beam_validator: Stop validating the 'aligned' flag for binaries

The run-time system stopped paying attention the 'aligned' flag in bit
syntax construction and matching when bitstrings were introduced in
language.

The beam_asm compiler pass will crash if the 'aligned' flag is given
in bit syntax instructions.

beam_validator still validates the 'aligned' flag. Before
912fea0b712a (which removed the possibility to validate existing
BEAM files), the 'aligned' flag could actually be encountered
when validating a BEAM file.

Since the validation of 'aligned' no longer serves any useful
purpose, remove the validation code.

4 files changed, 27 insertions, 146 deletions

diff --git a/lib/compiler/src/beam_validator.erl b/lib/compiler/src/beam_validator.erl
index ce6cd60ab1..780826b126 100644
--- a/lib/compiler/src/beam_validator.erl
+++ b/lib/compiler/src/beam_validator.erl
@@ -28,7 +28,7 @@
 
 -include("beam_disasm.hrl").
 
--import(lists, [reverse/1,foldl/3,foreach/2,member/2,dropwhile/2]).
+-import(lists, [reverse/1,foldl/3,foreach/2,dropwhile/2]).
 
 -define(MAXREG, 1024).
 
@@ -153,7 +153,6 @@ validate_0(Module, [{function,Name,Ar,Entry,Code}|Fs], Ft) ->
 	 hf=0,				%Available heap size for floats.
 	 fls=undefined,			%Floating point state.
 	 ct=[],				%List of hot catch/try labels
-	 bits=undefined,	        %Number of bits in bit syntax binary.
 	 setelem=false			%Previous instruction was setelement/3.
 	}).
 
