Test suites for Dialyzer

This is a transcription of most of the cvs.srv.it.uu.se:/hipe repository
dialyzer_tests into test suites that use the test server framework.

See README for information on how to use the included scripts for
modifications and updates.

When testing Dialyzer it's important that several OTP modules
are included in the plt. The suites takes care of that too.

1 files changed, 801 insertions, 0 deletions

diff --git a/lib/dialyzer/test/options1_tests_SUITE_data/src/compiler/cerl_trees.erl b/lib/dialyzer/test/options1_tests_SUITE_data/src/compiler/cerl_trees.erl
new file mode 100644
index 0000000000..50384a6ff8
--- /dev/null
+++ b/lib/dialyzer/test/options1_tests_SUITE_data/src/compiler/cerl_trees.erl
@@ -0,0 +1,801 @@
+%% ``The contents of this file are subject to the Erlang Public License,
+%% Version 1.1, (the "License"); you may not use this file except in
+%% compliance with the License. You should have received a copy of the
+%% Erlang Public License along with this software. If not, it can be
+%% retrieved via the world wide web at http://www.erlang.org/.
+%% 
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and limitations
+%% under the License.
+%% 
+%% The Initial Developer of the Original Code is Richard Carlsson.
+%% Copyright (C) 1999-2002 Richard Carlsson.
+%% Portions created by Ericsson are Copyright 2001, Ericsson Utvecklings
+%% AB. All Rights Reserved.''
+%% 
+%%     $Id: cerl_trees.erl,v 1.2 2010/06/07 06:32:39 kostis Exp $
+
+%% @doc Basic functions on Core Erlang abstract syntax trees.
+%%
+%% <p>Syntax trees are defined in the module <a
+%% href=""><code>cerl</code></a>.</p>
+%%
+%% @type cerl() = cerl:cerl()
+
+-module(cerl_trees).
+
+-export([depth/1, fold/3, free_variables/1, label/1, label/2, map/2,
+	 mapfold/3, size/1, variables/1]).
+
+-import(cerl, [alias_pat/1, alias_var/1, ann_c_alias/3, ann_c_apply/3,
+	       ann_c_binary/2, ann_c_bitstr/6, ann_c_call/4,
+	       ann_c_case/3, ann_c_catch/2, ann_c_clause/4,
+	       ann_c_cons_skel/3, ann_c_fun/3, ann_c_let/4,
+	       ann_c_letrec/3, ann_c_module/5, ann_c_primop/3,
+	       ann_c_receive/4, ann_c_seq/3, ann_c_try/6,
+	       ann_c_tuple_skel/2, ann_c_values/2, apply_args/1,
+	       apply_op/1, binary_segments/1, bitstr_val/1,
+	       bitstr_size/1, bitstr_unit/1, bitstr_type/1,
+	       bitstr_flags/1, call_args/1, call_module/1, call_name/1,
+	       case_arg/1, case_clauses/1, catch_body/1, clause_body/1,
+	       clause_guard/1, clause_pats/1, clause_vars/1, concrete/1,
+	       cons_hd/1, cons_tl/1, fun_body/1, fun_vars/1, get_ann/1,
+	       let_arg/1, let_body/1, let_vars/1, letrec_body/1,
+	       letrec_defs/1, letrec_vars/1, module_attrs/1,
+	       module_defs/1, module_exports/1, module_name/1,
+	       module_vars/1, primop_args/1, primop_name/1,
+	       receive_action/1, receive_clauses/1, receive_timeout/1,
+	       seq_arg/1, seq_body/1, set_ann/2, subtrees/1, try_arg/1,
+	       try_body/1, try_vars/1, try_evars/1, try_handler/1,
+	       tuple_es/1, type/1, update_c_alias/3, update_c_apply/3,
+	       update_c_binary/2, update_c_bitstr/6, update_c_call/4,
+	       update_c_case/3, update_c_catch/2, update_c_clause/4,
+	       update_c_cons/3, update_c_cons_skel/3, update_c_fun/3,
+	       update_c_let/4, update_c_letrec/3, update_c_module/5,
+	       update_c_primop/3, update_c_receive/4, update_c_seq/3,
+	       update_c_try/6, update_c_tuple/2, update_c_tuple_skel/2,
+	       update_c_values/2, values_es/1, var_name/1]).
+
+
+%% ---------------------------------------------------------------------
+
+%% @spec depth(Tree::cerl) -> integer()
+%%
+%% @doc Returns the length of the longest path in the tree.  A leaf
+%% node has depth zero, the tree representing "<code>{foo,
+%% bar}</code>" has depth one, etc.
