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authorMagnus Lång <[email protected]>2016-05-10 17:22:25 +0200
committerMagnus Lång <[email protected]>2016-05-11 13:19:46 +0200
commit0f489445070cf65d96db7938f80ad118921c1f6a (patch)
treeeb31f67e5d9506ab000c3fd547c8f18aa92fadc4 /lib/hipe/llvm/hipe_llvm_main.erl
parent3dc060d7b6e0f2ea55e6649b23a47d226874b9d4 (diff)
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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.
Diffstat (limited to 'lib/hipe/llvm/hipe_llvm_main.erl')
-rw-r--r--lib/hipe/llvm/hipe_llvm_main.erl131
1 files changed, 69 insertions, 62 deletions
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]).