From 26ab7b8a79e6c901518d9136d00b79e2905dab58 Mon Sep 17 00:00:00 2001
From: Mihai Moldovan <ionic@ionic.de>
Date: Tue, 26 Dec 2017 04:06:40 +0100
Subject: nxagent: implement RPATH/RUNPATH override for libX11.

As discussed in ArcticaProject/nx-libs#610, we need a way to load
libNX_X11 as a fake version of libX11 into nxagent's address space.

For doing so, we have to link against libX11 at build-time and specify
a(n) RPATH/RUNPATH to our libX11 -> libNX_X11 compat symlinks.

This commit is essentially doing a cross between options 3 and 4
discussed in the provided GH issue.

We link libX11 early (before specifying -Lcompat_symlinks_dir), so that
the linker finds the "real" libX11 version with the libX11 SONAME. This
leads to our binary depending upon both libX11 and libNX_X11 SONAMEs. We
already always added RPATH/RUNPATH, but these values are not passed down
to dependent libraries.

What happens at run-time is that the loader searches for a libX11
SONAME, takes RPATH/RUNPATH into account and loads our libNX_X11 library
instead via the compat symlinks. This satisfies the libX11 SONAME and
dependent libraries will *not* load the system libX11 version again.

Debian's dpkg-shlibdeps isn't quite happy about this mismatching SONAME
situation, so instruct to look the other way while we're minding our
business.

Fixes: ArcticaProject/nx-libs#610
---
 nx-X11/config/cf/Imake.rules | 4 ++--
 nx-X11/config/cf/Imake.tmpl  | 1 +
 2 files changed, 3 insertions(+), 2 deletions(-)

(limited to 'nx-X11/config')

diff --git a/nx-X11/config/cf/Imake.rules b/nx-X11/config/cf/Imake.rules
index 06b78993b..f53a15bba 100644
--- a/nx-X11/config/cf/Imake.rules
+++ b/nx-X11/config/cf/Imake.rules
@@ -1103,11 +1103,11 @@ CplusplusProgramTargetHelper(program,SRCS10,OBJS10,DEPLIBS10,locallib,syslib)
 AllTarget(ProgramTargetName(server))					@@\
 ProgramTargetName(server): subdirs objects libs				@@\
 	MoveToBakFile($@)						@@\
-	LinkRule($@,$(LDOPTIONS),objects,libs $(LDLIBS) syslibs) @@\
+	LinkRule($@,$(SERVERLDOPTIONS),objects,libs $(LDLIBS) syslibs)	@@\
 									@@\
 Concat(load,server):							@@\
 	MoveToBakFile(ProgramTargetName(server))			@@\
-	LinkRule(ProgramTargetName(server),$(LDOPTIONS),objects,libs $(LDLIBS) syslibs) @@\
+	LinkRule(ProgramTargetName(server),$(SERVERLDOPTIONS),objects,libs $(LDLIBS) syslibs) @@\
 									@@\
 loadX:: Concat(load,server)						@@\
 									@@\
diff --git a/nx-X11/config/cf/Imake.tmpl b/nx-X11/config/cf/Imake.tmpl
index 5d989d1e0..307d00d94 100644
--- a/nx-X11/config/cf/Imake.tmpl
+++ b/nx-X11/config/cf/Imake.tmpl
@@ -1995,6 +1995,7 @@ XEXT_EXTRA_DEFINES =
          LDPRELIB = LdPreLib $(INSTALLED_LIBS)
         LDPOSTLIB = LdPostLib
         LDOPTIONS = $(CDEBUGFLAGS) $(CCOPTIONS)  $(EXTRA_LDOPTIONS) $(THREADS_LDFLAGS) $(LOCAL_LDFLAGS) $(LDPRELIBS)
+  SERVERLDOPTIONS = $(CDEBUGFLAGS) $(CCOPTIONS)  $(EXTRA_LDOPTIONS) $(THREADS_LDFLAGS) $(LOCAL_LDFLAGS)
      CXXLDOPTIONS = $(CXXDEBUGFLAGS) $(CXXOPTIONS) $(EXTRA_LDOPTIONS) $(THREADS_CXXLDFLAGS) $(LOCAL_LDFLAGS) $(LDPRELIBS)
 
            LDLIBS = $(LDPOSTLIBS) $(THREADS_LIBS) $(SYS_LIBRARIES) $(EXTRA_LIBRARIES)
-- 
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