A patch to make libgcc local in shared library

Fri Dec 11 14:07:00 GMT 1998

> > reached. But it ensures those symbols will be included in libfoo.so.
> 
> But you have to do this for _every_ routine in libgcc.a!  You might
> just as well use
> 
> ld ... foo.o -lc --whole-archive libgcc.a --no-whole-archive
> 
> to link everything.
> 
> Any libgcc.a routine may end up in a shared object, and any shared
> object might be changed so that its external interface doesn't change
> but the set of libgcc.a routines that it uses changes.
> 

Here is a patch for egcs. It will make function symbols local in
shared libraries.


H.J.
----
Fri Dec 11 07:08:59 1998  H.J. Lu  (hjl@gnu.org)

	* Makefile.in (OBJDUMP_FOR_TARGET): New.
	(LIBGCC_MAP): New. Set to empty.
	(all.cross, rest.cross, rest.encap): Add $(LIBGCC_MAP) to
	dependency.
	(install-common): Install libgcc.map if appropriate.
	(stage1-start, stage2-start, stage3-start, stage4-start): Copy
	libgcc.map if appropriate.
	(clean): Also remove libgcc.map.
	(libgcc.map): New rule.

	* config/t-linux (LIBGCC_MAP): New.
	(EXTRACT_LIBGCC): New.

	* config/t-linux-gnulibc1 (LIBGCC_MAP): Cleared.

	* config/linux.h (LIB_SPEC): Modefied if USE_GNULIBC_1 is not
	defined.

Index: Makefile.in
===================================================================
RCS file: /home/work/cvs/gnu/egcs/gcc/Makefile.in,v
retrieving revision 1.1.1.88
diff -u -r1.1.1.88 Makefile.in

--- Makefile.in	1998/12/10 22:51:22	1.1.1.88
+++ Makefile.in	1998/12/11 18:09:43
@@ -195,6 +196,16 @@
     fi; \
   fi`
 AR_FOR_TARGET_FLAGS = rc
+OBJDUMP_FOR_TARGET= ` \
+  if [ -f $(objdir)/../binutils/objdump ] ; then \
+    echo $(objdir)/../binutils/objdump ; \
+  else \
+    if [ "$(host_canonical)" = "$(target)" ] ; then \
+      echo objdump; \
+    else \
+       t='$(program_transform_name)'; echo objdump | sed -e $$t ; \
+    fi; \
+  fi`
 RANLIB_FOR_TARGET = ` \
   if [ -f $(objdir)/../binutils/ranlib ] ; then \
     echo $(objdir)/../binutils/ranlib ; \
@@ -355,6 +367,9 @@
 # libgcc1-test target (must also be overridable for a target)
 LIBGCC1_TEST = libgcc1-test
 
+# The libgcc symbol versioning map.
+LIBGCC_MAP=
+
 # List of extra executables that should be compiled for this target machine
 # that are used for compiling from source code to object code.
 # The rules for compiling them should be in the t-* file for the machine.
@@ -809,13 +824,14 @@
 # Note that we can compile enquire using the cross-compiler just built,
 # although we can't run it on this machine.
 all.cross: native gcc-cross specs stmp-headers $(STMP_FIXPROTO) $(LIBGCC) \
-	$(LIBGCC1_TEST) $(EXTRA_PARTS) lang.all.cross
+	$(LIBGCC_MAP) $(LIBGCC1_TEST) $(EXTRA_PARTS) lang.all.cross
 # This is what to compile if making gcc with a cross-compiler.
 all.build: native xgcc$(exeext) $(EXTRA_PARTS) lang.all.build
 # This is what must be made before installing GCC and converting libraries.
 start.encap: native xgcc$(exeext) specs $(LIBGCC1) xlimits.h lang.start.encap
 # These can't be made until after GCC can run.
-rest.encap: stmp-headers $(STMP_FIXPROTO) $(LIBGCC) $(EXTRA_PARTS) lang.rest.encap
+rest.encap: stmp-headers $(STMP_FIXPROTO) $(LIBGCC) $(LIBGCC_MAP) \
+	$(EXTRA_PARTS) lang.rest.encap
 # This is what is made with the host's compiler
 # whether making a cross compiler or not.
 native: config.status auto-host.h cpp$(exeext) $(LANGUAGES) \
@@ -830,7 +846,7 @@
 
 # On the target machine, finish building a cross compiler.
 # This does the things that can't be done on the host machine.
-rest.cross: $(LIBGCC) gfloat.h specs
+rest.cross: $(LIBGCC) $(LIBGCC_MAP) gfloat.h specs
 
