly simplified.
    
     - Replaced some other implicit var code with `filterFreeVarsToBind`.
    Co-authored-by: Ryan Scott's avatarRyan Scott <ryan.gl.scott@gmail.com>
    f8f18a40
  • Ben Gamari's avatar
    Bump process submodule · a7d31d89
    Ben Gamari authored
    Fixes #17926.
    a7d31d89
  • Ben Gamari's avatar
    users-guide: Clarify meaning of -haddock flag · c7639bb8
    Ben Gamari authored
    Fixes #18206.
    c7639bb8
  • Ben Gamari's avatar
    git: Add ignored commits file · f5f3e709
    Ben Gamari authored
    This can be used to tell git to ignore bulk renaming commits like the
    recently-finished module hierarchy refactoring. Configured with,
    
        git config blame.ignoreRevsFile .git-ignore-revs
    f5f3e709
# Configure git to ignore commits listed in this file with:
#
# git config blame.ignoreRevsFile .git-ignore-revs
# Module Hierarchy Renamings
af332442123878c1b61d236dce46418efcbe8750
255418da5d264fb2758bc70925adb2094f34adc3
1941ef4f050c0dfcb68229641fcbbde3a10f1072
528df8ecb4e2f9c78b1ae4ab7ff8230644e9b643
18a346a4b5a02b8c62e8eedb91b35c2d8e754b96
817f93eac4d13f680e8e3e7a25eb403b1864f82e
1b1067d14b656bbbfa7c47f156ec2700c9751549
240f5bf6f53515535be5bf3ef7632aa69ae21e3e
1500f0898e85316c7c97a2f759d83278a072ab0e
3ca52151881451ce5b3a7740d003e811b586140d
cf739945b8b28ff463dc44925348f20b3c1f22cb
da7f74797e8c322006eba385c9cbdce346dd1d43
6e2d9ee25bce06ae51d2f1cf8df4f7422106a383
d491a6795d507eabe35d8aec63c534d29f2d305b
99a9f51bf8207c79241fc0b685fadeb222a61292
eb6082358cdb5f271a8e4c74044a12f97352c52f
5119296440e6846c553c72b8a93afc5ecfa576f0
447864a94a1679b5b079e08bb7208a0005381cef
......@@ -349,6 +349,7 @@ basicKnownKeyNames
-- Strings and lists
unpackCStringName,
unpackCStringFoldrName, unpackCStringUtf8Name,
cstringLengthName,
-- Overloaded lists
isListClassName,
......@@ -1014,10 +1015,11 @@ modIntName = varQual gHC_CLASSES (fsLit "modInt#") modIntIdKey
-- Base strings Strings
unpackCStringName, unpackCStringFoldrName,
unpackCStringUtf8Name, eqStringName :: Name
unpackCStringUtf8Name, eqStringName, cstringLengthName :: Name
unpackCStringName = varQual gHC_CSTRING (fsLit "unpackCString#") unpackCStringIdKey
unpackCStringFoldrName = varQual gHC_CSTRING (fsLit "unpackFoldrCString#") unpackCStringFoldrIdKey
unpackCStringUtf8Name = varQual gHC_CSTRING (fsLit "unpackCStringUtf8#") unpackCStringUtf8IdKey
cstringLengthName = varQual gHC_CSTRING (fsLit "cstringLength#") cstringLengthIdKey
eqStringName = varQual gHC_BASE (fsLit "eqString") eqStringIdKey
-- The 'inline' function
......@@ -2097,7 +2099,7 @@ wildCardKey, absentErrorIdKey, augmentIdKey, appendIdKey,
unpackCStringUtf8IdKey, unpackCStringAppendIdKey,
unpackCStringFoldrIdKey, unpackCStringIdKey,
typeErrorIdKey, divIntIdKey, modIntIdKey,
absentSumFieldErrorIdKey :: Unique
absentSumFieldErrorIdKey, cstringLengthIdKey :: Unique
wildCardKey = mkPreludeMiscIdUnique 0 -- See Note [WildCard binders]
absentErrorIdKey = mkPreludeMiscIdUnique 1
......@@ -2124,6 +2126,7 @@ voidPrimIdKey = mkPreludeMiscIdUnique 21
typeErrorIdKey = mkPreludeMiscIdUnique 22
divIntIdKey = mkPreludeMiscIdUnique 23
modIntIdKey = mkPreludeMiscIdUnique 24
cstringLengthIdKey = mkPreludeMiscIdUnique 25
concatIdKey, filterIdKey, zipIdKey,
bindIOIdKey, returnIOIdKey, newStablePtrIdKey,
......
