File 2401-Fix-compiler-crash-for-literal-map-generator-pattern.patch of Package erlang
From 58cab53aa9c369cda8f1089676c35ed57bda1538 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Mon, 6 Feb 2023 13:12:10 +0100
Subject: [PATCH] Fix compiler crash for literal map generator patterns
---
lib/compiler/src/v3_core.erl | 10 ++++++----
lib/compiler/test/mc_SUITE.erl | 9 +++++++++
2 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/lib/compiler/src/v3_core.erl b/lib/compiler/src/v3_core.erl
index cedb162eef..8e0ba6ae26 100644
--- a/lib/compiler/src/v3_core.erl
+++ b/lib/compiler/src/v3_core.erl
@@ -87,7 +87,7 @@
-import(ordsets, [add_element/2,del_element/2,is_element/2,
union/1,union/2,intersection/2,subtract/2]).
-import(cerl, [ann_c_cons/3,ann_c_tuple/2,c_tuple/1,
- ann_c_map/3]).
+ ann_c_map/3,cons_hd/1,cons_tl/1]).
-include("core_parse.hrl").
@@ -1932,10 +1932,12 @@ generator(Line, {m_generate,Lg,{map_field_exact,_,K0,V0},E}, Gs, St0) ->
{Cg,St3} = lc_guard_tests(Gs, St2),
{Ce,Pre0,St4} = safe(E, St3),
AccPat = case Pat of
- #c_cons{hd=K,tl=V} ->
- #c_tuple{es=[K,V,IterVar]};
nomatch ->
- nomatch
+ nomatch;
+ _ ->
+ K = cons_hd(Pat),
+ V = cons_tl(Pat),
+ #c_tuple{es=[K,V,IterVar]}
end,
SkipPat = #c_tuple{es=[SkipK,SkipV,IterVar]},
diff --git a/lib/compiler/test/mc_SUITE.erl b/lib/compiler/test/mc_SUITE.erl
index 21aa2c017e..9da2b44479 100644
--- a/lib/compiler/test/mc_SUITE.erl
+++ b/lib/compiler/test/mc_SUITE.erl
@@ -97,6 +97,15 @@ basic(_Config) ->
[1] = [H || {_,_} := [H|_] <- Map],
[c, {b,42}] = lists:sort([K || K := [_|_] <- Map]),
+ %% Filtering using literal patterns.
+ [] = [0 || a := b <- #{}],
+ [] = [0 || a := b <- #{x => y}],
+ [0] = [0 || a := b <- #{a => b}],
+
+ <<>> = << <<0>> || a := b <- #{} >>,
+ <<>> = << <<0>> || a := b <- #{x => y} >>,
+ <<0>> = << <<0>> || a := b <- #{a => b} >>,
+
ok.
mc_double(Size) ->
--
2.35.3
