File 2746-Fix-crash-when-compiling-binary-comprehension.patch of Package erlang
From 826ac62f2590e0fb668bc669b10f829ef66c47e1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Sat, 5 Dec 2020 06:22:46 +0100
Subject: [PATCH] Fix crash when compiling binary comprehension
https://bugs.erlang.org/browse/ERL-1434
---
lib/compiler/src/beam_ssa_bc_size.erl | 48 ++++++++++++++++++++------
lib/compiler/test/bs_bincomp_SUITE.erl | 18 ++++++++--
2 files changed, 52 insertions(+), 14 deletions(-)
diff --git a/lib/compiler/src/beam_ssa_bc_size.erl b/lib/compiler/src/beam_ssa_bc_size.erl
index 2c3be55bc6..57318f2558 100644
--- a/lib/compiler/src/beam_ssa_bc_size.erl
+++ b/lib/compiler/src/beam_ssa_bc_size.erl
@@ -38,7 +38,7 @@
-module(beam_ssa_bc_size).
-export([opt/1]).
--import(lists, [any/2,reverse/1,sort/1]).
+-import(lists, [any/2,member/2,reverse/1,sort/1]).
-include("beam_ssa_opt.hrl").
@@ -53,8 +53,9 @@ opt([Id|Ids], StMap0) ->
opt([], StMap) -> StMap.
opt_function(Id, StMap) ->
- #opt_st{ssa=Linear0,cnt=Count0} = OptSt0 = map_get(Id, StMap),
- try opt_blks(Linear0, StMap, unchanged, Count0, []) of
+ #opt_st{anno=Anno,ssa=Linear0,cnt=Count0} = OptSt0 = map_get(Id, StMap),
+ ParamInfo = maps:get(parameter_info, Anno, #{}),
+ try opt_blks(Linear0, ParamInfo, StMap, unchanged, Count0, []) of
{Linear,Count} ->
OptSt = OptSt0#opt_st{ssa=Linear,cnt=Count},
StMap#{Id := OptSt};
@@ -67,29 +68,30 @@ opt_function(Id, StMap) ->
erlang:raise(Class, Error, Stack)
end.
-opt_blks([{L,#b_blk{is=Is}=Blk}|Blks], StMap, AnyChange, Count0, Acc0) ->
+opt_blks([{L,#b_blk{is=Is}=Blk}|Blks], ParamInfo, StMap, AnyChange, Count0, Acc0) ->
case Is of
[#b_set{op=bs_init_writable,dst=Dst}] ->
Bs = #{st_map => StMap, Dst => {writable,#b_literal{val=0}}},
- try opt_writable(Bs, L, Blk, Blks, Count0, Acc0) of
+ try opt_writable(Bs, L, Blk, Blks, ParamInfo, Count0, Acc0) of
{Acc,Count} ->
- opt_blks(Blks, StMap, changed, Count, Acc)
+ opt_blks(Blks, ParamInfo, StMap, changed, Count, Acc)
catch
throw:not_possible ->
- opt_blks(Blks, StMap, AnyChange, Count0, [{L,Blk}|Acc0])
+ opt_blks(Blks, ParamInfo, StMap, AnyChange, Count0, [{L,Blk}|Acc0])
end;
_ ->
- opt_blks(Blks, StMap, AnyChange, Count0, [{L,Blk}|Acc0])
+ opt_blks(Blks, ParamInfo, StMap, AnyChange, Count0, [{L,Blk}|Acc0])
end;
-opt_blks([], _StMap, changed, Count, Acc) ->
+opt_blks([], _ParamInfo, _StMap, changed, Count, Acc) ->
{reverse(Acc),Count};
-opt_blks([], _StMap, unchanged, _Count, _Acc) ->
+opt_blks([], _ParamInfo, _StMap, unchanged, _Count, _Acc) ->
none.
