Fix Java comment format.

TrimmedLines was copied from hidl-gen to do this, but we weren't using
it in the output.

For simplicity, this converts a single-line block comment to a
multi-line block comment.

Fixes: 202563750
Test: goldens
Change-Id: I2130a32702fb0bc87156363d9dc0e7e7edb57621

5 files changed, 48 insertions, 53 deletions

diff --git a/aidl_unittest.cpp b/aidl_unittest.cpp
index 78739b44..fd64309f 100644
--- a/aidl_unittest.cpp
+++ b/aidl_unittest.cpp
@@ -4630,22 +4630,18 @@ TEST_F(AidlTest, FormatCommentsForJava) {
       {{{"/*\n"
          " * Hello, world!\n"
          " */"}},
-       "/**\n"
-       " * Hello, world!\n"
-       " */"},
-      {{{"/* @hide */"}}, "/** @hide */"},
+       "/** Hello, world! */\n"},
+      {{{"/* @hide */"}}, "/** @hide */\n"},
       {{{"/**\n"
          "   @param foo ...\n"
          "*/"}},
-       "/**\n"
-       "   @param foo ...\n"
-       "*/"},
-      {{{"/* @hide */"}, {"/* @hide */"}}, "/* @hide *//** @hide */"},
+       "/** @param foo ... */\n"},
+      {{{"/* @hide */"}, {"/* @hide */"}}, "/* @hide */\n/** @hide */\n"},
       {{{"/* @deprecated first */"}, {"/* @deprecated second */"}},
-       "/* @deprecated first *//** @deprecated second */"},
-      {{{"/* @deprecated */"}, {"/** @param foo */"}}, "/* @deprecated *//** @param foo */"},
+       "/* @deprecated first */\n/** @deprecated second */\n"},
+      {{{"/* @deprecated */"}, {"/** @param foo */"}}, "/* @deprecated */\n/** @param foo */\n"},
       // Line comments are printed as they are
-      {{{"/* @deprecated */"}, {"// line comments\n"}}, "/* @deprecated */// line comments\n"},
+      {{{"/* @deprecated */"}, {"// line comments\n"}}, "/* @deprecated */\n// line comments\n"},
   };
   for (const auto& [input, formatted] : testcases) {
     EXPECT_EQ(formatted, FormatCommentsForJava(input));
diff --git a/comments.cpp b/comments.cpp
index afbdc8f8..8feee285 100644
--- a/comments.cpp
+++ b/comments.cpp
@@ -40,6 +40,7 @@ namespace {
 
 static const std::string_view kLineCommentBegin = "//";
 static const std::string_view kBlockCommentBegin = "/*";
+static const std::string_view kBlockCommentMid = " *";
 static const std::string_view kBlockCommentEnd = "*/";
 static const std::string_view kDocCommentBegin = "/**";
 static const std::string kTagDeprecated = "@deprecated";
@@ -222,15 +223,31 @@ std::string FormatCommentsForJava(const Comments& comments) {
   std::stringstream out;
   for (auto it = begin(comments); it != end(comments); it++) {
     const bool last = next(it) == end(comments);
-    // We only re-format the last/block comment which is not already a doc-style comment.
-    if (last && it->type == Comment::Type::BLOCK && !StartsWith(it->body, kDocCommentBegin)) {
-      out << kDocCommentBegin << ConsumePrefix(it->body, kBlockCommentBegin);
+    auto lines = TrimmedLines(*it);
+
+    if (it->type == Comment::Type::LINE) {
+      for (const auto& line : lines) {
+        out << kLineCommentBegin << line;
+      }
     } else {
-      out << it->body;
+      if (last || StartsWith(it->body, kDocCommentBegin)) {
+        out << kDocCommentBegin;
+      } else {
+        out << kBlockCommentBegin;
+      }
+      bool multiline = lines.size() > 1;
+
+      if (multiline) out << "\n";
+      for (const auto& line : lines) {
+        if (multiline) out << kBlockCommentMid;
+        out << " " << line;
+        if (multiline) out << "\n";
+      }
+      out << " " << kBlockCommentEnd << "\n";
     }
   }
   return out.str();
 }
 
 }  // namespace aidl
-}  // namespace android
\ No newline at end of file
+}  // namespace android
diff --git a/generate_java.cpp b/generate_java.cpp
index 6e96b809..52c92d56 100644
--- a/generate_java.cpp
+++ b/generate_java.cpp
@@ -290,11 +290,7 @@ namespace aidl {
 namespace java {
 
 std::string GenerateComments(const AidlCommentable& node) {
-  std::string comments = FormatCommentsForJava(node.GetComments());
-  if (!comments.empty() && comments.back() != '\n') {
-    comments += '\n';
-  }
-  return comments;
+  return FormatCommentsForJava(node.GetComments());
 }
 
