It must be better to have this workaround here, rather than in external.
(Thanks uwe@ for suggestion!)
Confirmed that the same files generated as before.
Implement m4 macro NB_CHECK_CC_FLAG(FLAG, [VAR=FLAG_DERIVED])
Determine if the C compiler supports FLAG,
and sets output variable VAR to FLAG if FLAG is supported.
If VAR is not provided, default to FLAG_DERIVED, which is
FLAG converted to upper-case and all special characters
replaced with "_", and the result prepended with "CC_".
FLAG_DERIVED is appended to the m4 macro NB_CHECK_CC_FLAG_VARS.
E.g., if FLAG is "-Wexample=yes", FLAG_DERIVED is "CC_WEXAMPLE_YES".
This is implemented in separate buildaux/nb_check_cc_flag.m4,
based on configure's NB_CC_FLAG(), but supports VAR override.
Adapt configure from internal NB_CC_FLAG() to NB_CHECK_CC_FLAG().
(Note: AX_CHECK_COMPILE_FLAG() from autoconf-archive could be enhanced
to support the clang and gcc workarounds I've implemented here.)
autoconf 2.69 generates @DEFS@ with definitions with
quoted embedded spaces, so rework how docmd() is invoked
to avoid weird quoting issues.
As part of this, remove all the shell variables containing @var@
and just use @var@ directly.
tools/Makefile.host revision 1.35 changed from
setting various NOxxx variables and .include <bsd.own.mk>
to
.include <bsd.hostinit.mk>
which sets the same NOxxx variables, .include <bsd.init.mk>
which optionally .include ../Makefile.inc before .include <bsd.own.mk>.
This chnage caused build failures with HAVE_LLVM=yes, so revert rev 1.35.
(Maybe to do with the .include ../Makefile.inc. The tools/llvm* build is
tricky, and it's easier to revert this change than debug.)
bsd.hostinit.mk sets a bunch of NOxxx variables before
including bsd.init.mk (which includes bsd.own.mk),
so simplify instead of replicating the NOxxx setup
for host tools.
Check the host CC support for all the warnings now in <bsd.own.mk>
and override appropriately in defs.mk.
In general there's a 1:1 mapping, with the special case
CC_WNO_ADDRESS_OF_PACKED_MEMBER which is set from both
@CC_WNO_ADDRESS_OF_PACKED_MEMBER@ (gcc) and
@CC_WNO_ERROR_ADDRESS_OF_PACKED_MEMBER@ (clang).
Rename compiler-warning-disable variables from
GCC_NO_warning
to
CC_WNO_warning
where warning is the full warning name as used by the compiler.
GCC_NO_IMPLICIT_FALLTHRU is CC_WNO_IMPLICIT_FALLTHROUGH
Using the convention CC_compilerflag, where compilerflag
is based on the full compiler flag name.
Building LLVM with a host gcc 13 fails and suggests including <cstdint>
in external/apache2/llvm/dist/llvm/include/llvm/Support/Signals.h .
Instead of this, joerg@ suggested not modifying the llvm vendor branch
but instead working around this in our LLVM build infrastructure.
Determine if the host CC supports flags to disable various
warnings similar to <bsd.own.mk> GCC_*, CLANG_*, and CC_*,
and override the <bsd.own.mk> equivalents in defs.mk.
Silences "warning: unknown warning option '...'" from our source.
External source (e.g., binutils and gcc) need their own fixes
to enhance their detection of supported clang compiler flags.
Define NB_CC_FLAG(FLAG) to use AX_CHECK_COMPILE_FLAG
to determine if the host compiler supports FLAG
and define and AC_SUBST CC_FLAG if so.
Use workarounds to force clang to hard-fail on unknown -Wwarning,
and gcc to use -WWARN to check unknown -Wno-WARN because the
latter doesn't cause an error in gcc.
In the future we could use NB_CC_FLAG([-fcommon]) for
older NetBSD release branches compiled with host gcc 10+.
Rework Darwin -no-cpp-precomp check to use NB_CC_FLAG().
Note: this flag probably hasn't been required on macOS (Darwin)
for a long time, but serves as a good example on how to use this.
Display varaibles at the end of configure to show what was detected.
Use "NB_" prefix not "AC_" for our macros ("AC_" is for autoconf).
Fail is NB_ macro isn't defined.
Use AC_DEFUN() instead of define().
Consistently use () in zero argument macro calls.
Use dispatch_semaphore_create() if present instead of sem_init().
macOS doesn't actually implement sem_init() (et al)
(even though it provides the prototypes as deprecated).
This was detected by the previous commit to ctfmerge
that added error handling.
Implement ctfmerge's barrier operations in terms of
dispatch(3) APIs such as dispatch_semaphore_create() (et al).
Update tools/compat/configure.ac to find dispatch_semaphore_create().
Fixes ctfmerge on macOS hosts.
Inspired by https://stackoverflow.com/a/27847103.
palle