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Diffstat (limited to 'lib/dialyzer/test/options1_SUITE_data/src/compiler/beam_validator.erl')
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1 files changed, 1022 insertions, 0 deletions
diff --git a/lib/dialyzer/test/options1_SUITE_data/src/compiler/beam_validator.erl b/lib/dialyzer/test/options1_SUITE_data/src/compiler/beam_validator.erl new file mode 100644 index 0000000000..87c1c54d0f --- /dev/null +++ b/lib/dialyzer/test/options1_SUITE_data/src/compiler/beam_validator.erl @@ -0,0 +1,1022 @@ +%% ``The contents of this file are subject to the Erlang Public License, +%% Version 1.1, (the "License"); you may not use this file except in +%% compliance with the License. You should have received a copy of the +%% Erlang Public License along with this software. If not, it can be +%% retrieved via the world wide web at http://www.erlang.org/. +%% +%% Software distributed under the License is distributed on an "AS IS" +%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See +%% the License for the specific language governing rights and limitations +%% under the License. +%% +%% The Initial Developer of the Original Code is Ericsson Utvecklings AB. +%% Portions created by Ericsson are Copyright 1999, Ericsson Utvecklings +%% AB. All Rights Reserved.'' +%% +%% $Id: beam_validator.erl,v 1.1 2008/12/17 09:53:41 mikpe Exp $ + +-module(beam_validator). + +-export([file/1,files/1]). + +%% Interface for compiler. +-export([module/2,format_error/1]). + +-import(lists, [reverse/1,foldl/3]). + +-define(MAXREG, 1024). + +-define(DEBUG, 1). +-undef(DEBUG). +-ifdef(DEBUG). +-define(DBG_FORMAT(F, D), (io:format((F), (D)))). +-else. +-define(DBG_FORMAT(F, D), ok). +-endif. + +%%% +%%% API functions. +%%% + +files([F|Fs]) -> + ?DBG_FORMAT("# Verifying: ~p~n", [F]), + case file(F) of + ok -> ok; + {error,Es} -> + io:format("~p:~n~s~n", [F,format_error(Es)]) + end, + files(Fs); +files([]) -> ok. + +file(Name) when is_list(Name) -> + case case filename:extension(Name) of + ".S" -> s_file(Name); + ".beam" -> beam_file(Name) + end of + [] -> ok; + Es -> {error,Es} + end. + +%% To be called by the compiler. +module({Mod,Exp,Attr,Fs,Lc}=Code, _Opts) + when is_atom(Mod), is_list(Exp), is_list(Attr), is_integer(Lc) -> + case validate(Fs) of + [] -> {ok,Code}; + Es0 -> + Es = [{?MODULE,E} || E <- Es0], + {error,[{atom_to_list(Mod),Es}]} + end. + +format_error([]) -> []; +format_error([{{M,F,A},{I,Off,Desc}}|Es]) -> + [io_lib:format(" ~p:~p/~p+~p:~n ~p - ~p~n", + [M,F,A,Off,I,Desc])|format_error(Es)]; +format_error({{_M,F,A},{I,Off,Desc}}) -> + io_lib:format( + "function ~p/~p+~p:~n" + " Internal consistency check failed - please report this bug.~n" + " Instruction: ~p~n" + " Error: ~p:~n", [F,A,Off,I,Desc]). + +%%% +%%% Local functions follow. +%%% + +s_file(Name) -> + {ok,Is} = file:consult(Name), + Fs = find_functions(Is), + validate(Fs). + +find_functions(Fs) -> + find_functions_1(Fs, none, [], []). + +find_functions_1([{function,Name,Arity,Entry}|Is], Func, FuncAcc, Acc0) -> + Acc = add_func(Func, FuncAcc, Acc0), + find_functions_1(Is, {Name,Arity,Entry}, [], Acc); +find_functions_1([I|Is], Func, FuncAcc, Acc) -> + find_functions_1(Is, Func, [I|FuncAcc], Acc); +find_functions_1([], Func, FuncAcc, Acc) -> + reverse(add_func(Func, FuncAcc, Acc)). + +add_func(none, _, Acc) -> Acc; +add_func({Name,Arity,Entry}, Is, Acc) -> + [{function,Name,Arity,Entry,reverse(Is)}|Acc]. + +beam_file(Name) -> + try beam_disasm:file(Name) of + {error,beam_lib,Reason} -> [{beam_lib,Reason}]; + {beam_file,L} -> + {value,{code,Code0}} = lists:keysearch(code, 1, L), + Code = beam_file_1(Code0, []), + validate(Code) + catch _:_ -> [disassembly_failed] + end. + +beam_file_1([F0|Fs], Acc) -> + F = conv_func(F0), + beam_file_1(Fs, [F|Acc]); +beam_file_1([], Acc) -> reverse(Acc). + +%% Convert from the disassembly format to the internal format +%% used by the compiler (as passed to the assembler). + +conv_func(Is) -> + conv_func_1(labels(Is)). + +conv_func_1({Ls,[{func_info,[{atom,M},{atom,F},Ar]}, + {label,Entry}=Le|Is]}) -> + %% The