+
+depth(T) ->
+    case subtrees(T) of
+	[] ->
+	    0;
+	Gs ->
+	    1 + lists:foldl(fun (G, A) -> erlang:max(depth_1(G), A) end, 0, Gs)
+    end.
+
+depth_1(Ts) ->
+    lists:foldl(fun (T, A) -> erlang:max(depth(T), A) end, 0, Ts).
+
+%% max(X, Y) when X > Y -> X;
+%% max(_, Y) -> Y.
+
+
+%% @spec size(Tree::cerl()) -> integer()
+%%
+%% @doc Returns the number of nodes in <code>Tree</code>.
+
+size(T) ->
+    fold(fun (_, S) -> S + 1 end, 0, T).
+
+
+%% ---------------------------------------------------------------------
+
+%% @spec map(Function, Tree::cerl()) -> cerl()
+%%
+%%	   Function = (cerl()) -> cerl()
+%%	   
+%% @doc Maps a function onto the nodes of a tree. This replaces each
+%% node in the tree by the result of applying the given function on
+%% the original node, bottom-up.
+%%
+%% @see mapfold/3
+
+map(F, T) ->
+    F(map_1(F, T)).
+
+map_1(F, T) ->
+    case type(T) of
+ 	literal ->
+	    case concrete(T) of
+		[_ | _] ->
+		    update_c_cons(T, map(F, cons_hd(T)),
+				  map(F, cons_tl(T)));
+		V when tuple_size(V) > 0 ->
+		    update_c_tuple(T, map_list(F, tuple_es(T)));
+		_ ->
+		    T
+	    end;
+ 	var ->
+ 	    T;
+	values ->
+ 	    update_c_values(T, map_list(F, values_es(T)));
+	cons ->
+	    update_c_cons_skel(T, map(F, cons_hd(T)),
+			       map(F, cons_tl(T)));
+ 	tuple ->
+	    update_c_tuple_skel(T, map_list(F, tuple_es(T)));
+ 	'let' ->
+	    update_c_let(T, map_list(F, let_vars(T)),
+			 map(F, let_arg(T)),
+			 map(F, let_body(T)));
+	seq ->
+ 	    update_c_seq(T, map(F, seq_arg(T)),
+			 map(F, seq_body(T)));
+ 	apply ->
+	    update_c_apply(T, map(F, apply_op(T)),
+			   map_list(F, apply_args(T)));
+ 	call ->
+ 	    update_c_call(T, map(F, call_module(T)),
+			  map(F, call_name(T)),
+			  map_list(F, call_args(T)));
+ 	primop ->
+	    update_c_primop(T, map(F, primop_name(T)),
+			    map_list(F, primop_args(T)));
+ 	'case' ->
+ 	    update_c_case(T, map(F, case_arg(T)),
+			  map_list(F, case_clauses(T)));
+ 	clause ->
+ 	    update_c_clause(T, map_list(F, clause_pats(T)),
+			    map(F, clause_guard(T)),
+			    map(F, clause_body(T)));
+ 	alias ->
+	    update_c_alias(T, map(F, alias_var(T)),
+			   map(F, alias_pat(T)));
+ 	'fun' ->
+	    update_c_fun(T, map_list(F, fun_vars(T)),
+			 map(F, fun_body(T)));
+ 	'receive' ->
+	    update_c_receive(T, map_list(F, receive_clauses(T)),
+			     map(F, receive_timeout(T)),
+			     map(F, receive_action(T)));
+ 	'try' ->
+ 	    update_c_try(T, map(F, try_arg(T)),
+			 map_list(F, try_vars(T)),
+			 map(F, try_body(T)),
+			 map_list(F, try_evars(T)),
+			 map(F, try_handler(T)));
+ 	'catch' ->
+	    update_c_catch(T, map(F, catch_body(T)));
+	binary ->
+	    update_c_binary(T, map_list(F, binary_segments(T)));
+	bitstr ->
+	    update_c_bitstr(T, map(F, bitstr_val(T)),
+			    map(F, bitstr_size(T)),
+			    map(F, bitstr_unit(T)),
+			    map(F, bitstr_type(T)),
+			    map(F, bitstr_flags(T)));
+	letrec ->
+	    update_c_letrec(T, map_pairs(F, letrec_defs(T)),
+			    map(F, letrec_body(T)));
+	module ->
+	    update_c_module(T, map(F, module_name(T)),
+			    map_list(F, module_exports(T)),
+			    map_pairs(F, module_attrs(T)),
+			    map_pairs(F, module_defs(T)))
+    end.
