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| author | Max Bolingbroke <batterseapower@hotmail.com> | 2011-07-05 09:23:58 +0100 |
|---|---|---|
| committer | Max Bolingbroke <batterseapower@hotmail.com> | 2011-07-05 09:53:57 +0100 |
| commit | 54843b5bfdc81b7af6df36a06f7f434c7b74f796 (patch) | |
| tree | 5e87d9d92707d9a955559b15b6e849fb0594a0e1 /compiler/cmm/CmmParse.y | |
| parent | e01fffc60ba6a71487f0402f6c79ba2f0a684765 (diff) | |
| download | haskell-54843b5bfdc81b7af6df36a06f7f434c7b74f796.tar.gz | |
Refactoring: use a structured CmmStatics type rather than [CmmStatic]
I observed that the [CmmStatics] within CmmData uses the list in a very stylised way.
The first item in the list is almost invariably a CmmDataLabel. Many parts of the
compiler pattern match on this list and fail if this is not true.
This patch makes the invariant explicit by introducing a structured type CmmStatics
that holds the label and the list of remaining [CmmStatic].
There is one wrinkle: the x86 backend sometimes wants to output an alignment directive just
before the label. However, this can be easily fixed up by parameterising the native codegen
over the type of CmmStatics (though the GenCmmTop parameterisation) and using a pair
(Alignment, CmmStatics) there instead.
As a result, I think we will be able to remove CmmAlign and CmmDataLabel from the CmmStatic
data type, thus nuking a lot of code and failing pattern matches. This change will come as part
of my next patch.
Diffstat (limited to 'compiler/cmm/CmmParse.y')
| -rw-r--r-- | compiler/cmm/CmmParse.y | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/compiler/cmm/CmmParse.y b/compiler/cmm/CmmParse.y index 60f3bb5623..eceff8350d 100644 --- a/compiler/cmm/CmmParse.y +++ b/compiler/cmm/CmmParse.y @@ -188,21 +188,24 @@ cmmtop :: { ExtCode } -- * we can derive closure and info table labels from a single NAME cmmdata :: { ExtCode } - : 'section' STRING '{' statics '}' - { do ss <- sequence $4; - code (emitData (section $2) (concat ss)) } + : 'section' STRING '{' static_label statics '}' + { do lbl <- $4; + ss <- sequence $5; + code (emitData (section $2) (Statics lbl $ concat ss)) } statics :: { [ExtFCode [CmmStatic]] } : {- empty -} { [] } | static statics { $1 : $2 } +static_label :: { ExtFCode CLabel } + : NAME ':' + {% withThisPackage $ \pkg -> + return (mkCmmDataLabel pkg $1) } + -- Strings aren't used much in the RTS HC code, so it doesn't seem -- worth allowing inline strings. C-- doesn't allow them anyway. static :: { ExtFCode [CmmStatic] } - : NAME ':' - {% withThisPackage $ \pkg -> - return [CmmDataLabel (mkCmmDataLabel pkg $1)] } - + : static_label { liftM (\x -> [CmmDataLabel x]) $1 } | type expr ';' { do e <- $2; return [CmmStaticLit (getLit e)] } | type ';' { return [CmmUninitialised |