entry label gets maybe not correct here + {function,F,Ar,Entry, + [{label,L}||L<-Ls]++[{func_info,{atom,M},{atom,F},Ar},Le|Is]}. + +%%% +%%% The validator follows. +%%% +%%% The purpose of the validator is find errors in the generated code +%%% that may cause the emulator to crash or behave strangely. +%%% We don't care about type errors in the user's code that will +%%% cause a proper exception at run-time. +%%% + +%%% Things currently not checked. XXX +%%% +%%% - That floating point registers are initialized before used. +%%% - That fclearerror and fcheckerror are used properly. +%%% - Heap allocation for floating point numbers. +%%% - Heap allocation for binaries. +%%% - That a catchtag or trytag is not overwritten by the wrong +%%% type of instruction (such as move/2). +%%% - Make sure that all catchtags and trytags have been removed +%%% from the stack at return/tail call. +%%% - Verify get_list instructions. +%%% + +%% validate([Function]) -> [] | [Error] +%% A list of functions with their code. The code is in the same +%% format as used in the compiler and in .S files. +validate([]) -> []; +validate([{function,Name,Ar,Entry,Code}|Fs]) -> + try validate_1(Code, Name, Ar, Entry) of + _ -> validate(Fs) + catch + Error -> + [Error|validate(Fs)]; + error:Error -> + [validate_error(Error, Name, Ar)|validate(Fs)] + end. + +-ifdef(DEBUG). +validate_error(Error, Name, Ar) -> + exit(validate_error_1(Error, Name, Ar)). +-else. +validate_error(Error, Name, Ar) -> + validate_error_1(Error, Name, Ar). +-endif. +validate_error_1(Error, Name, Ar) -> + {{'_',Name,Ar}, + {internal_error,'_',{Error,erlang:get_stacktrace()}}}. + +-record(st, %Emulation state + {x=init_regs(0, term), %x register info. + y=init_regs(0, initialized), %y register info. + numy=none, %Number of y registers. + h=0, %Available heap size. + ct=[] %List of hot catch/try labels + }). + +-record(vst, %Validator state + {current=none, %Current state + branched=gb_trees:empty() %States at jumps + }). + +-ifdef(DEBUG). +print_st(#st{x=Xs,y=Ys,numy=NumY,h=H,ct=Ct}) -> + io:format(" #st{x=~p~n" + " y=~p~n" + " numy=~p,h=~p,ct=~w~n", + [gb_trees:to_list(Xs),gb_trees:to_list(Ys),NumY,H,Ct]). +-endif. + +validate_1(Is, Name, Arity, Entry) -> + validate_2(labels(Is), Name, Arity, Entry). + +validate_2({Ls1,[{func_info,{atom,Mod},{atom,Name},Arity}=_F|Is]}, + Name, Arity, Entry) -> + lists:foreach(fun (_L) -> ?DBG_FORMAT(" ~p.~n", [_L]) end, Ls1), + ?DBG_FORMAT(" ~p.~n", [_F]), + validate_3(labels(Is), Name, Arity, Entry, Mod, Ls1); +validate_2({Ls1,Is}, Name, Arity, _Entry) -> + error({{'_',Name,Arity},{first(Is),length(Ls1),illegal_instruction}}). + +validate_3({Ls2,Is}, Name, Arity, Entry, Mod, Ls1) -> + lists:foreach(fun (_L) -> ?DBG_FORMAT(" ~p.~n", [_L]) end, Ls2), + Offset = 1 + length(Ls2), + case lists:member(Entry, Ls2) of + true -> + St = init_state(Arity), + Vst = #vst{current=St, + branched=gb_trees_from_list([{L,St} || L <- Ls1])}, + valfun(Is, {Mod,Name,Arity}, Offset, Vst); + false -> + error({{Mod,Name,Arity},{first(Is),Offset,no_entry_label}}) + end. + +first([X|_]) -> X; +first([]) -> []. + +labels(Is) -> + labels_1(Is, []). + +labels_1([{label,L}|Is], R) -> + labels_1(Is, [L|R]); +labels_1(Is, R) -> + {lists:reverse(R),Is}. + +init_state(Arity) -> + Xs = init_regs(Arity, term), + Ys = init_regs(0, initialized), + #st{x=Xs,y=Ys,numy=none,h=0,ct=[]}. + +init_regs(0, _) -> + gb_trees:empty(); +init_regs(N, Type) -> + gb_trees_from_list([{R,Type} || R <- lists:seq(0, N-1)]). + +valfun([], _MFA, _Offset, Vst) -> Vst; +valfun([I|Is], MFA, Offset, Vst) -> + ?DBG_FORMAT(" ~p.