Re: install_name for libraries and frameworks on OS X

[Blake Nicholson]

On May 18, 2008, at 8:02 AM, Nicola Pero wrote:
> > 1) Update configure.ac in gnustep-make so it prints a warning if the
> > user is on darwin and uses a filesystem layout other than 'apple'.
> > This warning will tell the user they need to either set
> > DYLD_LIBRARY_PATH and DYLD_FRAMEWORK_PATH in their shell's  
> > environment
> > as well as in ~/.MacOSX/environment.plist, or they need to install
> > libraries and frameworks with an absolute install name (see below).
>
> It looks good
>
> Maybe you could make the warning specific to using the 'apple-apple- 
> apple'
> library-combo (ie, building using the Apple frameworks).  If you are  
> using
> the 'gnu-gnu-gnu' library-combo, then the right thing to do might be  
> to
> source GNUstep.sh in your shell ?

I've put together a patch to add this capability.  I print a warning  
if: (1) the target_os is darwin, (2) the filesystem is not 'apple',  
*and* (3) the user has not enabled absolute install paths (a new  
option to configure, see below).  This warning informs the user that  
they need to set DYLD_LIBRARY_PATH and DYLD_FRAMEWORK_PATH and  
mentions that this is typically accomplished by sourcing GNUstep.sh.

> > 2) Add an option to make to use an absolute install name when linking
> > the library or framework.  I tend to like the single word options to
> > make.  Would you be opposed to me simply calling the option
> > 'absolute'?  The end user could then simply type "make absolute=yes"
> > when building the library or framework.
>
> It looks good.  I had a look around and I realized that most  
> platform options
> we have at the moment are set at configure time though.  Would that  
> make
> things easier ?  We could also use a longer expressive name there  
> (you have
> to type it only once), ie
>
> ./configure --enable-absolute-install-paths
>
> that could set a variable (ABSOLUTE_INSTALL_PATHS = YES/NO) in  
> config.make.
> The same variable could then be overridden on the command-line (as  
> in, make
> ABSOLUTE_INSTALL_PATHS=NO) if needed for a special occasion, but I'd  
> expect
> that most people will consistently either use the option, or not use  
> it, so
> they'd set it once in ./configure and be happy.

I added this option to configure.ac for gnustep-make.  As you  
recommend, this setting gets passed on to config.make (via  
config.make.in).  I also updated library.make and framework.make to  
check this setting when building on darwin and modify the  
LIB_LINK_INSTALL_NAME accordingly.  I re-generated configure (not  
shown in my patch below) and tested several combinations of settings,  
and everything seems to work well.  I also tested overriding the  
absolute install paths setting when invoking make, and that works too.

Please let me know if you have any feedback on my patch below, or if  
you think it is ready to commit.


Thanks,
Blake



Index: configure.ac
===================================================================
--- configure.ac        (revision 26548)
+++ configure.ac        (working copy)
@@ -288,6 +288,51 @@
   exit 1
 fi

+
+# Need to do some checks related to building dylibs on darwin.
+case "$target_os" in
+  darwin*)
+    AC_MSG_CHECKING([if we should build dynamic libraries with an  
absolute install_name])
+    AC_ARG_ENABLE(absolute-install-paths, [
+--enable-absolute-install-paths
+  Enable the use of absolute paths for the install_name of dynamic
+  libraries on Darwin.  This option is specific to Darwin and is
+  ignored on all other platforms.  Any code that links against a
+  dynamic library with an absolute install_name will tell dyld to
+  find the library at that location.  Enabling this option allows
+  one to place libraries in non-standard locations without having
+  to set DYLD_LIBRARY_PATH and DYLD_FRAMEWORK_PATH in the shell
+  and ~/.MacOSX/environment.plist, but libraries built with an
+  absolute install_name are not relocatable.  By default, this
+  setting is disabled.
+    ],
+      ac_cv_absolute_install_paths=$enableval,
+      ac_cv_absolute_install_paths="no")
+
+    if test "$ac_cv_absolute_install_paths" = "yes"; then
+      AC_MSG_RESULT(yes)
+      GNUSTEP_ABSOLUTE_INSTALL_PATHS=yes;
+    else
+      AC_MSG_RESULT(no)
+      GNUSTEP_ABSOLUTE_INSTALL_PATHS=;
+
+      if test ! x"$GNUSTEP_FILESYSTEM_LAYOUT_FILE" = x"apple"; then
+        echo ""
+        echo "*******************************************************"
+        echo "WARNING: To use a layout other than 'apple' on Mac OS X"
+        echo "without enabling absolute install paths you must set"
+        echo "DYLD_LIBRARY_PATH and DYLD_FRAMEWORK_PATH in your shell"
+        echo "start-up script (typically by sourcing GNUstep.sh) and"
+        echo "also in ~/.MacOSX/environment.plist."
+        echo "*******************************************************"
+        echo ""
+      fi
+    fi
+    AC_SUBST(GNUSTEP_ABSOLUTE_INSTALL_PATHS)
+
+    ;;
+esac
+
 #-------------------------------------------------------------------
 # Read filesystem layout from file
 #-------------------------------------------------------------------
Index: config.make.in
===================================================================
--- config.make.in      (revision 26548)
+++ config.make.in      (working copy)
@@ -171,3 +171,9 @@
 # Whether the compiler is GCC with precompiled header support
 #
 GCC_WITH_PRECOMPILED_HEADERS = @GCC_WITH_PRECOMPILED_HEADERS@
+
+#
+# Whether the install_name for dynamic libraries on darwin should
+# be an absolute path.
+#
+GNUSTEP_ABSOLUTE_INSTALL_PATHS = @GNUSTEP_ABSOLUTE_INSTALL_PATHS@
Index: Instance/library.make
===================================================================
--- Instance/library.make       (revision 26548)
+++ Instance/library.make       (working copy)
@@ -239,6 +239,13 @@
 LIB_LINK_INSTALL_NAME = $(SONAME_LIBRARY_FILE)
 LIB_LINK_INSTALL_DIR = $(FINAL_LIBRARY_INSTALL_DIR)

+# On Mac OS X, set absolute install_name if requested
+ifeq ($(findstring darwin, $(GNUSTEP_TARGET_OS)), darwin)
+  ifeq ($(GNUSTEP_ABSOLUTE_INSTALL_PATHS), yes)
+    LIB_LINK_INSTALL_NAME = $(LIB_LINK_INSTALL_DIR)/$ 
(SONAME_LIBRARY_FILE)
+  endif
+endif
+
 #
 # Internal targets
 #
Index: Instance/framework.make
===================================================================
--- Instance/framework.make     (revision 26548)
+++ Instance/framework.make     (working copy)
@@ -309,6 +309,13 @@
 else
   # Use a relative path for easy relocation.
   LIB_LINK_INSTALL_NAME = $(GNUSTEP_INSTANCE).framework/$ 
(GNUSTEP_INSTANCE)
+
+  # On Mac OS X, set absolute install_name if requested
+  ifeq ($(findstring darwin, $(GNUSTEP_TARGET_OS)), darwin)
+    ifeq ($(GNUSTEP_ABSOLUTE_INSTALL_PATHS), yes)
+      LIB_LINK_INSTALL_NAME = $(LIB_LINK_INSTALL_DIR)/$ 
(GNUSTEP_INSTANCE)
+    endif
+  endif
 endif