%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1994
+% (c) The University of Glasgow, 1992-2003
%
%************************************************************************
%* *
%************************************************************************
\begin{code}
-#include "HsVersions.h"
-
module SrcLoc (
- SrcLoc, -- abstract
+ SrcLoc, -- Abstract
+
+ mkSrcLoc, isGoodSrcLoc, mkGeneralSrcLoc,
+ noSrcLoc, -- "I'm sorry, I haven't a clue"
+ advanceSrcLoc,
+
+ importedSrcLoc, -- Unknown place in an interface
+ wiredInSrcLoc, -- Something wired into the compiler
+ generatedSrcLoc, -- Code generated within the compiler
+ interactiveSrcLoc, -- Code from an interactive session
+
+ srcLocFile, -- return the file name part
+ srcLocLine, -- return the line part
+ srcLocCol, -- return the column part
+ pprDefnLoc,
- mkSrcLoc, mkSrcLoc2, -- the usual
- mkUnknownSrcLoc, -- "I'm sorry, I haven't a clue"
- mkBuiltinSrcLoc, -- something wired into the compiler
- mkGeneratedSrcLoc, -- code generated within the compiler
- unpackSrcLoc
+ SrcSpan, -- Abstract
+ noSrcSpan,
+ mkGeneralSrcSpan,
+ isGoodSrcSpan,
+ mkSrcSpan, srcLocSpan,
+ combineSrcSpans,
+ srcSpanFile,
+ srcSpanStartLine, srcSpanEndLine,
+ srcSpanStartCol, srcSpanEndCol,
+ srcSpanStart, srcSpanEnd,
+
+ Located(..), getLoc, unLoc, noLoc, eqLocated, cmpLocated, combineLocs, addCLoc
) where
-import Ubiq
+#include "HsVersions.h"
-import PprStyle ( PprStyle(..) )
-import Pretty
+import Util ( thenCmp )
+import Outputable
+import FastString
\end{code}
%************************************************************************
this is the obvious stuff:
\begin{code}
data SrcLoc
- = SrcLoc FAST_STRING -- source file name
- FAST_STRING -- line number in source file
- | SrcLoc2 FAST_STRING -- same, but w/ an Int line#
- FAST_INT
+ = SrcLoc FastString -- A precise location (file name)
+ !Int -- line number, begins at 1
+ !Int -- column number, begins at 0
+ -- Don't ask me why lines start at 1 and columns start at
+ -- zero. That's just the way it is, so there. --SDM
+
+ | ImportedLoc String -- Module name
+
+ | UnhelpfulLoc FastString -- Just a general indication
\end{code}
Note that an entity might be imported via more than one route, and
Things to make 'em:
\begin{code}
-mkSrcLoc = SrcLoc
-mkSrcLoc2 x IBOX(y) = SrcLoc2 x y
-mkUnknownSrcLoc = SrcLoc SLIT("<unknown>") SLIT("<unknown>")
-mkBuiltinSrcLoc = SrcLoc SLIT("<built-into-the-compiler>") SLIT("<none>")
-mkGeneratedSrcLoc = SrcLoc SLIT("<compiler-generated-code>") SLIT("<none>")
-
-unpackSrcLoc (SrcLoc src_file src_line) = (src_file, src_line)
-unpackSrcLoc (SrcLoc2 src_file src_line) = (src_file, _PK_ (show IBOX(src_line)))
+mkSrcLoc x line col = SrcLoc x line col
+noSrcLoc = UnhelpfulLoc FSLIT("<no location info>")
+generatedSrcLoc = UnhelpfulLoc FSLIT("<compiler-generated code>")
+wiredInSrcLoc = UnhelpfulLoc FSLIT("<wired into compiler>")
+interactiveSrcLoc = UnhelpfulLoc FSLIT("<interactive session>")
+
+mkGeneralSrcLoc :: FastString -> SrcLoc
+mkGeneralSrcLoc = UnhelpfulLoc
+
+importedSrcLoc :: String -> SrcLoc
+importedSrcLoc mod_name = ImportedLoc mod_name
+
+isGoodSrcLoc (SrcLoc _ _ _) = True
+isGoodSrcLoc other = False
+
+srcLocFile :: SrcLoc -> FastString
+srcLocFile (SrcLoc fname _ _) = fname
