Fix static provider linking: introduce TRACEPOINT_PROBE_DYNAMIC_LINKAGE

[lttng-ust.git] / README

diff --git a/README b/README
index a3979763353d079bd8a6c1c1261f13446d3ca382..23b831978a748d7acc1cd63e16c11ad7c9082714 100644 (file)
--- a/README
+++ b/README
@@ -56,14 +56,31 @@ USAGE:
 
   - Create an instrumentation header following the tracepoint examples.
     See lttng/tracepoint.h, and examples.
-  - Either compile the Tracepoint probes with the application:
+
+  There are 2 ways to compile the Tracepoint Provider with the
+  application: either statically or dynamically. Please follow
+  carefully:
+
+  1.1) Compile the Tracepoint provider with the application, either
+       directly or through a static library (.a):
+    - Into exactly one object of your application: define
+      "TRACEPOINT_DEFINE" and include the tracepoint provider.
     - Use "-I." for the compilation unit containing the tracepoint
       provider include (e.g. tp.c).
     - Link application with "-ldl -llttng-ust".
+    - Include the tracepoint provider header into all C files using
+      the provider.
     - Example:
         tests/hello/  hello.c tp.c ust_tests_hello.h Makefile.example
-  - Or compile the Tracepoint probes separately from the application,
-    using dynamic linking:
+
+  2) Compile the Tracepoint Provider separately from the application,
+     using dynamic linking:
+    - Into exactly one object of your application: define
+      "TRACEPOINT_DEFINE" _and_ also define
+      "TRACEPOINT_PROBE_DYNAMIC_LINKAGE", then include the tracepoint
+      provider header.
+    - Include the tracepoint provider header into all instrumented C
+      files that use the provider.
     - Compile the tracepoint provider with "-I.".
     - Link the tracepoint provider with "-llttng-ust".
     - Link application with "-ldl".
@@ -72,6 +89,7 @@ USAGE:
       needed.
     - Example:
       - tests/demo/   demo.c  tp*.c ust_tests_demo*.h demo-trace
+
   - Note about dlopen() usage: due to locking side-effects due to the
     way libc lazily resolves Thread-Local Storage (TLS) symbols when a
     library is dlopen'd, linking the tracepoint probe or liblttng-ust