......@@ -66,6 +66,7 @@ import qualified Data.ByteString as BS
import Data.Int
import Data.Ratio
import Data.Word
import Data.Maybe (fromMaybe)
{-
Note [Constant folding]
......@@ -1257,6 +1258,8 @@ builtinRules
ru_nargs = 4, ru_try = match_append_lit },
BuiltinRule { ru_name = fsLit "EqString", ru_fn = eqStringName,
ru_nargs = 2, ru_try = match_eq_string },
BuiltinRule { ru_name = fsLit "CStringLength", ru_fn = cstringLengthName,
ru_nargs = 1, ru_try = match_cstring_length },
BuiltinRule { ru_name = fsLit "Inline", ru_fn = inlineIdName,
ru_nargs = 2, ru_try = \_ _ _ -> match_inline },
BuiltinRule { ru_name = fsLit "MagicDict", ru_fn = idName magicDictId,
......@@ -1477,6 +1480,30 @@ match_eq_string _ id_unf _
match_eq_string _ _ _ _ = Nothing
-----------------------------------------------------------------------
-- Illustration of this rule:
--
-- cstringLength# "foobar"# --> 6
-- cstringLength# "fizz\NULzz"# --> 4
--
-- Nota bene: Addr# literals are suffixed by a NUL byte when they are
-- compiled to read-only data sections. That's why cstringLength# is
-- well defined on Addr# literals that do not explicitly have an embedded
-- NUL byte.
--
-- See GHC issue #5218, MR 2165, and bytestring PR 191. This is particularly
-- helpful when using OverloadedStrings to create a ByteString since the
-- function computing the length of such ByteStrings can often be constant
-- folded.
match_cstring_length :: RuleFun
match_cstring_length env id_unf _ [lit1]
| Just (LitString str) <- exprIsLiteral_maybe id_unf lit1
-- If elemIndex returns Just, it has the index of the first embedded NUL
-- in the string. If no NUL bytes are present (the common case) then use
-- full length of the byte string.
= let len = fromMaybe (BS.length str) (BS.elemIndex 0 str)
in Just (Lit (mkLitInt (roPlatform env) (fromIntegral len)))
match_cstring_length _ _ _ _ = Nothing
---------------------------------------------------
-- The rule is this:
......
......@@ -830,6 +830,21 @@ Ticks into the LHS, which makes matching trickier. #10665, #10745.
Doing this to either side confounds tools like HERMIT, which seek to reason
about and apply the RULES as originally written. See #10829.
There is, however, one case where we are pretty much /forced/ to transform the
LHS of a rule: postInlineUnconditionally. For instance, in the case of
let f = g @Int in f
We very much want to inline f into the body of the let. However, to do so (and
be able to safely drop f's binding) we must inline into all occurrences of f,
including those in the LHS of rules.
This can cause somewhat surprising results; for instance, in #18162 we found
that a rule template contained ticks in its arguments, because
postInlineUnconditionally substituted in a trivial expression that contains
ticks. See Note [Tick annotations in RULE matching] in GHC.Core.Rules for
details.
Note [No eta expansion in stable unfoldings]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If we have a stable unfolding
......@@ -1251,6 +1266,10 @@ it's best to inline it anyway. We often get a=E; b=a from desugaring,
with both a and b marked NOINLINE. But that seems incompatible with
our new view that inlining is like a RULE, so I'm sticking to the 'active'
story for now.
NB: unconditional inlining of this sort can introduce ticks in places that
may seem surprising; for instance, the LHS of rules. See Note [Simplfying
rules] for details.
