Skylark parser: make the end position of location ranges inclusive.

Previously, the end line and column of a location were the position past the actual end of a location. This makes sense for the end offset, because one can use `input.substring(startOffset, endOffset)` to get the string belonging to an ASTNode.

However the line and column (as opposed to the offset) aren't used for that. Therefore I made the change that the end line and column now point to the last character in the location. This is also they way every compiler I know does it.

RELNOTES: none
PiperOrigin-RevId: 170723732

1 files changed, 12 insertions, 7 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/events/Location.java b/src/main/java/com/google/devtools/build/lib/events/Location.java
index 842025436a..24d2c2dcb8 100644
--- a/src/main/java/com/google/devtools/build/lib/events/Location.java
+++ b/src/main/java/com/google/devtools/build/lib/events/Location.java
@@ -17,7 +17,6 @@ package com.google.devtools.build.lib.events;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.lib.vfs.PathFragment;
-
 import java.io.Serializable;
 import java.util.Objects;
 
@@ -117,11 +116,11 @@ public abstract class Location implements Serializable {
   }
 
   /**
-   * Returns the end offset relative to the beginning of the file the object
-   * resides in.
+   * Returns the end offset relative to the beginning of the file the object resides in.
    *
-   * <p>The end offset is one position past the actual end position, making this method
-   * behave in a compatible fashion with {@link String#substring(int, int)}.
+   * <p>The end offset is one position past the last character in range, making this method behave
+   * in a compatible fashion with {@link String#substring(int, int)}. (By contrast, {@link
+   * #getEndLineAndColumn} returns the actual end position.)
    *
    * <p>To compute the length of this location, use {@code getEndOffset() - getStartOffset()}.
    */
@@ -161,8 +160,14 @@ public abstract class Location implements Serializable {
   }
 
   /**
-   * Returns a (line, column) pair corresponding to the position denoted by
-   * getEndOffset.  Returns null if this information is not available.
+   * Returns a (line, column) pair corresponding to the end position or null if this information is
+   * unavailable.
+   *
+   * <p>The returned line and column are the position of the last character in the location range.
+   * (By contrast, {@link #getEndOffset} returns the position <strong>past</strong> the actual end
+   * position.) In particular, this means that the location spans {@code
+   * getEndLineAndColumn().getColumn() - getStartLineAndColumn().getColumn() + 1} columns but
+   * contains {@code getEndOffset() - getStartOffset()} characters.
    */
   public LineAndColumn getEndLineAndColumn() {
     return null;