genode/base/mk/lib.mk
2011-12-22 16:19:25 +01:00

179 lines
4.9 KiB
Makefile

##
## Rules for building a library target
##
## The following variables must be passed when calling this file:
##
## BASE_DIR - base directory of the build system
## REPOSITORIES - repositories providing libs and headers
## VERBOSE - build verboseness modifier
## VERBOSE_DIR - verboseness modifier for changing directories
## VERBOSE_MK - verboseness of make calls
## BUILD_BASE_DIR - base of build directory tree
## LIB_CACHE_DIR - library build cache location
## INSTALL_DIR - program target build directory
## DEPS - library dependencies
## REP_DIR - repository where the library resides
##
#
# Prevent <libname>.mk rules to be executed as default rule
#
all:
#
# Function that searches for files in all
# repositories and returns the first match.
#
select_from_repositories = $(firstword $(foreach REP,$(REPOSITORIES),$(wildcard $(REP)/$(1))))
#
# Include specifics, for example platform, kernel-api etc.
#
include $(SPEC_FILES)
#
# Include library build instructions
#
# We set the 'called_from_lib_mk' variable to allow the library decription file
# to respond to the build pass.
#
BACKUP_INC_DIR := $(INC_DIR)
called_from_lib_mk = yes
include $(LIB_MK)
#
# Sanity check for INC_DIR overrides
#
ifneq ($(filter-out $(INC_DIR),$(BACKUP_INC_DIR)),)
all: error_inc_dir_override
endif
error_inc_dir_override:
@$(ECHO) "Error: $(LIB_MK) overrides INC_DIR instead of appending" ; false
#
# Include lib-import descriptions of all used libraries and the target library
#
include $(foreach LIB,$(LIBS),$(call select_from_repositories,lib/import/import-$(LIB).mk))
#
# Include global definitions
#
include $(BASE_DIR)/mk/global.mk
#
# Name of <libname>.lib.a or <libname>.lib.so file to create
#
ifndef SHARED_LIB
LIB_A := $(addsuffix .lib.a,$(LIB))
LIB_FILENAME := $(LIB_A)
else
LIB_SO := $(addsuffix .lib.so,$(LIB))
INSTALL_SO := $(INSTALL_DIR)/$(LIB_SO)
LIB_FILENAME := $(LIB_SO)
endif
LIB_TAG := $(addsuffix .lib.tag,$(LIB))
#
# Link libgcc to shared libraries
#
# For static libraries, libgcc is not needed because it will be linked
# against the final target.
#
ifdef SHARED_LIB
LIBGCC = $(shell $(CC) $(CC_MARCH) -print-libgcc-file-name)
endif
#
# Build libraries position-independent
#
# This option is required for building shared objects but also for static
# libraries that are (potentially) linked against shared objects. Hence,
# we build all libraries with '-fPIC'.
#
CC_OPT_PIC ?= -fPIC
CC_OPT += $(CC_OPT_PIC)
#
# Print message for the currently built library
#
all: message
message:
$(MSG_LIB)$(LIB)
#
# Trigger the creation of the <libname>.lib.a or <libname>.lib.so file
#
all: $(LIB_TAG)
$(LIB_TAG): $(LIB_A) $(LIB_SO) $(INSTALL_SO)
@touch $@
include $(BASE_DIR)/mk/generic.mk
#
# Rule to build the <libname>.lib.a file
#
# Use $(OBJECTS) instead of $^ for specifying the list of objects to include
# in the archive because $^ may also contain non-object phony targets, e.g.,
# used by the integration of Qt4's meta-object compiler into the Genode
# build system.
#
$(LIB_A): $(OBJECTS)
$(MSG_MERGE)$(LIB_A)
$(VERBOSE)$(AR) -rc $@ $(OBJECTS)
#
# The 'sort' is needed to ensure the same link order regardless
# of the find order, which uses to vary among different systems.
#
STATIC_LIBS := $(foreach l,$(DEPS:.lib=),$(LIB_CACHE_DIR)/$l/$l.lib.a)
STATIC_LIBS := $(sort $(wildcard $(STATIC_LIBS)))
STATIC_LIBS_BRIEF := $(subst $(LIB_CACHE_DIR),$$libs,$(STATIC_LIBS))
#
# Rule to build the <libname>.lib.so file
#
# The 'LIBS' variable may contain static and shared sub libraries. When linking
# the shared library, we have to link all shared sub libraries to the library
# to store the library-dependency information in the library. Because we do not
# know which sub libraries are static or shared prior calling 'build_libs.mk',
# we use an explicit call to the 'lib_so_wildcard' macro to determine the subset
# of libraries that are shared.
#
# The 'ldso-startup/startup.o' object file, which contains the support code for
# constructing static objects must be specified as object file to prevent the
# linker from garbage-collecting it.
#
USED_SHARED_LIBS := $(filter $(DEPS:.lib=),$(SHARED_LIBS))
USED_SO_FILES := $(foreach s,$(USED_SHARED_LIBS),$(LIB_CACHE_DIR)/$s/$s.lib.so)
#
# Don't link ld libary against shared objects
#
USED_SO_FILES := $(filter-out %ld.lib.so,$(USED_SO_FILES))
#
# Default entry point of shared libraries
#
ENTRY_POINT ?= 0x0
$(LIB_SO): $(STATIC_LIBS) $(OBJECTS) $(wildcard $(LD_SCRIPT_SO))
$(MSG_MERGE)$(LIB_SO)
$(VERBOSE)libs=$(LIB_CACHE_DIR); $(LD) -o $(LIB_SO) -shared --eh-frame-hdr \
$(LD_OPT) \
-T $(LD_SCRIPT_SO) \
--entry=$(ENTRY_POINT) \
--whole-archive \
--start-group \
$(USED_SO_FILES) $(STATIC_LIBS_BRIEF) $(OBJECTS) \
--end-group \
--no-whole-archive \
$(LIBGCC)
$(INSTALL_SO):
$(VERBOSE)ln -sf `pwd`/$(LIB_SO) $@