Track Option placement within a priority category.

An option has precedence over previous options at the same enum-valued priority. Track its placement in this ordering explicitly.

This will allow after-the-fact expansion of expansion options such that they correctly take precedence or not compared to other mentions of the same flag. This is needed to fix --config's expansion.

RELNOTES: None.
PiperOrigin-RevId: 172367996

1 files changed, 83 insertions, 35 deletions

diff --git a/src/main/java/com/google/devtools/common/options/OptionPriority.java b/src/main/java/com/google/devtools/common/options/OptionPriority.java
index a28f012822..96c471ed74 100644
--- a/src/main/java/com/google/devtools/common/options/OptionPriority.java
+++ b/src/main/java/com/google/devtools/common/options/OptionPriority.java
@@ -13,50 +13,98 @@
 // limitations under the License.
 package com.google.devtools.common.options;
 
+import java.util.Objects;
+
 /**
- * The priority of option values, in order of increasing priority.
- *
- * <p>In general, new values for options can only override values with a lower or
- * equal priority. Option values provided in annotations in an options class are
- * implicitly at the priority {@code DEFAULT}.
+ * The position of an option in the interpretation order. Options are interpreted using a
+ * last-option-wins system for single valued options, and are listed in that order for
+ * multiple-valued options.
  *
- * <p>The ordering of the priorities is the source-code order. This is consistent
- * with the automatically generated {@code compareTo} method as specified by the
- * Java Language Specification. DO NOT change the source-code order of these
- * values, or you will break code that relies on the ordering.
+ * <p>The position of the option is in category order, and within the priority category in index
+ * order.
  */
-public enum OptionPriority {
+public class OptionPriority implements Comparable<OptionPriority> {
+  private final PriorityCategory priorityCategory;
+  private final int index;
 
-  /**
-   * The priority of values specified in the {@link Option} annotation. This
-   * should never be specified in calls to {@link OptionsParser#parse}.
-   */
-  DEFAULT,
+  private OptionPriority(PriorityCategory priorityCategory, int index) {
+    this.priorityCategory = priorityCategory;
+    this.index = index;
+  }
 
-  /**
-   * Overrides default options at runtime, while still allowing the values to be
-   * overridden manually.
-   */
-  COMPUTED_DEFAULT,
+  public static OptionPriority lowestOptionPriorityAtCategory(PriorityCategory category) {
+    return new OptionPriority(category, 0);
+  }
 
-  /**
-   * For options coming from a configuration file or rc file.
-   */
-  RC_FILE,
+  public static OptionPriority nextOptionPriority(OptionPriority priority) {
+    return new OptionPriority(priority.priorityCategory, priority.index + 1);
+  }
 
-  /**
-   * For options coming from the command line.
-   */
-  COMMAND_LINE,
+  public PriorityCategory getPriorityCategory() {
+    return priorityCategory;
+  }
 
-  /**
-   * For options coming from invocation policy.
-   */
-  INVOCATION_POLICY,
+  @Override
+  public int compareTo(OptionPriority o) {
+    if (priorityCategory.equals(o.priorityCategory)) {
+      return index - o.index;
+    }
+    return priorityCategory.ordinal() - o.priorityCategory.ordinal();
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (o instanceof OptionPriority) {
+      OptionPriority other = (OptionPriority) o;
+      return other.priorityCategory.equals(priorityCategory) && other.index == index;
+    }
+    return false;
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(priorityCategory, index);
+  }
 
   /**
-   * This priority can be used to unconditionally override any user-provided options.
-   * This should be used rarely and with caution!
+   * The priority of option values, in order of increasing priority.
+   *
+   * <p>In general, new values for options can only override values with a lower or equal priority.
+   * Option values provided in annotations in an options class are implicitly at the priority {@code
+   * DEFAULT}.
+   *
+   * <p>The ordering of the priorities is the source-code order. This is consistent with the
+   * automatically generated {@code compareTo} method as specified by the Java Language
+   * Specification. DO NOT change the source-code order of these values, or you will break code that
+   * relies on the ordering.
    */
-  SOFTWARE_REQUIREMENT;
+  public enum PriorityCategory {
+
+    /**
+     * The priority of values specified in the {@link Option} annotation. This should never be
+     * specified in calls to {@link OptionsParser#parse}.
+     */
+    DEFAULT,
+
+    /**
+     * Overrides default options at runtime, while still allowing the values to be overridden
+     * manually.
+     */
+    COMPUTED_DEFAULT,
+
+    /** For options coming from a configuration file or rc file. */
+    RC_FILE,
+
+    /** For options coming from the command line. */
+    COMMAND_LINE,
+
+    /** For options coming from invocation policy. */
+    INVOCATION_POLICY,
+
+    /**
+     * This priority can be used to unconditionally override any user-provided options. This should
+     * be used rarely and with caution!
+     */
+    SOFTWARE_REQUIREMENT
+  }
 }