+srcLocFile other = FSLIT("<unknown file")
+
+srcLocLine :: SrcLoc -> Int
+srcLocLine (SrcLoc _ l c) = l
+srcLocLine other = panic "srcLocLine: unknown line"
+
+srcLocCol :: SrcLoc -> Int
+srcLocCol (SrcLoc _ l c) = c
+srcLocCol other = panic "srcLocCol: unknown col"
+
+advanceSrcLoc :: SrcLoc -> Char -> SrcLoc
+advanceSrcLoc (SrcLoc f l c) '\n' = SrcLoc f (l + 1) 0
+advanceSrcLoc (SrcLoc f l c) _ = SrcLoc f l (c + 1)
+advanceSrcLoc loc _ = loc -- Better than nothing
\end{code}
%************************************************************************
%************************************************************************
\begin{code}
+-- SrcLoc is an instance of Ord so that we can sort error messages easily
+instance Eq SrcLoc where
+ loc1 == loc2 = case loc1 `cmpSrcLoc` loc2 of
+ EQ -> True
+ other -> False
+
+instance Ord SrcLoc where
+ compare = cmpSrcLoc
+
+cmpSrcLoc (UnhelpfulLoc s1) (UnhelpfulLoc s2) = s1 `compare` s2
+cmpSrcLoc (UnhelpfulLoc _) other = LT
+
+cmpSrcLoc (ImportedLoc _) (UnhelpfulLoc _) = GT
+cmpSrcLoc (ImportedLoc m1) (ImportedLoc m2) = m1 `compare` m2
+cmpSrcLoc (ImportedLoc _) other = LT
+
+cmpSrcLoc (SrcLoc s1 l1 c1) (SrcLoc s2 l2 c2)
+ = (s1 `compare` s2) `thenCmp` (l1 `cmpline` l2) `thenCmp` (c1 `cmpline` c2)
+ where
+ l1 `cmpline` l2 | l1 < l2 = LT
+ | l1 == l2 = EQ
+ | otherwise = GT
+cmpSrcLoc (SrcLoc _ _ _) other = GT
+
instance Outputable SrcLoc where
- ppr PprForUser (SrcLoc src_file src_line)
- = ppBesides [ ppChar '"', ppPStr src_file, ppPStr SLIT("\", line "), ppPStr src_line ]
+ ppr (SrcLoc src_path src_line src_col)
+ = getPprStyle $ \ sty ->
+ if userStyle sty || debugStyle sty then
+ hcat [ ftext src_path, char ':',
+ int src_line,
+ char ':', int src_col
+ ]
+ else
+ hcat [text "{-# LINE ", int src_line, space,
+ char '\"', ftext src_path, text " #-}"]
+
+ ppr (ImportedLoc mod) = ptext SLIT("Imported from") <+> text mod
+ ppr (UnhelpfulLoc s) = ftext s
+\end{code}
+
+%************************************************************************
+%* *
+\subsection[SrcSpan]{Source Spans}
+%* *
+%************************************************************************
+
+\begin{code}
+{- |
+A SrcSpan delimits a portion of a text file. It could be represented
+by a pair of (line,column) coordinates, but in fact we optimise
+slightly by using more compact representations for single-line and
+zero-length spans, both of which are quite common.
+
+The end position is defined to be the column *after* the end of the
+span. That is, a span of (1,1)-(1,2) is one character long, and a
+span of (1,1)-(1,1) is zero characters long.
+-}
+data SrcSpan
+ = SrcSpanOneLine -- a common case: a single line
+ { srcSpanFile :: FastString,
+ srcSpanLine :: !Int,
+ srcSpanSCol :: !Int,
+ srcSpanECol :: !Int
+ }
+
+ | SrcSpanMultiLine
+ { srcSpanFile :: FastString,
+ srcSpanSLine :: !Int,
+ srcSpanSCol :: !Int,
+ srcSpanELine :: !Int,
+ srcSpanECol :: !Int
+ }
+
+ | SrcSpanPoint
+ { srcSpanFile :: FastString,
+ srcSpanLine :: !Int,
+ srcSpanCol :: !Int
+ }
+
+ | ImportedSpan String -- Module name
+
+ | UnhelpfulSpan FastString -- Just a general indication
+ -- also used to indicate an empty span
+
+ deriving Eq
+
+-- We want to order SrcSpans first by the start point, then by the end point.
