Don't use dlopen() for libebl modules

Currently, architecture-specific code for libebl exists in separate
libebl_$ARCH.so libraries which libebl loads with dlopen() at runtime.
This makes it impossible to have standalone, statically-linked binaries
which use libdwfl if they depend on any architecture-specific
functionality. Additionally, when these libraries cannot be found, the
failure modes are non-obvious. So, let's get rid of libebl_$arch.so and
move it all into libdw.so/libdw.a, which simplifies things considerably.

Signed-off-by: Omar Sandoval <osandov@fb.com>

2 files changed, 21 insertions, 80 deletions

diff --git a/backends/ChangeLog b/backends/ChangeLog
index 3faee13e..3f5f9bb0 100644
--- a/backends/ChangeLog
+++ b/backends/ChangeLog
@@ -2,6 +2,7 @@
 
 	* Makefile.am: Replace libcpu_{i386,x86_64,bpf}.a with libcpu.a.
 	Replace libcpu.a with libcpu_pic.a.
+	Combine libebl_CPU.so modules into libebl_backends{,_pic}.a.
 
 2019-07-13 Mao Han <han_mao@c-sky.com>
 
diff --git a/backends/Makefile.am b/backends/Makefile.am
index be470528..f4052125 100644
--- a/backends/Makefile.am
+++ b/backends/Makefile.am
@@ -28,96 +28,60 @@
 ## the GNU Lesser General Public License along with this program.  If
 ## not, see <http://www.gnu.org/licenses/>.
 include $(top_srcdir)/config/eu.am
+if BUILD_STATIC
+AM_CFLAGS += $(fpic_CFLAGS)
+endif
 AM_CPPFLAGS += -I$(top_srcdir)/libebl -I$(top_srcdir)/libasm \
 	   -I$(top_srcdir)/libelf -I$(top_srcdir)/libdw
 
+noinst_LIBRARIES = libebl_backends.a libebl_backends_pic.a
 
 modules = i386 sh x86_64 ia64 alpha arm aarch64 sparc ppc ppc64 s390 \
 	  tilegx m68k bpf riscv csky
-libebl_pic = libebl_i386_pic.a libebl_sh_pic.a libebl_x86_64_pic.a    \
-	     libebl_ia64_pic.a libebl_alpha_pic.a libebl_arm_pic.a    \
-	     libebl_aarch64_pic.a libebl_sparc_pic.a libebl_ppc_pic.a \
-	     libebl_ppc64_pic.a libebl_s390_pic.a libebl_tilegx_pic.a \
-	     libebl_m68k_pic.a libebl_bpf_pic.a libebl_riscv_pic.a    \
-	     libebl_csky_pic.a
-noinst_LIBRARIES = $(libebl_pic)
-noinst_DATA = $(libebl_pic:_pic.a=.so)
-
-
-libcpu = ../libcpu/libcpu_pic.a
-libelf = ../libelf/libelf.so
-libdw = ../libdw/libdw.so
-libeu = ../lib/libeu.a
 
 i386_SRCS = i386_init.c i386_symbol.c i386_corenote.c i386_cfi.c \
 	    i386_retval.c i386_regs.c i386_auxv.c i386_syscall.c \
 	    i386_initreg.c i386_unwind.c
-libebl_i386_pic_a_SOURCES = $(i386_SRCS)
-am_libebl_i386_pic_a_OBJECTS = $(i386_SRCS:.c=.os)
 
 sh_SRCS = sh_init.c sh_symbol.c sh_corenote.c sh_regs.c sh_retval.c
-libebl_sh_pic_a_SOURCES = $(sh_SRCS)
-am_libebl_sh_pic_a_OBJECTS = $(sh_SRCS:.c=.os)
 
 x86_64_SRCS = x86_64_init.c x86_64_symbol.c x86_64_corenote.c x86_64_cfi.c \
-	      x86_64_retval.c x86_64_regs.c i386_auxv.c x86_64_syscall.c \
-	      x86_64_initreg.c x86_64_unwind.c x32_corenote.c
-libebl_x86_64_pic_a_SOURCES = $(x86_64_SRCS)
-am_libebl_x86_64_pic_a_OBJECTS = $(x86_64_SRCS:.c=.os)
+	      x86_64_retval.c x86_64_regs.c x86_64_syscall.c x86_64_initreg.c \
+	      x86_64_unwind.c x32_corenote.c
+
 
