Patch from Stefan Allius to make adding libgcc functions to the library an

option, to avoid the possibility of adding non PIC code into the shared PIC
uClibc library, thereby making the .text segment unshareable.

2 files changed, 35 insertions, 11 deletions

diff --git a/extra/Configs/Config.in b/extra/Configs/Config.in
index 6dd0c4e20..c02c28c8f 100644
--- a/extra/Configs/Config.in
+++ b/extra/Configs/Config.in
@@ -27,6 +27,23 @@ config HAVE_SHARED
 	  answer Y here.  If you only want to build uClibc as a static library,
 	  then answer N.
 
+config ADD_LIBGCC_FUNCTIONS
+	bool "Add unresolved libgcc symbols to uClibc"
+	depends on HAVE_SHARED
+	default n
+	help
+	  If you answer Y here, all unresolved functions provided by the libgcc
+	  library that are used by uClibc will be added directly into the
+	  uClibc library.  If your gcc compiler only provides a static libgcc
+	  library, then enabling this option can reduce the size of your
+	  binaries by preventing these functions from being staticly linked
+	  into every binary.  If you have compiled uClibc as PIC code, one
+	  potential size effect of this option is that you may end up adding
+	  non-PIC libgcc code into your shared uClibc library, resulting in a
+	  non shareable text segment (thereby wasting a bunch of ram).  If your
+	  compiler supports a shared libgcc library, you should certainly leave
+	  this option disabled.  Regardless, the safest answer is N.
+
 config BUILD_UCLIBC_LDSO
 	bool "Compile native shared library loader"
 	depends on HAVE_SHARED
@@ -39,7 +56,7 @@ config BUILD_UCLIBC_LDSO
 
 config FORCE_SHAREABLE_TEXT_SEGMENTS
 	bool "Only load shared libraries which can share their text segment"
-	depends on BUILD_UCLIBC_LDSO && UCLIBC_COMPLETELY_PIC
+	depends on BUILD_UCLIBC_LDSO && UCLIBC_COMPLETELY_PIC && !ADD_LIBGCC_SYMBOLS
 	default n
 	help
 	  If you answer Y here, the uClibc native shared library loader will
diff --git a/libc/Makefile b/libc/Makefile
index 04f8e674e..a9a7e3244 100644
--- a/libc/Makefile
+++ b/libc/Makefile
@@ -36,6 +36,12 @@ else
 CRTOBJS="../../lib/crt0.o"
 endif
 
+ifeq ($(strip $(ADD_LIBGCC_FUNCTIONS)),y)
+LIBGCC_NEED=./tmp/libgcc-need.a
+else
+LIBGCC=
+endif
+
 DIRS = misc pwd_grp stdio string termios inet signal stdlib sysdeps unistd
 
 # Check if the target architecture has a version script for
@@ -54,17 +60,11 @@ ar-target:
 $(LIBNAME): subdirs ar-target
 
 
-shared: $(TOPDIR)lib/$(LIBNAME)
-	@rm -rf tmp
-	@mkdir tmp
-	$(AR) rv ./tmp/libgcc-need.a
-	@(cd tmp && CC=$(CC) LD=$(LD) LDFLAGS=$(CPU_LDFLAGS-y) NM=$(NM) AR=$(AR) \
-		LIBGCC=$(LIBGCC) CRTOBJS=$(CRTOBJS) \
-		/bin/sh $(TOPDIR)../extra/scripts/get-needed-libgcc-objects.sh)
+shared: $(TOPDIR)lib/$(LIBNAME) $(LIBGCC_NEED)
 	$(LD) $(LDFLAGS) $(VERSION_SCRIPT) -soname=$(SHARED_MAJORNAME) -o $(SHARED_FULLNAME) \
-		--whole-archive ./tmp/libgcc-need.a $(LIBNAME) --no-whole-archive \
-		-init __uClibc_init $(TOPDIR)/libc/misc/internals/interp.o \
-		$(LIBGCC)
+		--whole-archive $(LIBGCC_NEED) $(LIBNAME) \
+		$(TOPDIR)/libc/misc/internals/interp.o --no-whole-archive \
+		-init __uClibc_init $(LIBGCC)
 	@true #rm -rf tmp
 	install -d $(TOPDIR)lib
 	rm -f $(TOPDIR)lib/$(SHARED_FULLNAME)
@@ -72,6 +72,13 @@ shared: $(TOPDIR)lib/$(LIBNAME)
 	(cd ../lib && ln -sf $(SHARED_FULLNAME) libc.so);
 	(cd ../lib && ln -sf $(SHARED_FULLNAME) $(SHARED_MAJORNAME));
 
+$(LIBGCC_NEED): $(TOPDIR)lib/$(LIBNAME)
+	@rm -rf tmp
+	@mkdir tmp
+	$(AR) rv $@
+	@(cd tmp && CC=$(CC) LD=$(LD) LDFLAGS=$(CPU_LDFLAGS-y) NM=$(NM) AR=$(AR) \
+		LIBGCC=$(LIBGCC) CRTOBJS=$(CRTOBJS) \
+		/bin/sh $(TOPDIR)../extra/scripts/get-needed-libgcc-objects.sh)
 
 halfclean:
 	@rm -f $(LIBNAME) uClibc_config.h