+instance Ord SrcSpan where
+ a `compare` b =
+ (srcSpanStart a `compare` srcSpanStart b) `thenCmp`
+ (srcSpanEnd a `compare` srcSpanEnd b)
+
+noSrcSpan = UnhelpfulSpan FSLIT("<no location info>")
+
+mkGeneralSrcSpan :: FastString -> SrcSpan
+mkGeneralSrcSpan = UnhelpfulSpan
+
+isGoodSrcSpan SrcSpanOneLine{} = True
+isGoodSrcSpan SrcSpanMultiLine{} = True
+isGoodSrcSpan SrcSpanPoint{} = True
+isGoodSrcSpan _ = False
+
+srcSpanStartLine SrcSpanOneLine{ srcSpanLine=l } = l
+srcSpanStartLine SrcSpanMultiLine{ srcSpanSLine=l } = l
+srcSpanStartLine SrcSpanPoint{ srcSpanLine=l } = l
+srcSpanStartLine _ = panic "SrcLoc.srcSpanStartLine"
+
+srcSpanEndLine SrcSpanOneLine{ srcSpanLine=l } = l
+srcSpanEndLine SrcSpanMultiLine{ srcSpanELine=l } = l
+srcSpanEndLine SrcSpanPoint{ srcSpanLine=l } = l
+srcSpanEndLine _ = panic "SrcLoc.srcSpanEndLine"
+
+srcSpanStartCol SrcSpanOneLine{ srcSpanSCol=l } = l
+srcSpanStartCol SrcSpanMultiLine{ srcSpanSCol=l } = l
+srcSpanStartCol SrcSpanPoint{ srcSpanCol=l } = l
+srcSpanStartCol _ = panic "SrcLoc.srcSpanStartCol"
+
+srcSpanEndCol SrcSpanOneLine{ srcSpanECol=c } = c
+srcSpanEndCol SrcSpanMultiLine{ srcSpanECol=c } = c
+srcSpanEndCol SrcSpanPoint{ srcSpanCol=c } = c
+srcSpanEndCol _ = panic "SrcLoc.srcSpanEndCol"
+
+srcSpanStart (ImportedSpan str) = ImportedLoc str
+srcSpanStart (UnhelpfulSpan str) = UnhelpfulLoc str
+srcSpanStart s =
+ mkSrcLoc (srcSpanFile s)
+ (srcSpanStartLine s)
+ (srcSpanStartCol s)
+
+srcSpanEnd (ImportedSpan str) = ImportedLoc str
+srcSpanEnd (UnhelpfulSpan str) = UnhelpfulLoc str
+srcSpanEnd s =
+ mkSrcLoc (srcSpanFile s)
+ (srcSpanEndLine s)
+ (srcSpanEndCol s)
+
+srcLocSpan :: SrcLoc -> SrcSpan
+srcLocSpan (ImportedLoc str) = ImportedSpan str
+srcLocSpan (UnhelpfulLoc str) = UnhelpfulSpan str
+srcLocSpan (SrcLoc file line col) = SrcSpanPoint file line col
+
+mkSrcSpan :: SrcLoc -> SrcLoc -> SrcSpan
+mkSrcSpan (ImportedLoc str) _ = ImportedSpan str
+mkSrcSpan (UnhelpfulLoc str) _ = UnhelpfulSpan str
+mkSrcSpan _ (ImportedLoc str) = ImportedSpan str
+mkSrcSpan _ (UnhelpfulLoc str) = UnhelpfulSpan str
+mkSrcSpan loc1 loc2
+ | line1 == line2 = if col1 == col2
+ then SrcSpanPoint file line1 col1
+ else SrcSpanOneLine file line1 col1 col2
+ | otherwise = SrcSpanMultiLine file line1 col1 line2 col2
+ where
+ line1 = srcLocLine loc1
+ line2 = srcLocLine loc2
+ col1 = srcLocCol loc1
+ col2 = srcLocCol loc2
+ file = srcLocFile loc1
+
+combineSrcSpans :: SrcSpan -> SrcSpan -> SrcSpan
+-- Assumes the 'file' part is the same in both
+combineSrcSpans (ImportedSpan str) _ = ImportedSpan str
+combineSrcSpans (UnhelpfulSpan str) r = r -- this seems more useful
+combineSrcSpans _ (ImportedSpan str) = ImportedSpan str
+combineSrcSpans l (UnhelpfulSpan str) = l
+combineSrcSpans start end
+ = case line1 `compare` line2 of
+ EQ -> case col1 `compare` col2 of
+ EQ -> SrcSpanPoint file line1 col1
+ LT -> SrcSpanOneLine file line1 col1 col2
+ GT -> SrcSpanOneLine file line1 col2 col1
+ LT -> SrcSpanMultiLine file line1 col1 line2 col2
+ GT -> SrcSpanMultiLine file line2 col2 line1 col1
+ where
+ line1 = srcSpanStartLine start
+ col1 = srcSpanStartCol start
+ line2 = srcSpanEndLine end
+ col2 = srcSpanEndCol end
+ file = srcSpanFile start
+
+pprDefnLoc :: SrcLoc -> SDoc
+-- "defined at ..." or "imported from ..."
