#
# 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 = $(if $(filter 1,$(ENABLE_LTO)),$(1),$(shell $(1) --print-prog-name ld.bfd 2>$(nul)))
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))))