Custom upgrade: wire up configure --enable-custom-upgrade-conflicting-symbols

This custom configure switch allows selecting between those two
behaviors for symbols which clash between lttng-ust 2.12 and 2.13:

Disabled (default): only emit and use symbols with "1" suffix. This
is meant to be used alonside lttng-ust 2.12.

Enabled: emit both symbols with and without "1" suffix, and use the
symbol without suffix. This is meant to be used after there are no
more users of lttng-ust 2.12 to gradually transition back to an upstream
lttng-ust 2.13 as applications are rebuilt.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I7ed02b2f0f9bd8c7b7b24fce28d2f23d61c970a3

diff --git a/configure.ac b/configure.ac
index e0d6c163f6c42df9830c9ba4a947fc649ba58b1f..4dfc011a3adf269588fdfbbbb1b71cfa5c0e698b 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -371,6 +371,11 @@ AE_FEATURE([examples],[Do not build and install examples])
 AE_FEATURE_DEFAULT_ENABLE
 AE_FEATURE([man-pages],[Do not build and install man pages (already built in a distributed tarball)])
 
+# Custom upgrade conflicting symbols
+# Disabled by default
+AE_FEATURE_DEFAULT_DISABLE
+AE_FEATURE([custom-upgrade-conflicting-symbols],[Emit and use original symbols for custom upgrade from 2.12 to 2.13])
+
 # Systemtap sdt.h integration
 # Disabled by default
 AC_ARG_WITH([sdt],
@@ -508,6 +513,11 @@ they will not be installed.
   ])
 ])
 
+# Emit and use original symbols for custom upgrade from 2.12 to 2.13
+AE_IF_FEATURE_ENABLED([custom-upgrade-conflicting-symbols], [
+  AC_DEFINE([LTTNG_UST_CUSTOM_UPGRADE_CONFLICTING_SYMBOLS], [1], [Emit and use original symbols for custom upgrade from 2.12 to 2.13])
+])
+
 AS_IF([test "x$with_sdt" = "xyes"], [
   AC_MSG_CHECKING([STAP_PROBEV()])
   AC_COMPILE_IFELSE([AC_LANG_SOURCE([[

diff --git a/include/lttng/ust-config.h.in b/include/lttng/ust-config.h.in
index fb6e371c5235f16c526a4b0b46c4ca7137c3e0ff..70ac4db72530117576dcda4cf558e63e4b96152a 100644 (file)
--- a/include/lttng/ust-config.h.in
+++ b/include/lttng/ust-config.h.in
@@ -10,4 +10,7 @@
 /* DTrace/GDB/SystemTap integration via sdt.h */
 #undef LTTNG_UST_HAVE_SDT_INTEGRATION
 
+/* Emit and use original symbols for custom upgrade from 2.12 to 2.13 */
+#undef LTTNG_UST_CUSTOM_UPGRADE_CONFLICTING_SYMBOLS
+
 #endif