@@ -696,8 +695,7 @@ valfun_4({bs_init2,{f,Fail},Sz,Heap,Live,_,Dst}, Vst0) ->
     end,
     Vst1 = heap_alloc(Heap, Vst0),
     Vst2 = branch_state(Fail, Vst1),
-    Vst3 = prune_x_regs(Live, Vst2),
-    Vst = bs_zero_bits(Vst3),
+    Vst = prune_x_regs(Live, Vst2),
     set_type_reg(binary, Dst, Vst);
 valfun_4({bs_init_bits,{f,Fail},Sz,Heap,Live,_,Dst}, Vst0) ->
     verify_live(Live, Vst0),
@@ -709,8 +707,7 @@ valfun_4({bs_init_bits,{f,Fail},Sz,Heap,Live,_,Dst}, Vst0) ->
     end,
     Vst1 = heap_alloc(Heap, Vst0),
     Vst2 = branch_state(Fail, Vst1),
-    Vst3 = prune_x_regs(Live, Vst2),
-    Vst = bs_zero_bits(Vst3),
+    Vst = prune_x_regs(Live, Vst2),
     set_type_reg(binary, Dst, Vst);
 valfun_4({bs_append,{f,Fail},Bits,Heap,Live,_Unit,Bin,_Flags,Dst}, Vst0) ->
     verify_live(Live, Vst0),
@@ -718,43 +715,35 @@ valfun_4({bs_append,{f,Fail},Bits,Heap,Live,_Unit,Bin,_Flags,Dst}, Vst0) ->
     assert_term(Bin, Vst0),
     Vst1 = heap_alloc(Heap, Vst0),
     Vst2 = branch_state(Fail, Vst1),
-    Vst3 = prune_x_regs(Live, Vst2),
-    Vst = bs_zero_bits(Vst3),
+    Vst = prune_x_regs(Live, Vst2),
     set_type_reg(binary, Dst, Vst);
 valfun_4({bs_private_append,{f,Fail},Bits,_Unit,Bin,_Flags,Dst}, Vst0) ->
     assert_term(Bits, Vst0),
     assert_term(Bin, Vst0),
-    Vst1 = branch_state(Fail, Vst0),
-    Vst = bs_zero_bits(Vst1),
+    Vst = branch_state(Fail, Vst0),
     set_type_reg(binary, Dst, Vst);
 valfun_4({bs_put_string,Sz,_}, Vst) when is_integer(Sz) ->
     Vst;
-valfun_4({bs_put_binary,{f,Fail},Sz,_,_,Src}=I, Vst0) ->
-    assert_term(Sz, Vst0),
-    assert_term(Src, Vst0),
-    Vst = bs_align_check(I, Vst0),
+valfun_4({bs_put_binary,{f,Fail},Sz,_,_,Src}, Vst) ->
+    assert_term(Sz, Vst),
+    assert_term(Src, Vst),
     branch_state(Fail, Vst);
-valfun_4({bs_put_float,{f,Fail},Sz,_,_,Src}=I, Vst0) ->
-    assert_term(Sz, Vst0),
-    assert_term(Src, Vst0),
-    Vst = bs_align_check(I, Vst0),
+valfun_4({bs_put_float,{f,Fail},Sz,_,_,Src}, Vst) ->
+    assert_term(Sz, Vst),
+    assert_term(Src, Vst),
     branch_state(Fail, Vst);
-valfun_4({bs_put_integer,{f,Fail},Sz,_,_,Src}=I, Vst0) ->
-    assert_term(Sz, Vst0),
-    assert_term(Src, Vst0),
-    Vst = bs_align_check(I, Vst0),
+valfun_4({bs_put_integer,{f,Fail},Sz,_,_,Src}, Vst) ->
+    assert_term(Sz, Vst),
+    assert_term(Src, Vst),
     branch_state(Fail, Vst);
-valfun_4({bs_put_utf8,{f,Fail},_,Src}=I, Vst0) ->
-    assert_term(Src, Vst0),
-    Vst = bs_align_check(I, Vst0),
+valfun_4({bs_put_utf8,{f,Fail},_,Src}, Vst) ->
+    assert_term(Src, Vst),
     branch_state(Fail, Vst);
-valfun_4({bs_put_utf16,{f,Fail},_,Src}=I, Vst0) ->
-    assert_term(Src, Vst0),
-    Vst = bs_align_check(I, Vst0),
+valfun_4({bs_put_utf16,{f,Fail},_,Src}, Vst) ->
+    assert_term(Src, Vst),
     branch_state(Fail, Vst);
-valfun_4({bs_put_utf32,{f,Fail},_,Src}=I, Vst0) ->
-    assert_term(Src, Vst0),
-    Vst = bs_align_check(I, Vst0),
+valfun_4({bs_put_utf32,{f,Fail},_,Src}, Vst) ->
+    assert_term(Src, Vst),
     branch_state(Fail, Vst);
 %% Map instructions.
 valfun_4({put_map_assoc,{f,Fail},Src,Dst,Live,{list,List}}, Vst) ->
@@ -1067,55 +1056,7 @@ bsm_restore(Reg, SavePoint, Vst) ->
 	    end;
 	_ -> error({illegal_restore,SavePoint,range})
     end.
-    
-
-%%%
-%%% Validation of alignment in the bit syntax. (Currently, construction only.)
-%%%
-%%% We make sure that the aligned flag is only set when we can be sure of the
-%%% aligment.
-%%%
 