-}
postInlineUnconditionally
......
......@@ -714,11 +714,15 @@ match :: RuleMatchEnv
-> CoreExpr -- Target
-> Maybe RuleSubst
-- We look through certain ticks. See note [Tick annotations in RULE matching]
-- We look through certain ticks. See Note [Tick annotations in RULE matching]
match renv subst e1 (Tick t e2)
| tickishFloatable t
= match renv subst' e1 e2
where subst' = subst { rs_binds = rs_binds subst . mkTick t }
match renv subst (Tick t e1) e2
-- Ignore ticks in rule template.
| tickishFloatable t
= match renv subst e1 e2
match _ _ e@Tick{} _
= pprPanic "Tick in rule" (ppr e)
......@@ -1016,7 +1020,7 @@ Hence, (a) the guard (not (isLocallyBoundR v2))
Note [Tick annotations in RULE matching]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We used to unconditionally look through Notes in both template and
We used to unconditionally look through ticks in both template and
expression being matched. This is actually illegal for counting or
cost-centre-scoped ticks, because we have no place to put them without
changing entry counts and/or costs. So now we just fail the match in
......@@ -1025,6 +1029,11 @@ these cases.
On the other hand, where we are allowed to insert new cost into the
tick scope, we can float them upwards to the rule application site.
Moreover, we may encounter ticks in the template of a rule. There are a few
ways in which these may be introduced (e.g. #18162, #17619). Such ticks are
ignored by the matcher. See Note [Simplifying rules] in
GHC.Core.Opt.Simplify.Utils for details.
cf Note [Notes in call patterns] in GHC.Core.Opt.SpecConstr
Note [Matching lets]
......
......@@ -128,8 +128,9 @@ import Foreign
import GHC.Conc.Sync (sharedCAF)
#endif
import GHC.Base ( unpackCString#, unpackNBytes# )
#if __GLASGOW_HASKELL__ < 811
import GHC.Base (unpackCString#,unpackNBytes#)
#endif
-- | Gives the UTF-8 encoded bytes corresponding to a 'FastString'
bytesFS :: FastString -> ByteString
......
......@@ -53,7 +53,7 @@ data HsLit x
-- ^ Unboxed character
| HsString (XHsString x) {- SourceText -} FastString
-- ^ String
| HsStringPrim (XHsStringPrim x) {- SourceText -} ByteString
| HsStringPrim (XHsStringPrim x) {- SourceText -} !ByteString
-- ^ Packed bytes
| HsInt (XHsInt x) IntegralLit
-- ^ Genuinely an Int; arises from
......
This diff is collapsed.
......@@ -59,7 +59,7 @@ import GHC.Types.Basic ( pprRuleName, TypeOrKind(..) )
import GHC.Data.FastString
import GHC.Types.SrcLoc as SrcLoc
import GHC.Driver.Session
import GHC.Utils.Misc ( debugIsOn, filterOut, lengthExceeds, partitionWith )
import GHC.Utils.Misc ( debugIsOn, lengthExceeds, partitionWith )
import GHC.Driver.Types ( HscEnv, hsc_dflags )
import GHC.Data.List.SetOps ( findDupsEq, removeDups, equivClasses )
import GHC.Data.Graph.Directed ( SCC, flattenSCC, flattenSCCs, Node(..)
......@@ -664,7 +664,9 @@ rnClsInstDecl (ClsInstDecl { cid_poly_ty = inst_ty, cid_binds = mbinds
rnFamInstEqn :: HsDocContext
-> AssocTyFamInfo
-> [Located RdrName] -- Kind variables from the equation's RHS
-> [Located RdrName]
-- ^ Kind variables from the equation's RHS to be implicitly bound
-- if no explicit forall.
-> FamInstEqn GhcPs rhs
-> (HsDocContext -> rhs -> RnM (rhs', FreeVars))
-> RnM (FamInstEqn GhcRn rhs', FreeVars)
......@@ -683,20 +685,36 @@ rnFamInstEqn doc atfi rhs_kvars
-- Use the "...Dups" form because it's needed
-- below to report unused binder on the LHS
-- Implicitly bound variables, empty if we have an explicit 'forall'.
