[ruby-core:38351] [Ruby 1.9 - Bug #5068][Assigned] Issue with "duplicated when clause is ignored"

Issue #5068 has been updated by Yusuke Endoh.

Status changed from Open to Assigned
Assignee set to Yusuke Endoh
Target version set to 1.9.x

Here is a patch.  It became bigger than expected...
I'll commit it unless there is objection.


diff --git a/compile.c b/compile.c
index 53149ca..c1012f7 100644
--- a/compile.c
+++ b/compile.c
@@ -1275,6 +1275,18 @@ static const struct st_hash_type cdhash_type = {
     cdhash_hash,
 };
 
+static int
+translate_cdhash(st_data_t key, st_data_t val, st_data_t arg)
+{
+    VALUE lit = (VALUE)key;
+    LABEL *lobj = (LABEL *)(val & ~1);
+    VALUE *p = (VALUE *)arg;
+
+    rb_hash_aset(p[0], key, INT2FIX(lobj->position - FIX2INT(p[1])));
+    return ST_CONTINUE;
+}
+
+
 /**
   ruby insn object list -> raw instruction sequence
  */
@@ -1402,30 +1414,11 @@ iseq_set_sequence(rb_iseq_t *iseq, LINK_ANCHOR *anchor)
 			     * [obj, label, ...]
 			     */
 			    int i;
-			    VALUE lits = operands[j];
-			    VALUE map = rb_hash_new();
-			    RHASH_TBL(map)->type = &cdhash_type;
-
-			    for (i=0; i < RARRAY_LEN(lits); i+=2) {
-				VALUE obj = rb_ary_entry(lits, i);
-				VALUE lv  = rb_ary_entry(lits, i+1);
-				lobj = (LABEL *)(lv & ~1);
-
-				if (!lobj->set) {
-				    rb_compile_error(RSTRING_PTR(iseq->filename), iobj->line_no,
-						     "unknown label");
-				}
-				if (!st_lookup(rb_hash_tbl(map), obj, 0)) {
-				    rb_hash_aset(map, obj, INT2FIX(lobj->position - (pos+len)));
-				}
-				else {
-				    rb_compile_warning(RSTRING_PTR(iseq->filename), iobj->line_no,
-						       "duplicated when clause is ignored");
-				}
-			    }
-			    hide_obj(map);
-			    generated_iseq[pos + 1 + j] = map;
-			    iseq_add_mark_object(iseq, map);
+			    VALUE lits = operands[j], arg[2] = { lits, INT2FIX(pos+len) };
+			    st_foreach(RHASH_TBL(lits), translate_cdhash, (st_data_t)arg);
+			    hide_obj(lits);
+			    generated_iseq[pos + 1 + j] = lits;
+			    iseq_add_mark_object(iseq, lits);
 			    break;
 			}
 		      case TS_LINDEX:
@@ -2345,7 +2338,7 @@ case_when_optimizable_literal(NODE * node)
 }
 
 static VALUE
-when_vals(rb_iseq_t *iseq, LINK_ANCHOR *cond_seq, NODE *vals, LABEL *l1, VALUE special_literals)
+when_vals(rb_iseq_t *iseq, LINK_ANCHOR *cond_seq, NODE *vals, LABEL *l1, VALUE special_literal_opt, VALUE special_literals)
 {
     while (vals) {
 	VALUE lit;
@@ -2353,13 +2346,17 @@ when_vals(rb_iseq_t *iseq, LINK_ANCHOR *cond_seq, NODE *vals, LABEL *l1, VALUE s
 
 	val = vals->nd_head;
 
-	if (special_literals &&
-	    (lit = case_when_optimizable_literal(val)) != Qfalse) {
-	    rb_ary_push(special_literals, lit);
-	    rb_ary_push(special_literals, (VALUE)(l1) | 1);
+	if ((lit = case_when_optimizable_literal(val)) != Qfalse) {
+	    if (!st_lookup(rb_hash_tbl(special_literals), lit, 0)) {
+		rb_hash_aset(special_literals, lit, (VALUE)(l1) | 1);
+	    }
+	    else {
+		rb_compile_warning(RSTRING_PTR(iseq->filename), nd_line(val),
+				   "duplicated when clause is ignored");
+	    }
 	}
 	else {
-	    special_literals = Qfalse;
+	    special_literal_opt = Qfalse;
 	}
 
 	if (nd_type(val) == NODE_STR) {
@@ -2375,7 +2372,7 @@ when_vals(rb_iseq_t *iseq, LINK_ANCHOR *cond_seq, NODE *vals, LABEL *l1, VALUE s
 	ADD_INSNL(cond_seq, nd_line(val), branchif, l1);
 	vals = vals->nd_next;
     }
-    return special_literals;
+    return special_literal_opt;
 }
 