+pprDefnLoc loc
+ | isGoodSrcLoc loc = ptext SLIT("Defined at") <+> ppr loc
+ | otherwise = ppr loc
+
+instance Outputable SrcSpan where
+ ppr span
+ = getPprStyle $ \ sty ->
+ if userStyle sty || debugStyle sty then
+ pprUserSpan span
+ else
+ hcat [text "{-# LINE ", int (srcSpanStartLine span), space,
+ char '\"', ftext (srcSpanFile span), text " #-}"]
+
+
+pprUserSpan (SrcSpanOneLine src_path line start_col end_col)
+ = hcat [ ftext src_path, char ':',
+ int line,
+ char ':', int start_col
+ ]
+ <> if end_col - start_col <= 1
+ then empty
+ -- for single-character or point spans, we just output the starting
+ -- column number
+ else char '-' <> int (end_col-1)
+
+pprUserSpan (SrcSpanMultiLine src_path sline scol eline ecol)
+ = hcat [ ftext src_path, char ':',
+ parens (int sline <> char ',' <> int scol),
+ char '-',
+ parens (int eline <> char ',' <>
+ if ecol == 0 then int ecol else int (ecol-1))
+ ]
+
+pprUserSpan (SrcSpanPoint src_path line col)
+ = hcat [ ftext src_path, char ':',
+ int line,
+ char ':', int col
+ ]
+
+pprUserSpan (ImportedSpan mod) = ptext SLIT("Imported from") <+> quotes (text mod)
+pprUserSpan (UnhelpfulSpan s) = ftext s
+\end{code}
+
+%************************************************************************
+%* *
+\subsection[Located]{Attaching SrcSpans to things}
+%* *
+%************************************************************************
+
+\begin{code}
+-- | We attach SrcSpans to lots of things, so let's have a datatype for it.
+data Located e = L SrcSpan e
+
+unLoc :: Located e -> e
+unLoc (L _ e) = e
+
+getLoc :: Located e -> SrcSpan
+getLoc (L l _) = l
+
+noLoc :: e -> Located e
+noLoc e = L noSrcSpan e
+
+combineLocs :: Located a -> Located b -> SrcSpan
+combineLocs a b = combineSrcSpans (getLoc a) (getLoc b)
+
+addCLoc :: Located a -> Located b -> c -> Located c
+addCLoc a b c = L (combineSrcSpans (getLoc a) (getLoc b)) c
+
+-- not clear whether to add a general Eq instance, but this is useful sometimes:
+eqLocated :: Eq a => Located a -> Located a -> Bool
+eqLocated a b = unLoc a == unLoc b
+
+-- not clear whether to add a general Eq instance, but this is useful sometimes:
+cmpLocated :: Ord a => Located a -> Located a -> Ordering
+cmpLocated a b = unLoc a `compare` unLoc b
- ppr sty (SrcLoc src_file src_line)
- = ppBesides [ppPStr SLIT("{-# LINE "), ppPStr src_line, ppSP,
- ppChar '"', ppPStr src_file, ppPStr SLIT("\" #-}")]
+instance Functor Located where
+ fmap f (L l e) = L l (f e)
- ppr sty (SrcLoc2 src_file src_line)
- = ppr sty (SrcLoc src_file (_PK_ (show IBOX(src_line))))
+instance Outputable e => Outputable (Located e) where
+ ppr (L span e) = ppr e
+ -- do we want to dump the span in debugSty mode?
\end{code}