-- See Note [forall-or-nothing rule] in GHC.Rename.HsType.
; let imp_vars = nubL $ forAllOrNothing (isJust mb_bndrs) pat_kity_vars_with_dups
; imp_var_names <- mapM (newTyVarNameRn mb_cls) imp_vars
; let bndrs = fromMaybe [] mb_bndrs
bnd_vars = map hsLTyVarLocName bndrs
payload_kvars = filterOut (`elemRdr` (bnd_vars ++ imp_vars)) rhs_kvars
-- Make sure to filter out the kind variables that were explicitly
-- bound in the type patterns.
; payload_kvar_names <- mapM (newTyVarNameRn mb_cls) payload_kvars
-- all names not bound in an explicit forall
; let all_imp_var_names = imp_var_names ++ payload_kvar_names
-- all_imp_vars represent the implicitly bound type variables. This is
-- empty if we have an explicit `forall` (see
-- Note [forall-or-nothing rule] in GHC.Rename.HsType), which means
-- ignoring:
--
-- - pat_kity_vars_with_dups, the variables mentioned in the LHS of
-- the equation, and
-- - rhs_kvars, the kind variables mentioned in an outermost kind
-- signature on the RHS of the equation. (See
-- Note [Implicit quantification in type synonyms] in
-- GHC.Rename.HsType for why these are implicitly quantified in the
-- absence of an explicit forall).
--
-- For example:
--
-- @
-- type family F a b
-- type instance forall a b c. F [(a, b)] c = a -> b -> c
-- -- all_imp_vars = []
-- type instance F [(a, b)] c = a -> b -> c
-- -- all_imp_vars = [a, b, c]
-- @
; all_imp_vars <- forAllOrNothing (isJust mb_bndrs) $
-- No need to filter out explicit binders (the 'mb_bndrs = Just
-- explicit_bndrs' case) because there must be none if we're going
-- to implicitly bind anything, per the previous comment.
nubL $ pat_kity_vars_with_dups ++ rhs_kvars
; all_imp_var_names <- mapM (newTyVarNameRn mb_cls) all_imp_vars
-- All the free vars of the family patterns
-- with a sensible binding location
......@@ -2096,14 +2114,14 @@ rnConDecl decl@(ConDeclGADT { con_names = names
-- That order governs the order the implicitly-quantified type
-- variable, and hence the order needed for visible type application
-- See #14808.
free_tkvs = extractHsTvBndrs explicit_tkvs $
extractHsTysRdrTyVarsDups (theta ++ arg_tys ++ [res_ty])
; implicit_bndrs <- forAllOrNothing explicit_forall
$ extractHsTvBndrs explicit_tkvs
$ extractHsTysRdrTyVarsDups (theta ++ arg_tys ++ [res_ty])
ctxt = ConDeclCtx new_names
; let ctxt = ConDeclCtx new_names
mb_ctxt = Just (inHsDocContext ctxt)
; traceRn "rnConDecl" (ppr names $$ ppr free_tkvs $$ ppr explicit_forall )
; rnImplicitBndrs (forAllOrNothing explicit_forall free_tkvs) $ \ implicit_tkvs ->
; rnImplicitBndrs implicit_bndrs $ \ implicit_tkvs ->
bindLHsTyVarBndrs ctxt mb_ctxt Nothing explicit_tkvs $ \ explicit_tkvs ->
do { (new_cxt, fvs1) <- rnMbContext ctxt mcxt
; (new_args, fvs2) <- rnConDeclDetails (unLoc (head new_names)) ctxt args
......
