ctf: compile plugin as C++

[babeltrace.git] / src / plugins / ctf / common / metadata / ctf-meta-update-alignments.cpp

diff --git a/src/plugins/ctf/common/metadata/ctf-meta-update-alignments.cpp b/src/plugins/ctf/common/metadata/ctf-meta-update-alignments.cpp
new file mode 100644 (file)
index 0000000..6e93b67
--- /dev/null
+++ b/src/plugins/ctf/common/metadata/ctf-meta-update-alignments.cpp
@@ -0,0 +1,173 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright 2020 Philippe Proulx <pproulx@efficios.com>
+ */
+
+#include <babeltrace2/babeltrace.h>
+#include "common/macros.h"
+#include "common/assert.h"
+#include <glib.h>
+#include <stdint.h>
+#include <string.h>
+#include <inttypes.h>
+
+#include "ctf-meta-visitors.hpp"
+
+static inline
+int set_alignments(struct ctf_field_class *fc)
+{
+       int ret = 0;
+       uint64_t i;
+
+       if (!fc) {
+               goto end;
+       }
+
+       switch (fc->type) {
+       case CTF_FIELD_CLASS_TYPE_STRUCT:
+       {
+               struct ctf_field_class_struct *struct_fc = ctf_field_class_as_struct(fc);
+
+               for (i = 0; i < struct_fc->members->len; i++) {
+                       struct ctf_named_field_class *named_fc =
+                               ctf_field_class_struct_borrow_member_by_index(
+                                       struct_fc, i);
+
+                       ret = set_alignments(named_fc->fc);
+                       if (ret) {
+                               goto end;
+                       }
+
+                       if (named_fc->fc->alignment > fc->alignment) {
+                               fc->alignment = named_fc->fc->alignment;
+                       }
+               }
+
+               break;
+       }
+       case CTF_FIELD_CLASS_TYPE_VARIANT:
+       {
+               struct ctf_field_class_variant *var_fc = ctf_field_class_as_variant(fc);
+
+               for (i = 0; i < var_fc->options->len; i++) {
+                       struct ctf_named_field_class *named_fc =
+                               ctf_field_class_variant_borrow_option_by_index(
+                                       var_fc, i);
+
+                       ret = set_alignments(named_fc->fc);
+                       if (ret) {
+                               goto end;
+                       }
+               }
+
+               break;
+       }
+       case CTF_FIELD_CLASS_TYPE_ARRAY:
+       case CTF_FIELD_CLASS_TYPE_SEQUENCE:
+       {
+               struct ctf_field_class_array_base *array_fc = ctf_field_class_as_array_base(fc);
+
+               ret = set_alignments(array_fc->elem_fc);
+               if (ret) {
+                       goto end;
+               }
+
+               /*
+                * Use the alignment of the array/sequence field class's
+                * element FC as its own alignment.
+                *
+                * This is especially important when the array/sequence
+                * field's effective length is zero: as per CTF 1.8, the
+                * stream data decoding process still needs to align the
+                * cursor using the element's alignment [1]:
+                *
+                * > Arrays are always aligned on their element
+                * > alignment requirement.
+                *
+                * For example:
+                *
+                *     struct {
+                *         integer { size = 8; } a;
+                *         integer { size = 8; align = 16; } b[0];
+                *         integer { size = 8; } c;
+                *     };
+                *
+                * When using this to decode the bytes 1, 2, and 3, then
+                * the decoded values are:
+                *
+                * `a`: 1
+                * `b`: []
+                * `c`: 3
+                *
+                * [1]: https://diamon.org/ctf/#spec4.2.3
+                */
+               array_fc->base.alignment = array_fc->elem_fc->alignment;
+               break;
+       }
+       default:
+               break;
+       }
+
+end:
+       return ret;
+}
+
+BT_HIDDEN
+int ctf_trace_class_update_alignments(
+               struct ctf_trace_class *ctf_tc)
+{
+       int ret = 0;
+       uint64_t i;
+
+       if (!ctf_tc->is_translated) {
+               ret = set_alignments(ctf_tc->packet_header_fc);
+               if (ret) {
+                       goto end;
+               }
+       }
+
+       for (i = 0; i < ctf_tc->stream_classes->len; i++) {
+               ctf_stream_class *sc = (ctf_stream_class *) ctf_tc->stream_classes->pdata[i];
+               uint64_t j;
+
+               if (!sc->is_translated) {
+                       ret = set_alignments(sc->packet_context_fc);
+                       if (ret) {
+                               goto end;
+                       }
+
+                       ret = set_alignments(sc->event_header_fc);
+                       if (ret) {
+                               goto end;
+                       }
+
+                       ret = set_alignments(sc->event_common_context_fc);
+                       if (ret) {
+                               goto end;
+                       }
+               }
+
+               for (j = 0; j < sc->event_classes->len; j++) {
+                       struct ctf_event_class *ec =
+                               (ctf_event_class *) sc->event_classes->pdata[j];
+
+                       if (ec->is_translated) {
+                               continue;
+                       }
+
+                       ret = set_alignments(ec->spec_context_fc);
+                       if (ret) {
+                               goto end;
+                       }
+
+                       ret = set_alignments(ec->payload_fc);
+                       if (ret) {
+                               goto end;
+                       }
+               }
+       }
+
+end:
+       return ret;
+}