+
+map_list(F, [T | Ts]) ->
+    [map(F, T) | map_list(F, Ts)];
+map_list(_, []) ->
+    [].
+
+map_pairs(F, [{T1, T2} | Ps]) ->
+    [{map(F, T1), map(F, T2)} | map_pairs(F, Ps)];
+map_pairs(_, []) ->
+    [].
+
+
+%% @spec fold(Function, Unit::term(), Tree::cerl()) -> term()
+%%
+%%    Function = (cerl(), term()) -> term()
+%%
+%% @doc Does a fold operation over the nodes of the tree. The result
+%% is the value of <code>Function(X1, Function(X2, ... Function(Xn,
+%% Unit) ... ))</code>, where <code>X1, ..., Xn</code> are the nodes
+%% of <code>Tree</code> in a post-order traversal.
+%%
+%% @see mapfold/3
+
+fold(F, S, T) ->
+    F(T, fold_1(F, S, T)).
+
+fold_1(F, S, T) ->
+    case type(T) of
+ 	literal ->
+	    case concrete(T) of
+		[_ | _] ->
+		    fold(F, fold(F, S, cons_hd(T)), cons_tl(T));
+		V when tuple_size(V) > 0 ->
+		    fold_list(F, S, tuple_es(T));
+		_ ->
+		    S
+	    end;
+ 	var ->
+ 	    S;
+	values ->
+ 	    fold_list(F, S, values_es(T));
+	cons ->
+	    fold(F, fold(F, S, cons_hd(T)), cons_tl(T));
+	tuple ->
+	    fold_list(F, S, tuple_es(T));
+ 	'let' ->
+	    fold(F, fold(F, fold_list(F, S, let_vars(T)),
+			 let_arg(T)),
+		 let_body(T));
+	seq ->
+	    fold(F, fold(F, S, seq_arg(T)), seq_body(T));
+	apply ->
+	    fold_list(F, fold(F, S, apply_op(T)), apply_args(T));
+ 	call ->
+	    fold_list(F, fold(F, fold(F, S, call_module(T)),
+			      call_name(T)),
+		      call_args(T));
+ 	primop ->
+	    fold_list(F, fold(F, S, primop_name(T)), primop_args(T));
+ 	'case' ->
+	    fold_list(F, fold(F, S, case_arg(T)), case_clauses(T));
+ 	clause ->
+	    fold(F, fold(F, fold_list(F, S, clause_pats(T)),
+			 clause_guard(T)),
+		 clause_body(T));
+ 	alias ->
+	    fold(F, fold(F, S, alias_var(T)), alias_pat(T));
+ 	'fun' ->
+	    fold(F, fold_list(F, S, fun_vars(T)), fun_body(T));
+ 	'receive' ->
+	    fold(F, fold(F, fold_list(F, S, receive_clauses(T)),
+			 receive_timeout(T)),
+		 receive_action(T));
+ 	'try' ->
+	    fold(F, fold_list(F, fold(F, fold_list(F, fold(F, S, try_arg(T)),
+						   try_vars(T)),
+				      try_body(T)),
+			      try_evars(T)),
+		 try_handler(T));
+ 	'catch' ->
+	    fold(F, S, catch_body(T));
+	binary ->
+	    fold_list(F, S, binary_segments(T));
+	bitstr ->
+	    fold(F,
+		 fold(F,
+		      fold(F,
+			   fold(F,
+				fold(F, S, bitstr_val(T)),
+				bitstr_size(T)),
+			   bitstr_unit(T)),
+		      bitstr_type(T)),
+		 bitstr_flags(T));
+	letrec ->
+	    fold(F, fold_pairs(F, S, letrec_defs(T)), letrec_body(T));
+	module ->
+	    fold_pairs(F, 
+		       fold_pairs(F, 
+				  fold_list(F,
+					    fold(F, S, module_name(T)),
+					    module_exports(T)),
+				  module_attrs(T)),
+		       module_defs(T))
+    end.
+
+fold_list(F, S, [T | Ts]) ->
+    fold_list(F, fold(F, S, T), Ts);
+fold_list(_, S, []) ->
+    S.
+
+fold_pairs(F, S, [{T1, T2} | Ps]) ->
+    fold_pairs(F, fold(F, fold(F, S, T1), T2), Ps);
+fold_pairs(_, S, []) ->
+    S.
