From 0f489445070cf65d96db7938f80ad118921c1f6a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Magnus=20L=C3=A5ng?= Date: Tue, 10 May 2016 17:22:25 +0200 Subject: hipe: Extract some records into elf_format.hrl This allows for much more robust interpretation of relocations, symbols and sections in hipe_llvm_main, without the clunkiness of an abstract interface between two internal modules that belong to the same subsystem anyway. --- lib/hipe/llvm/hipe_llvm_main.erl | 131 +++++++++++++++++++++------------------ 1 file changed, 69 insertions(+), 62 deletions(-) (limited to 'lib/hipe/llvm/hipe_llvm_main.erl') diff --git a/lib/hipe/llvm/hipe_llvm_main.erl b/lib/hipe/llvm/hipe_llvm_main.erl index 60833d4af9..3ab213f94c 100644 --- a/lib/hipe/llvm/hipe_llvm_main.erl +++ b/lib/hipe/llvm/hipe_llvm_main.erl @@ -26,11 +26,10 @@ rtl_to_native(MFA, RTL, Roots, Options) -> ObjBin = open_object_file(ObjectFile), Obj = elf_format:read(ObjBin), %% Get labels info (for switches and jump tables) - Labels = elf_format:get_rodata_relocs(Obj), - {Switches, Closures} = get_tables(Obj), + Labels = elf_format:extract_rela(Obj, ?RODATA), + Tables = get_tables(Obj), %% Associate Labels with Switches and Closures with stack args - {SwitchInfos, ExposedClosures} = - correlate_labels(Switches ++ Closures, Labels), + {SwitchInfos, ExposedClosures} = correlate_labels(Tables, Labels), %% SwitchInfos: [{"table_50", [Labels]}] %% ExposedClosures: [{"table_closures", [Labels]}] @@ -38,7 +37,7 @@ rtl_to_native(MFA, RTL, Roots, Options) -> %% used for switch's jump tables LabelMap = create_labelmap(MFA, SwitchInfos, RelocsDict), %% Get relocation info - TextRelocs = elf_format:get_text_relocs(Obj), + TextRelocs = elf_format:extract_rela(Obj, ?TEXT), %% AccRefs contains the offsets of all references to relocatable symbols in %% the code: AccRefs = fix_relocations(TextRelocs, RelocsDict, MFA), @@ -158,12 +157,10 @@ trans_optlev_flag(Tool, Options) -> %%------------------------------------------------------------------------------ %% @doc Get switch table and closure table. +-spec get_tables(elf_format:elf()) -> [elf_sym()]. get_tables(Elf) -> - %% Search Symbol Table for an entry with name prefixed with "table_": - Triples = elf_format:get_tab_entries(Elf), - Switches = [T || T={"table_" ++ _, _, _} <- Triples], - Closures = [T || T={"table_closures" ++ _, _, _} <- Switches], - {Switches, Closures}. + %% Search Symbol Table for entries where name is prefixed with "table_": + [S || S=#elf_sym{name="table_" ++ _} <- elf_format:elf_symbols(Elf)]. %% @doc This function associates symbols who point to some table of labels with %% the corresponding offsets of the labels in the code. These tables can @@ -171,14 +168,12 @@ get_tables(Elf) -> %% of blocks that contain closure calls with more than ?NR_ARG_REGS. correlate_labels([], _L) -> {[], []}; correlate_labels(Tables, Labels) -> - %% Sort "Tables" based on "ValueOffsets" - OffsetSortedTb = lists:ukeysort(2, Tables), - %% Unzip offset-sorted list of "Switches" - {Names, _Offsets, TablesSizeList} = lists:unzip3(OffsetSortedTb), - %% Associate switch names with labels - L = split_list(Labels, TablesSizeList), - %% Zip back! (to [{SwitchName, Values}]) - NamesValues = lists:zip(Names, L), + %% Assumes that the relocations are sorted + RelocTree = gb_trees:from_orddict( + [{Rel#elf_rel.offset, Rel#elf_rel.addend} || Rel <- Labels]), + %% Lookup all relocations pertaining to each symbol + NamesValues = [{Name, lookup_range(Value, Value+Size, RelocTree)} + || #elf_sym{name=Name, value=Value, size=Size} <- Tables], case lists:keytake("table_closures", 1, NamesValues) of false -> %% No closures in the code, no closure table {NamesValues, []}; @@ -186,6 +181,17 @@ correlate_labels(Tables, Labels) -> {SwitchesNV, ClosureTableNV} end. +%% Fetches all values with a key in [Low, Hi) +-spec lookup_range(_::K, _::K, gb_trees:tree(K,V)) -> [_::V]. +lookup_range(Low, Hi, Tree) -> + lookup_range_1(Hi, gb_trees:iterator_from(Low, Tree)). + +lookup_range_1(Hi, Iter0) -> + case gb_trees:next(Iter0) of + {Key, Value, Iter} when Key < Hi -> [Value | lookup_range_1(Hi, Iter)]; + _ -> [] + end. + %% @doc Create a gb_tree which contains information about the labels that used %% for switch's jump tables. The keys of the gb_tree are of the form %% {MFA, Label} and the values are the actual Offsets. @@ -216,37 +222,53 @@ insert_to_labelmap([{Key, Value}|Rest], LabelMap) -> %% @doc Correlate object file relocation symbols with info