- Changed Tree.Block(Tree[]) to Tree.Block(Tree...

- Changed Tree.Block(Tree[]) to Tree.Block(Tree[],Tree)

4 files changed, 104 insertions, 53 deletions

diff --git a/sources/scalac/ast/Transformer.java.tmpl b/sources/scalac/ast/Transformer.java.tmpl
index 69aef7dfca..1af073fc86 100644
--- a/sources/scalac/ast/Transformer.java.tmpl
+++ b/sources/scalac/ast/Transformer.java.tmpl
@@ -206,8 +206,8 @@ public class GenTransformer {
             Symbol symbol = getSymbolFor(tree);
             return gen.LabelDef(symbol, transform(params), transform(rhs));
 
-        case Block(Tree[] stats):
-            return gen.Block(tree.pos, transform(stats));
+        case Block(Tree[] stats, Tree value):
+            return gen.Block(tree.pos, transform(stats), transform(value));
 
         // case Sequence(Tree[] trees):
         // case Alternative(Tree[] trees):
diff --git a/sources/scalac/ast/TreeGen.java b/sources/scalac/ast/TreeGen.java
index 1ebcaf7c53..27b168abd8 100644
--- a/sources/scalac/ast/TreeGen.java
+++ b/sources/scalac/ast/TreeGen.java
@@ -468,7 +468,7 @@ public class TreeGen implements Kinds, Modifiers, TypeTags {
     // Public Methods - Building expressions - Simple nodes
 
     /** Flattens the given tree array by inlining Block nodes. */
-    public Tree[] flatten(Tree[] trees) {
+    public Tree[] flatten_(Tree[] trees) {
         boolean copy = false;
         int length = 0;
         for (int i = 0; i < trees.length; i++) {
@@ -477,10 +477,9 @@ public class TreeGen implements Kinds, Modifiers, TypeTags {
                 copy = true;
                 length -= 1;
                 continue;
-            case Block(Tree[] stats):
-                if (stats.length == 0) break; // preserve unit literals
+            case Block(Tree[] stats, Tree value):
                 copy = true;
-                length += stats.length;
+                length += stats.length + 1;
                 continue;
             }
             length += 1;
@@ -491,9 +490,9 @@ public class TreeGen implements Kinds, Modifiers, TypeTags {
             switch (trees[i]) {
             case Empty:
                 continue;
-            case Block(Tree[] stats):
-                if (stats.length == 0) break; // preserve unit literals
+            case Block(Tree[] stats, Tree value):
                 for (int j = 0; j < stats.length; j++) clone[o++] = stats[j];
+                clone[o++] = value;
                 continue;
             }
             clone[o++] = trees[i];
@@ -530,16 +529,43 @@ public class TreeGen implements Kinds, Modifiers, TypeTags {
         return mkAsInstanceOf(value.pos, value, type);
     }
 
-    /** Builds an expression with given non-empty tree array. */
-    public Tree mkBlock(int pos, Tree[] trees) {
-        assert trees.length != 0;
-        Tree[] flatten = flatten(trees);
-        assert flatten.length != 0: Debug.show(trees);
-        return Block(pos, flatten);
+    /** Builds an expression of type Unit with given statements. */
+    public Tree mkUnitBlock(int pos, Tree[] stats) {
+        return mkBlock(pos, stats, mkUnitLit(pos));
     }
-    public Tree mkBlock(Tree[] trees) {
-        assert trees.length != 0;
-        return mkBlock(trees[0].pos, trees);
+
+    /** Builds an expression of type Unit with given statement. */
+    public Tree mkUnitBlock(int pos, Tree stat) {
+        return mkUnitBlock(pos, new Tree[]{stat});
+    }
+    public Tree mkUnitBlock(Tree stat) {
+        return mkUnitBlock(stat.pos, stat);
+    }
+
+    /** Builds an expression with given statements and value. */
+    public Tree mkBlock(int pos, Tree[] stats, Tree value) {
+        if (stats.length == 0) return value;
+        return Block(pos, stats, value); // !!! add flatten?
+    }
+    public Tree mkBlock(Tree[] stats, Tree value) {
+        return mkBlock((stats.length!=0 ? stats[0] : value).pos, stats, value);
+    }
+
+    /** Builds an expression with given statement and value. */
+    public Tree mkBlock(int pos, Tree stat, Tree value) {
+        switch (stat) {
+        case Empty:
+            return value;
+        case Block(Tree[] block_stats, Tree block_value):
+            Tree[] stats = Tree.cloneArray(block_stats, 1);
+            stats[block_stats.length] = block_value;
+            return Block(stat.pos, stats, value);
+        default:
+            return Block(pos, new Tree[]{stat}, value);
+        }
+    }
+    public Tree mkBlock(Tree stat, Tree value) {
+        return mkBlock(stat.pos, stat, value);
     }
 
     /** Builds an Import node with given qualifier and names. */
@@ -562,20 +588,29 @@ public class TreeGen implements Kinds, Modifiers, TypeTags {
         return tree;
     }
 