+
+
+%% @spec mapfold(Function, Initial::term(), Tree::cerl()) ->
+%%           {cerl(), term()}
+%%
+%%    Function = (cerl(), term()) -> {cerl(), term()}
+%%
+%% @doc Does a combined map/fold operation on the nodes of the
+%% tree. This is similar to <code>map/2</code>, but also propagates a
+%% value from each application of <code>Function</code> to the next,
+%% starting with the given value <code>Initial</code>, while doing a
+%% post-order traversal of the tree, much like <code>fold/3</code>.
+%%
+%% @see map/2
+%% @see fold/3
+
+mapfold(F, S0, T) ->
+    case type(T) of
+ 	literal ->
+	    case concrete(T) of
+		[_ | _] ->
+		    {T1, S1} = mapfold(F, S0, cons_hd(T)),
+		    {T2, S2} = mapfold(F, S1, cons_tl(T)),
+		    F(update_c_cons(T, T1, T2), S2);
+		V when tuple_size(V) > 0 ->
+		    {Ts, S1} = mapfold_list(F, S0, tuple_es(T)),
+		    F(update_c_tuple(T, Ts), S1);
+		_ ->
+		    F(T, S0)
+	    end;
+ 	var ->
+ 	    F(T, S0);
+	values ->
+	    {Ts, S1} = mapfold_list(F, S0, values_es(T)),
+ 	    F(update_c_values(T, Ts), S1);
+	cons ->
+	    {T1, S1} = mapfold(F, S0, cons_hd(T)),
+	    {T2, S2} = mapfold(F, S1, cons_tl(T)),
+	    F(update_c_cons_skel(T, T1, T2), S2);
+ 	tuple ->
+	    {Ts, S1} = mapfold_list(F, S0, tuple_es(T)),
+	    F(update_c_tuple_skel(T, Ts), S1);
+ 	'let' ->
+	    {Vs, S1} = mapfold_list(F, S0, let_vars(T)),
+	    {A, S2} = mapfold(F, S1, let_arg(T)),
+	    {B, S3} = mapfold(F, S2, let_body(T)),
+	    F(update_c_let(T, Vs, A, B), S3);
+	seq ->
+	    {A, S1} = mapfold(F, S0, seq_arg(T)),
+	    {B, S2} = mapfold(F, S1, seq_body(T)),
+ 	    F(update_c_seq(T, A, B), S2);
+ 	apply ->
+	    {E, S1} = mapfold(F, S0, apply_op(T)),
+	    {As, S2} = mapfold_list(F, S1, apply_args(T)),
+	    F(update_c_apply(T, E, As), S2);
+ 	call ->
+	    {M, S1} = mapfold(F, S0, call_module(T)),
+	    {N, S2} = mapfold(F, S1, call_name(T)),
+	    {As, S3} = mapfold_list(F, S2, call_args(T)),
+ 	    F(update_c_call(T, M, N, As), S3);
+ 	primop ->
+	    {N, S1} = mapfold(F, S0, primop_name(T)),
+	    {As, S2} = mapfold_list(F, S1, primop_args(T)),
+	    F(update_c_primop(T, N, As), S2);
+ 	'case' ->
+	    {A, S1} = mapfold(F, S0, case_arg(T)),
+	    {Cs, S2} = mapfold_list(F, S1, case_clauses(T)),
+ 	    F(update_c_case(T, A, Cs), S2);
+ 	clause ->
+	    {Ps, S1} = mapfold_list(F, S0, clause_pats(T)),
+	    {G, S2} = mapfold(F, S1, clause_guard(T)),
+	    {B, S3} = mapfold(F, S2, clause_body(T)),
+	    F(update_c_clause(T, Ps, G, B), S3);
+ 	alias ->
+	    {V, S1} = mapfold(F, S0, alias_var(T)),
+	    {P, S2} = mapfold(F, S1, alias_pat(T)),
+	    F(update_c_alias(T, V, P), S2);
+ 	'fun' ->
+	    {Vs, S1} = mapfold_list(F, S0, fun_vars(T)),
