File 0846-erl_lint-Fix-forbidden-segments-in-binary-... of Package erlang

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File 0846-erl_lint-Fix-forbidden-segments-in-binary-generators.patch of Package erlang (Revision cfea4cb463bae0c770730e27e14c06dd)

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From 5c220217cac088033af989bba102a0e6278d5a6a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Tue, 4 Feb 2020 06:53:25 +0100
Subject: [PATCH 05/13] erl_lint: Fix forbidden segments in binary generators

In the pattern for bit string generators, segments without size are
not allowed. Thus erl_lint correctly generates an error for the
following bit string generator:

foo(Bin) ->
	[ [X] || <<X/bitstring>> <= Bin ].

However, if the pattern matched a literal erl_lint would not generate
an error:

bar(Bin) ->
	[ 42 || <<42/bitstring>> <= Bin ].

For this particular example, the compiler would crash later. For
variations of this code, the compiler would not crash but would
generate nonsensical code.
---
 lib/stdlib/src/erl_lint.erl        |  2 +-
 lib/stdlib/test/erl_lint_SUITE.erl | 22 +++++++++++++++++-----
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/lib/stdlib/src/erl_lint.erl b/lib/stdlib/src/erl_lint.erl
index 4dd30019d9..8be07e6c45 100644
--- a/lib/stdlib/src/erl_lint.erl
+++ b/lib/stdlib/src/erl_lint.erl
@@ -3513,7 +3513,7 @@ handle_generator(P,E,Vt,Uvt,St0) ->
 
 handle_bitstring_gen_pat({bin,_,Segments=[_|_]},St) ->
     case lists:last(Segments) of
-        {bin_element,Line,{var,_,_},default,Flags} when is_list(Flags) ->
+        {bin_element,Line,_,default,Flags} when is_list(Flags) ->
             case member(binary, Flags) orelse member(bytes, Flags)
               orelse member(bits, Flags) orelse member(bitstring, Flags) of
                 true ->
diff --git a/lib/stdlib/test/erl_lint_SUITE.erl b/lib/stdlib/test/erl_lint_SUITE.erl
index a5de033e89..0f27702f14 100644
--- a/lib/stdlib/test/erl_lint_SUITE.erl
+++ b/lib/stdlib/test/erl_lint_SUITE.erl
@@ -1298,6 +1298,10 @@ unsized_binary_in_bin_gen_pattern(Config) when is_list(Config) ->
 		  << <<X,Tail/bits>> || <<X,Tail/bits>> <= Bin >>;
 	      t({bc,bitstring,Bin}) ->
 		  << <<X,Tail/bits>> || <<X,Tail/bitstring>> <= Bin >>;
+              t({bc,binary_lit,Bin}) ->
+		  << <<X>> || <<X,1/binary>> <= Bin >>;
+	      t({bc,bytes_lit,Bin}) ->
+		  << <<X>> || <<X,a/bytes>> <= Bin >>;
 	      t({lc,binary,Bin}) ->
 		  [ {X,Tail} || <<X,Tail/binary>> <= Bin ];
 	      t({lc,bytes,Bin}) ->
@@ -1305,17 +1309,25 @@ unsized_binary_in_bin_gen_pattern(Config) when is_list(Config) ->
 	      t({lc,bits,Bin}) ->
 		  [ {X,Tail} || <<X,Tail/bits>> <= Bin ];
 	      t({lc,bitstring,Bin}) ->
-		  [ {X,Tail} || <<X,Tail/bitstring>> <= Bin ].">>,
+		  [ {X,Tail} || <<X,Tail/bitstring>> <= Bin ];
+              t({lc,bits_lit,Bin}) ->
+		  [ X || <<X,42/bits>> <= Bin ];
+	      t({lc,bitstring_lit,Bin}) ->
+		  [ X || <<X,b/bitstring>> <= Bin ].">>,
 	   [],
 	   {errors,
 	    [{2,erl_lint,unsized_binary_in_bin_gen_pattern},
 	     {4,erl_lint,unsized_binary_in_bin_gen_pattern},
 	     {6,erl_lint,unsized_binary_in_bin_gen_pattern},
 	     {8,erl_lint,unsized_binary_in_bin_gen_pattern},
-	     {10,erl_lint,unsized_binary_in_bin_gen_pattern},
-	     {12,erl_lint,unsized_binary_in_bin_gen_pattern},
-	     {14,erl_lint,unsized_binary_in_bin_gen_pattern},
-	     {16,erl_lint,unsized_binary_in_bin_gen_pattern}],
+             {10,erl_lint,unsized_binary_in_bin_gen_pattern},
+             {12,erl_lint,unsized_binary_in_bin_gen_pattern},
+             {14,erl_lint,unsized_binary_in_bin_gen_pattern},
+             {16,erl_lint,unsized_binary_in_bin_gen_pattern},
+	     {18,erl_lint,unsized_binary_in_bin_gen_pattern},
+	     {20,erl_lint,unsized_binary_in_bin_gen_pattern},
+	     {22,erl_lint,unsized_binary_in_bin_gen_pattern},
+	     {24,erl_lint,unsized_binary_in_bin_gen_pattern}],
 	     []}}],
     [] = run(Config, Ts),
     ok.
-- 
2.16.4

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File 0846-erl_lint-Fix-forbidden-segments-in-binary-generators.patch of Package erlang (Revision cfea4cb463bae0c770730e27e14c06dd)

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