 static int
@@ -3049,13 +3046,14 @@ iseq_compile_each(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE * node, int poped)
 	break;
       }
       case NODE_CASE:{
+	VALUE special_literals;
 	NODE *vals;
 	NODE *tempnode = node;
 	LABEL *endlabel, *elselabel;
 	DECL_ANCHOR(head);
 	DECL_ANCHOR(body_seq);
 	DECL_ANCHOR(cond_seq);
-	VALUE special_literals = rb_ary_tmp_new(1);
+	VALUE special_literal_opt = Qtrue;
 
 	INIT_ANCHOR(head);
 	INIT_ANCHOR(body_seq);
@@ -3068,6 +3066,8 @@ iseq_compile_each(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE * node, int poped)
 
 	node = node->nd_body;
 	type = nd_type(node);
+	special_literals = rb_hash_new();
+	RHASH_TBL(special_literals)->type = &cdhash_type;
 
 	if (type != NODE_WHEN) {
 	    COMPILE_ERROR((ERROR_ARGS "NODE_CASE: unexpected node. must be NODE_WHEN, but %s", ruby_node_name(type)));
@@ -3091,12 +3091,12 @@ iseq_compile_each(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE * node, int poped)
 	    if (vals) {
 		switch (nd_type(vals)) {
 		  case NODE_ARRAY:
-		    special_literals = when_vals(iseq, cond_seq, vals, l1, special_literals);
+		    special_literal_opt = when_vals(iseq, cond_seq, vals, l1, special_literal_opt, special_literals);
 		    break;
 		  case NODE_SPLAT:
 		  case NODE_ARGSCAT:
 		  case NODE_ARGSPUSH:
-		    special_literals = 0;
+		    special_literal_opt = 0;
 		    COMPILE(cond_seq, "when/cond splat", vals);
 		    ADD_INSN1(cond_seq, nd_line(vals), checkincludearray, Qtrue);
 		    ADD_INSNL(cond_seq, nd_line(vals), branchif, l1);
@@ -3133,7 +3133,7 @@ iseq_compile_each(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE * node, int poped)
 	    ADD_INSNL(cond_seq, nd_line(tempnode), jump, endlabel);
 	}
 
-	if (special_literals) {
+	if (special_literal_opt) {
 	    ADD_INSN(ret, nd_line(tempnode), dup);
 	    ADD_INSN2(ret, nd_line(tempnode), opt_case_dispatch,
 		      special_literals, elselabel);
@@ -5381,16 +5381,17 @@ iseq_build_from_ary_body(rb_iseq_t *iseq, LINK_ANCHOR *anchor,
 		      case TS_CDHASH:
 			{
 			    int i;
+			    VALUE map = rb_hash_new();
 			    op = rb_convert_type(op, T_ARRAY, "Array", "to_ary");
 			    op = rb_ary_dup(op);
 			    for (i=0; i<RARRAY_LEN(op); i+=2) {
 				VALUE sym = rb_ary_entry(op, i+1);
 				LABEL *label =
 				  register_label(iseq, labels_table, sym);
-				rb_ary_store(op, i+1, (VALUE)label | 1);
+				rb_hash_aset(map, rb_ary_entry(op, i), (VALUE)label | 1);
 			    }
-			    argv[j] = op;
-			    iseq_add_mark_object_compile_time(iseq, op);
+			    argv[j] = map;
+			    iseq_add_mark_object_compile_time(iseq, map);
 			}
 			break;
 		      default:

-- 
Yusuke Endoh <[e-mail]>
----------------------------------------
Bug #5068: Issue with "duplicated when clause is ignored"
http://redmine.ruby-lang.org/issues/5068

Author: Stefano Mioli
Status: Assigned
Priority: Normal
Assignee: Yusuke Endoh
Category: 
Target version: 1.9.x
ruby -v: 1.9.2-p{180,290}


I'm filing this ticket as suggested by Ryan Davis here:

  http://www.ruby-forum.com/topic/2154866#1011303

Let's consider this snippet:

  x = 0
  case x
  when 1
  when 0
  when 1
  end

Executing a file containing this code with ruby -w, the interpreter will print out this warning:

   warning: duplicated when clause is ignored

Let's consider this one instead:

  x = 0
  case x
  when 1
  when 0 + 1
  when 1
  end

This will *not* print out the same warning, even though we still have a duplicated 'when'.



-- 
http://redmine.ruby-lang.org