\n", [I]), + valfun(Is, MFA, Offset+1, + try valfun_1(I, Vst) + catch Error -> + error({MFA,{I,Offset,Error}}) + end). + +%% Instructions that are allowed in dead code or when failing, +%% that is while the state is undecided in some way. +valfun_1({label,Lbl}, #vst{current=St0,branched=B}=Vst) -> + St = merge_states(Lbl, St0, B), + Vst#vst{current=St,branched=gb_trees:enter(Lbl, St, B)}; +valfun_1(_I, #vst{current=none}=Vst) -> + %% Ignore instructions after erlang:error/1,2, which + %% the original R10B compiler thought would return. + ?DBG_FORMAT("Ignoring ~p\n", [_I]), + Vst; +valfun_1({badmatch,Src}, Vst) -> + assert_term(Src, Vst), + kill_state(Vst); +valfun_1({case_end,Src}, Vst) -> + assert_term(Src, Vst), + kill_state(Vst); +valfun_1(if_end, Vst) -> + kill_state(Vst); +valfun_1({try_case_end,Src}, Vst) -> + assert_term(Src, Vst), + kill_state(Vst); +%% Instructions that can not cause exceptions +valfun_1({move,Src,Dst}, Vst) -> + Type = get_term_type(Src, Vst), + set_type_reg(Type, Dst, Vst); +valfun_1({fmove,Src,{fr,_}}, Vst) -> + assert_type(float, Src, Vst); +valfun_1({fmove,{fr,_},Dst}, Vst) -> + set_type_reg({float,[]}, Dst, Vst); +valfun_1({kill,{y,_}=Reg}, Vst) -> + set_type_y(initialized, Reg, Vst); +valfun_1({test_heap,Heap,Live}, Vst) -> + test_heap(Heap, Live, Vst); +valfun_1({bif,_Op,nofail,Src,Dst}, Vst) -> + validate_src(Src, Vst), + set_type_reg(term, Dst, Vst); +%% Put instructions. +valfun_1({put_list,A,B,Dst}, Vst0) -> + assert_term(A, Vst0), + assert_term(B, Vst0), + Vst = eat_heap(2, Vst0), + set_type_reg(cons, Dst, Vst); +valfun_1({put_tuple,Sz,Dst}, Vst0) when is_integer(Sz) -> + Vst = eat_heap(1, Vst0), + set_type_reg({tuple,Sz}, Dst, Vst); +valfun_1({put,Src}, Vst) -> + assert_term(Src, Vst), + eat_heap(1, Vst); +valfun_1({put_string,Sz,_,Dst}, Vst0) when is_integer(Sz) -> + Vst = eat_heap(2*Sz, Vst0), + set_type_reg(cons, Dst, Vst); +%% Allocate and deallocate, et.al +valfun_1({allocate,Stk,Live}, Vst) -> + allocate(false, Stk, 0, Live, Vst); +valfun_1({allocate_heap,Stk,Heap,Live}, Vst) -> + allocate(false, Stk, Heap, Live, Vst); +valfun_1({allocate_zero,Stk,Live}, Vst) -> + allocate(true, Stk, 0, Live, Vst); +valfun_1({allocate_heap_zero,Stk,Heap,Live}, Vst) -> + allocate(true, Stk, Heap, Live, Vst); +valfun_1({init,{y,_}=Reg}, Vst) -> + set_type_y(initialized, Reg, Vst); +valfun_1({deallocate,StkSize}, #vst{current=#st{numy=StkSize,ct=[]}}=Vst) -> + deallocate(Vst); +valfun_1({deallocate,_}, #vst{current=#st{numy=NumY,ct=[]}}) -> + error({allocated,NumY}); +valfun_1({deallocate,_}, #vst{current=#st{ct=Fails}}) -> + error({catch_try_stack,Fails}); +%% Catch & try. +valfun_1({'catch',Dst,{f,Fail}}, Vst0) when Fail /= none -> + Vst = #vst{current=#st{ct=Fails}=St} = + set_type_y({catchtag,Fail}, Dst, Vst0), + Vst#vst{current=St#st{ct=[Fail|Fails]}}; +valfun_1({'try',Dst,{f,Fail}}, Vst0) -> + Vst = #vst{current=#st{ct=Fails}=St} = + set_type_y({trytag,Fail}, Dst, Vst0), + Vst#vst{current=St#st{ct=[Fail|Fails]}}; +%% Do a postponed state branch if necessary and try next set of instructions +valfun_1(I, #vst{current=#st{ct=[]}}=Vst) -> + valfun_2(I, Vst); +valfun_1(I, #vst{current=#st{ct=Fails}}=Vst0) -> + %% Perform a postponed state branch + Vst = #vst{current=St} = lists:foldl(fun branch_state/2, Vst0, Fails), + valfun_2(I, Vst#vst{current=St#st{ct=[]}}). + +%% Instructions that can cause exceptions. +valfun_2({apply,Live}, Vst) -> + call(Live+2, Vst); +valfun_2({apply_last,Live,_}, Vst) -> + tail_call(Live+2, Vst); +valfun_2({call_fun,Live}, Vst) -> + call(Live, Vst); +valfun_2({call,Live,_}, Vst) -> + call(Live, Vst); +valfun_2({call_ext,Live,Func}, Vst) -> + call(Func, Live, Vst); +valfun_2({call_only,Live,_}, Vst) -> + tail_call(Live, Vst); +valfun_2({call_ext_only,Live,_}, Vst) -> + tail_call(Live, Vst); +valfun_2({call_last,Live,_,_}, Vst) -> + tail_call(Live, Vst); +valfun_2({call_ext_last,Live,_,_}, Vst) -> + tail_call(Live, Vst); +valfun_2({make_fun,_,_,Live}, Vst) -> + call(Live, Vst); +valfun_2({make_fun2,_,_,_,Live}, Vst) -> + call(Live, Vst); +%% Floating point. +valfun_2({fconv,Src,{fr,_}}, Vst) -> + assert_term(Src, Vst); +valfun_2({bif,fadd,_,[{fr,_},{fr,_}],{fr,_}}, Vst) -> + Vst; +valfun_2({bif,fdiv,_,[{fr,_},{fr,_}],{fr,_}}, Vst) -> + Vst; +valfun_2({bif,fmul,_,[{fr,_},{fr,_}],{fr,_}}, Vst) -> + Vst; +valfun_2({bif,fnegate,_,[{fr,_}],{fr,_}}, Vst) -> + Vst; +valfun_2({bif,fsub,_,[{fr,_},{fr,_}],{fr,_}}, Vst) -> + Vst; +valfun_2(fclearerror, Vst) -> + Vst; +valfun_2({fcheckerror,_}, Vst) -> + Vst; +%% Other