 ia64_SRCS = ia64_init.c ia64_symbol.c ia64_regs.c ia64_retval.c
-libebl_ia64_pic_a_SOURCES = $(ia64_SRCS)
-am_libebl_ia64_pic_a_OBJECTS = $(ia64_SRCS:.c=.os)
 
 alpha_SRCS = alpha_init.c alpha_symbol.c alpha_retval.c alpha_regs.c \
 	     alpha_corenote.c alpha_auxv.c
-libebl_alpha_pic_a_SOURCES = $(alpha_SRCS)
-am_libebl_alpha_pic_a_OBJECTS = $(alpha_SRCS:.c=.os)
 
 arm_SRCS = arm_init.c arm_symbol.c arm_regs.c arm_corenote.c \
 	   arm_auxv.c arm_attrs.c arm_retval.c arm_cfi.c arm_initreg.c
-libebl_arm_pic_a_SOURCES = $(arm_SRCS)
-am_libebl_arm_pic_a_OBJECTS = $(arm_SRCS:.c=.os)
 
 aarch64_SRCS = aarch64_init.c aarch64_regs.c aarch64_symbol.c	\
 	       aarch64_corenote.c aarch64_retval.c aarch64_cfi.c \
 	       aarch64_initreg.c aarch64_unwind.c
-libebl_aarch64_pic_a_SOURCES = $(aarch64_SRCS)
-am_libebl_aarch64_pic_a_OBJECTS = $(aarch64_SRCS:.c=.os)
 
 sparc_SRCS = sparc_init.c sparc_symbol.c sparc_regs.c sparc_retval.c \
 	     sparc_corenote.c sparc64_corenote.c sparc_auxv.c sparc_attrs.c \
              sparc_cfi.c sparc_initreg.c
-libebl_sparc_pic_a_SOURCES = $(sparc_SRCS)
-am_libebl_sparc_pic_a_OBJECTS = $(sparc_SRCS:.c=.os)
 
 ppc_SRCS = ppc_init.c ppc_symbol.c ppc_retval.c ppc_regs.c \
 	   ppc_corenote.c ppc_auxv.c ppc_attrs.c ppc_syscall.c \
 	   ppc_cfi.c ppc_initreg.c
-libebl_ppc_pic_a_SOURCES = $(ppc_SRCS)
-am_libebl_ppc_pic_a_OBJECTS = $(ppc_SRCS:.c=.os)
 
-ppc64_SRCS = ppc64_init.c ppc64_symbol.c ppc64_retval.c \
-	     ppc64_corenote.c ppc_regs.c ppc_auxv.c ppc_attrs.c ppc_syscall.c \
-	     ppc_cfi.c ppc_initreg.c ppc64_unwind.c ppc64_resolve_sym.c
-libebl_ppc64_pic_a_SOURCES = $(ppc64_SRCS)
-am_libebl_ppc64_pic_a_OBJECTS = $(ppc64_SRCS:.c=.os)
+ppc64_SRCS = ppc64_init.c ppc64_symbol.c ppc64_retval.c ppc64_corenote.c \
+	     ppc64_unwind.c ppc64_resolve_sym.c
 
 s390_SRCS = s390_init.c s390_symbol.c s390_regs.c s390_retval.c \
 	    s390_corenote.c s390x_corenote.c s390_cfi.c s390_initreg.c \
 	    s390_unwind.c
-libebl_s390_pic_a_SOURCES = $(s390_SRCS)
-am_libebl_s390_pic_a_OBJECTS = $(s390_SRCS:.c=.os)
 
 tilegx_SRCS = tilegx_init.c tilegx_symbol.c tilegx_regs.c \
               tilegx_retval.c tilegx_corenote.c
-libebl_tilegx_pic_a_SOURCES = $(tilegx_SRCS)
-am_libebl_tilegx_pic_a_OBJECTS = $(tilegx_SRCS:.c=.os)
 
 m68k_SRCS = m68k_init.c m68k_symbol.c m68k_regs.c \
 	    m68k_retval.c m68k_corenote.c m68k_cfi.c m68k_initreg.c
-libebl_m68k_pic_a_SOURCES = $(m68k_SRCS)
-am_libebl_m68k_pic_a_OBJECTS = $(m68k_SRCS:.c=.os)
 