-    /** Builds a Block node with given statements. */
-    public Tree Block(int pos, Tree[] stats) {
-        Block tree = make.Block(pos, stats);
-        global.nextPhase();
-        tree.setType(stats.length == 0
-            ? definitions.UNIT_TYPE()
-            : stats[stats.length - 1].type);
-        global.prevPhase();
+    /** Builds a Block node with given statements and value. */
+    public Block Block(int pos, Tree[] stats, Tree value) {
+        inline:
+        switch (value) {
+        case Block(Tree[] value_stats, Tree value_value):
+            int count = 0;
+            for (int i = 0; i < value_stats.length; i++) {
+                if (value_stats[i].definesSymbol()) break inline;
+                if (value_stats[i] != Tree.Empty) count++;
+            }
+            Tree[] array = Tree.cloneArray(stats, count);
+            for (int i = 0, j = stats.length; i < value_stats.length; i++) {
+                if (value_stats[i] != Tree.Empty) array[j++] = value_stats[i];
+            }
+            stats = array;
+            value = value_value;
+        }
+        Block tree = make.Block(pos, stats, value);
+        tree.setType(value.type());
 	return tree;
     }
-
-    /** Builds a Block node with given non-empty statements list. */
-    public Tree Block(Tree[] stats) {
-	return Block(stats[0].pos, stats);
+    public Block Block(Tree[] stats, Tree value) {
+        return Block((stats.length != 0 ? stats[0] : value).pos, stats, value);
     }
 
     /** Builds an Assign node corresponding to "<lhs> = <rhs>". */
@@ -762,14 +797,13 @@ public class TreeGen implements Kinds, Modifiers, TypeTags {
      */
     public Tree mkNewArray(int pos, Type element, Tree[] values, Symbol owner){
         if (values.length == 0) return mkNewArray(pos, element, 0);
-        Tree[] trees = new Tree[1 + values.length + 1];
+        Tree[] trees = new Tree[1 + values.length];
         Symbol array =
             newLocal(pos, Names.array, owner, definitions.ARRAY_TYPE(element));
         trees[0] = ValDef(array, mkNewArray(pos, element, values.length));
         for (int i = 0; i < values.length; i++)
             trees[1 + i] = mkArraySet(Ident(pos, array), i, values[i]);
-        trees[values.length + 1] = Ident(pos, array);
-        return Block(pos, trees);
+        return Block(pos, trees, Ident(pos, array));
     }
 
     /** Builds an array length operation. */
@@ -1101,7 +1135,7 @@ public class TreeGen implements Kinds, Modifiers, TypeTags {
         Tree classDef = ClassDef(clazz, memberTrees);
 	Tree alloc = New(mkApply__(mkPrimaryConstructorLocalRef(pos, clazz)))
             .setType(parentTypes[1]); // !!!
-	return Block(new Tree[]{classDef, alloc});
+	return mkBlock(classDef, alloc);
     }
 
 
@@ -1123,7 +1157,7 @@ public class TreeGen implements Kinds, Modifiers, TypeTags {
         Tree classDef = ClassDef(clazz, memberTrees);
 	Tree alloc = New(mkApply__(mkPrimaryConstructorLocalRef(pos, clazz)))
 	    .setType(parentTypes[1]); // !!!
-	return Block(new Tree[]{classDef, alloc});
+	return mkBlock(classDef, alloc);
     }
     //where
 	private Tree makeVisitorMethod(int pos, Name name, Tree visitor,
@@ -1172,7 +1206,7 @@ public class TreeGen implements Kinds, Modifiers, TypeTags {
 		.setInfo(obj.type);
 	    Tree tmpdef = ValDef(tmp, obj);
 	    Tree expr = postfixApply(Ident(obj.pos, tmp), fn, owner);
-	    return Block(new Tree[]{tmpdef, expr});
+	    return mkBlock(tmpdef, expr);
 	}
     }
 
diff --git a/sources/scalac/ast/parser/Parser.java b/sources/scalac/ast/parser/Parser.java
index 12226aa922..6cbf3e342a 100644
--- a/sources/scalac/ast/parser/Parser.java
+++ b/sources/scalac/ast/parser/Parser.java
@@ -15,6 +15,7 @@ import scalac.*;
 import scalac.util.*;
 import scalac.symtab.Modifiers;
 import scalac.ast.*;
+import scalac.atree.AConstant;
 import Tree.*;
 
 /** A recursive descent parser for the programming language Scala.
@@ -243,10 +244,10 @@ public class Parser implements Tokens {
                 Name x = fresh();
                 return make.Block(pos,
                     new Tree[]{
-                        make.ValDef(pos, 0, x, Tree.Empty, left),
+                        make.ValDef(pos, 0, x, Tree.Empty, left)},
                         make.Apply(pos,
                             make.Select(pos, right, NameTransformer.encode(op)),
-                            new Tree[]{make.Ident(left.pos, x)})});
+                            new Tree[]{make.Ident(left.pos, x)}));
             }
         } else {
             return make.Apply(pos,
@@ -370,8 +371,8 @@ public class Parser implements Tokens {
         Tree rhs = make.If(
             pos,
             cond,
-            make.Block(body.pos, new Tree[]{body, continu}),
-            make.Block(pos, Tree.EMPTY_ARRAY));
+            make.Block(body.pos, new Tree[]{body}, continu),
+            gen.mkUnitLit(pos));
         return make.LabelDef(pos, lname, new Ident[0], rhs);
     }
 