BIFs +valfun_2({bif,element,{f,Fail},[Pos,Tuple],Dst}, Vst0) -> + TupleType0 = get_term_type(Tuple, Vst0), + PosType = get_term_type(Pos, Vst0), + Vst1 = branch_state(Fail, Vst0), + TupleType = upgrade_type({tuple,[get_tuple_size(PosType)]}, TupleType0), + Vst = set_type(TupleType, Tuple, Vst1), + set_type_reg(term, Dst, Vst); +valfun_2({bif,Op,{f,Fail},Src,Dst}, Vst0) -> + validate_src(Src, Vst0), + Vst = branch_state(Fail, Vst0), + Type = bif_type(Op, Src, Vst), + set_type_reg(Type, Dst, Vst); +valfun_2(return, #vst{current=#st{numy=none}}=Vst) -> + kill_state(Vst); +valfun_2(return, #vst{current=#st{numy=NumY}}) -> + error({stack_frame,NumY}); +valfun_2({jump,{f,_}}, #vst{current=none}=Vst) -> + %% Must be an unreachable jump which was not optimized away. + %% Do nothing. + Vst; +valfun_2({jump,{f,Lbl}}, Vst) -> + kill_state(branch_state(Lbl, Vst)); +valfun_2({loop_rec,{f,Fail},Dst}, Vst0) -> + Vst = branch_state(Fail, Vst0), + set_type_reg(term, Dst, Vst); +valfun_2(remove_message, Vst) -> + Vst; +valfun_2({wait,_}, Vst) -> + kill_state(Vst); +valfun_2({wait_timeout,_,Src}, Vst) -> + assert_term(Src, Vst); +valfun_2({loop_rec_end,_}, Vst) -> + kill_state(Vst); +valfun_2(timeout, #vst{current=St}=Vst) -> + Vst#vst{current=St#st{x=init_regs(0, term)}}; +valfun_2(send, Vst) -> + call(2, Vst); +%% Catch & try. +valfun_2({catch_end,Reg}, Vst0) -> + case get_type(Reg, Vst0) of + {catchtag,_} -> + Vst = #vst{current=St} = set_type_reg(initialized, Reg, Vst0), + Xs = gb_trees_from_list([{0,term}]), + Vst#vst{current=St#st{x=Xs}}; + Type -> + error({bad_type,Type}) + end; +valfun_2({try_end,Reg}, Vst) -> + case get_type(Reg, Vst) of + {trytag,_} -> + set_type_reg(initialized, Reg, Vst); + Type -> + error({bad_type,Type}) + end; +valfun_2({try_case,Reg}, Vst0) -> + case get_type(Reg, Vst0) of + {trytag,_} -> + Vst = #vst{current=St} = set_type_reg(initialized, Reg, Vst0), + Xs = gb_trees_from_list([{0,{atom,[]}},{1,term},{2,term}]), + Vst#vst{current=St#st{x=Xs}}; + Type -> + error({bad_type,Type}) + end; +valfun_2({set_tuple_element,Src,Tuple,I}, Vst) -> + assert_term(Src, Vst), + assert_type({tuple_element,I+1}, Tuple, Vst); +%% Match instructions. +valfun_2({select_val,Src,{f,Fail},{list,Choices}}, Vst) -> + assert_term(Src, Vst), + Lbls = [L || {f,L} <- Choices]++[Fail], + kill_state(foldl(fun(L, S) -> branch_state(L, S) end, Vst, Lbls)); +valfun_2({select_tuple_arity,Tuple,{f,Fail},{list,Choices}}, Vst) -> + assert_type(tuple, Tuple, Vst), + kill_state(branch_arities(Choices, Tuple, branch_state(Fail, Vst))); +valfun_2({get_list,Src,D1,D2}, Vst0) -> + assert_term(Src, Vst0), + Vst = set_type_reg(term, D1, Vst0), + set_type_reg(term, D2, Vst); +valfun_2({get_tuple_element,Src,I,Dst}, Vst) -> + assert_type({tuple_element,I+1}, Src, Vst), + set_type_reg(term, Dst, Vst); +valfun_2({bs_restore,_}, Vst) -> + Vst; +valfun_2({bs_save,_}, Vst) -> + Vst; +valfun_2({bs_start_match,{f,Fail},Src}, Vst) -> + assert_term(Src, Vst), + branch_state(Fail, Vst); +valfun_2({test,bs_skip_bits,{f,Fail},[Src,_,_]}, Vst) -> + assert_term(Src, Vst), + branch_state(Fail, Vst); +valfun_2({test,_,{f,Fail},[_,_,_,Dst]}, Vst0) -> + Vst = branch_state(Fail, Vst0), + set_type_reg({integer,[]}, Dst, Vst); +valfun_2({test,bs_test_tail,{f,Fail},_}, Vst) -> + branch_state(Fail, Vst); +%% Other test instructions. +valfun_2({test,is_float,{f,Lbl},[Float]}, Vst0) -> + assert_term(Float, Vst0), + Vst = branch_state(Lbl, Vst0), + set_type({float,[]}, Float, Vst); +valfun_2({test,is_tuple,{f,Lbl},[Tuple]}, Vst0) -> + assert_term(Tuple, Vst0), + Vst = branch_state(Lbl, Vst0), + set_type({tuple,[0]}, Tuple, Vst); +valfun_2({test,test_arity,{f,Lbl},[Tuple,Sz]}, Vst0) when is_integer(Sz) -> + assert_type(tuple, Tuple, Vst0), + Vst = branch_state(Lbl, Vst0), + set_type_reg({tuple,Sz}, Tuple, Vst); +valfun_2({test,_Op,{f,Lbl},Src}, Vst) -> + validate_src(Src, Vst), + branch_state(Lbl, Vst); +valfun_2({bs_add,{f,Fail},[A,B,_],Dst}, Vst0) -> + assert_term(A, Vst0), + assert_term(B, Vst0), + Vst = branch_state(Fail, Vst0), + set_type_reg({integer,[]}, Dst, Vst); +valfun_2({bs_bits_to_bytes,{f,Fail},Src,Dst}, Vst0) -> + assert_term(Src, Vst0), + Vst = branch_state(Fail, Vst0), + set_type_reg({integer,[]}, Dst, Vst); +valfun_2({bs_init2,{f,Fail},_,Heap,_,_,Dst}, Vst0) -> + Vst1 = heap_alloc(Heap, Vst0), + Vst = branch_state(Fail, Vst1), + set_type_reg(binary, Dst, Vst); +valfun_2({bs_put_string,Sz,_}, Vst) when is_integer(Sz) -> + Vst; +valfun_2({bs_put_binary,{f,Fail},_,_,_,Src}, Vst0) -> + assert_term(Src, Vst0), + branch_state(Fail, Vst0); +valfun_2({bs_put_float,{f,Fail},_,_,_,Src}, Vst0) -> + assert_term(Src, Vst0), + branch_state(Fail, Vst0); +valfun_2({bs_put_integer,{f,Fail},_,_,_,Src}, Vst0) -> + assert_term(Src, Vst0), + branch_state(Fail, Vst0); +%% Old bit syntax construction (before R10B). +valfun_2({bs_init,_,_}, Vst) -> Vst; +valfun_2({bs_need_buf,_}, Vst) -> Vst; +valfun_2({bs_final,{f,Fail},Dst}, Vst0) -> + Vst = branch_state(Fail, Vst0), + set_type_reg(binary, Dst, Vst); +%% Misc. +valfun_2({'%live',Live}, Vst) -> + verify_live(Live, Vst), + Vst; +valfun_2(_, _) -> + error(unknown_instruction). + +kill_state(#vst{current=#st{ct=[]}}=Vst) -> + Vst#vst{current=none}; +kill_state(#vst{current=#st{ct=Fails}}=Vst0) -> + Vst = lists:foldl(fun branch_state/2, Vst0, Fails), + Vst#vst{current=none}. + +%% A "plain" call. +%% The stackframe must have a known size and be initialized. +%% The instruction will return to the instruction following the call. +call(Live, #vst{current=St}=Vst) -> + verify_live(Live, Vst), + verify_y_init(Vst), + Xs = gb_trees_from_list([{0,term}]), + Vst#vst{current=St#st{x=Xs}}. + +%% A "plain" call. +%% The stackframe must have a known size and be initialized. +%% The instruction will return to the instruction following the call. +call(Name, Live, #vst{current=St}=Vst) -> + verify_live(Live, Vst), + case return_type(Name, Vst) of + exception -> + kill_state(Vst); + Type -> + verify_y_init(Vst), + Xs = gb_trees_from_list([{0,Type}]), + Vst#vst{current=St#st{x=Xs}} + end. + +%% Tail call. +%% The stackframe must have a known size and be initialized. +%% Does not return to the instruction following the call. +tail_call(Live, Vst) -> + kill_state(call(Live, Vst)). + +allocate(Zero, Stk, Heap, Live, #vst{current=#st{numy=none}=St}=Vst) -> + verify_live(Live, Vst), + Ys = init_regs(case Zero of + true -> Stk; + false -> 0 + end, initialized), + Vst#vst{current=St#st{y=Ys,numy=Stk,h=heap_alloc_1(Heap)}}; +allocate(_, _, _, _, #vst{current=#st{numy=Numy}}) -> + error({existing_stack_frame,{size,Numy}}). + +deallocate(#vst{current=St}=Vst) -> + Vst#vst{current=St#st{y=init_regs(0, initialized),numy=none}}. + +test_heap(Heap, Live, Vst) -> + verify_live(Live, Vst), + heap_alloc(Heap, Vst). + +heap_alloc(Heap, #vst{current=St}=Vst) -> + Vst#vst{current=St#st{h=heap_alloc_1(Heap)}}. + +heap_alloc_1({alloc,Alloc}) -> + {value,{_,Heap}} = lists:keysearch(words, 1, Alloc), + Heap; +heap_alloc_1(Heap) when is_integer(Heap) -> Heap. + + +set_type(Type, {x,_}=Reg, Vst) -> set_type_reg(Type, Reg, Vst); +set_type(Type, {y,_}=Reg, Vst) -> set_type_y(Type, Reg, Vst); +set_type(_, _, #vst{}=Vst) -> Vst. + +set_type_reg(Type, {x,X}, #vst{current=#st{x=Xs}=St}=Vst) + when 0 =< X, X < ?MAXREG -> + Vst#vst{current=St#st{x=gb_trees:enter(X, Type, Xs)}}; +set_type_reg(Type, Reg, Vst) -> + set_type_y(Type, Reg, Vst). + +set_type_y(Type, {y,Y}=Reg, #vst{current=#st{y=Ys,numy=NumY}=St}=Vst) + when is_integer(Y), 0 =< Y, Y < ?MAXREG -> + case {Y,NumY} of + {_,none} -> + error({no_stack_frame,Reg}); + {_,_} when Y > NumY -> + error({y_reg_out_of_range,Reg,NumY}); + {_,_} -> + Vst#vst{current=St#st{y=gb_trees:enter(Y, Type, Ys)}} + end; +set_type_y(Type, Reg, #vst{}) -> error({invalid_store,Reg,Type}). + +assert_term(Src, Vst) -> + get_term_type(Src, Vst), + Vst. + +%% The possible types. +%% +%% First non-term types: +%% +%% initialized Only for Y registers. Means that the Y register +%% has been initialized with some valid term so that +%% it is safe to pass to the garbage collector. +%% NOT safe to use in any other way (will not crash the +%% emulator, but clearly