 # Verify that it works to compile and link libgcc1-test.
 # If it does, then there are sufficient replacements for libgcc1.a.
@@ -2267,7 +2285,7 @@
 # Using unprotoize.c is not quite right in the first place, 
 # but what better way is there?
 	-rm -f libgcc.a libgcc1.a libgcc1-asm.a libgcc2.a libgcc2.ready
-	-rm -f libgcc1.null
+	-rm -f libgcc1.null libgcc.map
 	-rm -f *.dvi
 	-rm -f */*.dvi
 	-if [ -f md.pre-cpp ]; then \
@@ -2416,6 +2434,12 @@
 	  $(INSTALL_DATA) specs $(libsubdir)/specs; \
 	  chmod a-x $(libsubdir)/specs; \
 	fi
+# Install libgcc.map if it exists.
+	-if [ -n "$(LIBGCC_MAP)" -a -f libgcc.map ] ; then \
+	  rm -f $(libsubdir)/libgcc.map; \
+	  $(INSTALL_DATA) libgcc.map $(libsubdir)/libgcc.map; \
+	  chmod a-x $(libsubdir)/libgcc.map; \
+	fi
 # Install protoize if it was compiled.
 	-if [ -f protoize$(exeext) ]; \
 	then \
@@ -2903,6 +2934,10 @@
 	-if [ -f collect-ld$(exeext) ] ; then $(LN_S) ../collect-ld$(exeext) stage1 ; else true ; fi
 	-rm -f stage1/libgcc.a
 	-cp libgcc.a stage1
+	-if [ -n "$(LIBGCC_MAP)" -a -f libgcc.map ] ; then \
+	  rm -f stage1/libgcc.map; \
+	  cp libgcc.map stage1; \
+	fi
 	-if $(RANLIB_TEST) ; then $(RANLIB) stage1/libgcc.a; else true; fi
 	-for f in .. $(EXTRA_MULTILIB_PARTS); do if [ x$${f} != x.. ]; then \
 	  cp stage1/$${f} . ; \
@@ -2924,6 +2959,10 @@
 	-if [ -f collect-ld ] ; then $(LN_S) ../collect-ld$(exeext) stage2 ; else true ; fi
 	-rm -f stage2/libgcc.a
 	-cp libgcc.a stage2
+	-if [ -n "$(LIBGCC_MAP)" -a -f libgcc.map ] ; then \
+	  rm -f stage2/libgcc.map; \
+	  cp libgcc.map stage2; \
+	fi
 	-if $(RANLIB_TEST) ; then $(RANLIB) stage2/libgcc.a; else true; fi
 	-for f in .. $(EXTRA_MULTILIB_PARTS); do if [ x$${f} != x.. ]; then \
 	  cp stage2/$${f} . ; \
@@ -2945,6 +2984,10 @@
 	-if [ -f collect-ld$(exeext) ] ; then $(LN_S) ../collect-ld$(exeext) stage3 ; else true ; fi
 	-rm -f stage3/libgcc.a
 	-cp libgcc.a stage3
+	-if [ -n "$(LIBGCC_MAP)" -a -f libgcc.map ] ; then \
+	  rm -f stage3/libgcc.map; \
+	  cp libgcc.map stage3; \
+	fi
 	-if $(RANLIB_TEST) ; then $(RANLIB) stage3/libgcc.a; else true; fi
 	-for f in .. $(EXTRA_MULTILIB_PARTS); do if [ x$${f} != x.. ]; then \
 	  cp stage3/$${f} . ; \
@@ -2966,6 +3009,10 @@
 	-if [ -f collect-ld$(exeext) ] ; then $(LN_S) ../collect-ld$(exeext) stage4 ; else true ; fi
 	-rm -f stage4/libgcc.a
 	-cp libgcc.a stage4
+	-if [ -n "$(LIBGCC_MAP)" -a -f libgcc.map ] ; then \
+	  rm -f stage4/libgcc.map; \
+	  cp libgcc.map stage4; \
+	fi
 	-if $(RANLIB_TEST) ; then $(RANLIB) stage4/libgcc.a; else true; fi
 	-for f in .. $(EXTRA_MULTILIB_PARTS); do if [ x$${f} != x.. ]; then \
 	  cp stage4/$${f} . ; \
@@ -3047,3 +3094,9 @@
 	echo "#endif" >> t-float.h-cross
 	mv t-float.h-cross float.h-cross
 
+# Rule to generate the libgcc symbol versioning map.
+libgcc.map: libgcc.a
+	echo "GCC.INTERNAL {" > $@
+	echo "  local:" >> $@
+	$(EXTRACT_LIBGCC) >> $@
+	echo "};" >> $@
Index: config/t-linux
===================================================================
RCS file: /home/work/cvs/gnu/egcs/gcc/config/t-linux,v
retrieving revision 1.1.1.2
diff -u -r1.1.1.2 t-linux
--- config/t-linux	1998/02/28 03:52:25	1.1.1.2
+++ config/t-linux	1998/12/11 18:10:48
@@ -14,3 +14,9 @@
 LIBGCC1 = 
 CROSS_LIBGCC1 =
 LIBGCC1_TEST =
+
+# Make glocal functions in libgcc.a local to the shared library with
+# symbol versioning.
+LIBGCC_MAP=libgcc.map
+EXTRACT_LIBGCC=$(OBJDUMP_FOR_TARGET) --syms libgcc.a | \
+  grep "[ 	]g[ 	]\+F[ 	]" | awk '{print "    "$$6";";}' | sort 
Index: config/t-linux-gnulibc1
===================================================================
RCS file: /home/work/cvs/gnu/egcs/gcc/config/t-linux-gnulibc1,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 t-linux-gnulibc1
--- config/t-linux-gnulibc1	1997/08/26 00:20:43	1.1.1.1
+++ config/t-linux-gnulibc1	1998/12/11 14:30:53
@@ -1,2 +1,5 @@
 # We are building for the Linux C library 5.
 T_CFLAGS = -DUSE_GNULIBC_1
+
+# No symbol versioning.
+LIBGCC_MAP=
Index: config/linux.h
===================================================================
RCS file: /home/work/cvs/gnu/egcs/gcc/config/linux.h,v
retrieving revision 1.1.1.7
diff -u -r1.1.1.7 linux.h
--- config/linux.h	1998/05/07 16:44:24	1.1.1.7
+++ config/linux.h	1998/12/11 14:36:16
@@ -103,7 +103,7 @@
      %{!profile:%{!ggdb:-lc} %{ggdb:-lg}}}"
 #else
 #define LIB_SPEC \
-  "%{shared: -lc} \
+  "%{shared: -lc --version-script libgcc.map%s} \
    %{!shared: %{mieee-fp:-lieee} %{pthread:-lpthread} \
 	%{profile:-lc_p} %{!profile: -lc}}"
 #endif

