2 * SPDX-License-Identifier: MIT
4 * Copyright 2020 Philippe Proulx <pproulx@efficios.com>
7 #include <babeltrace2/babeltrace.h>
8 #include "common/macros.h"
9 #include "common/assert.h"
15 #include "ctf-meta-visitors.hpp"
17 static inline int set_alignments(struct ctf_field_class
*fc
)
27 case CTF_FIELD_CLASS_TYPE_STRUCT
:
29 struct ctf_field_class_struct
*struct_fc
= ctf_field_class_as_struct(fc
);
31 for (i
= 0; i
< struct_fc
->members
->len
; i
++) {
32 struct ctf_named_field_class
*named_fc
=
33 ctf_field_class_struct_borrow_member_by_index(struct_fc
, i
);
35 ret
= set_alignments(named_fc
->fc
);
40 if (named_fc
->fc
->alignment
> fc
->alignment
) {
41 fc
->alignment
= named_fc
->fc
->alignment
;
47 case CTF_FIELD_CLASS_TYPE_VARIANT
:
49 struct ctf_field_class_variant
*var_fc
= ctf_field_class_as_variant(fc
);
51 for (i
= 0; i
< var_fc
->options
->len
; i
++) {
52 struct ctf_named_field_class
*named_fc
=
53 ctf_field_class_variant_borrow_option_by_index(var_fc
, i
);
55 ret
= set_alignments(named_fc
->fc
);
63 case CTF_FIELD_CLASS_TYPE_ARRAY
:
64 case CTF_FIELD_CLASS_TYPE_SEQUENCE
:
66 struct ctf_field_class_array_base
*array_fc
= ctf_field_class_as_array_base(fc
);
68 ret
= set_alignments(array_fc
->elem_fc
);
74 * Use the alignment of the array/sequence field class's
75 * element FC as its own alignment.
77 * This is especially important when the array/sequence
78 * field's effective length is zero: as per CTF 1.8, the
79 * stream data decoding process still needs to align the
80 * cursor using the element's alignment [1]:
82 * > Arrays are always aligned on their element
83 * > alignment requirement.
88 * integer { size = 8; } a;
89 * integer { size = 8; align = 16; } b[0];
90 * integer { size = 8; } c;
93 * When using this to decode the bytes 1, 2, and 3, then
94 * the decoded values are:
100 * [1]: https://diamon.org/ctf/#spec4.2.3
102 array_fc
->base
.alignment
= array_fc
->elem_fc
->alignment
;
113 int ctf_trace_class_update_alignments(struct ctf_trace_class
*ctf_tc
)
118 if (!ctf_tc
->is_translated
) {
119 ret
= set_alignments(ctf_tc
->packet_header_fc
);
125 for (i
= 0; i
< ctf_tc
->stream_classes
->len
; i
++) {
126 ctf_stream_class
*sc
= (ctf_stream_class
*) ctf_tc
->stream_classes
->pdata
[i
];
129 if (!sc
->is_translated
) {
130 ret
= set_alignments(sc
->packet_context_fc
);
135 ret
= set_alignments(sc
->event_header_fc
);
140 ret
= set_alignments(sc
->event_common_context_fc
);
146 for (j
= 0; j
< sc
->event_classes
->len
; j
++) {
147 struct ctf_event_class
*ec
= (ctf_event_class
*) sc
->event_classes
->pdata
[j
];
149 if (ec
->is_translated
) {
153 ret
= set_alignments(ec
->spec_context_fc
);
158 ret
= set_alignments(ec
->payload_fc
);