points to a bug in the compiler). +%% +%% {catchtag,Lbl} A special term used within a catch. Must only be used +%% by the catch instructions; NOT safe to use in other +%% instructions. +%% +%% {trytag,Lbl} A special term used within a try block. Must only be +%% used by the catch instructions; NOT safe to use in other +%% instructions. +%% +%% exception Can only be used as a type returned by return_type/2 +%% (which gives the type of the value returned by a BIF). +%% Thus 'exception' is never stored as type descriptor +%% for a register. +%% +%% Normal terms: +%% +%% term Any valid Erlang (but not of the special types above). +%% +%% bool The atom 'true' or the atom 'false'. +%% +%% cons Cons cell: [_|_] +%% +%% nil Empty list: [] +%% +%% {tuple,[Sz]} Tuple. An element has been accessed using +%% element/2 or setelement/3 so that it is known that +%% the type is a tuple of size at least Sz. +%% +%% {tuple,Sz} Tuple. A test_arity instruction has been seen +%% so that it is known that the size is exactly Sz. +%% +%% {atom,[]} Atom. +%% {atom,Atom} +%% +%% {integer,[]} Integer. +%% {integer,Integer} +%% +%% {float,[]} Float. +%% {float,Float} +%% +%% number Integer or Float of unknown value +%% + +assert_type(WantedType, Term, Vst) -> + assert_type(WantedType, get_type(Term, Vst)), + Vst. + +assert_type(float, {float,_}) -> ok; +assert_type(tuple, {tuple,_}) -> ok; +assert_type({tuple_element,I}, {tuple,[Sz]}) + when 1 =< I, I =< Sz -> + ok; +assert_type({tuple_element,I}, {tuple,Sz}) + when is_integer(Sz), 1 =< I, I =< Sz -> + ok; +assert_type(Needed, Actual) -> + error({bad_type,{needed,Needed},{actual,Actual}}). + +%% upgrade_type/2 is used when linear code finds out more and +%% more information about a type, so the type gets "narrower" +%% or perhaps inconsistent. In the case of inconsistency +%% we mostly widen the type to 'term' to make subsequent +%% code fail if it assumes anything about the type. + +upgrade_type(Same, Same) -> Same; +upgrade_type(term, OldT) -> OldT; +upgrade_type(NewT, term) -> NewT; +upgrade_type({Type,New}=NewT, {Type,Old}=OldT) + when Type == atom; Type == integer; Type == float -> + if New =:= Old -> OldT; + New =:= [] -> OldT; + Old =:= [] -> NewT; + true -> term + end; +upgrade_type({Type,_}=NewT, number) + when Type == integer; Type == float -> + NewT; +upgrade_type(number, {Type,_}=OldT) + when Type == integer; Type == float -> + OldT; +upgrade_type(bool, {atom,A}) -> + upgrade_bool(A); +upgrade_type({atom,A}, bool) -> + upgrade_bool(A); +upgrade_type({tuple,[Sz]}, {tuple,[OldSz]}) + when is_integer(Sz) -> + {tuple,[max(Sz, OldSz)]}; +upgrade_type({tuple,Sz}=T, {tuple,[_]}) + when is_integer(Sz) -> + %% This also takes care of the user error when a tuple element + %% is accesed outside the known exact tuple size; there is + %% no more type information, just a runtime error which is not + %% our problem. + T; +upgrade_type({tuple,[Sz]}, {tuple,_}=T) + when is_integer(Sz) -> + %% Same as the previous clause but mirrored. + T; +upgrade_type(_A, _B) -> + %%io:format("upgrade_type: ~p ~p\n", [_A,_B]), + term. + +upgrade_bool([]) -> bool; +upgrade_bool(true) -> {atom,true}; +upgrade_bool(false) -> {atom,false}; +upgrade_bool(_) -> term. + +get_tuple_size({integer,[]}) -> 0; +get_tuple_size({integer,Sz}) -> Sz; +get_tuple_size(_) -> 0. + +validate_src(Ss, Vst) when is_list(Ss) -> + foldl(fun(S, _) -> get_type(S, Vst) end, ok, Ss). + +get_term_type(Src, Vst) -> + case get_type(Src, Vst) of + initialized -> error({not_assigned,Src}); + exception -> error({exception,Src}); + {catchtag,_} -> error({catchtag,Src}); + {trytag,_} -> error({trytag,Src}); + Type -> Type + end. + +get_type(nil=T, _) -> T; +get_type({atom,A}=T, _) when is_atom(A) -> T; +get_type({float,F}=T, _) when is_float(F) -> T; +get_type({integer,I}=T, _) when is_integer(I) -> T; +get_type({x,X}=Reg, #vst{current=#st{x=Xs}}) when is_integer(X) -> + case gb_trees:lookup(X, Xs) of + {value,Type} -> Type; + none -> error({uninitialized_reg,Reg}) + end; +get_type({y,Y}=Reg, #vst{current=#st{y=Ys}}) when is_integer(Y) -> + case