Up until recently the build system accepted an arbitrary value for `AS`
and, unbeknownst to anybody, was simply not making use of it. Recent
feedback has revealed that a number of contributors have `AS` explicitly
configured to use the GNU assembler, which is not a supported assembler,
and this breakage has yielded some cryptic error messages, e.g.:
aarch64-none-elf-as: unrecognized option '-x'
This change introduces human-readable diagnostics to help developers
with diagnosing unsupported toolchain tools:
The configured AArch64 assembler could not be identified and may not
be supported:
aarch64-none-elf-as
The default AArch64 assembler is:
aarch64-none-elf-gcc
The following tools are supported:
- Arm® Compiler for Embedded `armclang`
- LLVM Clang (`clang`)
- GNU GCC (`gcc`)
The build system will treat this assembler as GNU GCC (`gcc`).
Change-Id: I316036c83be2d45ee83a88846cf65c6ce7ae3c26
Signed-off-by: Chris Kay <chris.kay@arm.com>
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>