+	    {B, S2} = mapfold(F, S1, fun_body(T)),
+	    F(update_c_fun(T, Vs, B), S2);
+ 	'receive' ->
+	    {Cs, S1} = mapfold_list(F, S0, receive_clauses(T)),
+	    {E, S2} = mapfold(F, S1, receive_timeout(T)),
+	    {A, S3} = mapfold(F, S2, receive_action(T)),
+	    F(update_c_receive(T, Cs, E, A), S3);
+ 	'try' ->
+	    {E, S1} = mapfold(F, S0, try_arg(T)),
+	    {Vs, S2} = mapfold_list(F, S1, try_vars(T)),
+	    {B, S3} = mapfold(F, S2, try_body(T)),
+	    {Evs, S4} = mapfold_list(F, S3, try_evars(T)),
+	    {H, S5} = mapfold(F, S4, try_handler(T)),
+	    F(update_c_try(T, E, Vs, B, Evs, H), S5);
+ 	'catch' ->
+	    {B, S1} = mapfold(F, S0, catch_body(T)),
+	    F(update_c_catch(T, B), S1);
+	binary ->
+	    {Ds, S1} = mapfold_list(F, S0, binary_segments(T)),
+	    F(update_c_binary(T, Ds), S1);
+	bitstr ->
+	    {Val, S1} = mapfold(F, S0, bitstr_val(T)),
+	    {Size, S2} = mapfold(F, S1, bitstr_size(T)),
+	    {Unit, S3} = mapfold(F, S2, bitstr_unit(T)),
+	    {Type, S4} = mapfold(F, S3, bitstr_type(T)),
+	    {Flags, S5} = mapfold(F, S4, bitstr_flags(T)),
+	    F(update_c_bitstr(T, Val, Size, Unit, Type, Flags), S5);
+	letrec ->
+	    {Ds, S1} = mapfold_pairs(F, S0, letrec_defs(T)),
+	    {B, S2} = mapfold(F, S1, letrec_body(T)),
+	    F(update_c_letrec(T, Ds, B), S2);
+	module ->
+	    {N, S1} = mapfold(F, S0, module_name(T)),
+	    {Es, S2} = mapfold_list(F, S1, module_exports(T)),
+	    {As, S3} = mapfold_pairs(F, S2, module_attrs(T)),
+	    {Ds, S4} = mapfold_pairs(F, S3, module_defs(T)),
+	    F(update_c_module(T, N, Es, As, Ds), S4)
+    end.
+
+mapfold_list(F, S0, [T | Ts]) ->
+    {T1, S1} = mapfold(F, S0, T),
+    {Ts1, S2} = mapfold_list(F, S1, Ts),
+    {[T1 | Ts1], S2};
+mapfold_list(_, S, []) ->
+    {[], S}.
+
+mapfold_pairs(F, S0, [{T1, T2} | Ps]) ->
+    {T3, S1} = mapfold(F, S0, T1),
+    {T4, S2} = mapfold(F, S1, T2),
+    {Ps1, S3} = mapfold_pairs(F, S2, Ps),
+    {[{T3, T4} | Ps1], S3};
+mapfold_pairs(_, S, []) ->
+    {[], S}.
+
+
+%% ---------------------------------------------------------------------
+
+%% @spec variables(Tree::cerl()) -> [var_name()]
+%%
+%%	    var_name() = integer() | atom() | {atom(), integer()}
+%%
+%% @doc Returns an ordered-set list of the names of all variables in
+%% the syntax tree. (This includes function name variables.) An
+%% exception is thrown if <code>Tree</code> does not represent a
+%% well-formed Core Erlang syntax tree.
+%%
+%% @see free_variables/1
+
+variables(T) ->
+    variables(T, false).
+
+
+%% @spec free_variables(Tree::cerl()) -> [var_name()]
+%%
+%% @doc Like <code>variables/1</code>, but only includes variables
+%% that are free in the tree.
+%%
+%% @see variables/1
+
+free_variables(T) ->
+    variables(T, true).
