Support building shared libraries on OS/2

Change-Id: I5750db0504cb69ead52f9f44bf583e693bffbb7e

build/make/Makefile

@@ -310,6 +310,18 @@ $(1):
         $$(filter %.o,$$^) $$(extralibs)
 endef
 
+define dll_template
+# Not using a pattern rule here because we don't want to generate empty
+# archives when they are listed as a dependency in files not responsible
+# for creating them.
+$(1):
+	$(if $(quiet),@echo "    [LD] $$@")
+	$(qexec)$$(LD) -Zdll $$(LDFLAGS) \
+        -o $$@ \
+        $$(filter %.o,$$^) $$(extralibs) $$(EXPORTS_FILE)
+endef
+
+
 #
 # Get current configuration
 #
@@ -367,6 +379,7 @@ LIBS=$(call enabled,LIBS)
 $(foreach lib,$(filter %_g.a,$(LIBS)),$(eval $(call archive_template,$(lib))))
 $(foreach lib,$(filter %so.$(SO_VERSION_MAJOR).$(SO_VERSION_MINOR).$(SO_VERSION_PATCH),$(LIBS)),$(eval $(call so_template,$(lib))))
 $(foreach lib,$(filter %$(SO_VERSION_MAJOR).dylib,$(LIBS)),$(eval $(call dl_template,$(lib))))
+$(foreach lib,$(filter %$(SO_VERSION_MAJOR).dll,$(LIBS)),$(eval $(call dll_template,$(lib))))
 
 INSTALL-LIBS=$(call cond_enabled,CONFIG_INSTALL_LIBS,INSTALL-LIBS)
 ifeq ($(MAKECMDGOALS),dist)

configure

@@ -494,11 +494,11 @@ process_detect() {
         # Can only build shared libs on a subset of platforms. Doing this check
         # here rather than at option parse time because the target auto-detect
         # magic happens after the command line has been parsed.
-        if ! enabled linux; then
+        if ! enabled linux && ! enabled os2; then
             if enabled gnu; then
                 echo "--enable-shared is only supported on ELF; assuming this is OK"
             else
-                die "--enable-shared only supported on ELF for now"
+                die "--enable-shared only supported on ELF and OS/2 for now"
             fi
         fi
     fi

examples.mk

@@ -281,7 +281,15 @@ BINS-$(NOT_MSVS)           += $(addprefix $(BUILD_PFX),$(ALL_EXAMPLES:.c=$(EXE_S
 
 # Instantiate linker template for all examples.
 CODEC_LIB=$(if $(CONFIG_DEBUG_LIBS),vpx_g,vpx)
-SHARED_LIB_SUF=$(if $(filter darwin%,$(TGT_OS)),.dylib,.so)
+ifneq ($(filter darwin%,$(TGT_OS)),)
+SHARED_LIB_SUF=.dylib
+else
+ifneq ($(filter os2%,$(TGT_OS)),)
+SHARED_LIB_SUF=_dll.a
+else
+SHARED_LIB_SUF=.so
+endif
+endif
 CODEC_LIB_SUF=$(if $(CONFIG_SHARED),$(SHARED_LIB_SUF),.a)
 $(foreach bin,$(BINS-yes),\
     $(eval $(bin):$(LIB_PATH)/lib$(CODEC_LIB)$(CODEC_LIB_SUF))\

libs.mk

@@ -228,19 +228,30 @@ SO_VERSION_MINOR := 0
 SO_VERSION_PATCH := 0
 ifeq ($(filter darwin%,$(TGT_OS)),$(TGT_OS))
 LIBVPX_SO               := libvpx.$(SO_VERSION_MAJOR).dylib
+SHARED_LIB_SUF          := .dylib
 EXPORT_FILE             := libvpx.syms
 LIBVPX_SO_SYMLINKS      := $(addprefix $(LIBSUBDIR)/, \
                              libvpx.dylib  )
 else
+ifeq ($(filter os2%,$(TGT_OS)),$(TGT_OS))
+LIBVPX_SO               := libvpx$(SO_VERSION_MAJOR).dll
+SHARED_LIB_SUF          := _dll.a
+EXPORT_FILE             := libvpx.def
+LIBVPX_SO_SYMLINKS      :=
+LIBVPX_SO_IMPLIB        := libvpx_dll.a
+else
 LIBVPX_SO               := libvpx.so.$(SO_VERSION_MAJOR).$(SO_VERSION_MINOR).$(SO_VERSION_PATCH)
+SHARED_LIB_SUF          := .so
 EXPORT_FILE             := libvpx.ver
 LIBVPX_SO_SYMLINKS      := $(addprefix $(LIBSUBDIR)/, \
                              libvpx.so libvpx.so.$(SO_VERSION_MAJOR) \
                              libvpx.so.$(SO_VERSION_MAJOR).$(SO_VERSION_MINOR))
 endif
+endif
 
