Merge pull request #6965 from bjorng/bjorn/compiler/fix-lost-map-exce…

…ption/GH-6960/OTP-18497 Fix lost exception from map update
erlang · Mar 10, 2023 · 5063a62 · 5063a62
2 parents 2454b14 + a5cb4f6
commit 5063a62
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Showing 2 changed files with 31 additions and 17 deletions.
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl
@@ -215,15 +215,15 @@ expr(#c_tuple{anno=Anno,es=Es0}=Tuple, Ctxt, Sub) ->
 	    ann_c_tuple(Anno, Es)
     end;
 expr(#c_map{anno=Anno,arg=V0,es=Es0}=Map, Ctxt, Sub) ->
-    Es = pair_list(Es0, Ctxt, descend(Map, Sub)),
+    %% Warn for useless building, but always build the map
+    %% anyway to preserve a possible exception.
     case Ctxt of
-	effect ->
-            warn_useless_building(Map, Sub),
-	    make_effect_seq(Es, Sub);
-	value ->
-	    V = expr(V0, Ctxt, Sub),
-	    ann_c_map(Anno,V,Es)
-    end;
+        effect -> warn_useless_building(Map, Sub);
+        value -> ok
+    end,
+    Es = pair_list(Es0, descend(Map, Sub)),
+    V = expr(V0, value, Sub),
+    ann_c_map(Anno, V, Es);
 expr(#c_binary{segments=Ss}=Bin0, Ctxt, Sub) ->
     %% Warn for useless building, but always build the binary
     %% anyway to preserve a possible exception.
@@ -490,14 +490,12 @@ ifes_list(_FVar, [], _Safe) ->
 expr_list(Es, Ctxt, Sub) ->
     [expr(E, Ctxt, Sub) || E <- Es].
 
-pair_list(Es, Ctxt, Sub) ->
-    [pair(E, Ctxt, Sub) || E <- Es].
+pair_list(Es, Sub) ->
+    [pair(E, Sub) || E <- Es].
 
-pair(#c_map_pair{key=K,val=V}, effect, Sub) ->
-    make_effect_seq([K,V], Sub);
-pair(#c_map_pair{key=K0,val=V0}=Pair, value=Ctxt, Sub) ->
-    K = expr(K0, Ctxt, Sub),
-    V = expr(V0, Ctxt, Sub),
+pair(#c_map_pair{key=K0,val=V0}=Pair, Sub) ->
+    K = expr(K0, value, Sub),
+    V = expr(V0, value, Sub),
     Pair#c_map_pair{key=K,val=V}.
 
 bitstr_list(Es, Sub) ->

diff --git a/lib/compiler/test/core_fold_SUITE.erl b/lib/compiler/test/core_fold_SUITE.erl
@@ -29,7 +29,7 @@
 	 no_no_file/1,configuration/1,supplies/1,
          redundant_stack_frame/1,export_from_case/1,
          empty_values/1,cover_letrec_effect/1,
-         receive_effect/1]).
+         receive_effect/1,map_effect/1]).
 
 -export([foo/0,foo/1,foo/2,foo/3]).
 
@@ -50,7 +50,7 @@ groups() ->
        no_no_file,configuration,supplies,
        redundant_stack_frame,export_from_case,
        empty_values,cover_letrec_effect,
-       receive_effect]}].
+       receive_effect,map_effect]}].
 
 
 init_per_suite(Config) ->
@@ -700,4 +700,20 @@ receive_effect(_Config) ->
 do_receive_effect() ->
     {} = receive _ -> {} = {} end.
 
+map_effect(_Config) ->
+    {'EXIT',{{badkey,key},_}} = catch map_effect_1(),
+
+    {'EXIT',{{badkey,key},_}} = catch map_effect_2(#{}),
+    {'EXIT',{{badmap,no_map},_}} = catch map_effect_2(no_map),
+
+    ok.
+
+map_effect_1() ->
+    #{}#{key := value},
+    ok.
+
+map_effect_2(Map) ->
+    Map#{key := value},
+    ok.
+
 id(I) -> I.