@@ -381,12 +382,12 @@ public class Parser implements Tokens {
         Tree rhs = make.Block(
             body.pos,
             new Tree[]{
-                body,
+                body},
                 make.If(
                     cond.pos,
                     cond,
                     continu,
-                    make.Block(pos, Tree.EMPTY_ARRAY))});
+                    gen.mkUnitLit(pos)));
         return make.LabelDef(pos, lname, new Ident[0], rhs);
     }
 
@@ -399,8 +400,8 @@ public class Parser implements Tokens {
         case Ident(_):
         case Typed(Ident(_), _):
             return new ValDef[]{convertToParam(t)};
-        case Block(Tree[] stats):
-            if (stats.length == 0) return Tree.ValDef_EMPTY_ARRAY;
+        case Literal(AConstant.UNIT):
+            return Tree.ValDef_EMPTY_ARRAY; // !!!
         }
         syntaxError(t.pos, "malformed formal parameter list", false);
         return Tree.ValDef_EMPTY_ARRAY;
@@ -912,7 +913,7 @@ public class Parser implements Tokens {
 	} else if (s.token == RETURN) {
             int pos = s.skipToken();
             Tree e = (isExprIntro()) ? expr()
-                : make.Block(pos, Tree.EMPTY_ARRAY);
+                : gen.mkUnitLit(pos);
             return make.Return(pos, e);
         } else if (s.token == THROW) {
             int pos = s.skipToken();
@@ -1031,7 +1032,7 @@ public class Parser implements Tokens {
             int pos = s.skipToken();
             if (s.token == RPAREN) {
                 s.nextToken();
-                t = make.Block(pos, Tree.EMPTY_ARRAY);
+                t = gen.mkUnitLit(pos);
             } else {
                 t = expr();
                 if (s.token == COMMA) {
@@ -1126,9 +1127,20 @@ public class Parser implements Tokens {
     /** Block ::= BlockStatSeq
      */
     Tree block(int pos) {
-        Tree[] stats = blockStatSeq(new TreeList());
-        if (stats.length == 1 && stats[0].isTerm()) return stats[0];
-        else return make.Block(pos, stats);
+        return block(pos, blockStatSeq(new TreeList()));
+    }
+    private Tree block(int pos, Tree[] stats) {
+        if (stats.length == 0)
+            return gen.mkUnitLit(pos);
+        else if (!stats[stats.length - 1].isTerm())
+            return make.Block(pos, stats, gen.mkUnitLit(pos));
+        else if (stats.length == 1)
+            return stats[0];
+        else {
+            Tree[] trees = new Tree[stats.length - 1];
+            System.arraycopy(stats, 0, trees, 0, trees.length);
+            return make.Block(pos, trees, stats[stats.length - 1]);
+        }
     }
 
     /** CaseClause ::= case Pattern [if PostfixExpr] `=>' Block
@@ -1832,7 +1844,7 @@ public class Parser implements Tokens {
                 stats = statlist.toArray();
             }
             accept(RBRACE);
-            return make.Block(pos, stats);
+            return block(pos, stats);
         } else {
             return selfInvocation();
         }
@@ -2070,13 +2082,13 @@ public class Parser implements Tokens {
                 stats.append(defOrDcl(0));
                 accept(SEMI);
                 if (s.token == RBRACE || s.token == CASE) {
-                    stats.append(make.Block(s.pos, Tree.EMPTY_ARRAY));
+                    stats.append(gen.mkUnitLit(s.pos));
                 }
             } else if (isLocalModifier()) {
                 stats.append(clsDef(localClassModifiers()));
                 accept(SEMI);
                 if (s.token == RBRACE || s.token == CASE) {
-                    stats.append(make.Block(s.pos, Tree.EMPTY_ARRAY));
+                    stats.append(gen.mkUnitLit(s.pos));
                 }
             } else if (s.token == SEMI) {
                 s.nextToken();
diff --git a/sources/scalac/ast/printer/TextTreePrinter.java b/sources/scalac/ast/printer/TextTreePrinter.java
index 9cefa783d8..6a8be8f696 100644
--- a/sources/scalac/ast/printer/TextTreePrinter.java
+++ b/sources/scalac/ast/printer/TextTreePrinter.java
@@ -391,8 +391,13 @@ public class TextTreePrinter implements TreePrinter {
             print(rhs);
             break;
 
-        case Block(Tree[] stats):
-            printArray(stats, TXT_BLOCK_BEGIN, TXT_BLOCK_END, TXT_BLOCK_SEP);
+        case Block(Tree[] stats, Tree value):
+            printArray(stats, TXT_BLOCK_BEGIN, TXT_SEMICOLON, TXT_BLOCK_SEP);
+            indent();
+            printNewLine();
+            print(value);
+            undent();
+            print(TXT_BLOCK_END);
             printType(tree);
             break;