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mshinwellmshinwell
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DWARF inlined frames support (#1754)
1 parent 7ede840 commit c07e8b7

19 files changed

+951
-56
lines changed

‎backend/debug/dwarf/dwarf_flags/dwarf_flags.ml

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Original file line numberDiff line numberDiff line change
@@ -141,3 +141,5 @@ let default_gdwarf_self_tail_calls = true
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let gdwarf_self_tail_calls = ref default_gdwarf_self_tail_calls
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let gdwarf_may_alter_codegen = ref false
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let dwarf_inlined_frames = ref false

‎backend/debug/dwarf/dwarf_flags/dwarf_flags.mli

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Original file line numberDiff line numberDiff line change
@@ -68,3 +68,9 @@ val default_ddebug_invariants : bool
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val ddebug_invariants : bool ref
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val gdwarf_may_alter_codegen : bool ref
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(** Setting this to [true] will emit sufficient DWARF to get inlined frame
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information, but won't emit information e.g. about local variables (unless
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[restrict_to_upstream_dwarf] is set to [false], although that implies
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this variable being set to [true]). *)
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val dwarf_inlined_frames : bool ref

‎backend/debug/dwarf/dwarf_ocaml/dwarf.ml

Lines changed: 18 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -61,6 +61,9 @@ let create ~sourcefile ~unit_name ~asm_directives ~get_file_id ~code_begin
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DS.create ~compilation_unit_header_label ~compilation_unit_proto_die
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~value_type_proto_die ~start_of_code_symbol debug_loc_table
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debug_ranges_table address_table location_list_table
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~get_file_num:get_file_id
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(* CR mshinwell: does get_file_id successfully emit .file directives for
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files we haven't seen before? *)
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in
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{ state;
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asm_directives;
@@ -75,18 +78,29 @@ type fundecl =
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}
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let dwarf_for_fundecl t fundecl ~fun_end_label =
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if not (!Clflags.debug && not !Dwarf_flags.restrict_to_upstream_dwarf)
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if not
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(!Clflags.debug
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&& ((not !Dwarf_flags.restrict_to_upstream_dwarf)
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|| !Dwarf_flags.dwarf_inlined_frames))
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then { fun_end_label; fundecl }
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else
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let available_ranges_vars, fundecl =
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Profile.record "debug_available_ranges_vars"
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(fun fundecl -> Available_ranges_vars.create fundecl)
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if not !Dwarf_flags.restrict_to_upstream_dwarf
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then
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Profile.record "debug_available_ranges_vars"
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(fun fundecl -> Available_ranges_vars.create fundecl)
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~accumulate:true fundecl
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else Available_ranges_vars.empty, fundecl
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in
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let inlined_frame_ranges, fundecl =
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Profile.record "debug_inlined_frame_ranges"
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(fun fundecl -> Inlined_frame_ranges.create fundecl)
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~accumulate:true fundecl
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in
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Dwarf_concrete_instances.for_fundecl ~get_file_id:t.get_file_id t.state
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fundecl
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~fun_end_label:(Asm_label.create_int Text fun_end_label)
89-
available_ranges_vars;
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available_ranges_vars inlined_frame_ranges;
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{ fun_end_label; fundecl }
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92106
let emit t ~basic_block_sections ~binary_backend_available =

