Add -stubsourceonly option

Add option to cause Doclava to only generate stubs for classes whose
source is provided. This makes it possible to create stubs for a subset
of all the classes in a package.

This is needed for generating stubs for the JUnit and related classes
being removed from the Android API which includes
com.android.internal.util.Predicate.

Bug: 30188076
Test: make update-legacy-test-api
Change-Id: Icc7355cb562072f5604b6c25c4d620002924317c

2 files changed, 15 insertions, 2 deletions

diff --git a/src/com/google/doclava/Doclava.java b/src/com/google/doclava/Doclava.java
index 9d3f1b6..4a41b32 100644
--- a/src/com/google/doclava/Doclava.java
+++ b/src/com/google/doclava/Doclava.java
@@ -183,6 +183,7 @@ public class Doclava {
     String exactApiFile = null;
     String debugStubsFile = "";
     HashSet<String> stubPackages = null;
+    boolean stubSourceOnly = false;
     ArrayList<String> knownTagsFiles = new ArrayList<String>();
 
     root = r;
@@ -281,6 +282,8 @@ public class Doclava {
         for (String pkg : a[1].split(":")) {
           stubPackages.add(pkg);
         }
+      } else if (a[0].equals("-stubsourceonly")) {
+        stubSourceOnly = true;
       } else if (a[0].equals("-sdkvalues")) {
         sdkValuePath = a[1];
       } else if (a[0].equals("-api")) {
@@ -517,7 +520,8 @@ public class Doclava {
     if (stubsDir != null || apiFile != null || proguardFile != null || removedApiFile != null
         || exactApiFile != null) {
       Stubs.writeStubsAndApi(stubsDir, apiFile, proguardFile, removedApiFile, exactApiFile,
-          stubPackages);
+          stubPackages,
+          stubSourceOnly);
     }
 
     Errors.printErrors();
@@ -788,6 +792,9 @@ public class Doclava {
     if (option.equals("-stubpackages")) {
       return 2;
     }
+    if (option.equals("-stubsourceonly")) {
+      return 1;
+    }
     if (option.equals("-sdkvalues")) {
       return 2;
     }
diff --git a/src/com/google/doclava/Stubs.java b/src/com/google/doclava/Stubs.java
index fdd9d0d..d1dae32 100644
--- a/src/com/google/doclava/Stubs.java
+++ b/src/com/google/doclava/Stubs.java
@@ -28,6 +28,8 @@ import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.PrintStream;
 import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -44,7 +46,8 @@ import java.util.stream.Collectors;
 
 public class Stubs {
   public static void writeStubsAndApi(String stubsDir, String apiFile, String keepListFile,
-      String removedApiFile, String exactApiFile, HashSet<String> stubPackages) {
+      String removedApiFile, String exactApiFile, HashSet<String> stubPackages,
+      boolean stubSourceOnly) {
     // figure out which classes we need
     final HashSet<ClassInfo> notStrippable = new HashSet<ClassInfo>();
     ClassInfo[] all = Converter.allClasses();
@@ -188,6 +191,9 @@ public class Stubs {
     final HashSet<Pattern> stubPackageWildcards = extractWildcards(stubPackages);
     for (ClassInfo cl : notStrippable) {
       if (!cl.isDocOnly()) {
+        if (stubSourceOnly && !Files.exists(Paths.get(cl.position().file))) {
+          continue;
+        }
         if (shouldWriteStub(cl.containingPackage().name(), stubPackages, stubPackageWildcards)) {
           // write out the stubs
           if (stubsDir != null) {