The mapping of architectures to optimization flags is now retrieved from
Hardware::CPU and the selected flags are passed as an environmen
variable, rather than duplicated in the cc wrapper and re-calculated on
every invocation of the compiler.
ClosesHomebrew/homebrew#24540.
Constructing the path relative to a file in the repository is incorrect
on some supported configurations (i.e., the repository is located in a
different place than the prefix).
ClosesHomebrew/homebrew#24418.
The cc wrapper's make_fuss is only enabled when HOMEBREW_CCCFG contains
'O', which is set by the make wrapper. This means it is disable when
running configure scripts. However, this does not include configure
scripts invoked by make, which inherit the value of HOMEBREW_CCCFG from
the make process. make_fuss will be enabled for these scripts, cause
breakage.
Configure scripts generated by autoconf 2.56 (November 2002) or later
export DUALCASE into the environment of subprocesses. This variable is
only used by the MKS shell, so we can use it as a heuristic to determine
if we are running as a subprocess of a configure script.
* Don't encode "-Qunused-arguments", as this is only supported in Clang
and will break building when C/C++ compiler is switched during the
process, e.g. building gcc. The warning is harmless without
"-Werror".
* Add new ENV function for selecting stdlib for Clang.
- The selection is no-op for non-system-clang compilers.
- Both superenv and stdenv are handled.
* Add new HOMEBREW_CCCFG flag and ccwrapper handling.
* Add options and ENV method to specify building in C++11 mode.
- Set C++ compiler flags to enable C++11 mode.
- To add options to support C++11 mode, a formula can now use
option :cxx11
to provide "--c++11" option, and detect and enable C++11 support in
install method using
ENV.cxx11 if build.cxx11?
ClosesHomebrew/homebrew#22453.
If @compiler isn't set/checked by ENV.compiler and the ENV.clang/etc.
methods, ENV.compiler may return unexpected results after fails_with
picks a fallback compiler.
See Homebrew/homebrew#22674.
This moves the CompilerSelector fails_with logic into the build
environment setup, making the compiler selection available before
performing actions that depends on knowing what the compiler is, e.g.
setting up PATH.
ENV.setup_build_environment now optionally takes a Formula argument
to provide the information necessary to do the fails_with, and the new
ENV.validate_cc! extracts the fails_with logic from Build.install.
ENV.compiler is called outside setting up the build environment, where
values unsupported for user input might have been specified - for
example, GNU GCC executables.
This adds support for non-Apple GCC compilers in the fails_with code.
A fails_with block for a non-Apple compiler looks like:
fails_with :gcc => '4.8.1' do
cause 'Foo'
end
Non-Apple compilers don't have build numbers, so compiler failures are
based on version strings instead.
Internally non-Apple compilers can be distinguished because they are
passed around as strings instead of symbols.
In addition, this alters the priority list for compilers, with the
following changes:
* Apple GCC 4.2 and LLVM-GCC swap positions, with GCC now taking
priority. (Maybe LLVM-GCC should just go away.)
* Non-Apple GCC compilers are ranked below GCC 4.2 but above LLVM-GCC
and Apple GCC 4.0.
