X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fust-app.cpp;h=11d604ea9a463e7c32126b5189e46707e74f7ce1;hb=b6bbb1d666531bf061f29884da1b0d7c10f59aa0;hp=9690115d66c56ca83b06f6adb6e92e888249ec00;hpb=eda1aa02582ba8af1f30d40f131f4a32d2b372ab;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/ust-app.cpp b/src/bin/lttng-sessiond/ust-app.cpp
index 9690115d6..11d604ea9 100644
--- a/src/bin/lttng-sessiond/ust-app.cpp
+++ b/src/bin/lttng-sessiond/ust-app.cpp
@@ -6430,7 +6430,8 @@ static int handle_app_register_channel_notification(int sock,
 		auto app_context_fields = lsu::create_trace_fields_from_ust_ctl_fields(
 				*locked_registry_session, ust_ctl_context_fields.get(),
 				context_field_count,
-				lst::field_location::root::EVENT_RECORD_COMMON_CONTEXT);
+				lst::field_location::root::EVENT_RECORD_COMMON_CONTEXT,
+				lsu::ctl_field_quirks::UNDERSCORE_PREFIXED_VARIANT_TAG_MAPPINGS);
 
 		if (!ust_reg_chan.is_registered()) {
 			lst::type::cuptr event_context = app_context_fields.size() ?
@@ -6566,7 +6567,9 @@ static int add_event_ust_registry(int sock, int sobjd, int cobjd, const char *na
 								*locked_registry, fields.get(),
 								nr_fields,
 								lst::field_location::root::
-										EVENT_RECORD_PAYLOAD),
+										EVENT_RECORD_PAYLOAD,
+								lsu::ctl_field_quirks::
+										UNDERSCORE_PREFIXED_VARIANT_TAG_MAPPINGS),
 						loglevel_value,
 						model_emf_uri.get() ?
 								nonstd::optional<std::string>(
@@ -7892,3 +7895,30 @@ error:
 	rcu_read_unlock();
 	return ret;
 }
+
+lsu::ctl_field_quirks ust_app::ctl_field_quirks() const
+{
+	/*
+	 * Application contexts are expressed as variants. LTTng-UST announces
+	 * those by registering an enumeration named `..._tag`. It then registers a
+	 * variant as part of the event context that contains the various possible
+	 * types.
+	 *
+	 * Unfortunately, the names used in the enumeration and variant don't
+	 * match: the enumeration names are all prefixed with an underscore while
+	 * the variant type tag fields aren't.
+	 *
+	 * While the CTF 1.8.3 specification mentions that
+	 * underscores *should* (not *must*) be removed by CTF readers. Babeltrace
+	 * 1.x (and possibly others) expect a perfect match between the names used
+	 * by tags and variants.
+	 *
+	 * When the UNDERSCORE_PREFIXED_VARIANT_TAG_MAPPINGS quirk is enabled,
+	 * the variant's fields are modified to match the mappings of its tag.
+	 *
+	 * From ABI version >= 10.x, the variant fields and tag mapping names
+	 * correctly match, making this quirk unnecessary.
+	 */
+	return v_major <= 9 ? lsu::ctl_field_quirks::UNDERSCORE_PREFIXED_VARIANT_TAG_MAPPINGS :
+		lsu::ctl_field_quirks::NONE;
+}
\ No newline at end of file