genode/repos/base/mk/a.mk
Norman Feske 5ae0dab6c5 mk: remove implicit build of shared libraries
This patch removes the implicit build of all shared libraries a target
depends on. Targets only depend on the respective ABIs instead. This
alleviates the need to locally build complex shared libraries (think of
Qt) when developing applications. Instead, application developers can
use binary depot archives.

The implementation splits the mk/lib.mk file into three files:
- mk/a.mk   for building one static library (.lib.a)
- mk/so.mk  for building one shared object  (.lib.so)
- mk/abi.mk for building one ABI stub       (.abi.so)

Furthermore, the commit moves messages and the collection of build
artifacts to var/libdeps, triggers the build of kernel-specific
ld-<kernel>.lib.so, and prunes the lib-dependency tree at ABIs.

Fixes 
2023-11-28 14:44:29 +01:00

101 lines
2.7 KiB
Makefile

##
## Rules for building a static library archive (.lib.a)
##
## The following variables must be passed when calling this file:
##
## LIB - library name
## BASE_DIR - base directory of the build system
## 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 - installation directory for stripped shared objects
## DEBUG_DIR - installation directory for unstripped shared objects
## SHARED_LIBS - shared-library dependencies of the library
## ARCHIVES - archive dependencies of the library
## REP_DIR - repository where the library resides
## CONTRIB_DIR - location of ported 3rd-party source codes
##
LIB_A := $(addsuffix .lib.a,$(LIB))
#
# Prevent <libname>.mk rules to be executed as default rule
#
all:
@true # prevent nothing-to-be-done message
#
# Include common utility functions
#
include $(BASE_DIR)/mk/util.inc
#
# Include specifics, for example platform, kernel-api etc.
#
include $(SPEC_FILES)
ORIG_INC_DIR := $(INC_DIR)
#
# Include library build instructions
#
# We set the 'called_from_lib_mk' variable to allow the library description file
# to respond to the build pass.
#
called_from_lib_mk = yes
include $(LIB_MK)
#
# 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))
#
# Sanity check for INC_DIR overrides
#
ifneq ($(filter-out $(INC_DIR),$(ORIG_INC_DIR)),)
all: error_inc_dir_override
endif
error_inc_dir_override:
@$(ECHO) "Error: INC_DIR overridden instead of appended" ; false
#
# Include global definitions
#
include $(BASE_DIR)/mk/global.mk
include $(BASE_DIR)/mk/generic.mk
#
# Trigger the creation of the <libname>.lib.a
#
LIB_TAG := $(addsuffix .lib.tag,$(LIB))
all: $(LIB_TAG)
#
# Trigger the build of host tools
#
# We make '$(LIB_TAG)' depend on the host tools to support building host tools
# from pseudo libraries with no actual source code. In this case '$(OBJECTS)'
# is empty.
#
$(LIB_TAG) $(OBJECTS): $(HOST_TOOLS)
#
# 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 Qt's meta-object compiler into the Genode
# build system.
#
$(LIB_A): $(OBJECTS)
$(MSG_MERGE)$(LIB_A)
$(VERBOSE)$(RM) -f $@
$(VERBOSE)$(AR) -rcs $@ $(OBJECTS)
$(LIB_TAG): $(CUSTOM_TARGET_DEPS) $(LIB_A)
@touch $@