+
+
+%% This is not exported
+
+variables(T, S) ->
+    case type(T) of
+	literal ->
+	    [];
+	var ->
+	    [var_name(T)];
+	values ->
+	    vars_in_list(values_es(T), S);
+	cons ->
+	    ordsets:union(variables(cons_hd(T), S),
+			  variables(cons_tl(T), S));
+	tuple ->
+	    vars_in_list(tuple_es(T), S);
+	'let' ->
+	    Vs = variables(let_body(T), S),
+	    Vs1 = var_list_names(let_vars(T)),
+	    Vs2 = case S of
+		      true ->
+			  ordsets:subtract(Vs, Vs1);
+		      false ->
+			  ordsets:union(Vs, Vs1)
+		  end,
+	    ordsets:union(variables(let_arg(T), S), Vs2);
+	seq ->
+	    ordsets:union(variables(seq_arg(T), S),
+			  variables(seq_body(T), S));
+	apply ->
+	    ordsets:union(
+	      variables(apply_op(T), S),
+	      vars_in_list(apply_args(T), S));
+	call ->
+	    ordsets:union(variables(call_module(T), S),
+			  ordsets:union(
+			    variables(call_name(T), S),
+			    vars_in_list(call_args(T), S)));
+	primop ->
+	    vars_in_list(primop_args(T), S);
+	'case' ->
+	    ordsets:union(variables(case_arg(T), S),
+			  vars_in_list(case_clauses(T), S));
+	clause ->
+	    Vs = ordsets:union(variables(clause_guard(T), S),
+			       variables(clause_body(T), S)),
+	    Vs1 = vars_in_list(clause_pats(T), S),
+	    case S of
+		true ->
+		    ordsets:subtract(Vs, Vs1);
+		false ->
+		    ordsets:union(Vs, Vs1)
+	    end;
+	alias ->
+	    ordsets:add_element(var_name(alias_var(T)),
+				variables(alias_pat(T)));
+	'fun' ->
+	    Vs = variables(fun_body(T), S),
+	    Vs1 = var_list_names(fun_vars(T)),
+	    case S of
+		true ->
+		    ordsets:subtract(Vs, Vs1);
+		false ->
+		    ordsets:union(Vs, Vs1)
+	    end;
+	'receive' ->
+	    ordsets:union(
+	      vars_in_list(receive_clauses(T), S),
+	      ordsets:union(variables(receive_timeout(T), S),
+			    variables(receive_action(T), S)));
+	'try' ->
+	    Vs = variables(try_body(T), S),
+	    Vs1 = var_list_names(try_vars(T)),
+	    Vs2 = case S of
+		      true ->
+			  ordsets:subtract(Vs, Vs1);
+		      false ->
+			  ordsets:union(Vs, Vs1)
+		  end,
+	    Vs3 = variables(try_handler(T), S),
+	    Vs4 = var_list_names(try_evars(T)),
+	    Vs5 = case S of
+		      true ->
+			  ordsets:subtract(Vs3, Vs4);
+		      false ->
+			  ordsets:union(Vs3, Vs4)
+		  end,
+	    ordsets:union(variables(try_arg(T), S),
+			  ordsets:union(Vs2, Vs5));
+	'catch' ->
+	    variables(catch_body(T), S);
+	binary ->
+	    vars_in_list(binary_segments(T), S);
+	bitstr ->
+	    ordsets:union(variables(bitstr_val(T), S),
+			  variables(bitstr_size(T), S));
+	letrec ->
+	    Vs = vars_in_defs(letrec_defs(T), S),
+	    Vs1 = ordsets:union(variables(letrec_body(T), S), Vs),
+	    Vs2 = var_list_names(letrec_vars(T)),
+	    case S of
+		true ->
+		    ordsets:subtract(Vs1, Vs2);
+		false ->
+		    ordsets:union(Vs1, Vs2)
+	    end;
+	module ->
+	    Vs = vars_in_defs(module_defs(T), S),
+	    Vs1 = ordsets:union(vars_in_list(module_exports(T), S), Vs),
+	    Vs2 = var_list_names(module_vars(T)),
+	    case S of
+		true ->
+		    ordsets:subtract(Vs1, Vs2);
+		false ->
+		    ordsets:union(Vs1, Vs2)
+	    end
+    end.
+
+vars_in_list(Ts, S) ->
+    vars_in_list(Ts, S, []).
+
+vars_in_list([T | Ts], S, A) ->
+    vars_in_list(Ts, S, ordsets:union(variables(T, S), A));
+vars_in_list([], _, A) ->
+    A.
+
+%% Note that this function only visits the right-hand side of function
+%% definitions.
+
+vars_in_defs(Ds, S) ->
+    vars_in_defs(Ds, S, []).
+
+vars_in_defs([{_, F} | Ds], S, A) ->
+    vars_in_defs(Ds, S, ordsets:union(variables(F, S), A));
+vars_in_defs([], _, A) ->
+    A.
+
+%% This amounts to insertion sort. Since the lists are generally short,
+%% it is hardly worthwhile to use an asymptotically better sort.
+
+var_list_names(Vs) ->
+    var_list_names(Vs, []).
+
+var_list_names([V | Vs], A) ->
+    var_list_names(Vs, ordsets:add_element(var_name(V), A));
+var_list_names([], A) ->
+    A.
+
+
+%% ---------------------------------------------------------------------
+
+%% label(Tree::cerl()) -> {cerl(), integer()}
+%%
+%% @equiv label(Tree, 0)
+
+label(T) ->
+    label(T, 0).