 LIBS-$(CONFIG_SHARED) += $(BUILD_PFX)$(LIBVPX_SO)\
-                           $(notdir $(LIBVPX_SO_SYMLINKS))
+                           $(notdir $(LIBVPX_SO_SYMLINKS)) \
+                           $(if $(LIBVPX_SO_IMPLIB), $(BUILD_PFX)$(LIBVPX_SO_IMPLIB))
 $(BUILD_PFX)$(LIBVPX_SO): $(LIBVPX_OBJS) $(EXPORT_FILE)
 $(BUILD_PFX)$(LIBVPX_SO): extralibs += -lm
 $(BUILD_PFX)$(LIBVPX_SO): SONAME = libvpx.so.$(SO_VERSION_MAJOR)
@@ -258,6 +269,19 @@ libvpx.syms: $(call enabled,CODEC_EXPORTS)
 	$(qexec)awk '{print "_"$$2}' $^ >$@
 CLEAN-OBJS += libvpx.syms
 
+libvpx.def: $(call enabled,CODEC_EXPORTS)
+	@echo "    [CREATE] $@"
+	$(qexec)echo LIBRARY $(LIBVPX_SO:.dll=) INITINSTANCE TERMINSTANCE > $@
+	$(qexec)echo "DATA MULTIPLE NONSHARED" >> $@
+	$(qexec)echo "EXPORTS" >> $@
+	$(qexec)awk '!/vpx_svc_*/ {print "_"$$2}' $^ >>$@
+CLEAN-OBJS += libvpx.def
+
+libvpx_dll.a: $(LIBVPX_SO)
+	@echo "    [IMPLIB] $@"
+	$(qexec)emximp -o $@ $<
+CLEAN-OBJS += libvpx_dll.a
+
 define libvpx_symlink_template
 $(1): $(2)
 	@echo "    [LN]     $(2) $$@"
@@ -275,6 +299,7 @@ $(eval $(call libvpx_symlink_template,\
 
 INSTALL-LIBS-$(CONFIG_SHARED) += $(LIBVPX_SO_SYMLINKS)
 INSTALL-LIBS-$(CONFIG_SHARED) += $(LIBSUBDIR)/$(LIBVPX_SO)
+INSTALL-LIBS-$(CONFIG_SHARED) += $(if $(LIBVPX_SO_IMPLIB),$(LIBSUBDIR)/$(LIBVPX_SO_IMPLIB))
 
 
 LIBS-yes += vpx.pc
@@ -454,7 +479,7 @@ OBJS-yes += $(LIBVPX_TEST_OBJS)
 BINS-yes += $(LIBVPX_TEST_BIN)
 
 CODEC_LIB=$(if $(CONFIG_DEBUG_LIBS),vpx_g,vpx)
-CODEC_LIB_SUF=$(if $(CONFIG_SHARED),.so,.a)
+CODEC_LIB_SUF=$(if $(CONFIG_SHARED),$(SHARED_LIB_SUF),.a)
 TEST_LIBS := lib$(CODEC_LIB)$(CODEC_LIB_SUF) libgtest.a
 $(LIBVPX_TEST_BIN): $(TEST_LIBS)
 $(eval $(call linkerxx_template,$(LIBVPX_TEST_BIN), \

vpx/exports_dec

 text vpx_codec_dec_init_ver
 text vpx_codec_decode
 text vpx_codec_get_frame
-text vpx_codec_get_mem_map
 text vpx_codec_get_stream_info
 text vpx_codec_peek_stream_info
 text vpx_codec_register_put_frame_cb
 text vpx_codec_register_put_slice_cb
 text vpx_codec_set_frame_buffer_functions
-text vpx_codec_set_mem_map