-opt_writable(Bs0, L, Blk, Blks, Count0, Acc0) ->
+opt_writable(Bs0, L, Blk, Blks, ParamInfo, Count0, Acc0) ->
case {Blk,Blks} of
{#b_blk{last=#b_br{succ=Next,fail=Next}},
[{Next,#b_blk{is=[#b_set{op=call,args=[_|Args],dst=Dst}=Call|_]}}|_]} ->
+ ensure_not_match_context(Call, ParamInfo),
ArgTypes = maps:from_list([{Arg,{arg,Arg}} || Arg <- Args]),
Bs = maps:merge(ArgTypes, Bs0),
Result = map_get(Dst, call_size_func(Call, Bs)),
@@ -99,6 +101,30 @@ opt_writable(Bs0, L, Blk, Blks, Count0, Acc0) ->
throw(not_possible)
end.
+ensure_not_match_context(#b_set{anno=Anno,args=[_|Args]}, ParamInfo) ->
+ case maps:get(bsm_info, Anno, []) of
+ context_reused ->
+ %% The generator is a match context. The optimization is
+ %% not safe. Example:
+ %%
+ %% f(<<B/binary>>) ->
+ %% << <<V>> || <<V>> <= B >>.
+ throw(not_possible);
+ _ ->
+ case any(fun(V) ->
+ member(accepts_match_context,
+ maps:get(V, ParamInfo, []))
+ end, Args) of
+ true ->
+ %% Match context is passed from the calling function. Example:
+ %% f0(<<B/binary>>) -> f1(B).
+ %% f1(B) -> << <<V>> || <<V>> <= B >>.
+ throw(not_possible);
+ false ->
+ ok
+ end
+ end.
+
%%%
%%% Traverse the SSA code of the binary comprehension functions to
%%% figure out the exact size for the writable binary. This algorithm
diff --git a/lib/compiler/test/bs_bincomp_SUITE.erl b/lib/compiler/test/bs_bincomp_SUITE.erl
index 15fed1d4a9..a3900c7a9a 100644
--- a/lib/compiler/test/bs_bincomp_SUITE.erl
+++ b/lib/compiler/test/bs_bincomp_SUITE.erl
@@ -143,6 +143,9 @@ mixed(Config) when is_list(Config) ->
gen_data(256),
gen_data(512),
+ <<1,2,3>> = cs_default(match_context_1(<<1,2,3>>)),
+ <<4,5,6>> = cs_default(match_context_2(<<4,5,6>>)),
+
cs_end().
mixed_nested(L) ->
@@ -174,6 +177,15 @@ gen_data(Size) ->
Data = << <<C>> || _ <- lists:seq(1, Size div 256),
C <- lists:seq(0, 255) >>.
+match_context_1(<<B/binary>>) ->
+ << <<V>> || <<V>> <= B >>.
+
+match_context_2(<<B/binary>>) ->
+ do_match_context_2(B).
+
+do_match_context_2(B) ->
+ << <<V>> || <<V>> <= B >>.
+
filters(Config) when is_list(Config) ->
cs_init(),
<<"BDF">> =
@@ -329,14 +341,14 @@ sizes(Config) when is_list(Config) ->
%% Binary generators.
Fun10 = fun(Bin) ->
- cs(<< <<E:16>> || <<E:8>> <= Bin >>)
+ cs(<< <<E:16>> || <<E:8>> <= id(Bin) >>)
end,
<<>> = Fun10(<<>>),
<<1:16>> = Fun10(<<1>>),
<<1:16,2:16>> = Fun10(<<1,2>>),
Fun11 = fun(Bin) ->
- cs(<< <<E:8>> || <<E:16>> <= Bin >>)
+ cs(<< <<E:8>> || <<E:16>> <= id(Bin) >>)
end,
<<>> = Fun11(<<>>),
<<1>> = Fun11(<<1:16>>),
@@ -348,7 +360,7 @@ sizes(Config) when is_list(Config) ->
<<1,2>> = Fun11(<<1:16,2:16,255:15>>),
Fun12 = fun(Bin, Sz1, Sz2) ->
- cs(<< <<E:Sz1>> || <<E:Sz2>> <= Bin >>)
+ cs(<< <<E:Sz1>> || <<E:Sz2>> <= id(Bin) >>)
end,
<<>> = Fun12(<<>>, 1, 1),
Binary = list_to_binary(lists:seq(0, 255)),
--
2.26.2