 # m68k prstatus core notes are described by a packed structure
 # which has not naturally aligned fields. Since we don't access
@@ -127,47 +91,23 @@ am_libebl_m68k_pic_a_OBJECTS = $(m68k_SRCS:.c=.os)
 m68k_corenote_no_Wpacked_not_aligned = yes
 
 bpf_SRCS = bpf_init.c bpf_regs.c bpf_symbol.c
-libebl_bpf_pic_a_SOURCES = $(bpf_SRCS)
-am_libebl_bpf_pic_a_OBJECTS = $(bpf_SRCS:.c=.os)
 
 riscv_SRCS = riscv_init.c riscv_symbol.c riscv_cfi.c riscv_regs.c \
 	     riscv_initreg.c riscv_corenote.c riscv64_corenote.c riscv_retval.c
-libebl_riscv_pic_a_SOURCES = $(riscv_SRCS)
-am_libebl_riscv_pic_a_OBJECTS = $(riscv_SRCS:.c=.os)
 
 csky_SRCS = csky_attrs.c csky_init.c csky_symbol.c csky_cfi.c \
 	    csky_regs.c csky_initreg.c csky_corenote.c
-libebl_csky_pic_a_SOURCES = $(csky_SRCS)
-am_libebl_csky_pic_a_OBJECTS = $(csky_SRCS:.c=.os)
-
-libebl_%.so libebl_%.map: libebl_%_pic.a $(libcpu) $(libelf) $(libdw) $(libeu)
-	@rm -f $(@:.so=.map)
-	$(AM_V_at)echo 'ELFUTILS_$(PACKAGE_VERSION) { global: $*_init; local: *; };' \
-	  > $(@:.so=.map)
-	$(AM_V_CCLD)$(LINK) $(dso_LDFLAGS) -o $(@:.map=.so) \
-		-Wl,--whole-archive $< $(libcpu) -Wl,--no-whole-archive \
-		-Wl,--version-script,$(@:.so=.map),--no-undefined \
-		-Wl,--as-needed $(libelf) $(libdw) $(libeu)
-	@$(textrel_check)
-
-install: install-am install-ebl-modules
-install-ebl-modules:
-	$(mkinstalldirs) $(DESTDIR)$(libdir)/$(LIBEBL_SUBDIR)
-	for m in $(modules); do \
-	  $(INSTALL_PROGRAM) libebl_$${m}.so $(DESTDIR)$(libdir)/$(LIBEBL_SUBDIR)/libebl_$${m}-$(PACKAGE_VERSION).so; \
-	  ln -fs libebl_$${m}-$(PACKAGE_VERSION).so $(DESTDIR)$(libdir)/$(LIBEBL_SUBDIR)/libebl_$${m}.so; \
-	done
-
-uninstall: uninstall-am
-	for m in $(modules); do \
-	  rm -f $(DESTDIR)$(libdir)/$(LIBEBL_SUBDIR)/libebl_$${m}-$(PACKAGE_VERSION).so; \
-	  rm -f $(DESTDIR)$(libdir)/$(LIBEBL_SUBDIR)/libebl_$${m}.so; \
-	done
-	rmdir --ignore-fail-on-non-empty $(DESTDIR)$(libdir)/$(LIBEBL_SUBDIR)
+
+libebl_backends_a_SOURCES = $(i386_SRCS) $(sh_SRCS) $(x86_64_SRCS) \
+			    $(ia64_SRCS) $(alpha_SRCS) $(arm_SRCS) \
+			    $(aarch64_SRCS) $(sparc_SRCS) $(ppc_SRCS) \
+			    $(ppc64_SRCS) $(s390_SRCS) $(tilegx_SRCS) \
+			    $(m68k_SRCS) $(bpf_SRCS) $(riscv_SRCS) $(csky_SRCS)
+
+libebl_backends_pic_a_SOURCES =
+am_libebl_backends_pic_a_OBJECTS = $(libebl_backends_a_SOURCES:.c=.os)
 
 noinst_HEADERS = libebl_CPU.h common-reloc.c linux-core-note.c x86_corenote.c
-EXTRA_DIST = $(foreach m,$(modules),$($(m)_SRCS)) $(modules:=_reloc.def)
+EXTRA_DIST = $(modules:=_reloc.def)
 
-CLEANFILES += $(foreach m,$(modules),\
-			libebl_$(m).map libebl_$(m).so \
-			$(am_libebl_$(m)_pic_a_OBJECTS))
+MOSTLYCLEANFILES = $(am_libebl_backends_pic_a_OBJECTS)