Fix NPE in vfs profile output

Also removed some unused code while I was here.

Fixes https://github.com/bazelbuild/bazel/issues/726.

--
MOS_MIGRATED_REVID=113758464

3 files changed, 17 insertions, 26 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/profiler/output/PhaseHtml.java b/src/main/java/com/google/devtools/build/lib/profiler/output/PhaseHtml.java
index 0403768112..1184b221f8 100644
--- a/src/main/java/com/google/devtools/build/lib/profiler/output/PhaseHtml.java
+++ b/src/main/java/com/google/devtools/build/lib/profiler/output/PhaseHtml.java
@@ -28,6 +28,8 @@ import java.io.PrintStream;
 import java.util.Arrays;
 import java.util.EnumMap;
 
+import javax.annotation.Nullable;
+
 /**
  * Output {@link PhaseSummaryStatistics}, {@link PhaseStatistics} and {@link PhaseVfsStatistics}
  * in HTML format.
@@ -223,8 +225,8 @@ public final class PhaseHtml extends HtmlPrinter {
    * by descending duration. If multiple of the same VFS operation were logged for the same path,
    * print the total duration.
    */
-  private void printVfsStatistics(PhaseVfsStatistics stats) {
-    if (vfsStatsLimit == 0 || stats.isEmpty()) {
+  private void printVfsStatistics(@Nullable PhaseVfsStatistics stats) {
+    if (vfsStatsLimit == 0 || stats == null || stats.isEmpty()) {
       return;
     }
 
diff --git a/src/main/java/com/google/devtools/build/lib/profiler/output/PhaseText.java b/src/main/java/com/google/devtools/build/lib/profiler/output/PhaseText.java
index f3b71098bf..71be9dca4c 100644
--- a/src/main/java/com/google/devtools/build/lib/profiler/output/PhaseText.java
+++ b/src/main/java/com/google/devtools/build/lib/profiler/output/PhaseText.java
@@ -27,6 +27,8 @@ import java.io.PrintStream;
 import java.util.Arrays;
 import java.util.EnumMap;
 
+import javax.annotation.Nullable;
+
 /**
  * Output {@link PhaseSummaryStatistics}, {@link PhaseStatistics} and {@link PhaseVfsStatistics}
  * in text format.
@@ -107,10 +109,7 @@ public final class PhaseText extends TextPrinter {
     if (!stats.isEmpty()) {
       printTimingDistribution(stats);
       printLn();
-      if (vfsStatsLimit != 0) {
-        printVfsStatistics(stats.getVfsStatistics());
-        printLn();
-      }
+      printVfsStatistics(stats.getVfsStatistics());
     }
   }
 
@@ -171,10 +170,7 @@ public final class PhaseText extends TextPrinter {
       printLn();
     }
 
-    if (vfsStatsLimit != 0) {
-      printVfsStatistics(execPhase.getVfsStatistics());
-      printLn();
-    }
+    printVfsStatistics(execPhase.getVfsStatistics());
   }
 
   /**
@@ -199,10 +195,13 @@ public final class PhaseText extends TextPrinter {
    * sorted by descending duration. If multiple of the same VFS operation were logged for the same
    * path, print the total duration.
    */
-  private void printVfsStatistics(PhaseVfsStatistics stats) {
+  private void printVfsStatistics(@Nullable PhaseVfsStatistics stats) {
+    if (vfsStatsLimit == 0 || stats == null || stats.isEmpty()) {
+      return;
+    }
+
     lnPrint("VFS path statistics:");
     lnPrintf("%15s %10s %10s %s", "Type", "Frequency", "Duration", "Path");
-
     for (ProfilerTask type : stats) {
       int numPrinted = 0;
       for (Stat stat : stats.getSortedStatistics(type)) {
@@ -218,6 +217,7 @@ public final class PhaseText extends TextPrinter {
             stat.path);
       }
     }
+    printLn();
   }
 }
 
diff --git a/src/main/java/com/google/devtools/build/lib/profiler/statistics/PhaseStatistics.java b/src/main/java/com/google/devtools/build/lib/profiler/statistics/PhaseStatistics.java
index 55655576d9..b8e303b3f1 100644
--- a/src/main/java/com/google/devtools/build/lib/profiler/statistics/PhaseStatistics.java
+++ b/src/main/java/com/google/devtools/build/lib/profiler/statistics/PhaseStatistics.java
@@ -26,6 +26,8 @@ import java.util.EnumMap;
 import java.util.Iterator;
 import java.util.List;
 
+import javax.annotation.Nullable;
+
 /**
  * Extracts and keeps statistics for one {@link ProfilePhase} for formatting to various outputs.
  */
@@ -38,7 +40,6 @@ public final class PhaseStatistics implements Iterable<ProfilerTask> {
   private final EnumMap<ProfilerTask, Long> taskCounts;
   private final PhaseVfsStatistics vfsStatistics;
   private boolean wasExecuted;
-  private int count;
 
   public PhaseStatistics(ProfilePhase phase, boolean generateVfsStatistics) {
     this.phase = phase;
@@ -84,7 +85,6 @@ public final class PhaseStatistics implements Iterable<ProfilerTask> {
         add(taskCounts, type, count);
         add(taskDurations, type, totalTime);
       }
-      count++;
     }
   }
 
@@ -107,21 +107,14 @@ public final class PhaseStatistics implements Iterable<ProfilerTask> {
         add(taskCounts, type, otherCount);
         add(taskDurations, type, otherDuration);
       }
-      count++;
     }
   }
 
-  /**
-   * @return how many executions of this phase were accumulated
-   */
-  public int getPhaseCount() {
-    return count;
-  }
-
   public ProfilePhase getProfilePhase() {
     return phase;
   }
 
+  @Nullable
   public PhaseVfsStatistics getVfsStatistics() {
     return vfsStatistics;
   }
@@ -144,10 +137,6 @@ public final class PhaseStatistics implements Iterable<ProfilerTask> {
     return phaseDurationNanos;
   }
 
-  public long getTotalDurationNanos() {
-    return totalDurationNanos;
-  }
-
   /**
    * @return true if a task of the given {@link ProfilerTask} type was executed in this phase
    */