......@@ -6,6 +6,7 @@
This module converts Template Haskell syntax into Hs syntax
-}
{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE DeriveFunctor #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE ScopedTypeVariables #-}
......@@ -1232,8 +1233,7 @@ cvtLit (CharPrimL c) = do { force c; return $ HsCharPrim NoSourceText c }
cvtLit (StringL s) = do { let { s' = mkFastString s }
; force s'
; return $ HsString (quotedSourceText s) s' }
cvtLit (StringPrimL s) = do { let { s' = BS.pack s }
; force s'
cvtLit (StringPrimL s) = do { let { !s' = BS.pack s }
; return $ HsStringPrim NoSourceText s' }
cvtLit (BytesPrimL (Bytes fptr off sz)) = do
let bs = unsafePerformIO $ withForeignPtr fptr $ \ptr ->
......
......@@ -114,7 +114,7 @@ data Literal
-- See Note [Types of LitNumbers] below for the
-- Type field.
| LitString ByteString -- ^ A string-literal: stored and emitted
| LitString !ByteString -- ^ A string-literal: stored and emitted
-- UTF-8 encoded, we'll arrange to decode it
-- at runtime. Also emitted with a @\'\\0\'@
-- terminator. Create with 'mkLitString'
......
......@@ -79,12 +79,15 @@ Language
* GHC now consistently does eager instantiation during type inference.
As a consequence, visible type application (VTA) now only works when
the head of the application is:
* A variable
* An expression with a type signature
For example `(let x = blah in id) @Bool True` no longer typechecks.
You should write `let x = blah in id @Bool True` instead.
This change prepares the way for Quick Look impredicativity.
For example ``(let x = blah in id) @Bool True`` no longer typechecks.
You should write ``let x = blah in id @Bool True`` instead.
This change prepares the way for `Quick Look impredicativity
<https://gitlab.haskell.org/ghc/ghc/issues/18126>`_.
* GHC now allows users to manually define the specificity of type variable
binders. By marking a variable with braces ``{tyvar}`` or ``{tyvar :: kind}``,
......@@ -110,60 +113,65 @@ Runtime system
Template Haskell
~~~~~~~~~~~~~~~~
- Implement the Overloaded Quotations proposal (#246). The type of all quotation
forms have now been generalised in terms of a minimal interface necessary for the
implementation rather than the overapproximation of the ``Q`` monad.
- Implement the `Overloaded Quotations proposal (#246) <https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0246-overloaded-bracket.rst>`_.
The type of all quotation forms have now been generalised in terms of a
minimal interface necessary (the ``Quote`` type class) for the
implementation rather than the overapproximation of the ``Q`` monad.
- Template Haskell quotes now handle fixity declarations in ``let`` and
``where`` bindings properly. Previously, such fixity declarations would
be dropped when quoted due to a Template Haskell bug.
- Template Haskell quotes now handle fixity declarations in ``let`` and
``where`` bindings properly. Previously, such fixity declarations would
be dropped when quoted due to a Template Haskell bug.
- The ``-XTemplateHaskellQuotes`` extension now allows nested splices as nested
splices do not lead directly to compile-time evaluation. (!2288)
- The ``-XTemplateHaskellQuotes`` extension now allows nested splices as nested
splices do not lead directly to compile-time evaluation. (Merge request
`!2288 <https://gitlab.haskell.org/ghc/ghc/-/merge_requests/2288>`_)
Arrow notation
~~~~~~~~~~~~~~
- When combined with :extension:`Arrows`, the :extension:`LambdaCase` extension
now additionally allows ``\case`` syntax to be used as a command in ``proc``
notation.
- When combined with :extension:`Arrows`, the :extension:`LambdaCase` extension
now additionally allows ``\case`` syntax to be used as a command in ``proc``
notation.
- When combined with :extension:`Arrows`, the effects of the
:extension:`BlockArguments` extension now also apply to applications of
arrow control operators in ``(|`` banana brackets ``|)``: ::
- When combined with :extension:`Arrows`, the effects of the
:extension:`BlockArguments` extension now also apply to applications of
arrow control operators in ``(|`` banana brackets ``|)``: ::
(| untilA (increment -< x + y) do
within 0.5 -< x
... |)
(| untilA (increment -< x + y) do
within 0.5 -< x
... |)
``ghc-prim`` library
~~~~~~~~~~~~~~~~~~~~
- Add a known-key ``cstringLength#`` to ``GHC.CString`` that is eligible
for constant folding by a built-in rule.
