From a04289a5f30f39b62c7d245f272f486cfd70e6a8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Thu, 2 Jun 2016 06:40:09 +0200
Subject: Avoid the dreaded "no_file" in warnings

Add more filename/line number annotations while translating to
Core Erlang in v3_core, and ensure that sys_core_fold retains
existing annotations. The goal is to avoid that sys_core_fold
generate warnings with "no_file" instead of a filename.
---
 lib/compiler/src/sys_core_fold.erl    | 14 +++++-----
 lib/compiler/src/v3_core.erl          | 11 +++++---
 lib/compiler/test/core_fold_SUITE.erl | 49 +++++++++++++++++++++++++++++++++--
 3 files changed, 61 insertions(+), 13 deletions(-)

diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl
index dbc27db377..e0de50f3ae 100644
--- a/lib/compiler/src/sys_core_fold.erl
+++ b/lib/compiler/src/sys_core_fold.erl
@@ -786,7 +786,7 @@ fold_lit_args(Call, Module, Name, Args0) ->
 	Val ->
 	    case cerl:is_literal_term(Val) of
 		true ->
-		    cerl:abstract(Val);
+		    cerl:ann_abstract(cerl:get_ann(Call), Val);
 		false ->
 		    %% Successful evaluation, but it was not possible
 		    %% to express the computed value as a literal.
@@ -2176,24 +2176,22 @@ opt_not_in_let_1(V, Call, Body) ->
 	#c_call{module=#c_literal{val=erlang},
 		name=#c_literal{val='not'},
 		args=[#c_var{name=V}]} ->
-	    opt_not_in_let_2(Body);
+	    opt_not_in_let_2(Body, Call);
 	_ ->
 	    no
     end.
 
-opt_not_in_let_2(#c_case{clauses=Cs0}=Case) ->
+opt_not_in_let_2(#c_case{clauses=Cs0}=Case, NotCall) ->
     Vars = make_vars([], 1),
-    Body = #c_call{module=#c_literal{val=erlang},
-		   name=#c_literal{val='not'},
-		   args=Vars},
+    Body = NotCall#c_call{args=Vars},
     Cs = [begin
 	      Let = #c_let{vars=Vars,arg=B,body=Body},
 	      C#c_clause{body=opt_not_in_let(Let)}
 	  end || #c_clause{body=B}=C <- Cs0],
     {yes,Case#c_case{clauses=Cs}};
-opt_not_in_let_2(#c_call{}=Call0) ->
+opt_not_in_let_2(#c_call{}=Call0, _NotCall) ->
     invert_call(Call0);
-opt_not_in_let_2(_) -> no.
+opt_not_in_let_2(_, _) -> no.
 
 invert_call(#c_call{module=#c_literal{val=erlang},
 		    name=#c_literal{val=Name0},
diff --git a/lib/compiler/src/v3_core.erl b/lib/compiler/src/v3_core.erl
index a3b0236134..d71411de80 100644
--- a/lib/compiler/src/v3_core.erl
+++ b/lib/compiler/src/v3_core.erl
@@ -868,12 +868,16 @@ try_exception(Ecs0, St0) ->
     {Evs,St1} = new_vars(3, St0), % Tag, Value, Info
     {Ecs1,Ceps,St2} = clauses(Ecs0, St1),
     [_,Value,Info] = Evs,
-    Ec = #iclause{anno=#a{anno=[compiler_generated]},
+    LA = case Ecs1 of
+	     [] -> [];
+	     [C|_] -> get_lineno_anno(C)
+	 end,
+    Ec = #iclause{anno=#a{anno=[compiler_generated|LA]},
 		  pats=[c_tuple(Evs)],guard=[#c_literal{val=true}],
 		  body=[#iprimop{anno=#a{},       %Must have an #a{}
 				 name=#c_literal{val=raise},
 				 args=[Info,Value]}]},
-    Hs = [#icase{anno=#a{},args=[c_tuple(Evs)],clauses=Ecs1,fc=Ec}],
+    Hs = [#icase{anno=#a{anno=LA},args=[c_tuple(Evs)],clauses=Ecs1,fc=Ec}],
     {Evs,Ceps++Hs,St2}.
 
 try_after(As, St0) ->
@@ -2098,7 +2102,8 @@ upattern(#c_var{name=V}=Var, Ks, St0) ->
 	true ->
 	    {N,St1} = new_var_name(St0),
 	    New = #c_var{name=N},
-	    Test = #icall{anno=#a{us=add_element(N, [V])},
+	    LA = get_lineno_anno(Var),
+	    Test = #icall{anno=#a{anno=LA,us=add_element(N, [V])},
 			  module=#c_literal{val=erlang},
 			  name=#c_literal{val='=:='},
 			  args=[New,Var]},
diff --git a/lib/compiler/test/core_fold_SUITE.erl b/lib/compiler/test/core_fold_SUITE.erl
index 442b2d424c..376d2c8e9a 100644
--- a/lib/compiler/test/core_fold_SUITE.erl
+++ b/lib/compiler/test/core_fold_SUITE.erl
@@ -25,7 +25,8 @@
 	 eq/1,nested_call_in_case/1,guard_try_catch/1,coverage/1,
 	 unused_multiple_values_error/1,unused_multiple_values/1,
 	 multiple_aliases/1,redundant_boolean_clauses/1,
-	 mixed_matching_clauses/1,unnecessary_building/1]).
+	 mixed_matching_clauses/1,unnecessary_building/1,
+	 no_no_file/1]).
 
 -export([foo/0,foo/1,foo/2,foo/3]).
 
@@ -43,7 +44,8 @@ groups() ->
        eq,nested_call_in_case,guard_try_catch,coverage,
        unused_multiple_values_error,unused_multiple_values,
        multiple_aliases,redundant_boolean_clauses,
-       mixed_matching_clauses,unnecessary_building]}].
+       mixed_matching_clauses,unnecessary_building,
+       no_no_file]}].
 
 
 init_per_suite(Config) ->
@@ -454,4 +456,47 @@ do_unnecessary_building_2({a,_,_}=T) ->
      [_,_] = [T,none],
      x}.
 
+%% This test tests that v3_core has provided annotations and that
+%% sys_core_fold retains them, so that warnings produced by
+%% sys_core_fold will have proper filenames and line numbers. Thus, no
+%% "no_file" warnings.
+no_no_file(_Config) ->
+    {'EXIT',{{case_clause,0},_}} = (catch source(true, any)),
+    surgery = (tim(#{reduction => any}))(),
+
+    false = soul(#{[] => true}),
+    {'EXIT',{{case_clause,true},_}} = (catch soul(#{[] => false})),
+
+    ok = experiment(),
+    ok.
+
+source(true, Activities) ->
+    case 0 of
+	Activities when [] ->
+	    Activities
+    end.
+
+tim(#{reduction := Emergency}) ->
+    try
+	fun() -> surgery end
+    catch
+	_ when [] ->
+	    planet
+    end.
+
+soul(#{[] := Properly}) ->
+    not case true of
+	    Properly -> true;
+	    Properly -> 0
+	end.
+
+experiment() ->
+    case kingdom of
+	_ ->
+	    +case "map" of
+		 _ -> 0.0
+	     end
+    end,
+    ok.
+
 id(I) -> I.
-- 
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