‎backend/debug/dwarf/dwarf_ocaml/dwarf_abstract_instances.ml

Lines changed: 180 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,180 @@
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(******************************************************************************
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* flambda-backend *
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* Mark Shinwell, Jane Street *
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* -------------------------------------------------------------------------- *
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* MIT License *
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* *
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* Copyright (c) 2024 Jane Street Group LLC *
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* [email protected] *
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* *
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* Permission is hereby granted, free of charge, to any person obtaining a *
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* copy of this software and associated documentation files (the "Software"), *
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* to deal in the Software without restriction, including without limitation *
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* the rights to use, copy, modify, merge, publish, distribute, sublicense, *
14+
* and/or sell copies of the Software, and to permit persons to whom the *
15+
* Software is furnished to do so, subject to the following conditions: *
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* *
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* The above copyright notice and this permission notice shall be included *
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* in all copies or substantial portions of the Software. *
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* *
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
22+
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
23+
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER *
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING *
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER *
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* DEALINGS IN THE SOFTWARE. *
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******************************************************************************)
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open! Asm_targets
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open! Dwarf_low
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open! Dwarf_high
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module DAH = Dwarf_attribute_helpers
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module DS = Dwarf_state
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module L = Linear
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let attributes fun_name =
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[DAH.create_name fun_name; DAH.create_external ~is_visible_externally:true]
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let abstract_instance_proto_die_symbol ~fun_symbol =
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Asm_symbol.create (Asm_symbol.to_raw_string fun_symbol ^ "_absinst")
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let add_empty state ~compilation_unit_proto_die ~fun_symbol ~demangled_name =
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let abstract_instance_proto_die =
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(* DWARF-5 specification section 3.3.8.1, page 82. *)
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Proto_die.create ~parent:(Some compilation_unit_proto_die) ~tag:Subprogram
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~attribute_values:
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[ DAH.create_name (Asm_symbol.encode fun_symbol);
48+
DAH.create_linkage_name ~linkage_name:demangled_name;
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DAH.create_external ~is_visible_externally:true ]
50+
()
51+
in
52+
let abstract_instance_proto_die_symbol =
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abstract_instance_proto_die_symbol ~fun_symbol
54+
in
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Proto_die.set_name abstract_instance_proto_die
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abstract_instance_proto_die_symbol;
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Asm_symbol.Tbl.add
58+
(DS.function_abstract_instances state)
59+
fun_symbol
60+
(abstract_instance_proto_die, abstract_instance_proto_die_symbol);
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abstract_instance_proto_die, abstract_instance_proto_die_symbol
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63+
let add_root state ~parent ~demangled_name fun_symbol ~location_attributes =
64+
let attributes =
65+
[ DAH.create_name (Asm_symbol.encode fun_symbol);
66+
DAH.create_linkage_name ~linkage_name:demangled_name;
67+
DAH.create_external ~is_visible_externally:true ]
68+
@ location_attributes
69+
in
70+
let attribute_values =
71+
attributes
72+
@ [ (* We assume every function might potentially be inlined (and possibly
73+
in the future), so we choose [DW_INL_inlined] as the most appropriate
74+
setting for [DW_AT_inline], even if it doesn't seem exactly correct.
75+
We must set something here to ensure that the subprogram is marked as
76+
an abstract instance root. *)
77+
(* CR mshinwell/xclerc: we could propagate "inline never" attributes to
78+
this point *)
79+
DAH.create_inline Inlined ]
80+
in
81+
let abstract_instance_proto_die_symbol =
82+
abstract_instance_proto_die_symbol ~fun_symbol
83+
in
84+
DS.Debug.log "add_root: fun_symbol=%a\n" Asm_symbol.print fun_symbol;
85+
let abstract_instance_proto_die =
86+
match
87+
Asm_symbol.Tbl.find (DS.function_abstract_instances state) fun_symbol
88+
with
89+
| proto_die, _symbol ->
90+
(* See below in [find] *)
91+
Proto_die.replace_all_attribute_values proto_die attribute_values
92+
| exception Not_found ->
93+
(* DWARF-5 specification section 3.3.8.1, page 82. *)
94+
Proto_die.create ~parent:(Some parent) ~tag:Subprogram ~attribute_values
95+
()
96+
in
97+
Proto_die.set_name abstract_instance_proto_die
98+
abstract_instance_proto_die_symbol;
99+
Asm_symbol.Tbl.add (* or replace *)
100+
(DS.function_abstract_instances state)
101+
fun_symbol
102+
(abstract_instance_proto_die, abstract_instance_proto_die_symbol);
103+
abstract_instance_proto_die, abstract_instance_proto_die_symbol
104+
105+
type decomposed_singleton_debuginfo =
106+
{ demangled_name : string;
107+
fun_symbol : Asm_symbol.t;
108+
compilation_unit : Compilation_unit.t
109+
}
110+
111+
let decompose_singleton_debuginfo dbg =
112+
let orig_dbg = dbg in
113+
match Debuginfo.to_items dbg with
114+
| [({ dinfo_scopes; dinfo_function_symbol; _ } as item)] -> (
115+
let module S = Debuginfo.Scoped_location in
116+
let compilation_unit = S.compilation_unit dinfo_scopes in
117+
let dbg = Debuginfo.of_items [item] in
118+
let fun_symbol =
119+
match dinfo_function_symbol with
120+
| Some dinfo_function_symbol -> Asm_symbol.create dinfo_function_symbol
121+
| None ->
122+
Misc.fatal_errorf
123+
"No function symbol in Debuginfo.t: orig_dbg=%a dbg=%a"
124+
Debuginfo.print_compact_extended orig_dbg
125+
Debuginfo.print_compact_extended dbg
126+
in
127+
let demangled_name =
128+
Debuginfo.Scoped_location.string_of_scopes dinfo_scopes
129+
|> Misc.remove_double_underscores
130+
in
131+
match compilation_unit with
132+
| Some compilation_unit -> { demangled_name; fun_symbol; compilation_unit }
133+
| None ->
134+
Misc.fatal_errorf "No compilation unit extracted from: %a"
135+
Debuginfo.print_compact_extended dbg)
136+
| [] -> Misc.fatal_error "Empty Debuginfo.t"
137+
| _ :: _ ->
138+
Misc.fatal_errorf "Non-singleton Debuginfo.t: %a"
139+
Debuginfo.print_compact_extended dbg
140+
141+
type find_result =
142+
| Ok of Asm_symbol.t
143+
| External_unit of
144+
{ demangled_name : string;
145+
fun_symbol : Asm_symbol.t
146+
}
147+
148+
let find state ~compilation_unit_proto_die (dbg : Debuginfo.t) =
149+
let { demangled_name; fun_symbol; compilation_unit = dbg_comp_unit } =
150+
decompose_singleton_debuginfo dbg
151+
in
152+
DS.Debug.log "found comp unit %a\n%!" Compilation_unit.print dbg_comp_unit;
153+
let this_comp_unit = Compilation_unit.get_current_exn () in
154+
if Compilation_unit.equal dbg_comp_unit this_comp_unit
155+
then (
156+
DS.Debug.log "looking in function_abstract_instances for %a\n%!"
157+
Asm_symbol.print fun_symbol;
158+
match
159+
Asm_symbol.Tbl.find (DS.function_abstract_instances state) fun_symbol
160+
with
161+
| existing_instance ->
162+
DS.Debug.log "...successfully found existing absint DIE\n%!";
163+
Ok (snd existing_instance)
164+
| exception Not_found ->
165+
(* Fabricate an empty abstract instance DIE to fill in later, just in case
166+
we haven't seen things in topological order. *)
167+
(* CR mshinwell: does that actually happen now? *)
168+
DS.Debug.log "...making empty absint DIE for %a\n" Asm_symbol.print
169+
fun_symbol;
170+
(* The empty abstract instances are parented to the compilation unit as
171+
they might be referenced by other DIEs in a completely different scope
172+
within the current unit. *)
173+
let _, die_symbol =
174+
add_empty state ~compilation_unit_proto_die ~fun_symbol ~demangled_name
175+
in
176+
Ok die_symbol)
177+
else
178+
(* abstract_instance_proto_die_symbol ~fun_symbol *)
179+
(* See the call site of this function *)
180+
External_unit { demangled_name; fun_symbol }

