Docs: allow NULL packet, stream and event headers, contexts and payloads

[babeltrace.git] / include / babeltrace / ctf-ir / trace.h

diff --git a/include/babeltrace/ctf-ir/trace.h b/include/babeltrace/ctf-ir/trace.h
index 840ebf372c2383327a71a623803bc6ef982249cb..ba6b28cdce3cb3f4e31a90b07600c698773adc80 100644 (file)
--- a/include/babeltrace/ctf-ir/trace.h
+++ b/include/babeltrace/ctf-ir/trace.h
@@ -478,11 +478,13 @@ extern int bt_ctf_trace_set_environment_field_string(
 @param[in] trace_class Trace class of which to get the packet
                        header field type.
 @returns               Packet header field type of \p trace_class,
-                       or \c NULL on error.
+                       or \c NULL if \p trace_class has no packet header field
+                       type or on error.
 
 @prenotnull{trace_class}
 @postrefcountsame{trace_class}
-@postsuccessrefcountretinc
+@post <strong>On success, if the return value is a field type</strong>, its
+       reference count is incremented.
 
 @sa bt_ctf_trace_set_packet_header_type(): Sets the packet
        header field type of a given trace class.
@@ -492,22 +494,29 @@ extern struct bt_ctf_field_type *bt_ctf_trace_get_packet_header_type(
 
 /**
 @brief Sets the packet header field type of the CTF IR trace class
-       \p trace_class to \p packet_context_type.
+       \p trace_class to \p packet_header_type, or unsets the current packet
+       header field type from \p trace_class.
+
+If \p packet_header_type is \c NULL, then this function unsets the current
+packet header field type from \p trace_class, effectively making \p trace_class
+a trace without a packet header field type.
 
-As of Babeltrace \btversion, \p packet_context_type \em must be a
-CTF IR structure field type object.
+As of Babeltrace \btversion, if \p packet_header_type is not \c NULL,
+\p packet_header_type \em must be a CTF IR structure field type object.
 
 @param[in] trace_class         Trace class of which to set the packet
                                header field type.
-@param[in] packet_header_type  Packet header field type.
+@param[in] packet_header_type  Packet header field type, or \c NULL to unset
+                               the current packet header field type.
 @returns                       0 on success, or a negative value on error.
 
 @prenotnull{trace_class}
-@prenotnull{packet_header_type}
 @prehot{trace_class}
-@preisstructft{packet_header_type}
+@pre <strong>\p packet_header_type, if not \c NULL</strong>, is a CTF IR
+       structure field type.
 @postrefcountsame{trace_class}
-@postsuccessrefcountinc{packet_header_type}
+@post <strong>On success, if \p packet_header_type is not \c NULL</strong>,
+       the reference count of \p packet_header_type is incremented.
 
 @sa bt_ctf_trace_get_packet_header_type(): Returns the packet
        header field type of a given trace class.