Documentation: document undefined behavior for NULL pointers

[lttng-ust.git] / doc / man / lttng-ust.3

diff --git a/doc/man/lttng-ust.3 b/doc/man/lttng-ust.3
index 228d2f896901e21902de3e46098c0ad089a413e5..8286e568b64ec915280aae67d1c589261fdb7545 100644 (file)
--- a/doc/man/lttng-ust.3
+++ b/doc/man/lttng-ust.3
@@ -1,7 +1,7 @@
 .TH "LTTNG-UST" "3" "February 16, 2012" "" ""
 
 .SH "NAME"
-lttng-ust \(em Linux Trace Toolkit Next Generation User-Space Tracer
+lttng-ust \(em Linux Trace Toolkit Next Generation User-Space Tracer 2.x
 
 .SH "SYNOPSIS"
 
@@ -116,6 +116,7 @@ TRACEPOINT_EVENT(
                 * ctf_array_text: a statically-sized array, printed as
                 * a string. No need to be terminated by a null
                 * character.
+                * Behavior is undefined if "text" field is NULL.
                 */ 
                ctf_array_text(char, arrfield2, text, 10)
 
@@ -123,6 +124,11 @@ TRACEPOINT_EVENT(
                 * ctf_sequence: a dynamically-sized array.
                 * args: (type, field name, argument expression,
                 *      type of length expression, length expression)
+                * The "type of length expression" needs to be an
+                * unsigned type. As a reminder, "unsigned char" should
+                * be preferred to "char", since the signedness of
+                * "char" is implementation-defined.
+                * Behavior is undefined if "text" field is NULL.
                 */ 
                ctf_sequence(char, seqfield1, text,
                             size_t, textlen)
@@ -130,6 +136,7 @@ TRACEPOINT_EVENT(
                /*
                 * ctf_sequence_text: a dynamically-sized array, printed
                 * as string. No need to be null-terminated.
+                * Behavior is undefined if "text" field is NULL.
                 */
                ctf_sequence_text(char, seqfield2, text,
                             size_t, textlen)
@@ -137,6 +144,7 @@ TRACEPOINT_EVENT(
                /*
                 * ctf_string: null-terminated string.
                 * args: (field name, argument expression)
+                * Behavior is undefined if "text" field is NULL.
                 */
                ctf_string(stringfield, text)
 
@@ -283,7 +291,7 @@ carefully:
       needed. Another way is to dlopen the tracepoint probe when needed
       by the application.
     - Example:
-      - tests/demo/   demo.c  tp*.c ust_tests_demo*.h demo-trace
+      - doc/examples/demo   demo.c  tp*.c ust_tests_demo*.h demo-trace
 
   - Note about dlclose() usage: it is not safe to use dlclose on a
     provider shared object that is being actively used for tracing due
@@ -366,7 +374,7 @@ lttng-sessiond(8)
 .SH "BUGS"
 
 .PP
-No knows bugs at this point.
+No known bugs at this point.
 
 If you encounter any issues or usability problem, please report it on
 our mailing list <lttng-dev@lists.lttng.org> to help improve this