from translation to %% llvm code. fix_relocations(Relocs, RelocsDict, MFA) -> - fix_relocs(Relocs, RelocsDict, MFA, []). - -fix_relocs([], _, _, RelocAcc) -> RelocAcc; -fix_relocs([{Name, Offset}|Rs], RelocsDict, {ModName,_,_}=MFA, RelocAcc) -> + lists:map(fun(Reloc) -> fix_reloc(Reloc, RelocsDict, MFA) end, Relocs). + +%% Relocation types and expected addends for x86 and amd64 +-define(PCREL_T, 'pc32'). +-define(PCREL_A, -4). %% Hard-coded in hipe_x86.c and hipe_amd64.c +-ifdef(BIT32). +-define(ABS_T, '32'). +-define(ABS_A, _). %% We support any addend +-else. +-define(ABS_T, '64'). +-define(ABS_A, 0). +-endif. + +fix_reloc(#elf_rel{symbol=#elf_sym{name=Name, section=undefined, type=notype}, + offset=Offset, type=?PCREL_T, addend=?PCREL_A}, + RelocsDict, {ModName,_,_}) when Name =/= "" -> case dict:fetch(Name, RelocsDict) of - {atom, AtomName} -> - fix_relocs(Rs, RelocsDict, MFA, - [{?LOAD_ATOM, Offset, AtomName}|RelocAcc]); - {constant, Label} -> - fix_relocs(Rs, RelocsDict, MFA, - [{?LOAD_ADDRESS, Offset, {constant, Label}}|RelocAcc]); - {switch, _, JTabLab} -> %% Treat switch exactly as constant - fix_relocs(Rs, RelocsDict, MFA, - [{?LOAD_ADDRESS, Offset, {constant, JTabLab}}|RelocAcc]); - {closure, _}=Closure -> - fix_relocs(Rs, RelocsDict, MFA, - [{?LOAD_ADDRESS, Offset, Closure}|RelocAcc]); - {call, {bif, BifName, _}} -> - fix_relocs(Rs, RelocsDict, MFA, - [{?CALL_LOCAL, Offset, BifName}|RelocAcc]); + {call, {bif, BifName, _}} -> {?CALL_LOCAL, Offset, BifName}; %% MFA calls to functions in the same module are of type 3, while all %% other MFA calls are of type 2. - {call, {ModName,_F,_A}=CallMFA} -> - fix_relocs(Rs, RelocsDict, MFA, - [{?CALL_LOCAL, Offset, CallMFA}|RelocAcc]); - {call, CallMFA} -> - fix_relocs(Rs, RelocsDict, MFA, - [{?CALL_REMOTE, Offset, CallMFA}|RelocAcc]); - Other -> - exit({?MODULE, fix_relocs, - {"Relocation not in relocation dictionary", Other}}) + %% XXX: Does this code break hot code loading (by transforming external + %% calls into local calls?) + {call, {ModName,_F,_A}=CallMFA} -> {?CALL_LOCAL, Offset, CallMFA}; + {call, CallMFA} -> {?CALL_REMOTE, Offset, CallMFA} + end; +fix_reloc(#elf_rel{symbol=#elf_sym{name=Name, section=undefined, type=notype}, + offset=Offset, type=?ABS_T, addend=?ABS_A}, + RelocsDict, _) when Name =/= "" -> + case dict:fetch(Name, RelocsDict) of + {atom, AtomName} -> {?LOAD_ATOM, Offset, AtomName}; + {constant, Label} -> {?LOAD_ADDRESS, Offset, {constant, Label}}; + {closure, _}=Closure -> {?LOAD_ADDRESS, Offset, Closure} + end; +fix_reloc(#elf_rel{symbol=#elf_sym{name=Name, section=#elf_shdr{name=?TEXT}, + type=func}, + offset=Offset, type=?PCREL_T, addend=?PCREL_A}, + RelocsDict, MFA) when Name =/= "" -> + case dict:fetch(Name, RelocsDict) of + {call, MFA} -> {?CALL_LOCAL, Offset, MFA} + end; +fix_reloc(#elf_rel{symbol=#elf_sym{name=Name, section=#elf_shdr{name=?RODATA}, + type=object}, + offset=Offset, type=?ABS_T, addend=?ABS_A}, + RelocsDict, _) when Name =/= "" -> + case dict:fetch(Name, RelocsDict) of + {switch, _, JTabLab} -> %% Treat switch exactly as constant + {?LOAD_ADDRESS, Offset, {constant, JTabLab}} end. %%------------------------------------------------------------------------------ @@ -278,7 +300,7 @@ get_sdescs(Elf) -> Roots/binary>> = NoteGC_bin, LiveRoots = get_liveroots(Roots, []), %% Extract the safe point offsets: - SPOffs = elf_format:get_rela_addends(RelaNoteGC), + SPOffs = [A || #elf_rel{addend=A} <- RelaNoteGC], %% Extract Exception Handler labels: ExnHandlers = elf_format:get_exn_handlers(Elf), %% Combine ExnHandlers and Safe point addresses (return addresses): @@ -476,18 +498,3 @@ unique_folder(FunName, Arity, Options) -> dir_exists(Filename) -> {Flag, Info} = file:read_file_info(Filename), (Flag =:= ok) andalso (element(3, Info) =:= directory). - -%% @doc Function that takes as arguments a list of integers and a list with -%% numbers indicating how many items should each tuple have and splits -%% the original list to a list of lists of integers (with the specified -%% number of elements), i.e. [ [...], [...] ]. --spec split_list([integer()], [integer()]) -> [ [integer()] ]. -split_list(List, ElemsPerTuple) -> - split_list(List, ElemsPerTuple, []). - --spec split_list([integer()], [integer()], [ [integer()] ]) -> [ [integer()] ]. -split_list([], [], Acc) -> - lists:reverse(Acc); -split_list(List, [NumOfElems | MoreNums], Acc) -> - {L1, L2} = lists:split(NumOfElems, List), - split_list(L2, MoreNums, [ L1 | Acc]). -- cgit v1.2.3