 std::string GenerateAnnotations(const AidlNode& node) {
diff --git a/tests/golden_output/aidl-test-interface-java-source/gen/android/aidl/tests/ByteEnum.java b/tests/golden_output/aidl-test-interface-java-source/gen/android/aidl/tests/ByteEnum.java
index 0f5a3ea0..42fe1ed3 100644
--- a/tests/golden_output/aidl-test-interface-java-source/gen/android/aidl/tests/ByteEnum.java
+++ b/tests/golden_output/aidl-test-interface-java-source/gen/android/aidl/tests/ByteEnum.java
@@ -2,9 +2,7 @@
  * This file is auto-generated.  DO NOT MODIFY.
  */
 package android.aidl.tests;
-/**
- * Hello, world!
- */
+/** Hello, world! */
 public @interface ByteEnum {
   // Comment about FOO.
   public static final byte FOO = 1;
diff --git a/tests/golden_output/aidl-test-interface-java-source/gen/android/aidl/tests/ITestService.java b/tests/golden_output/aidl-test-interface-java-source/gen/android/aidl/tests/ITestService.java
index 490450e0..5d8af5a4 100644
--- a/tests/golden_output/aidl-test-interface-java-source/gen/android/aidl/tests/ITestService.java
+++ b/tests/golden_output/aidl-test-interface-java-source/gen/android/aidl/tests/ITestService.java
@@ -2,9 +2,7 @@
  * This file is auto-generated.  DO NOT MODIFY.
  */
 package android.aidl.tests;
-/**
- * interface comment
- */
+/** interface comment */
 public interface ITestService extends android.os.IInterface
 {
   /** Default implementation for ITestService. */
@@ -26,9 +24,9 @@ public interface ITestService extends android.os.IInterface
       return 0;
     }
     /**
-         * @deprecated to make sure we have something in system/tools/aidl which does a compile check
-         *     of deprecated and make sure this is reflected in goldens
-         */
+     * @deprecated to make sure we have something in system/tools/aidl which does a compile check
+     *     of deprecated and make sure this is reflected in goldens
+     */
     @Override public void Deprecated() throws android.os.RemoteException
     {
     }
@@ -207,9 +205,7 @@ public interface ITestService extends android.os.IInterface
     {
       return null;
     }
-    /**
-         * comment before annotation
-         */
+    /** comment before annotation */
     @Override public android.aidl.tests.INamedCallback GetCallback(boolean return_null) throws android.os.RemoteException
     {
       return null;
@@ -999,9 +995,9 @@ public interface ITestService extends android.os.IInterface
         return _result;
       }
       /**
-           * @deprecated to make sure we have something in system/tools/aidl which does a compile check
-           *     of deprecated and make sure this is reflected in goldens
-           */
+       * @deprecated to make sure we have something in system/tools/aidl which does a compile check
+       *     of deprecated and make sure this is reflected in goldens
+       */
       @Override public void Deprecated() throws android.os.RemoteException
       {
         android.os.Parcel _data = android.os.Parcel.obtain(asBinder());
@@ -2173,9 +2169,7 @@ public interface ITestService extends android.os.IInterface
         }
         return _result;
       }
-      /**
-           * comment before annotation
-           */
+      /** comment before annotation */
       @Override public android.aidl.tests.INamedCallback GetCallback(boolean return_null) throws android.os.RemoteException
       {
         android.os.Parcel _data = android.os.Parcel.obtain(asBinder());
@@ -2466,14 +2460,10 @@ public interface ITestService extends android.os.IInterface
   }
   public static final java.lang.String DESCRIPTOR = "android$aidl$tests$ITestService".replace('$', '.');
   // Test that constants are accessible
-  /**
-       * extra doc comment
-       */// extra line comment
-  /*
-       * extra regular comment
-       *//**
-       * const comment
-       */
+  /** extra doc comment */
+  // extra line comment
+  /* extra regular comment */
+  /** const comment */
   public static final int TEST_CONSTANT = 42;
   public static final int TEST_CONSTANT2 = -42;
   public static final int TEST_CONSTANT3 = 42;
@@ -2564,9 +2554,9 @@ public interface ITestService extends android.os.IInterface
   // methods to be added and removed.
   public int UnimplementedMethod(int arg) throws android.os.RemoteException;
   /**
-       * @deprecated to make sure we have something in system/tools/aidl which does a compile check
-       *     of deprecated and make sure this is reflected in goldens
-       */
+   * @deprecated to make sure we have something in system/tools/aidl which does a compile check
+   *     of deprecated and make sure this is reflected in goldens
+   */
   @Deprecated
   public void Deprecated() throws android.os.RemoteException;
   public void TestOneway() throws android.os.RemoteException;
@@ -2619,9 +2609,7 @@ public interface ITestService extends android.os.IInterface
   public java.lang.String[] ReverseUtf8CppString(java.lang.String[] input, java.lang.String[] repeated) throws android.os.RemoteException;
   public java.lang.String[] ReverseNullableUtf8CppString(java.lang.String[] input, java.lang.String[] repeated) throws android.os.RemoteException;
   public java.util.List<java.lang.String> ReverseUtf8CppStringList(java.util.List<java.lang.String> input, java.util.List<java.lang.String> repeated) throws android.os.RemoteException;
-  /**
-       * comment before annotation
-       */
+  /** comment before annotation */
   public android.aidl.tests.INamedCallback GetCallback(boolean return_null) throws android.os.RemoteException;
   // Since this paracelable has clearly defined default values, it would be
   // inefficient to use an IPC to fill it out in practice.