build: factor out `pluginarchive` function to `src/Makefile.common.inc`

[babeltrace.git] / src / Makefile.common.inc

diff --git a/src/Makefile.common.inc b/src/Makefile.common.inc
new file mode 100644 (file)
index 0000000..0d71e95
--- /dev/null
+++ b/src/Makefile.common.inc
@@ -0,0 +1,21 @@
+# SPDX-FileCopyrightText: 2017-2024 EfficiOS, Inc.
+# SPDX-License-Identifier: MIT
+
+# Path to the plugins build directory.
+PLUGINS_PATH = $(abs_top_builddir)/src/plugins
+
+# Takes a plugin name and outputs the needed LDFLAGS to embed it.
+#
+# The --whole-archive option is important here. From the GNU linker's
+# documentation:
+#
+#     For each archive mentioned on the command line after the
+#     --whole-archive option, include every object file in the archive in
+#     the link, rather than searching the archive for the required object
+#     files.
+#
+# In our case, we find the plugins thanks to special sections in the
+# binary that are filled by plugin objects. If the linker discards those
+# symbols because the CLI does not use them directly, the CLI reports
+# no plugins found (plugins are effectively not embedded).
+pluginarchive = $(LD_WHOLE_ARCHIVE)$(PLUGINS_PATH)/$(1)/.libs/babeltrace-plugin-$(1).a$(LD_NO_WHOLE_ARCHIVE)