+
+%% @spec label(Tree::cerl(), N::integer()) -> {cerl(), integer()}
+%%
+%% @doc Labels each expression in the tree. A term <code>{label,
+%% L}</code> is prefixed to the annotation list of each expression node,
+%% where L is a unique number for every node, except for variables (and
+%% function name variables) which get the same label if they represent
+%% the same variable. Constant literal nodes are not labeled.
+%%
+%% <p>The returned value is a tuple <code>{NewTree, Max}</code>, where
+%% <code>NewTree</code> is the labeled tree and <code>Max</code> is 1
+%% plus the largest label value used. All previous annotation terms on
+%% the form <code>{label, X}</code> are deleted.</p>
+%%
+%% <p>The values of L used in the tree is a dense range from
+%% <code>N</code> to <code>Max - 1</code>, where <code>N =&lt; Max
+%% =&lt; N + size(Tree)</code>. Note that it is possible that no
+%% labels are used at all, i.e., <code>N = Max</code>.</p>
+%%
+%% <p>Note: All instances of free variables will be given distinct
+%% labels.</p>
+%%
+%% @see label/1
+%% @see size/1
+
+label(T, N) ->
+    label(T, N, dict:new()).
+
+label(T, N, Env) ->
+    case type(T) of
+ 	literal ->
+	    %% Constant literals are not labeled.
+	    {T, N};
+	var ->
+	    case dict:find(var_name(T), Env) of
+		{ok, L} ->
+		    {As, _} = label_ann(T, L),
+		    N1 = N;
+		error ->
+		    {As, N1} = label_ann(T, N)
+	    end,
+	    {set_ann(T, As), N1};
+	values ->
+	    {Ts, N1} = label_list(values_es(T), N, Env),
+	    {As, N2} = label_ann(T, N1),
+	    {ann_c_values(As, Ts), N2};
+	cons ->
+	    {T1, N1} = label(cons_hd(T), N, Env),
+	    {T2, N2} = label(cons_tl(T), N1, Env),
+	    {As, N3} = label_ann(T, N2),
+	    {ann_c_cons_skel(As, T1, T2), N3};
+ 	tuple ->
+	    {Ts, N1} = label_list(tuple_es(T), N, Env),
+	    {As, N2} = label_ann(T, N1),
+	    {ann_c_tuple_skel(As, Ts), N2};
+ 	'let' ->
+	    {A, N1} = label(let_arg(T), N, Env),
+	    {Vs, N2, Env1} = label_vars(let_vars(T), N1, Env),
+	    {B, N3} = label(let_body(T), N2, Env1),
+	    {As, N4} = label_ann(T, N3),
+	    {ann_c_let(As, Vs, A, B), N4};
+	seq ->
+	    {A, N1} = label(seq_arg(T), N, Env),
+	    {B, N2} = label(seq_body(T), N1, Env),
+	    {As, N3} = label_ann(T, N2),
+ 	    {ann_c_seq(As, A, B), N3};
+ 	apply ->
+	    {E, N1} = label(apply_op(T), N, Env),
+	    {Es, N2} = label_list(apply_args(T), N1, Env),
+	    {As, N3} = label_ann(T, N2),
+	    {ann_c_apply(As, E, Es), N3};
+ 	call ->
+	    {M, N1} = label(call_module(T), N, Env),
+	    {F, N2} = label(call_name(T), N1, Env),
+	    {Es, N3} = label_list(call_args(T), N2, Env),
+	    {As, N4} = label_ann(T, N3),
+ 	    {ann_c_call(As, M, F, Es), N4};
+ 	primop ->
+	    {F, N1} = label(primop_name(T), N, Env),
+	    {Es, N2} = label_list(primop_args(T), N1, Env),
+	    {As, N3} = label_ann(T, N2),
+	    {ann_c_primop(As, F, Es), N3};
+ 	'case' ->
+	    {A, N1} = label(case_arg(T), N, Env),
+	    {Cs, N2} = label_list(case_clauses(T), N1, Env),
+	    {As, N3} = label_ann(T, N2),
+ 	    {ann_c_case(As, A, Cs), N3};
+ 	clause ->
+	    {_, N1, Env1} = label_vars(clause_vars(T), N, Env),
+	    {Ps, N2} = label_list(clause_pats(T), N1, Env1),
+	    {G, N3} = label(clause_guard(T), N2, Env1),
