From 8c32dda686d2b964b08cc4614ba9c445039b3dd9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Thu, 23 Apr 2015 07:29:41 +0200 Subject: 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. --- lib/compiler/src/beam_validator.erl | 99 ++++++++----------------------------- 1 file changed, 20 insertions(+), 79 deletions(-) (limited to 'lib/compiler/src/beam_validator.erl') 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. %%% -- cgit v1.2.3