-bs_zero_bits(#vst{current=St}=Vst) ->
-    Vst#vst{current=St#st{bits=0}}.
-
-bs_align_check({bs_put_utf8,_,Flags,_}, #vst{current=#st{}=St}=Vst) ->
-    bs_verify_flags(Flags, St),
-    Vst;
-bs_align_check({bs_put_utf16,_,Flags,_}, #vst{current=#st{}=St}=Vst) ->
-    bs_verify_flags(Flags, St),
-    Vst;
-bs_align_check({bs_put_utf32,_,Flags,_}, #vst{current=#st{}=St}=Vst) ->
-    bs_verify_flags(Flags, St),
-    Vst;
-bs_align_check({_,_,Sz,U,Flags,_}, #vst{current=#st{bits=Bits}=St}=Vst) ->
-    bs_verify_flags(Flags, St),
-    bs_update_bits(Bits, Sz, U, St, Vst).
-
-bs_update_bits(undefined, _, _, _, Vst) -> Vst;
-bs_update_bits(Bits0, {integer,Sz}, U, St, Vst) ->
-    Bits = Bits0 + U*Sz,
-    Vst#vst{current=St#st{bits=Bits}};
-bs_update_bits(_, {atom,all}, _, _, Vst) ->
-    %% A binary will not change the alignment.
-    Vst;
-bs_update_bits(_, _, U, _, Vst) when U rem 8 =:= 0 ->
-    %% Units of 8, 16, and so on will not change the aligment.
-    Vst;
-bs_update_bits(_, _, _, St, Vst) ->
-    %% We can no longer be sure about aligment.
-    Vst#vst{current=St#st{bits=undefined}}.
-
-bs_verify_flags({field_flags,Fl}, #st{bits=Bits}) ->
-    case bs_is_aligned(Fl) of
-	false -> ok;
-	true when is_integer(Bits), Bits rem 8 =:= 0 -> ok;
-	true -> error({aligned_flag_set,{bits,Bits}})
-    end.
-
-bs_is_aligned(Fl) when is_integer(Fl) -> Fl band 1 =:= 1;
-bs_is_aligned(Fl) when is_list(Fl) -> member(aligned, Fl).
-    
 %%%
 %%% Keeping track of types.
 %%%
diff --git a/lib/compiler/test/beam_validator_SUITE.erl b/lib/compiler/test/beam_validator_SUITE.erl
index 6779a2cfec..e64dd6b9c3 100644
--- a/lib/compiler/test/beam_validator_SUITE.erl
+++ b/lib/compiler/test/beam_validator_SUITE.erl
@@ -28,7 +28,7 @@
 	 overwrite_catchtag/1,overwrite_trytag/1,accessing_tags/1,bad_catch_try/1,
 	 cons_guard/1,
 	 freg_range/1,freg_uninit/1,freg_state/1,
-	 bad_bin_match/1,bin_aligned/1,bad_dsetel/1,
+	 bad_bin_match/1,bad_dsetel/1,
 	 state_after_fault_in_catch/1,no_exception_in_catch/1,
 	 undef_label/1,illegal_instruction/1,failing_gc_guard_bif/1,
 	 map_field_lists/1]).
@@ -57,7 +57,7 @@ groups() ->
        unsafe_catch,dead_code,
        overwrite_catchtag,overwrite_trytag,accessing_tags,
        bad_catch_try,cons_guard,freg_range,freg_uninit,
-       freg_state,bad_bin_match,bin_aligned,bad_dsetel,
+       freg_state,bad_bin_match,bad_dsetel,
        state_after_fault_in_catch,no_exception_in_catch,
        undef_label,illegal_instruction,failing_gc_guard_bif,
        map_field_lists]}].
@@ -178,7 +178,7 @@ unsafe_catch(Config) when is_list(Config) ->
     ?line
 	[{{t,small,2},
 	  {{bs_put_integer,{f,0},{integer,16},1,
-	    {field_flags,[aligned,unsigned,big]},{y,0}},
+	    {field_flags,[unsigned,big]},{y,0}},
 	   20,
 	   {unassigned,{y,0}}}}] = Errors,
     ok.
@@ -299,19 +299,6 @@ bad_bin_match(Config) when is_list(Config) ->
 		do_val(bad_bin_match, Config),
 	ok.
 
