From 1c09b28e56fd75cf4c1d32ee0dd2595a3aed0308 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Fournier?= <clement.fournier76@gmail.com>
Date: Fri, 7 Feb 2020 23:23:54 +0100
Subject: [PATCH] Simplify Block::containsComment

Move logic out of the parser
---
 pmd-java/etc/grammar/Java.jjt                 | 39 ++++++++-----------
 .../pmd/lang/java/ast/ASTBlock.java           | 16 +++++---
 .../pmd/lang/java/ast/JavaTokenDocument.java  | 18 +++++++++
 3 files changed, 45 insertions(+), 28 deletions(-)

diff --git a/pmd-java/etc/grammar/Java.jjt b/pmd-java/etc/grammar/Java.jjt
index 716fb96d19..443e1daff8 100644
--- a/pmd-java/etc/grammar/Java.jjt
+++ b/pmd-java/etc/grammar/Java.jjt
@@ -299,17 +299,6 @@ class JavaParserImpl {
     return getToken(1).image.equals("assert");
   }
 
-  private boolean isPrecededByComment(JavaccToken tok) {
-      boolean res = false;
-      while (!res && tok.specialToken != null) {
-          tok = tok.specialToken;
-          res = tok.kind == SINGLE_LINE_COMMENT ||
-                tok.kind == FORMAL_COMMENT ||
-                tok.kind == MULTI_LINE_COMMENT;
-      }
-      return res;
-  }
-
   /**
    * Semantic lookahead to check if the next identifier is a
    * specific restricted keyword.
@@ -1064,14 +1053,22 @@ void VarargsDim() #ArrayTypeDim:
 
 
 void ConstructorDeclaration() :
-{JavaccToken t;}
+{}
 {
-    [ TypeParameters() ]
-   <IDENTIFIER>  {setLastTokenImage(jjtThis);} FormalParameters() [ ThrowsList() ]
-  ("{"
-    [ LOOKAHEAD(ExplicitConstructorInvocation()) ExplicitConstructorInvocation() ]
-    ( BlockStatement() )*
-  t = "}" { if (isPrecededByComment(t)) { jjtThis.setContainsComment(); } } ) #Block
+   [ TypeParameters() ]
+   <IDENTIFIER>  {setLastTokenImage(jjtThis);}
+   FormalParameters()
+   [ ThrowsList() ]
+   ConstructorBlock()
+}
+
+private void ConstructorBlock() #Block:
+{}
+{
+    "{"
+        [ LOOKAHEAD(ExplicitConstructorInvocation()) ExplicitConstructorInvocation() ]
+        ( BlockStatement() )*
+    "}"
 }
 
 void ExplicitConstructorInvocation() :
@@ -1954,11 +1951,9 @@ void LabeledStatement() :
 }
 
 void Block() :
-{JavaccToken t;}
+{}
 {
-      "{"
-
-      ( BlockStatement() )* t = "}" { if (isPrecededByComment(t)) { jjtThis.setContainsComment(); } }
+    "{" ( BlockStatement() )* "}"
 }
 
 void BlockStatement() #void:
diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/ASTBlock.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/ASTBlock.java
index 20106d123a..ca5334e590 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/ASTBlock.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/ASTBlock.java
@@ -6,6 +6,8 @@ package net.sourceforge.pmd.lang.java.ast;
 
 import java.util.Iterator;
 
+import net.sourceforge.pmd.lang.ast.impl.javacc.JavaccToken;
+
 /**
  * A block of code. This is a {@linkplain ASTStatement statement} that
  * contains other statements.
@@ -18,8 +20,6 @@ import java.util.Iterator;
  */
 public final class ASTBlock extends AbstractStatement implements Iterable<ASTStatement>, ASTSwitchArrowRHS {
 
-    private boolean containsComment;
-
     ASTBlock(int id) {
         super(id);
     }
@@ -37,11 +37,15 @@ public final class ASTBlock extends AbstractStatement implements Iterable<ASTSta
 
 
     public boolean containsComment() {
-        return this.containsComment;
-    }
+        JavaccToken t = jjtGetLastToken().getPreviousComment();
+        while (t != null) {
+            if (JavaTokenDocument.isComment(t)) {
+                return true;
+            }
+            t = t.getPreviousComment();
+        }
 
-    void setContainsComment() {
-        this.containsComment = true;
+        return false;
     }
 
     @Override
diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/JavaTokenDocument.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/JavaTokenDocument.java
index 2f8c1cf369..81d38d7ac2 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/JavaTokenDocument.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/JavaTokenDocument.java
@@ -4,9 +4,12 @@
 
 package net.sourceforge.pmd.lang.java.ast;
 
+import static net.sourceforge.pmd.lang.java.ast.JavaTokenKinds.FORMAL_COMMENT;
 import static net.sourceforge.pmd.lang.java.ast.JavaTokenKinds.GT;
+import static net.sourceforge.pmd.lang.java.ast.JavaTokenKinds.MULTI_LINE_COMMENT;
 import static net.sourceforge.pmd.lang.java.ast.JavaTokenKinds.RSIGNEDSHIFT;
 import static net.sourceforge.pmd.lang.java.ast.JavaTokenKinds.RUNSIGNEDSHIFT;
+import static net.sourceforge.pmd.lang.java.ast.JavaTokenKinds.SINGLE_LINE_COMMENT;
 import static net.sourceforge.pmd.lang.java.ast.JavaTokenKinds.WHITESPACE;
 
 import org.checkerframework.checker.nullness.qual.Nullable;
@@ -24,6 +27,21 @@ final class JavaTokenDocument extends JavaccTokenDocument {
         super(fullText);
     }
 
+    /**
+     * Returns true if the given token is a Java comment.
+     */
+    public static boolean isComment(JavaccToken t) {
+        switch (t.kind) {
+        case FORMAL_COMMENT:
+        case MULTI_LINE_COMMENT:
+        case SINGLE_LINE_COMMENT:
+            return true;
+        default:
+            return false;
+        }
+    }
+
+
     @Override
     protected @Nullable String describeKindImpl(int kind) {
         return JavaTokenKinds.describe(kind);