arm-trusted-firmware/make_helpers/toolchain.mk
Chris Kay 2f1c5e7eb1 build: use GCC to link by default
When configuring GNU GCC as the C compiler, we usually use the GNU BFD
linker directly to link by default. However, this complicates things
because we also need to support LTO, which can only be done when linking
is done via the C compiler, and we cannot change the linker later on if
some other part of the build system wants to enable LTO.

This change migrates the default choice of linker to GCC if the C
compiler is GCC, in order to enable this use-case. This should have no
impact on anything outside of the build system, as by default GCC merely
acts as a wrapper around BFD.

Change-Id: I40771be2b0571def67bbfde9e877e7629ec8cdaa
Signed-off-by: Chris Kay <chris.kay@arm.com>
2024-04-02 09:52:17 +00:00

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#
# Copyright (c) 2023-2024, Arm Limited and Contributors. All rights reserved.
#
# SPDX-License-Identifier: BSD-3-Clause
#
#
# TF-A uses three toolchains:
#
# - The host toolchain (`host`) for building native tools
#  - The AArch32 toolchain (`aarch32`) for building Arm AArch32 images
# - The AArch64 toolchain (`aarch64`) for building Arm AArch64 images
#
# In the main Makefile only one of the two Arm toolchains is enabled in any
# given build, but individual tools and libraries may need access to both.
#
toolchains ?= host $(ARCH)
ifneq ($(filter host,$(toolchains)),)
host-cc := $(HOSTCC)
host-cpp := $(HOSTCPP)
host-as := $(HOSTAS)
host-ld := $(HOSTLD)
host-oc := $(HOSTOC)
host-od := $(HOSTOD)
host-ar := $(HOSTAR)
host-dtc := $(HOSTDTC)
endif
ifneq ($(filter aarch32,$(toolchains)),)
aarch32-cc := $(if $(filter-out default,$(origin CC)),$(CC))
aarch32-cpp := $(if $(filter-out default,$(origin CPP)),$(CPP))
aarch32-as := $(if $(filter-out default,$(origin AS)),$(AS))
aarch32-ld := $(if $(filter-out default,$(origin LD)),$(LD))
aarch32-oc := $(if $(filter-out default,$(origin OC)),$(OC))
aarch32-od := $(if $(filter-out default,$(origin OD)),$(OD))
aarch32-ar := $(if $(filter-out default,$(origin AR)),$(AR))
aarch32-dtc := $(if $(filter-out default,$(origin DTC)),$(DTC))
endif
ifneq ($(filter aarch64,$(toolchains)),)
aarch64-cc := $(if $(filter-out default,$(origin CC)),$(CC))
aarch64-cpp := $(if $(filter-out default,$(origin CPP)),$(CPP))
aarch64-as := $(if $(filter-out default,$(origin AS)),$(AS))
aarch64-ld := $(if $(filter-out default,$(origin LD)),$(LD))
aarch64-oc := $(if $(filter-out default,$(origin OC)),$(OC))
aarch64-od := $(if $(filter-out default,$(origin OD)),$(OD))
aarch64-ar := $(if $(filter-out default,$(origin AR)),$(AR))
aarch64-dtc := $(if $(filter-out default,$(origin DTC)),$(DTC))
endif
include $(dir $(lastword $(MAKEFILE_LIST)))build_env.mk
include $(addprefix $(dir $(lastword $(MAKEFILE_LIST)))toolchains/, \
$(addsuffix .mk,$(toolchains)))
