genode/repos/base/mk/lib.mk
Norman Feske 4769e05626 mk: abi does not depend shared-lib dependencies
This patch cuts the superfluous dependency of abi.so files from the
library dependencies of the corresponding lib.so file. ABIs depend
only on symbol files.

Prior this patch, the second step of the following sequence would
wrongly re-build the abi.so file.

  arm_v6$ make init
  arm_v6$ make init KERNEL=hw

As the KERNEL argument does not affect the ABI, the abi.so should
better not be created twice.

Issue #4408
2022-02-21 15:44:22 +01:00

254 lines
7.2 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 - 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
##
include $(BASE_DIR)/mk/base-libs.mk
#
# Prevent <libname>.mk rules to be executed as default rule
#
all:
#
# Include common utility functions
#
include $(BASE_DIR)/mk/util.inc
#
# 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 description 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 $(BASE_DIR)/mk/global.mk
ifneq ($(SYMBOLS),)
SHARED_LIB := yes
endif
#
# If a symbol list is provided, we create an ABI stub named '<lib>.abi.so'
#
# The ABI-stub library does not contain any code or data but only the symbol
# information of the binary interface (ABI) of the shared library.
#
# The ABI stub is linked by the users of the library (executables or shared
# objects) instead of the real library. This effectively decouples the library
# users from the concrete library instance but binds them merely to the
# library's binary interface. Note that the ABI stub is not used at runtime at
# all. At runtime, the real library that implements the ABI is loaded by the
# dynamic linker.
#
# The symbol information are incorporated into the ABI stub via an assembly
# file named '<lib>.symbols.s' that is generated from the library's symbol
# list. We create a symbolic link from the symbol file to the local directory.
# By using '.symbols' as file extension, the pattern rule '%.symbols.s:
# %.symbols' defined in 'generic.mk' is automatically applied for creating the
# assembly file from the symbols file.
#
# The '.PRECIOUS' special target prevents make to remove the intermediate
# assembler file. Otherwise make would spill the build log with messages
# like "rm libc.symbols.s".
#
ifneq ($(SYMBOLS),)
ABI_SO := $(addsuffix .abi.so,$(LIB))
ABI_SONAME := $(addsuffix .lib.so,$(LIB))
$(LIB).symbols:
$(VERBOSE)ln -sf $(SYMBOLS) $@
.PRECIOUS: $(LIB).symbols.s
endif
#
# 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
#
# Print message for the currently built library
#
all: message
message:
$(MSG_LIB)$(LIB)
include $(BASE_DIR)/mk/generic.mk
#
# Name of <libname>.lib.a or <libname>.lib.so file to create
#
# Skip the creation and installation of an .so file if there are no
# ingredients. This is the case if the library is present as ABI only.
#
ifdef SHARED_LIB
ifneq ($(sort $(OBJECTS) $(LIBS)),)
LIB_SO := $(addsuffix .lib.so,$(LIB))
INSTALL_SO := $(INSTALL_DIR)/$(LIB_SO)
DEBUG_SO := $(DEBUG_DIR)/$(LIB_SO)
endif
else
LIB_A := $(addsuffix .lib.a,$(LIB))
endif
#
# Whenever an ABI is defined for a shared library, we check the consistency
# between both by invoking the 'check_abi' tool via the 'LIB_CHECKED'
# dependency.
#
ifneq ($(LIB_SO),)
ifneq ($(ABI_SO),)
LIB_CHECKED := $(addsuffix .lib.checked,$(LIB))
endif
endif
#
# Trigger the creation of the <libname>.lib.a or <libname>.lib.so file
#
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)
#
# Trigger build of additional library specific targets
#
$(LIB_TAG): $(CUSTOM_TARGET_DEPS)
$(LIB_TAG): $(LIB_A) $(LIB_SO) $(LIB_CHECKED) $(ABI_SO) $(INSTALL_SO) $(DEBUG_SO)
@touch $@
#
# 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 $@ $(OBJECTS)
#
# Link ldso-support library to each shared library to provide local hook
# functions for constructors and ARM
#
ifdef SHARED_LIB
override ARCHIVES += ldso_so_support.lib.a
endif
#
# Don't link base libraries against shared libraries except for ld.lib.so
#
ifneq ($(LIB_IS_DYNAMIC_LINKER),yes)
override ARCHIVES := $(filter-out $(BASE_LIBS:=.lib.a),$(ARCHIVES))
endif
#
# The 'sort' is needed to ensure the same link order regardless
# of the find order, which uses to vary among different systems.
#
STATIC_LIBS := $(sort $(foreach l,$(ARCHIVES:.lib.a=),$(LIB_CACHE_DIR)/$l/$l.lib.a))
STATIC_LIBS_BRIEF := $(subst $(LIB_CACHE_DIR),$$libs,$(STATIC_LIBS))
#
# Rule to build the <libname>.lib.so file
#
# When linking the shared library, we have to link all shared sub libraries
# (LIB_SO_DEPS) to the library to store the library-dependency information in
# the generated shared object.
#
#
# Default entry point of shared libraries
#
ENTRY_POINT ?= 0x0
$(LIB_SO): $(SHARED_LIBS)
$(LIB_SO): $(STATIC_LIBS) $(OBJECTS) $(wildcard $(LD_SCRIPT_SO)) $(LIB_SO_DEPS)
$(MSG_MERGE)$(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 \
$(SHARED_LIBS) $(STATIC_LIBS_BRIEF) $(OBJECTS) \
--end-group --no-whole-archive \
$(LIBGCC)
$(ABI_SO): $(LIB).symbols.o
$(MSG_MERGE)$(ABI_SO)
$(VERBOSE)$(LD) -o $(ABI_SO) -soname=$(ABI_SONAME) -shared --eh-frame-hdr $(LD_OPT) \
-T $(LD_SCRIPT_SO) \
--whole-archive --start-group \
$(LIB_SO_DEPS) $< \
--end-group --no-whole-archive
$(LIB_CHECKED): $(LIB_SO) $(SYMBOLS)
$(VERBOSE)$(BASE_DIR)/../../tool/check_abi $(LIB_SO) $(SYMBOLS) && touch $@
$(LIB_SO).stripped: $(LIB_SO)
$(VERBOSE)$(STRIP) -o $@ $<
$(DEBUG_SO): $(LIB_SO)
$(VERBOSE)ln -sf $(CURDIR)/$< $@
$(INSTALL_SO): $(LIB_SO).stripped
$(VERBOSE)ln -sf $(CURDIR)/$< $@