[mpg123] Allow cross-compiling, fix previous builds tainting rebuilds

[kevinlul]

Closes #11164

This would support cross-compiling to triplets like arm64-linux from x64 if an appropriate cross-compiling configuration or toolchain file is specified in the triplet.

I fixed a bug where previous builds were not cleaned up when building again. This came up when testing and I commented it; this could be separated into a different pull request.

I refactored the port a little bit to have common configure flags shared between debug and release builds; again, this could be in a different pull request.

Now for the meat of the problem I'm trying to solve: in the linked issue, JackBoosY suggests using the new vcpkg_configure_make. However, I found that this actually sets a bad combination of default flags for mpg123, resulting in attempting to macOS-specific CoreAudio code on Linux. I also noticed that it only attempts to detect autoconf --host if on Windows/MSYS, so I went with my own approach here of retrieving the prefix with -dumpmachine and passing it to configure and make.

[JackBoosY]

@Neumann-A Could you review this PR?

Thanks.

[Neumann-A]

The port needs a complete rewrite to use vcpkg_configure_make() and vcpkg_install_make()
a) use SET(ENV{CC} <somecompiler>) in the triplet or have it already be set in the environment which vcpkg uses. vcpkg_configure_make should automatically pick it up. (or more precisely configure should pick it up under linux)
b) (unreleated to the pr) the prefix passed to configure is completely wrong. Using vcpkg_configure_make() would solve part of that.
c) about the --host option VCPKG is currently missing a proper way to pass --build=something --target=something --host=something to configure. Even though it is currently not handled for linux in vcpkg_configure_make you can always use OPTIONS to pass these. I am thinking of adding something like VCPKG_(AUTOTOOLS_)CONFIGURE_(MAKE_)TRIPLET which is intended to be set be the users to specify --build=something --target=something --host=something in a custom triplet. I am still missing a proper name for that variable.

Conclusion:
a) Rewrite port to use vcpkg_configure_make() and vcpkg_install_make()
b) add a global variable to vcpkg_configure_make to specify --build=something --target=something --host=something which can be used for cross-compiling cases in custom triplets. (Because it should affect all autotools based ports. )

[kevinlul]

The default set of flags used by vcpkg_configure_make cause the build to fail. I tried to use it but as I noted, I found that this actually sets a bad combination of default flags for mpg123, resulting in attempting to macOS-specific CoreAudio code on Linux.

[Neumann-A]

I found that this actually sets a bad combination of default flags for mpg123, resulting in attempting to macOS-specific CoreAudio code on Linux.

Be more specific. If this is only due to --host this can be changed in vcpkg_configure_make as mentioned in my comment before

[kevinlul]

When I had tested, it seemed to be the result of the combination of --disable-silent-rules with --disable-shared added here

[Neumann-A]

When I had tested, it seemed to be the result of the combination of --disable-silent-rules with --disable-shared added here

Test again. The configure script has both rules baked into it so it should work.... (Otherwise check your autoconf version 2.69 is required)

[kevinlul]

By removing a bunch of flags, I got it to compile properly. Tomorrow I will verify that this is still working on macOS. This has a behaviour change: libmpg123.la and libout123.la are now installed to lib directories. Should these be removed?

Some thoughts:

• the make distclean could be moved to vcpkg_configure_make because it seems like it could affect other ports that have in-source builds too
• setting the --host triplet via -dumpmachine could also be moved to vcpkg_configure_make so more autoconf ports can be easily cross-compiled with vcpkg

[kevinlul]

I've verified that it compiles successfully on macOS, including the CoreAudio module.

[JackBoosY]

Please update the version info. See documentation.

[ras0219-msft]

LGTM if the merge from master doesn't break anything.

[kevinlul]

Turns out all those lines were unnecessary holdovers from the old version of this port and it's all taken care of by vcpkg_configure_make and vcpkg_install_make. Nifty!

[strega-nil]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[strega-nil]

I like this PR quite a lot! let's just run the PR tests and see if we can merge :)

[JackBoosY]

CMake Error at scripts/cmake/vcpkg_find_acquire_program.cmake:377 (message):
  Could not find yasm.  Please install it via your package manager:

      brew install yasm
Call Stack (most recent call first):
  ports/mpg123/portfile.cmake:39 (vcpkg_find_acquire_program)
  scripts/ports.cmake:79 (include)


Error: Building package mpg123:x64-osx failed with: BUILD_FAILED
Elapsed time for package mpg123:x64-osx: 1.314 s

[strega-nil]

Looks like this needs to update the scripts.

[JackBoosY]

I don't think mpg123 should use yasm in *nix, please change

vcpkg_find_acquire_program(YASM)
get_filename_component(YASM_EXE_PATH ${YASM} DIRECTORY)
set(ENV{PATH} "$ENV{PATH};${YASM_EXE_PATH}")

to

if (VCPKG_TARGET_IS_WINDOWS)
    vcpkg_find_acquire_program(YASM)
    get_filename_component(YASM_EXE_PATH ${YASM} DIRECTORY)
    set(ENV{PATH} "$ENV{PATH};${YASM_EXE_PATH}")
endif()

[kevinlul]

The assembler is used on all platforms if it is available. On my macOS CI I have to brew install yasm before installing mpg123. Turning that off would mean that we are not using the hand-optimized assembly on those platforms.