#
# Configure tool classes that we recognize.
#
# In the context of this build system, a tool class identifies a specific role
# or type of tool in the toolchain.
#
# C-related tools
tool-classes := cc # C compilers
tool-classes += cpp # C preprocessors
# Assembly-related tools
tool-classes += as # Assemblers
# Linking and object-handling tools
tool-classes += ld # Linkers
tool-classes += oc # Object copiers
tool-classes += od # Object dumpers
tool-classes += ar # Archivers
# Other tools
tool-classes += dtc # Device tree compilers
#
# Configure tools that we recognize.
#
# Here we declare the list of specific toolchain tools that we know how to
# interact with. We don't organize these into tool classes yet - that happens
# further down.
#
# Arm Compiler for Embedded
tools := arm-clang # armclang
tools += arm-link # armlink
tools += arm-ar # armar
tools += arm-fromelf # fromelf
# LLVM Project
tools += llvm-clang # clang
tools += llvm-lld # lld
tools += llvm-objcopy # llvm-objcopy
tools += llvm-objdump # llvm-objdump
tools += llvm-ar # llvm-ar
# GNU Compiler Collection & GNU Binary Utilities
tools += gnu-gcc # gcc
tools += gnu-ld # ld
tools += gnu-objcopy # objcopy
tools += gnu-objdump # objdump
tools += gnu-ar # gcc-ar
# Other tools
tools += dtc # Device Tree Compiler
#
# Assign tools to tool classes.
#
# Multifunctional tools, i.e. tools which can perform multiple roles in a
# toolchain, may be specified in multiple tool class lists. For example, a C
# compiler which can also perform the role of a linker may be placed in both
# `tools-cc` and `tools-ld`.
#
# C-related tools
tools-cc := arm-clang llvm-clang gnu-gcc # C compilers
tools-cpp := arm-clang llvm-clang gnu-gcc # C preprocessors
# Assembly-related tools
tools-as := arm-clang llvm-clang gnu-gcc # Assemblers
# Linking and object-handling tools
tools-ld := arm-clang arm-link llvm-clang llvm-lld gnu-gcc gnu-ld # Linkers
tools-oc := arm-fromelf llvm-objcopy gnu-objcopy # Object copiers
tools-od := arm-fromelf llvm-objdump gnu-objdump # Object dumpers
tools-ar := arm-ar llvm-ar gnu-ar # Archivers
# Other tools
tools-dtc := dtc # Device tree compilers
define check-tool-class-tools
$(eval tool-class := $(1))
ifndef tools-$(tool-class)
$$(error no tools registered to handle tool class `$(tool-class)`)
endif
endef
$(foreach tool-class,$(tool-classes), \
$(eval $(call check-tool-class-tools,$(tool-class))))
#
# Default tools for each toolchain.
#
# Toolchains can specify a default path to any given tool with a tool class.
# These values are used in the absence of user-specified values, and are
# configured by the makefile for each toolchain using variables of the form:
#
# - $(toolchain)-$(tool-class)-default
#
# For example, the default C compiler for the AArch32 and AArch64 toolchains
# could be configured with:
#
# - aarch32-cc-default
# - aarch64-cc-default
#
define check-toolchain-tool-class-default
$(eval toolchain := $(1))
$(eval tool-class := $(2))
ifndef $(toolchain)-$(tool-class)-default
$$(error no default value specified for tool class `$(tool-class)` of toolchain `$(toolchain)`)
endif
endef
define check-toolchain-tool-class-defaults
$(eval toolchain := $(1))
$(foreach tool-class,$(tool-classes), \
$(eval $(call check-toolchain-tool-class-default,$(toolchain),$(tool-class))))
endef
$(foreach toolchain,$(toolchains), \
$(eval $(call check-toolchain-tool-class-defaults,$(toolchain))))
#
# Helper functions to identify toolchain tools.
#
# The functions defined in this section return a tool identifier when given a
# path to a binary. We generally check a help or version string to more reliably
# identify tools than by looking at the path alone (e.g. `gcc` on macOS is
# actually Apple Clang).
#
# Each tool-guessing function (`guess-tool-$(tool)`) takes a single argument
# giving the path to the tool to guess, and returns a non-empty value if the
# tool corresponds to the tool identifier `$(tool)`:
#
# $(call guess-tool-llvm-clang,aarch64-none-elf-gcc) # <empty>
# $(call guess-tool-gnu-gcc,aarch64-none-elf-gcc) # <non-empty>
#
# The `guess-tool` function tries to find the corresponding tool identifier
# for a tool given its path. It takes two arguments:
#
# - $(1): a list of candidate tool identifiers to check
# - $(2): the path to the tool to identify
#
# If any of the guess functions corresponding to candidate tool identifiers
# return a non-empty value then the tool identifier of the first function to do
# so is returned:
#
# $(call guess-tool,gnu-gcc llvm-clang,armclang) # <empty>
# $(call guess-tool,gnu-gcc llvm-clang,clang-14) # llvm-clang
# $(call guess-tool,gnu-gcc llvm-clang,aarch64-none-elf-gcc-12) # gnu-gcc
#
# Tools are checked in the order that they appear in `tools-$(tool-class)`, and
# the first match is returned.
#
# Arm Compiler for Embedded
guess-tool-arm-clang = $(shell $(1) --version 2>&1 | grep -o "Tool: armclang")
guess-tool-arm-link = $(shell $(1) --help 2>&1 | grep -o "Tool: armlink")
guess-tool-arm-fromelf = $(shell $(1) --help 2>&1 | grep -o "Tool: fromelf")
guess-tool-arm-ar = $(shell $(1) --version 2>&1 | grep -o "Tool: armar")
# LLVM Project
guess-tool-llvm-clang = $(shell $(1) -v 2>&1 | grep -o "clang version")
guess-tool-llvm-lld = $(shell $(1) --help 2>&1 | grep -o "OVERVIEW: lld")
guess-tool-llvm-objcopy = $(shell $(1) --help 2>&1 | grep -o "llvm-objcopy tool")
guess-tool-llvm-objdump = $(shell $(1) --help 2>&1 | grep -o "llvm object file dumper")
guess-tool-llvm-ar = $(shell $(1) --help 2>&1 | grep -o "LLVM Archiver")
# GNU Compiler Collection & GNU Binary Utilities
guess-tool-gnu-gcc = $(shell $(1) -v 2>&1 | grep -o "gcc version")
guess-tool-gnu-ld = $(shell $(1) -v 2>&1 | grep -o "GNU ld")
guess-tool-gnu-objcopy = $(shell $(1) --version 2>&1 | grep -o "GNU objcopy")
guess-tool-gnu-objdump = $(shell $(1) --version 2>&1 | grep -o "GNU objdump")
guess-tool-gnu-ar = $(shell $(1) --version 2>&1 | grep -o "GNU ar")
# Other tools
guess-tool-dtc = $(shell $(1) --version 2>&1 | grep -o "Version: DTC")
guess-tool = $(firstword $(foreach candidate,$(1), \
$(if $(call guess-tool-$(candidate),$(2)),$(candidate))))