‎backend/debug/dwarf/dwarf_ocaml/dwarf_abstract_instances.mli

Lines changed: 59 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,59 @@
1+
(******************************************************************************
2+
* flambda-backend *
3+
* Mark Shinwell, Jane Street *
4+
* -------------------------------------------------------------------------- *
5+
* MIT License *
6+
* *
7+
* Copyright (c) 2024 Jane Street Group LLC *
8+
* [email protected] *
9+
* *
10+
* Permission is hereby granted, free of charge, to any person obtaining a *
11+
* copy of this software and associated documentation files (the "Software"), *
12+
* to deal in the Software without restriction, including without limitation *
13+
* the rights to use, copy, modify, merge, publish, distribute, sublicense, *
14+
* and/or sell copies of the Software, and to permit persons to whom the *
15+
* Software is furnished to do so, subject to the following conditions: *
16+
* *
17+
* The above copyright notice and this permission notice shall be included *
18+
* in all copies or substantial portions of the Software. *
19+
* *
20+
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
21+
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
22+
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
23+
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER *
24+
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING *
25+
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER *
26+
* DEALINGS IN THE SOFTWARE. *
27+
******************************************************************************)
28+
29+
(** Management of DWARF "abstract instances" for functions. *)
30+
31+
open! Asm_targets
32+
open! Dwarf_low
33+
open! Dwarf_high
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35+
val attributes : string -> Dwarf_attribute_values.Attribute_value.t list
36+
37+
(** Add an abstract instance root. *)
38+
val add_root :
39+
Dwarf_state.t ->
40+
parent:Proto_die.t ->
41+
demangled_name:string ->
42+
Asm_symbol.t ->
43+
location_attributes:Dwarf_attribute_values.Attribute_value.t list ->
44+
Proto_die.t * Asm_symbol.t
45+
46+
type find_result = private
47+
| Ok of Asm_symbol.t
48+
| External_unit of
49+
{ demangled_name : string;
50+
fun_symbol : Asm_symbol.t
51+
}
52+
53+
val find :
54+
Dwarf_state.t ->
55+
compilation_unit_proto_die:Proto_die.t ->
56+
Debuginfo.t ->
57+
find_result
58+
(* val find_maybe_in_another_unit_or_add : Dwarf_state.t ->
59+
function_proto_die:Proto_die.t -> Linear.fundecl -> Asm_symbol.t option *)

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