+	    {B, N4} = label(clause_body(T), N3, Env1),
+	    {As, N5} = label_ann(T, N4),
+	    {ann_c_clause(As, Ps, G, B), N5};
+ 	alias ->
+	    {V, N1} = label(alias_var(T), N, Env),
+	    {P, N2} = label(alias_pat(T), N1, Env),
+	    {As, N3} = label_ann(T, N2),
+	    {ann_c_alias(As, V, P), N3};
+ 	'fun' ->
+	    {Vs, N1, Env1} = label_vars(fun_vars(T), N, Env),
+	    {B, N2} = label(fun_body(T), N1, Env1),
+	    {As, N3} = label_ann(T, N2),
+	    {ann_c_fun(As, Vs, B), N3};
+ 	'receive' ->
+	    {Cs, N1} = label_list(receive_clauses(T), N, Env),
+	    {E, N2} = label(receive_timeout(T), N1, Env),
+	    {A, N3} = label(receive_action(T), N2, Env),
+	    {As, N4} = label_ann(T, N3),
+	    {ann_c_receive(As, Cs, E, A), N4};
+ 	'try' ->
+	    {E, N1} = label(try_arg(T), N, Env),
+	    {Vs, N2, Env1} = label_vars(try_vars(T), N1, Env),
+	    {B, N3} = label(try_body(T), N2, Env1),
+	    {Evs, N4, Env2} = label_vars(try_evars(T), N3, Env),
+	    {H, N5} = label(try_handler(T), N4, Env2),
+	    {As, N6} = label_ann(T, N5),
+	    {ann_c_try(As, E, Vs, B, Evs, H), N6};
+ 	'catch' ->
+	    {B, N1} = label(catch_body(T), N, Env),
+	    {As, N2} = label_ann(T, N1),
+	    {ann_c_catch(As, B), N2};
+	binary ->
+	    {Ds, N1} = label_list(binary_segments(T), N, Env),
+	    {As, N2} = label_ann(T, N1),
+	    {ann_c_binary(As, Ds), N2};
+	bitstr ->
+	    {Val, N1} = label(bitstr_val(T), N, Env),
+	    {Size, N2} = label(bitstr_size(T), N1, Env),
+	    {Unit, N3} = label(bitstr_unit(T), N2, Env),
+	    {Type, N4} = label(bitstr_type(T), N3, Env),
+	    {Flags, N5} = label(bitstr_flags(T), N4, Env),
+	    {As, N6} = label_ann(T, N5),
+	    {ann_c_bitstr(As, Val, Size, Unit, Type, Flags), N6};
+	letrec ->
+	    {_, N1, Env1} = label_vars(letrec_vars(T), N, Env),
+	    {Ds, N2} = label_defs(letrec_defs(T), N1, Env1),
+	    {B, N3} = label(letrec_body(T), N2, Env1),
+	    {As, N4} = label_ann(T, N3),
+	    {ann_c_letrec(As, Ds, B), N4};
+	module ->
+	    %% The module name is not labeled.
+	    {_, N1, Env1} = label_vars(module_vars(T), N, Env),
+	    {Ts, N2} = label_defs(module_attrs(T), N1, Env1),
+	    {Ds, N3} = label_defs(module_defs(T), N2, Env1),
+	    {Es, N4} = label_list(module_exports(T), N3, Env1),
+	    {As, N5} = label_ann(T, N4),
+	    {ann_c_module(As, module_name(T), Es, Ts, Ds), N5}
+    end.
+
+label_list([T | Ts], N, Env) ->
+    {T1, N1} = label(T, N, Env),
+    {Ts1, N2} = label_list(Ts, N1, Env),
+    {[T1 | Ts1], N2};
+label_list([], N, _Env) ->
+    {[], N}.
+
+label_vars([T | Ts], N, Env) ->
+    Env1 = dict:store(var_name(T), N, Env),
+    {As, N1} = label_ann(T, N),
+    T1 = set_ann(T, As),
+    {Ts1, N2, Env2} = label_vars(Ts, N1, Env1),
+    {[T1 | Ts1], N2, Env2};
+label_vars([], N, Env) ->
+    {[], N, Env}.
+
+label_defs([{F, T} | Ds], N, Env) ->
+    {F1, N1} = label(F, N, Env),
+    {T1, N2} = label(T, N1, Env),
+    {Ds1, N3} = label_defs(Ds, N2, Env),
+    {[{F1, T1} | Ds1], N3};
+label_defs([], N, _Env) ->
+    {[], N}.
+
+label_ann(T, N) ->
+    {[{label, N} | filter_labels(get_ann(T))], N + 1}.
+
+filter_labels([{label, _} | As]) ->
+    filter_labels(As);
+filter_labels([A | As]) ->
+    [A | filter_labels(As)];
+filter_labels([]) ->
+    [].