``ghc`` library
~~~~~~~~~~~~~~~
- The type of the ``getAnnotations`` function has changed to better reflect
the fact that it returns two different kinds of annotations, those on
names and those on modules: ::
- The type of the ``getAnnotations`` function has changed to better reflect
the fact that it returns two different kinds of annotations, those on
names and those on modules: ::
getAnnotations :: Typeable a
=> ([Word8] -> a) -> ModGuts
-> CoreM (ModuleEnv [a], NameEnv [a])
getAnnotations :: Typeable a
=> ([Word8] -> a) -> ModGuts
-> CoreM (ModuleEnv [a], NameEnv [a])
- The meaning of the ``hs_fixds`` field of ``HsGroup`` has changed slightly.
It now only contains fixity signatures defined for top-level declarations
and class methods defined *outside* of the class itself. Previously,
``hs_fixds`` would also contain fixity signatures for class methods defined
*inside* the class, such as the fixity signature for ``m`` in the following
example: ::
- The meaning of the ``hs_fixds`` field of ``HsGroup`` has changed slightly.
It now only contains fixity signatures defined for top-level declarations
and class methods defined *outside* of the class itself. Previously,
``hs_fixds`` would also contain fixity signatures for class methods defined
*inside* the class, such as the fixity signature for ``m`` in the following
example: ::
class C a where
infixl 4 `m`
m :: a -> a -> a
class C a where
infixl 4 `m`
m :: a -> a -> a
If you wish to attain the previous behavior of ``hs_fixds``, use the new
``hsGroupTopLevelFixitySigs`` function, which collects all top-level fixity
signatures, including those for class methods defined inside classes.
If you wish to attain the previous behavior of ``hs_fixds``, use the new
``hsGroupTopLevelFixitySigs`` function, which collects all top-level fixity
signatures, including those for class methods defined inside classes.
- The ``Exception`` module was boiled down acknowledging the existence of
the ``exceptions`` dependency. In particular, the ``ExceptionMonad``
......@@ -176,6 +184,15 @@ Arrow notation
``base`` library
~~~~~~~~~~~~~~~~
- ``ForeignPtrContents`` has a new nullary data constructor ``FinalPtr``.
``FinalPtr`` is intended for turning a primitive string literal into a
``ForeignPtr``. Unlike ``PlainForeignPtr``, ``FinalPtr`` does not have
a finalizer. Replacing ``PlainForeignPtr`` that has ``NoFinalizers`` with
``FinalPtr`` reduces allocations, reduces the size of compiled binaries,
and unlocks important Core-to-Core optimizations. ``FinalPtr`` will be used
in an upcoming ``bytestring`` release to improve the performance of
``ByteString`` literals created with ``OverloadedStrings``.
Build system
~~~~~~~~~~~~
......@@ -196,7 +213,7 @@ for further change information.
libraries/containers/containers/containers.cabal: Dependency of ``ghc`` library
libraries/deepseq/deepseq.cabal: Dependency of ``ghc`` library
libraries/directory/directory.cabal: Dependency of ``ghc`` library
libraries/exceptions/exceptions.cabal: Dependency of ``haskeline`` library
libraries/exceptions/exceptions.cabal: Dependency of ``ghc`` and ``haskeline`` library
libraries/filepath/filepath.cabal: Dependency of ``ghc`` library
compiler/ghc.cabal: The compiler itself
libraries/ghci/ghci.cabal: The REPL interface
......
......@@ -74,7 +74,7 @@ The :extension:`TemplateHaskellQuotes` extension is considered safe under
that declaration splices are not allowed anywhere except at top level
(outside any other declarations).
The ``Q`` monad is a monad defined in ``Language.Haskell.TH.Syntax`` which
The ``Q`` monad is a monad defined in :th-ref:`Language.Haskell.TH.Syntax.` which
supports several useful operations during code generation such as reporting
errors or looking up identifiers in the environment.
