From 324af5d76942d68ca06f02a15c993e7a5475d514 Mon Sep 17 00:00:00 2001
From: Martin Stein <martin.stein@genode-labs.com>
Date: Wed, 5 Feb 2014 14:58:37 +0100
Subject: [PATCH] os: make program ctors and dtors visible to LDSO

This is needed later when eliminating the need for a startup lib in
dynamic programs to enable LDSO to call ctors and dtors of the program.

Issue #1042
---
 base/mk/prg.mk                |  6 ++++++
 os/src/platform/genode_dyn.dl | 16 ++++++++++++++++
 2 files changed, 22 insertions(+)
 create mode 100644 os/src/platform/genode_dyn.dl

diff --git a/base/mk/prg.mk b/base/mk/prg.mk
index 898a074d1d..eec62acdd9 100644
--- a/base/mk/prg.mk
+++ b/base/mk/prg.mk
@@ -115,6 +115,12 @@ ifeq ($(SHARED_LIBS),)
 LD_SCRIPTS  := $(LD_SCRIPT_STATIC)
 FILTER_DEPS := $(DEPS:.lib=)
 else
+
+#
+# Add a list of symbols that shall always be added to the dynsym section
+#
+LD_OPT += --dynamic-list=$(call select_from_repositories,src/platform/genode_dyn.dl)
+
 LD_SCRIPTS  := $(LD_SCRIPT_DYN)
 LD_CMD      += -Wl,--dynamic-linker=$(DYNAMIC_LINKER).lib.so \
                -Wl,--eh-frame-hdr
diff --git a/os/src/platform/genode_dyn.dl b/os/src/platform/genode_dyn.dl
new file mode 100644
index 0000000000..21eab9d305
--- /dev/null
+++ b/os/src/platform/genode_dyn.dl
@@ -0,0 +1,16 @@
+/*
+ * Symbols that shall always be added to the section '.dynsym'
+ */
+{
+	/*
+	 * The ctors and dtors symbols are not used by a dynamic program as such
+	 * programs have no '_main' function. Hence the linker doesn't add them to
+	 * the dynsym section by itself. However, we need to lookup the ctors and
+	 * dtors arrays of the dynamic program in LDSO, which is why we must
+	 * explicitely add them to the dynsym section.
+	 */
+	_ctors_start;
+	_ctors_end;
+	_dtors_start;
+	_dtors_end;
+};