build: refactor toolchain detection
This change refactors how we identify the toolchain, with the ultimate
aim of eventually cleaning up the various mechanisms that we employ to
configure default tools, identify the tools in use, and configure
toolchain flags.
To do this, we introduce three new concepts in this change:
- Toolchain identifiers,
- Tool class identifiers, and
- Tool identifiers.
Toolchain identifiers identify a configurable chain of tools targeting
one platform/machine/architecture. Today, these are:
- The host machine, which receives the `host` identifier,
- The AArch32 architecture, which receives the `aarch32` identifier, and
- The AArch64 architecture, which receivs the `aarch64` identifier.
The tools in a toolchain may come from different vendors, and are not
necessarily expected to come from one single toolchain distribution. In
most cases it is perfectly valid to mix tools from different toolchain
distributions, with some exceptions (notably, link-time optimization
generally requires the compiler and the linker to be aligned).
Tool class identifiers identify a class (or "role") of a tool. C
compilers, assemblers and linkers are all examples of tool classes.
Tool identifiers identify a specific tool recognized and supported by
the build system. Every tool that can make up a part of a toolchain must
receive a tool identifier.
These new identifiers can be used to retrieve information about the
toolchain in a more standardized fashion.
For example, logic in a Makefile that should only execute when the C
compiler is GNU GCC can now check the tool identifier for the C compiler
in the relevant toolchain:
ifeq ($($(ARCH)-cc-id),gnu-gcc)
...
endif
Change-Id: Icc23e43aaa32f4fd01d8187c5202f5012a634e7c
Signed-off-by: Chris Kay <chris.kay@arm.com>
diff --git a/make_helpers/toolchain.mk b/make_helpers/toolchain.mk
new file mode 100644
index 0000000..505630e
--- /dev/null
+++ b/make_helpers/toolchain.mk
@@ -0,0 +1,343 @@
+#
+# 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)
+ $$(error no tools registered to handle tool class `$(tool-class)`)
+ endif
+endef
+
+$(foreach tool-class,$(tool-classes), \
+ $(eval $(call check-tool-class-tools,$(tool-class))))
+
+#
+# Default tools for each toolchain.
+#
+# Toolchains can specify a default path to any given tool with a tool class.
+# These values are used in the absence of user-specified values, and are
+# configured by the parent Makefile using variables of the form:
+#
+# - $(toolchain)-$(tool-class)-default
+#
+# For example, the default C compiler for the AArch32 and AArch64 toolchains
+# could be configured with:
+#
+# - aarch32-cc-default
+# - aarch64-cc-default
+#
+
+define check-toolchain-tool-class-default
+ $(eval toolchain := $(1))
+ $(eval tool-class := $(2))
+
+ ifndef $(toolchain)-$(tool-class)-default
+ $$(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))))