......@@ -92,9 +92,10 @@ The :extension:`TemplateHaskellQuotes` extension is considered safe under
- ``[p| ... |]``, where the "..." is a pattern; the quotation has
type ``Quote m => m Pat``.
The ``Quote`` type class is the minimal interface necessary to implement
the desugaring of quotations. The ``Q`` monad is an instance of ``Quote`` but
contains many more operations which are not needed for defining quotations.
The ``Quote`` type class (:th-ref:`Language.Haskell.TH.Syntax.Quote`) is
the minimal interface necessary to implement the desugaring of quotations.
The ``Q`` monad is an instance of ``Quote`` but contains many more
operations which are not needed for defining quotations.
See :ref:`pts-where` for using partial type signatures in quotations.
......@@ -402,7 +403,7 @@ Using Template Haskell
----------------------
- The data types and monadic constructor functions for Template Haskell
are in the library ``Language.Haskell.TH.Syntax``.
are in the library :th-ref:`Language.Haskell.TH.Syntax.`.
- You can only run a function at compile time if it is imported from
another module. That is, you can't define a function in a module, and
......@@ -645,7 +646,7 @@ Here are the salient features
(Only the first two are described in the paper.)
- A quoter is a value of type
``Language.Haskell.TH.Quote.QuasiQuoter``, which is defined thus: ::
:th-ref:`Language.Haskell.TH.Quote.QuasiQuoter`, which is defined thus: ::
data QuasiQuoter = QuasiQuoter { quoteExp :: String -> Q Exp,
quotePat :: String -> Q Pat,
......
......@@ -1136,10 +1136,11 @@ Haddock
single: haddock
.. ghc-flag:: -haddock
:shortdesc: Make the parser more strict about Haddock comments.
:shortdesc: With this flag GHC will parse Haddock comments and include them
in the interface file it produces.
:type: dynamic
:reverse: -no-haddock
:category: misc
:category: haddock
By default, GHC ignores Haddock comments (``-- | ...`` and ``-- ^ ...``)
and does not check that they're associated with a valid term, such as a
......
......@@ -54,6 +54,14 @@ module GHC.Exts
-- * Overloaded string literals
IsString(..),
-- * CString
unpackCString#,
unpackAppendCString#,
unpackFoldrCString#,
unpackCStringUtf8#,
unpackNBytes#,
cstringLength#,
-- * Debugging
breakpoint, breakpointCond,
......
This diff is collapsed.
{-# LANGUAGE MagicHash, NoImplicitPrelude, BangPatterns #-}
{-# LANGUAGE MagicHash, NoImplicitPrelude, BangPatterns, UnliftedFFITypes #-}
-----------------------------------------------------------------------------
-- |
-- Module : GHC.CString
......@@ -18,7 +17,7 @@
module GHC.CString (
unpackCString#, unpackAppendCString#, unpackFoldrCString#,
unpackCStringUtf8#, unpackNBytes#
unpackCStringUtf8#, unpackNBytes#, cstringLength#
) where
import GHC.Types
......@@ -174,3 +173,17 @@ unpackNBytes# addr len# = unpack [] (len# -# 1#)
case indexCharOffAddr# addr i# of
ch -> unpack (C# ch : acc) (i# -# 1#)
-- The return type is not correct here. We really want CSize,
-- but that type is defined in base. However, CSize should always
-- match the size of a machine word (I hope), so this is probably
-- alright on all platforms that GHC supports.
foreign import ccall unsafe "strlen" c_strlen :: Addr# -> Int#
-- | Compute the length of a NUL-terminated string. This address
-- must refer to immutable memory. GHC includes a built-in rule for
-- constant folding when the argument is a statically-known literal.
-- That is, a core-to-core pass reduces the expression
-- @cstringLength# "hello"#@ to the constant @5#@.
cstringLength# :: Addr# -> Int#
{-# INLINE[0] cstringLength# #-}
cstringLength# = c_strlen
## 0.6.2 (edit as necessary)
- Shipped with GHC 8.12.1
- Add known-key `cstringLength#` to `GHC.CString`. This is just the
C function `strlen`, but a built-in rewrite rule allows GHC to
compute the result at compile time when the argument is known.