#
# Locate and identify tools belonging to each toolchain.
#
# Each tool class in each toolchain receives a variable of the form
# `$(toolchain)-$(tool)` giving the associated path to the program. For example:
#
# - `aarch64-ld` gives the linker for the AArch64 toolchain,
# - `aarch32-oc` gives the object copier for the AArch32 toolchain, and
# - `host-cc` gives the C compiler for the host toolchain.
#
# For each of these variables, if no program path is explicitly provided by the
# parent Makefile then the C compiler is queried (if supported) for its
# location. This is done via the `guess-$(tool)-$(tool-class)` set of functions.
# For example:
#
# - `guess-arm-clang-ld` guesses the linker via Arm Clang,
# - `guess-llvm-clang-as` guesses the assembler via LLVM Clang, and
# - `guess-gnu-gcc-od` guesses the object dumper via GNU GCC.
#
# If the C compiler cannot provide the location (or the tool class is the C
# compiler), then it is assigned the value of the `$(toolchain)-$(tool)-default`
# variable.
#
guess-arm-clang-cpp = $(1) # Use the C compiler
guess-arm-clang-as = $(1) # Use the C compiler
guess-arm-clang-ld = # Fall back to `$(toolchain)-ld-default`
guess-arm-clang-oc = # Fall back to `$(toolchain)-oc-default`
guess-arm-clang-od = # Fall back to `$(toolchain)-od-default`
guess-arm-clang-ar = # Fall back to `$(toolchain)-ar-default`
guess-llvm-clang-cpp = $(1) # Use the C compiler
guess-llvm-clang-as = $(1) # Use the C compiler
guess-llvm-clang-ld = $(shell $(1) --print-prog-name ld.lld 2>$(nul))
guess-llvm-clang-oc = $(shell $(1) --print-prog-name llvm-objcopy 2>$(nul))
guess-llvm-clang-od = $(shell $(1) --print-prog-name llvm-objdump 2>$(nul))
guess-llvm-clang-ar = $(shell $(1) --print-prog-name llvm-ar 2>$(nul))
guess-gnu-gcc-cpp = $(1) # Use the C compiler
guess-gnu-gcc-as = $(1) # Use the C compiler
guess-gnu-gcc-ld = $(1) # Use the C compiler
guess-gnu-gcc-oc = $(shell $(1) --print-prog-name objcopy 2>$(nul))
guess-gnu-gcc-od = $(shell $(1) --print-prog-name objdump 2>$(nul))
guess-gnu-gcc-ar = $(patsubst %$(notdir $(1)),%$(subst gcc,gcc-ar,$(notdir $(1))),$(1))
define locate-toolchain-tool-cc
$(eval toolchain := $(1))
$(toolchain)-cc := $$(strip \
$$(or $$($(toolchain)-cc),$$($(toolchain)-cc-default)))
$(toolchain)-cc-id := $$(strip \
$$(call guess-tool,$$(tools-cc),$$($(toolchain)-cc)))
endef
define locate-toolchain-tool
$(eval toolchain := $(1))
$(eval tool-class := $(2))
ifndef $(toolchain)-$(tool-class)
$(toolchain)-$(tool-class) := $$(strip \
$$(call guess-$$($(toolchain)-cc-id)-$(tool-class),$$($(toolchain)-cc)))
ifeq ($$($(toolchain)-$(tool-class)),)
$(toolchain)-$(tool-class) := $$(strip \
$$($(toolchain)-$(tool-class)-default))
endif
endif
$(toolchain)-$(tool-class)-id := $$(strip \
$$(call guess-tool,$$(tools-$(tool-class)),$$($$(toolchain)-$(tool-class))))
endef
define canonicalize-toolchain-tool-path
$(eval toolchain := $(1))
$(eval tool-class := $(2))
$(toolchain)-$(tool-class) := $$(strip $$(or \
$$(call which,$$($(toolchain)-$(tool-class))), \
$$($(toolchain)-$(tool-class))))
endef
define locate-toolchain
$(eval toolchain := $(1))
$$(eval $$(call locate-toolchain-tool-cc,$(toolchain)))
$$(eval $$(call canonicalize-toolchain-tool-path,$(toolchain),cc))
$$(foreach tool-class,$$(filter-out cc,$$(tool-classes)), \
$$(eval $$(call locate-toolchain-tool,$(toolchain),$$(tool-class))) \
$$(eval $$(call canonicalize-toolchain-tool-path,$(toolchain),$$(tool-class))))
endef
$(foreach toolchain,$(toolchains), \
$(eval $(call locate-toolchain,$(toolchain))))