-bin_aligned(Config) when is_list(Config) ->
-    Errors = do_val(bin_aligned, Config),
-    ?line
-	[{{t,decode,1},
-	  {{bs_put_integer,{f,0},
-	    {integer,5},
-	    1,
-	    {field_flags,[unsigned,big,aligned]},
-	    {integer,0}},
-	   10,
-	   {aligned_flag_set,{bits,3}}}}] = Errors,
-    ok.
-
 bad_dsetel(Config) when is_list(Config) ->
     Errors = do_val(bad_dsetel, Config),
     ?line
diff --git a/lib/compiler/test/beam_validator_SUITE_data/bin_aligned.S b/lib/compiler/test/beam_validator_SUITE_data/bin_aligned.S
deleted file mode 100644
index a59f7ccc03..0000000000
--- a/lib/compiler/test/beam_validator_SUITE_data/bin_aligned.S
+++ /dev/null
@@ -1,47 +0,0 @@
-{module, bin_aligned}.  %% version = 0
-
-{exports, [{decode,1},{module_info,0},{module_info,1}]}.
-
-{attributes, []}.
-
-{labels, 7}.
-
-
-{function, decode, 1, 2}.
-  {label,1}.
-    {func_info,{atom,t},{atom,decode},1}.
-  {label,2}.
-    {move,{integer,1},{x,1}}.
-    {bif,size,{f,0},[{x,0}],{x,2}}.
-    {bs_add,{f,0},[{x,1},{x,2},1],{x,1}}.
-    {bs_init2,{f,0},{x,1},0,1,{field_flags,[]},{x,1}}.
-    {bs_put_integer,{f,0},
-                    {integer,3},
-                    1,
-                    {field_flags,[aligned,unsigned,big]},
-                    {integer,0}}.
-    {bs_put_binary,{f,0},{atom,all},8,{field_flags,[unsigned,big]},{x,0}}.
-    {bs_put_integer,{f,0},
-                    {integer,5},
-                    1,
-                    {field_flags,[unsigned,big,aligned]},
-                    {integer,0}}.
-    {move,{x,1},{x,0}}.
-    return.
-
-
-{function, module_info, 0, 4}.
-  {label,3}.
-    {func_info,{atom,t},{atom,module_info},0}.
-  {label,4}.
-    {move,{atom,t},{x,0}}.
-    {call_ext_only,1,{extfunc,erlang,get_module_info,1}}.
-
-
-{function, module_info, 1, 6}.
-  {label,5}.
-    {func_info,{atom,t},{atom,module_info},1}.
-  {label,6}.
-    {move,{x,0},{x,1}}.
-    {move,{atom,t},{x,0}}.
-    {call_ext_only,2,{extfunc,erlang,get_module_info,2}}.
diff --git a/lib/compiler/test/beam_validator_SUITE_data/unsafe_catch.S b/lib/compiler/test/beam_validator_SUITE_data/unsafe_catch.S
index 500ac11377..f7d3f805b3 100644
--- a/lib/compiler/test/beam_validator_SUITE_data/unsafe_catch.S
+++ b/lib/compiler/test/beam_validator_SUITE_data/unsafe_catch.S
@@ -17,7 +17,7 @@
     {bs_put_integer,{f,0},
                     {integer,8},
                     1,
-                    {field_flags,[aligned,unsigned,big]},
+                    {field_flags,[unsigned,big]},
                     {x,0}}.
     {move,{x,1},{y,0}}.
     {move,{x,2},{x,0}}.
@@ -34,7 +34,7 @@
     {bs_put_integer,{f,0},
                     {integer,16},
                     1,
-                    {field_flags,[aligned,unsigned,big]},
+                    {field_flags,[unsigned,big]},
                     {y,0}}.
     {move,{x,0},{y,0}}.
     {move,{x,1},{x,0}}.
@@ -55,12 +55,12 @@
     {bs_put_binary,{f,0},
                    {atom,all},
                    8,
-                   {field_flags,[aligned,unsigned,big]},
+                   {field_flags,[unsigned,big]},
                    {y,0}}.
     {bs_put_binary,{f,0},
                    {atom,all},
                    8,
-                   {field_flags,[aligned,unsigned,big]},
+                   {field_flags,[unsigned,big]},
                    {x,0}}.
     {move,{x,1},{x,0}}.
     {deallocate,2}.