## 0.6.1 (edit as necessary)
- Shipped with GHC 8.10.1
......
Subproject commit 8fffea5ca319e85e1bc9e7cac39e5a2c8effefcc
Subproject commit 1afc36ecd38c069251a836e1c1c8b3a3043ddc01
......@@ -43,6 +43,7 @@ Thumbs.db
*.prof.sample.normalised
*.run.stdout
*.run.stderr
*.dump-simpl
*.hp
tests/**/*.ps
......
......@@ -1344,6 +1344,26 @@ def compile_grep_asm(name: TestName,
# no problems found, this test passed
return passed()
def compile_grep_core(name: TestName,
way: WayName,
extra_hc_opts: str
) -> PassFail:
print('Compile only, extra args = ', extra_hc_opts)
result = simple_build(name + '.hs', way, '-ddump-to-file -dsuppress-all -ddump-simpl -O ' + extra_hc_opts, False, None, False, False)
if badResult(result):
return result
expected_pat_file = find_expected_file(name, 'substr-simpl')
actual_core_file = add_suffix(name, 'dump-simpl')
if not grep_output(join_normalisers(normalise_errmsg),
expected_pat_file, actual_core_file):
return failBecause('simplified core mismatch')
# no problems found, this test passed
return passed()
# -----------------------------------------------------------------------------
# Compile-and-run tests
......
{-# language MagicHash #-}
module CStringLengthCore
( ozymandias
) where
import GHC.Exts
ozymandias :: Int
ozymandias =
I# (cstringLength# "I met a traveller from an antique land"#)
test('CStringLength_core', normal, compile_grep_core, [''])
{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE MagicHash #-}
{-# LANGUAGE UnboxedTuples #-}
import GHC.Exts
main :: IO ()
main = do
putStr "A: "
print $
I# (cstringLength# "hello_world"#)
==
naiveStrlen "hello_world"# 0
putStr "B: "
print $
I# (cstringLength# "aaaaaaaaaaaaa\x00b"#)
==
naiveStrlen "aaaaaaaaaaaaa\x00b"# 0
putStr "C: "
print $
I# (cstringLength# "cccccccccccccccccc\x00b"#)
==
naiveStrlen "cccccccccccccccccc\x00b"# 0
putStr "D: "
print $
I# (cstringLength# "araña\NULb"#)
==
naiveStrlen "araña\NULb"# 0
naiveStrlen :: Addr# -> Int -> Int
naiveStrlen addr !n = case indexWord8OffAddr# addr 0# of
0## -> n
_ -> naiveStrlen (plusAddr# addr 1#) (n + 1)
......@@ -29,3 +29,4 @@ test('CmpWord16', normal, compile_and_run, [''])
test('ShrinkSmallMutableArrayA', normal, compile_and_run, [''])
test('ShrinkSmallMutableArrayB', normal, compile_and_run, [''])
test('T14664', normal, compile_and_run, [''])
test('CStringLength', normal, compile_and_run, ['-O2'])
{-# LANGUAGE ExplicitForAll #-}
{-# LANGUAGE TypeApplications #-}
{-# LANGUAGE PolyKinds #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE DataKinds #-}
module T18145 where
type family A :: k
type instance forall. A = Nothing :: Maybe a -- 'a' should be out of scope
class Foo x where
type B x :: Maybe a
type forall x. B x = Nothing :: Maybe a -- 'a' should be out of scope
instance Foo [x] where
type forall. B [x] = Nothing :: Maybe a -- 'a' should be out of scope
T18145.hs:10:44: error: Not in scope: type variable ‘a’
T18145.hs:14:41: error: Not in scope: type variable ‘a’
T18145.hs:17:41: error: Not in scope: type variable ‘a’
......@@ -153,3 +153,4 @@ test('T16504', normal, compile_fail, [''])
test('T14548', normal, compile_fail, [''])
test('T16610', normal, compile_fail, [''])
test('T17593', normal, compile_fail, [''])
test('T18145', normal, compile_fail, [''])