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Compiler for the Scala Programming Language
/* NSC -- new Scala compiler
* Copyright 2005-2012 LAMP/EPFL
* @author Martin Odersky
*/
package scala.reflect.internal.util
import scala.tools.nsc.io.{ AbstractFile, VirtualFile }
import scala.collection.mutable.ArrayBuffer
import annotation.tailrec
import java.util.regex.Pattern
import java.io.IOException
import scala.reflect.internal.Chars._
/** abstract base class of a source file used in the compiler */
abstract class SourceFile {
def content : Array[Char] // normalized, must end in SU
def file : AbstractFile
def isLineBreak(idx : Int) : Boolean
def isSelfContained: Boolean
def length : Int
def position(offset: Int) : Position = {
assert(offset < length, file + ": " + offset + " >= " + length)
new OffsetPosition(this, offset)
}
def position(line: Int, column: Int) : Position = new OffsetPosition(this, lineToOffset(line) + column)
def offsetToLine(offset: Int): Int
def lineToOffset(index : Int): Int
/** Map a position to a position in the underlying source file.
* For regular source files, simply return the argument.
*/
def positionInUltimateSource(position: Position) = position
override def toString() = file.name
def dbg(offset: Int) = (new OffsetPosition(this, offset)).dbgString
def path = file.path
def beginsWith(offset: Int, text: String): Boolean =
(content drop offset) startsWith text
def lineToString(index: Int): String =
content drop lineToOffset(index) takeWhile (c => !isLineBreakChar(c.toChar)) mkString ""
@tailrec
final def skipWhitespace(offset: Int): Int =
if (content(offset).isWhitespace) skipWhitespace(offset + 1) else offset
def identifier(pos: Position): Option[String] = None
}
/** An object representing a missing source file.
*/
object NoSourceFile extends SourceFile {
def content = Array()
def file = NoFile
def isLineBreak(idx: Int) = false
def isSelfContained = true
def length = -1
def offsetToLine(offset: Int) = -1
def lineToOffset(index : Int) = -1
override def toString = ""
}
object NoFile extends VirtualFile("", "")
object ScriptSourceFile {
/** Length of the script header from the given content, if there is one.
* The header begins with "#!" or "::#!" and ends with a line starting
* with "!#" or "::!#".
*/
def headerLength(cs: Array[Char]): Int = {
val headerPattern = Pattern.compile("""((?m)^(::)?!#.*|^.*/env .*)(\r|\n|\r\n)""")
val headerStarts = List("#!", "::#!")
if (headerStarts exists (cs startsWith _)) {
val matcher = headerPattern matcher cs.mkString
if (matcher.find) matcher.end
else throw new IOException("script file does not close its header with !# or ::!#")
}
else 0
}
def stripHeader(cs: Array[Char]): Array[Char] = cs drop headerLength(cs)
def apply(file: AbstractFile, content: Array[Char]) = {
val underlying = new BatchSourceFile(file, content)
val headerLen = headerLength(content)
val stripped = new ScriptSourceFile(underlying, content drop headerLen, headerLen)
stripped
}
}
import ScriptSourceFile._
class ScriptSourceFile(underlying: BatchSourceFile, content: Array[Char], override val start: Int) extends BatchSourceFile(underlying.file, content) {
override def isSelfContained = false
override def positionInUltimateSource(pos: Position) =
if (!pos.isDefined) super.positionInUltimateSource(pos)
else pos.withSource(underlying, start)
}
/** a file whose contents do not change over time */
class BatchSourceFile(val file : AbstractFile, val content0: Array[Char]) extends SourceFile {
def this(_file: AbstractFile) = this(_file, _file.toCharArray)
def this(sourceName: String, cs: Seq[Char]) = this(new VirtualFile(sourceName), cs.toArray)
def this(file: AbstractFile, cs: Seq[Char]) = this(file, cs.toArray)
// If non-whitespace tokens run all the way up to EOF,
// positions go wrong because the correct end of the last
// token cannot be used as an index into the char array.
// The least painful way to address this was to add a
// newline to the array.
val content = (
if (content0.length == 0 || !content0.last.isWhitespace)
content0 :+ '\n'
else content0
)
val length = content.length
def start = 0
def isSelfContained = true
override def identifier(pos: Position) =
if (pos.isDefined && pos.source == this && pos.point != -1) {
def isOK(c: Char) = isIdentifierPart(c) || isOperatorPart(c)
Some(new String(content drop pos.point takeWhile isOK))
} else {
super.identifier(pos)
}
def isLineBreak(idx: Int) =
if (idx >= length) false else {
val ch = content(idx)
// don't identify the CR in CR LF as a line break, since LF will do.
if (ch == CR) (idx + 1 == length) || (content(idx + 1) != LF)
else isLineBreakChar(ch)
}
def calculateLineIndices(cs: Array[Char]) = {
val buf = new ArrayBuffer[Int]
buf += 0
for (i <- 0 until cs.length) if (isLineBreak(i)) buf += i + 1
buf += cs.length // sentinel, so that findLine below works smoother
buf.toArray
}
private lazy val lineIndices: Array[Int] = calculateLineIndices(content)
def lineToOffset(index : Int): Int = lineIndices(index)
private var lastLine = 0
/** Convert offset to line in this source file
* Lines are numbered from 0
*/
def offsetToLine(offset: Int): Int = {
val lines = lineIndices
def findLine(lo: Int, hi: Int, mid: Int): Int =
if (offset < lines(mid)) findLine(lo, mid - 1, (lo + mid - 1) / 2)
else if (offset >= lines(mid + 1)) findLine(mid + 1, hi, (mid + 1 + hi) / 2)
else mid
lastLine = findLine(0, lines.length, lastLine)
lastLine
}
override def equals(that : Any) = that match {
case that : BatchSourceFile => file.path == that.file.path && start == that.start
case _ => false
}
override def hashCode = file.path.## + start.##
}