gb_trees:lookup(Y, Ys) of + {value,initialized} -> error({unassigned_reg,Reg}); + {value,Type} -> Type; + none -> error({uninitialized_reg,Reg}) + end; +get_type(Src, _) -> error({bad_source,Src}). + +branch_arities([], _, #vst{}=Vst) -> Vst; +branch_arities([Sz,{f,L}|T], Tuple, #vst{current=St}=Vst0) + when is_integer(Sz) -> + Vst1 = set_type_reg({tuple,Sz}, Tuple, Vst0), + Vst = branch_state(L, Vst1), + branch_arities(T, Tuple, Vst#vst{current=St}). + +branch_state(0, #vst{}=Vst) -> Vst; +branch_state(L, #vst{current=St,branched=B}=Vst) -> + Vst#vst{ + branched=case gb_trees:is_defined(L, B) of + false -> + gb_trees:insert(L, St#st{ct=[]}, B); + true -> + MergedSt = merge_states(L, St, B), + gb_trees:update(L, MergedSt#st{ct=[]}, B) + end}. + +%% merge_states/3 is used when there are more than one way to arrive +%% at this point, and the type states for the different paths has +%% to be merged. The type states are downgraded to the least common +%% subset for the subsequent code. + +merge_states(0, St, _Branched) -> St; +merge_states(L, St, Branched) -> + case gb_trees:lookup(L, Branched) of + none -> St; + {value,OtherSt} when St == none -> OtherSt; + {value,OtherSt} -> + merge_states_1(St, OtherSt) + end. + +merge_states_1(#st{x=Xs0,y=Ys0,numy=NumY0,h=H0}=St, + #st{x=Xs1,y=Ys1,numy=NumY1,h=H1}) -> + NumY = merge_stk(NumY0, NumY1), + Xs = merge_regs(Xs0, Xs1), + Ys = merge_regs(Ys0, Ys1), + St#st{x=Xs,y=Ys,numy=NumY,h=min(H0, H1)}. + +merge_stk(S, S) -> S; +merge_stk(_, _) -> undecided. + +merge_regs(Rs0, Rs1) -> + Rs = merge_regs_1(gb_trees:to_list(Rs0), gb_trees:to_list(Rs1)), + gb_trees_from_list(Rs). + +merge_regs_1([Same|Rs1], [Same|Rs2]) -> + [Same|merge_regs_1(Rs1, Rs2)]; +merge_regs_1([{R1,_}|Rs1], [{R2,_}|_]=Rs2) when R1 < R2 -> + merge_regs_1(Rs1, Rs2); +merge_regs_1([{R1,_}|_]=Rs1, [{R2,_}|Rs2]) when R1 > R2 -> + merge_regs_1(Rs1, Rs2); +merge_regs_1([{R,Type1}|Rs1], [{R,Type2}|Rs2]) -> + [{R,merge_types(Type1, Type2)}|merge_regs_1(Rs1, Rs2)]; +merge_regs_1([], []) -> []; +merge_regs_1([], [_|_]) -> []; +merge_regs_1([_|_], []) -> []. + +merge_types(T, T) -> T; +merge_types(initialized=I, _) -> I; +merge_types(_, initialized=I) -> I; +merge_types({tuple,Same}=T, {tuple,Same}) -> T; +merge_types({tuple,A}, {tuple,B}) -> + {tuple,[min(tuple_sz(A), tuple_sz(B))]}; +merge_types({Type,A}, {Type,B}) + when Type == atom; Type == integer; Type == float -> + if A =:= B -> {Type,A}; + true -> {Type,[]} + end; +merge_types({Type,_}, number) + when Type == integer; Type == float -> + number; +merge_types(number, {Type,_}) + when Type == integer; Type == float -> + number; +merge_types(bool, {atom,A}) -> + merge_bool(A); +merge_types({atom,A}, bool) -> + merge_bool(A); +merge_types(_, _) -> term. + +tuple_sz([Sz]) -> Sz; +tuple_sz(Sz) -> Sz. + +merge_bool([]) -> {atom,[]}; +merge_bool(true) -> bool; +merge_bool(false) -> bool; +merge_bool(_) -> {atom,[]}. + +verify_y_init(#vst{current=#st{numy=none}}) -> ok; +verify_y_init(#vst{current=#st{numy=undecided}}) -> + error(unknown_size_of_stackframe); +verify_y_init(#vst{current=#st{y=Ys,numy=NumY}}) -> + verify_y_init_1(NumY, Ys). + +verify_y_init_1(0, _) -> ok; +verify_y_init_1(N, Ys) -> + Y = N-1, + case gb_trees:is_defined(Y, Ys) of + false -> error({{y,Y},not_initialized}); + true -> verify_y_init_1(Y, Ys) + end. + +verify_live(0, #vst{}) -> ok; +verify_live(N, #vst{current=#st{x=Xs}}) -> + verify_live_1(N, Xs). + +verify_live_1(0, _) -> ok; +verify_live_1(N, Xs) -> + X = N-1, + case gb_trees:is_defined(X, Xs) of + false -> error({{x,X},not_live}); + true -> verify_live_1(X, Xs) + end. + +eat_heap(N, #vst{current=#st{h=Heap0}=St}=Vst) -> + case Heap0-N of + Neg when Neg < 0 -> + error({heap_overflow,{left,Heap0},{wanted,N}}); + Heap -> + Vst#vst{current=St#st{h=Heap}} + end. + +bif_type('-', Src, Vst) -> + arith_type(Src, Vst); +bif_type('+', Src, Vst) -> + arith_type(Src, Vst); +bif_type('*', Src, Vst) -> + arith_type(Src, Vst); +bif_type(abs, [Num], Vst) -> + case get_type(Num, Vst) of + {float,_}=T -> T; + {integer,_}=T -> T; + _ -> number + end; +bif_type(float, _, _) -> {float,[]}; +bif_type('/', _, _) -> {float,[]}; +%% Integer operations. +bif_type('div', [_,_], _) -> {integer,[]}; +bif_type('rem', [_,_], _) -> {integer,[]}; +bif_type(length, [_], _) -> {integer,[]}; +bif_type(size, [_], _) -> {integer,[]}; +bif_type(trunc, [_], _) -> {integer,[]}; +bif_type(round, [_], _) -> {integer,[]}; +bif_type('band', [_,_], _) -> {integer,[]}; +bif_type('bor', [_,_], _) -> {integer,[]}; +bif_type('bxor', [_,_], _) -> {integer,[]}; +bif_type('bnot', [_], _) -> {integer,[]}; +bif_type('bsl', [_,_], _) -> {integer,[]}; +bif_type('bsr', [_,_], _) -> {integer,[]}; +%% Booleans. +bif_type('==', [_,_], _) -> bool; +bif_type('/=', [_,_], _) -> bool; +bif_type('=<', [_,_], _) -> bool; +bif_type('<', [_,_], _) -> bool; +bif_type('>=', [_,_], _) -> bool; +bif_type('>', [_,_], _) -> bool; +bif_type('=:=', [_,_], _) -> bool; +bif_type('=/=', [_,_], _) -> bool; +bif_type('not', [_], _) -> bool; +bif_type('and', [_,_], _) -> bool; +bif_type('or', [_,_], _) -> bool; +bif_type('xor', [_,_], _) -> bool; +bif_type(is_atom, [_], _) -> bool; +bif_type(is_boolean, [_], _) -> bool; +bif_type(is_binary, [_], _) -> bool; +bif_type(is_constant, [_], _) -> bool; +bif_type(is_float, [_], _) -> bool; +bif_type(is_function, [_], _) -> bool; +bif_type(is_integer, [_], _) -> bool; +bif_type(is_list, [_], _) -> bool; +bif_type(is_number, [_], _) -> bool; +bif_type(is_pid, [_], _) -> bool; +bif_type(is_port, [_], _) -> bool; +bif_type(is_reference, [_], _) -> bool; +bif_type(is_tuple, [_], _) -> bool; +%% Misc. +bif_type(node, [], _) -> {atom,[]}; +bif_type(node, [_], _) -> {atom,[]}; +bif_type(hd, [_], _) -> term; +bif_type(tl, [_], _) -> term; +bif_type(get, [_], _) -> term; +bif_type(raise, [_,_], _) -> exception; +bif_type(_, _, _) -> term. + +arith_type([A,B], Vst) -> + case {get_type(A, Vst),get_type(B, Vst)} of + {{float,_},_} -> {float,[]}; + {_,{float,_}} -> {float,[]}; + {_,_} -> number + end; +arith_type(_, _) -> number. + +return_type({extfunc,M,F,A}, Vst) -> + return_type_1(M, F, A, Vst). + +return_type_1(erlang, setelement, 3, Vst) -> + Tuple = {x,1}, + TupleType = + case get_type(Tuple, Vst) of + {tuple,_}=TT -> TT; + _ -> {tuple,[0]} + end, + case get_type({x,0}, Vst) of + {integer,[]} -> TupleType; + {integer,I} -> upgrade_type({tuple,[I]}, TupleType); + _ -> TupleType + end; +return_type_1(erlang, F, A, _) -> + return_type_erl(F, A); +return_type_1(math, F, A, _) -> + return_type_math(F, A); +return_type_1(_, _, _, _) -> term. + +return_type_erl(exit, 1) -> exception; +return_type_erl(throw, 1) -> exception; +return_type_erl(fault, 1) -> exception; +return_type_erl(fault, 2) -> exception; +return_type_erl(error, 1) -> exception; +return_type_erl(error, 2) -> exception; +return_type_erl(_, _) -> term. + +return_type_math(cos, 1) -> {float,[]}; +return_type_math(cosh, 1) -> {float,[]}; +return_type_math(sin, 1) -> {float,[]}; +return_type_math(sinh, 1) -> {float,[]}; +return_type_math(tan, 1) -> {float,[]}; +return_type_math(tanh, 1) -> {float,[]}; +return_type_math(acos, 1) -> {float,[]}; +return_type_math(acosh, 1) -> {float,[]}; +return_type_math(asin, 1) -> {float,[]}; +return_type_math(asinh, 1) -> {float,[]}; +return_type_math(atan, 1) -> {float,[]}; +return_type_math(atanh, 1) -> {float,[]}; +return_type_math(erf, 1) -> {float,[]}; +return_type_math(erfc, 1) -> {float,[]}; +return_type_math(exp, 1) -> {float,[]}; +return_type_math(log, 1) -> {float,[]}; +return_type_math(log10, 1) -> {float,[]}; +return_type_math(sqrt, 1) -> {float,[]}; +return_type_math(atan2, 2) -> {float,[]}; +return_type_math(pow, 2) -> {float,[]}; +return_type_math(pi, 0) -> {float,[]}; +return_type_math(_, _) -> term. + +min(A, B) when is_integer(A), is_integer(B), A < B -> A; +min(A, B) when is_integer(A), is_integer(B) -> B. + +max(A, B) when is_integer(A), is_integer(B), A > B -> A; +max(A, B) when is_integer(A), is_integer(B) -> B. + +gb_trees_from_list(L) -> gb_trees:from_orddict(orddict:from_list(L)). + +-ifdef(DEBUG). +error(Error) -> exit(Error). +-else. +error(Error) -> throw(Error). +-endif. |