Makefiles are evaluated without building things. In a normal build,
the prerequisites would be built, and CC would be an actual thing. In
an INDEX build, though, they don't exists. Redirect stderr to get rid
of annoying messages, and assume that the compiler version is 0 if the
actual compiler can't tell us. Do this in preference to guessing based
on numbers because gcc410 might be 4.10, or 4.1.0 and without
carefully crafted special knowledge we differentiate between them
easily (also ming-gcc has no clues at all). Elsewhere, don't trust
the compiler version if it is 0.
with clang 3.3. Useful for test building -current on a -stable system
in individual directories. Potentially useful if we ever want to
support, say, gcc 4.8 or 4.9's new warnings when building with an
external toolchain (but such support not yet committed). Document
the bsd.compiler.mk interface.
versions. With its movement to src.opts.mk, bsd.prog.mk was testing
COMPILER_TYPE without including the bsd.compiler.mk anymore. In the
source tree, this caused no problems, for reasons that aren't clear,
but does cause problems outside of the source tree. Allow
bsd.compiler.mk to be included multiple times safely, and always
include bsd.compiler.mk at the top of bsd.prog.mk. Resist the urge to
put it in bsd.init.mk, since that would reintroduce the implicit
include.
When the compiler is clang add c++11 to COMPILER_FEATURES.
When the compiler supports c++11, default to building libc++. This will
not impact the compliation of programs, but will make it easier for
users with clang compiled systems to test libc++ by passing -stdlib=libc++
to their c++ compliations.
type of compiler is being used (currently clang or gcc). COMPILER_TYPE
is set in the new bsd.compiler.mk file based on the value of the CC
variable or, should it prove informative, by running ${CC} --version
and examining the output.
To avoid negative performance impacts in the default case and correct
value for COMPILER_TYPE type is determined and passed in the environment
of submake instances while building world.
Replace adhoc attempts at determining the compiler type by examining
CC or MK_CLANG_IS_CC with checks of COMPILER_TYPE. This eliminates
bootstrapping complications when first setting WITH_CLANG_IS_CC.
Sponsored by: DARPA, AFRL
Reviewed by: Yamaya Takashi <yamayan@kbh.biglobe.ne.jp>, imp, linimon
(with some modifications post review)
MFC after: 2 weeks
