Allow users of Blaze Lexer to explicitly specify the line-number table of a file.

--
MOS_MIGRATED_REVID=96039514

src/main/java/com/google/devtools/build/lib/syntax/Lexer.java

diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Lexer.java b/src/main/java/com/google/devtools/build/lib/syntax/Lexer.java
index 5f6c769..c4a58a9 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/Lexer.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Lexer.java
@@ -88,20 +88,26 @@
    * Constructs a lexer which tokenizes the contents of the specified
    * InputBuffer. Any errors during lexing are reported on "handler".
    */
-  public Lexer(ParserInputSource input, EventHandler eventHandler, boolean parsePython) {
+  public Lexer(ParserInputSource input, EventHandler eventHandler, boolean parsePython,
+      LineNumberTable lineNumberTable) {
     this.buffer = input.getContent();
     this.pos = 0;
     this.parsePython = parsePython;
     this.eventHandler = eventHandler;
-    this.locationInfo =
-        new LocationInfo(input.getPath(), LineNumberTable.create(buffer, input.getPath()));
+    this.locationInfo = new LocationInfo(input.getPath(), lineNumberTable);
 
     indentStack.push(0);
     tokenize();
   }
 
   public Lexer(ParserInputSource input, EventHandler eventHandler) {
-    this(input, eventHandler, false);
+    this(input, eventHandler, /*parsePython=*/false,
+        LineNumberTable.create(input.getContent(), input.getPath()));
+  }
+
+  public Lexer(ParserInputSource input, EventHandler eventHandler, boolean parsePython) {
+    this(input, eventHandler, parsePython,
+        LineNumberTable.create(input.getContent(), input.getPath()));
   }
 
   /**

src/main/java/com/google/devtools/build/lib/syntax/LineNumberTable.java

diff --git a/src/main/java/com/google/devtools/build/lib/syntax/LineNumberTable.java b/src/main/java/com/google/devtools/build/lib/syntax/LineNumberTable.java
index 7867455..3bcf0a0 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/LineNumberTable.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/LineNumberTable.java
@@ -35,7 +35,7 @@
  * their buffer using {@link #create}. The client can then ask for the line and column given a
  * position using ({@link #getLineAndColumn(int)}).
  */
-abstract class LineNumberTable implements Serializable {
+public abstract class LineNumberTable implements Serializable {
 
   /**
    * Returns the (line, column) pair for the specified offset.
@@ -67,7 +67,7 @@
    * offsets of newlines.
    */
   @Immutable
-  private static class Regular extends LineNumberTable  {
+  public static class Regular extends LineNumberTable {
 
     /**
      * A mapping from line number (line >= 1) to character offset into the file.
@@ -76,7 +76,7 @@
     private final PathFragment path;
     private final int bufferLength;
 
-    private Regular(char[] buffer, PathFragment path) {
+    public Regular(char[] buffer, PathFragment path) {
       // Compute the size.
       int size = 2;
       for (int i = 0; i < buffer.length; i++) {
@@ -154,7 +154,7 @@
    */
   // TODO(bazel-team): Use binary search instead of linear search.
   @Immutable
-  private static class HashLine extends LineNumberTable {
+  public static class HashLine extends LineNumberTable {
 
     /**
      * Represents a "#line" directive
@@ -185,7 +185,7 @@
     private final PathFragment defaultPath;
     private final int bufferLength;
 
-    private HashLine(char[] buffer, PathFragment defaultPath) {
+    public HashLine(char[] buffer, PathFragment defaultPath) {
       CharSequence bufString = CharBuffer.wrap(buffer);
       Matcher m = pattern.matcher(bufString);
       List<SingleHashLine> unorderedTable = new ArrayList<>();