From f0594a6f357ec2fe2ebef775a7bf1569f1414749 Mon Sep 17 00:00:00 2001
From: Michal Sojka <sojkam1@fel.cvut.cz>
Date: Wed, 29 Oct 2008 09:17:00 +0000
Subject: [PATCH] Added experimental support for shared library dependencies

In fact, I'm not sure, whether dependency of shared libraries is the
real problem. Currently, the problem appears if a shared library depends
on a static library. Then this static library must be created before the
shared one.

This change adds a new link-pseudo-pass, which is called after
library-pass and before binary-pass. This "pseudo" pass doesn't traverse
directories recursively, but instead it processes *.omkvar files
prepared during library-pass. Since the shared libraries are linked
after the static ones, we have no problems with dependencies described
in the previous paragraph.

In future, we will extend this approach to linking of libraries,
binaries and maybe even kernel modules. This allows to save at least
binary-pass and the compilation will be faster.

darcs-hash:20081029091745-f2ef6-daa7a8825364b2bbc40f1f00bfd51dd6676ea4d3.gz
---
 snippets/linux | 41 +++++++++++++++++++++++++++++++++--------
 1 file changed, 33 insertions(+), 8 deletions(-)

diff --git a/snippets/linux b/snippets/linux
index 57f43b8..c3b552b 100644
--- a/snippets/linux
+++ b/snippets/linux
@@ -136,6 +136,7 @@ endif
 
 USER_OBJS_DIR = $(USER_BUILD_DIR)/$(RELATIVE_DIR)
 KERN_OBJS_DIR = $(KERN_BUILD_DIR)/$(RELATIVE_DIR)
+OMK_WORK_DIR  = $(USER_OBJS_DIR)
 
 .PHONY: dep subdirs clean clean-custom cleandepend check-dir
 
@@ -143,7 +144,7 @@ KERN_OBJS_DIR = $(KERN_BUILD_DIR)/$(RELATIVE_DIR)
 ifneq ($(OMK_SERIALIZE_INCLUDED),y)
 include-pass: check-dir
 library-pass: include-pass
-binary-pass: library-pass
+binary-pass: library-pass link-pseudo-pass
 kernel-lib-pass: include-pass
 kernel-mod-pass: kernel-lib-pass
 kernel-modpost-pass: kernel-mod-pass
@@ -311,6 +312,7 @@ $(USER_LIB_DIR)/lib$(1).a: $$($(1)_OBJS)
 	$(Q) $(AR) rcs $$@ $$^
 endef
 
+.PHONY: FORCE
 
 # Syntax: $(call SOLIB_template,<library-name>)
 define SOLIB_template
@@ -332,15 +334,15 @@ $(1)_OBJSLO := $$(sort $$($(1)_OBJSLO:%/=%))
 SOLIB_OBJS  += $$($(1)_OBJSLO)
 SOLIB_SOURCES += $$($(1)_SOURCES)
 
-$(USER_LIB_DIR)/lib$(1).$(SOLIB_EXT): $$($(1)_OBJSLO)
-	@$(QUIET_CMD_ECHO) "  LINK    $$@"
-	$(Q) $(CC) --shared -Xlinker -soname=lib$(1).$(SOLIB_EXT) -o $$@ $$^ $$(LOADLIBES) $$($(1)_LIBS:%=-l%)
+$(OMK_WORK_DIR)/lib$(1).$(SOLIB_EXT).omkvar: $$($(1)_OBJSLO) FORCE
+	$(Q)echo '$(1)_objslo += $$$$(addprefix $(USER_OBJS_DIR)/,$$($(1)_OBJSLO))' > $$@.tmp; \
+	    echo '$(1)_libs += $$($(1)_LIBS) $$(lib_LOADLIBES)' >> $$@.tmp; \
+	    echo 'shared_libs := $$$$(sort $(1) $$$$(shared_libs))' >> $$@.tmp; \
+	    if cmp -s $$@.tmp $$@; then rm $$@.tmp; else mv $$@.tmp $$@; fi
 endef
 
-
-
 library-pass-local: $(addprefix $(USER_INCLUDE_DIR)/,$(cmetric_include_HEADERS)) \
-		    $(lib_LIBRARIES:%=$(USER_LIB_DIR)/lib%.a) $(shared_LIBRARIES:%=$(USER_LIB_DIR)/lib%.$(SOLIB_EXT))
+		    $(lib_LIBRARIES:%=$(USER_LIB_DIR)/lib%.a) $(shared_LIBRARIES:%=$(OMK_WORK_DIR)/lib%.$(SOLIB_EXT).omkvar)
 
 binary-pass-local: $(bin_PROGRAMS:%=$(USER_BIN_DIR)/%$(EXE_SUFFIX)) $(utils_PROGRAMS:%=$(USER_UTILS_DIR)/%$(EXE_SUFFIX)) $(test_PROGRAMS:%=$(USER_TESTS_DIR)/%$(EXE_SUFFIX))
 
@@ -371,7 +373,30 @@ $(foreach lib,$(shared_LIBRARIES),$(eval $(call SOLIB_template,$(lib))))
 
 -include $(USER_OBJS_DIR)/*.d
 
-endif
+endif # USER_RULE_TEMPLATES
+
+.PHONY: link-pseudo-pass
+link-pseudo-pass:
+	$(Q)$(MAKE) $(NO_PRINT_DIRECTORY) -C $(USER_BUILD_DIR) -f $(SOURCESDIR_MAKEFILE) link-shared-libs
+
+ifeq ($(MAKECMDGOALS),link-shared-libs)
+
+# Syntax: $(call solib_link_template,<library-name>)
+define solib_link_template
+$(1)_shared_libs = $$(patsubst %,$(USER_LIB_DIR)/lib%.$(SOLIB_EXT),$$(filter $$(shared_libs),$$($(1)_libs)))
+#$$(warning $(1)_shared_libs = $$($(1)_shared_libs))
+$(USER_LIB_DIR)/lib$(1).$(SOLIB_EXT): $$($(1)_shared_libs) $$($(1)_objslo)
+	@$(QUIET_CMD_ECHO) "  LINK    $$@"
+	$(Q) $(CC) --shared -Xlinker -soname=lib$(1).$(SOLIB_EXT) -o $$@ $$($(1)_objslo) $$(LOADLIBES) $$($(1)_libs:%=-l%)
+endef
+
+-include $(shell find $(USER_BUILD_DIR) -name 'lib*.omkvar')
+#$(warning $(shared_libs))
+$(foreach lib,$(shared_libs),$(eval $(call solib_link_template,$(lib))))
+
+.PHONY: link-shared-libs
+link-shared-libs: $(shared_libs:%=$(USER_LIB_DIR)/lib%.$(SOLIB_EXT))
+endif # link-shared-libs
 
 #=====================================================================
 # Kernel-space rules and templates to compile modules, libraries etc.
-- 
2.39.2