[scripts] add new function vcpkg_fixup_pkgconfig

[Neumann-A]

similar to vcpkg_fixup_cmake_targets.
Mainly prefix corrections and transforming absolute paths into relativ ones (relative to prefix).

tries to solve #3108

[vicroms]

/azp run

[Neumann-A]

@vicroms
set(ENV{PKG_CONFIG} "${PKGCONFIG} --define-variable=prefix=${_VCPKG_INSTALLED}")
seems to be always required since
./pkg-config.exe --exists --print-errors "xproto"
will always print
Variable 'prefix' not defined in 'd:/ma ke/installed/x64-windows/lib/pkgconfig\xproto.pc' if there is no prefix variable in it. Otherwise the reseating of the prefix is done automatically on windows even when prefix=nonsens with pkgconfig v0.29.2
pkg-config.exe --variable=prefix xproto -> d:/ma\ ke/installed/x64-windows
while on linux the result is (v0.28.0)
pkg-config.exe --variable=prefix xproto -> nonsens

[Neumann-A]

So my question now would be:
Should we let the prefix be defined on windows to leverage on the automatic prefix correction?
(while other OSes are required to use --define-variable=prefix=${_VCPKG_INSTALLED})

[vicroms]

We want to leverage the automatic correction, so if there's no other option we should define it as this PR did originally.

I think that internally we should pass --define-variable=prefix=${_VCPKG_INSTALLED} in our helper functions regardless of platform. For external consumers we could do something similar to the usage message we have for CMake config files and tell them to define the prefix.

[ras0219-msft]

set(ENV{PKG_CONFIG} "${PKGCONFIG} --define-variable=prefix=${_VCPKG_INSTALLED}")

+1 for this.

Just to reiterate the underlying sentiment and goal: we don't want packages to magically work on the original build machine, but randomly fail if you try to use them on another machine. Instead, we want them to fail consistently in both environments or work in both. If that requires users to throw --define-variable=prefix=..., so be it; we will find ways of making that more ergonomic.

[ras0219-msft]

As a note: we use a different comment style, which is extracted into .md files via docs/regenerate.ps1. See some other helpers like vcpkg_configure_cmake() for examples.

[Neumann-A]

changed but still not sure if its 100% correct.

[Neumann-A]

I'll add in a check which will check if the following:

Libs: -L${libdir} -lfreetype
Libs.private: 

really exist. Translates -l into lib.(a|lib) or .(a|lib) must exist. Most commonly, the debug name is false for CMake builds due to added debug suffixes while the library name is hardcoded in a *.pc.in

The same for

Requires:
Requires.private: zlib, bzip2, libpng

which means that a .pc file needs to exist

[MVoz]

@dan-shaw @ras0219-msft
merge!
in the course of work, any shortcomings will be identified, need to merge
the script does not yet carry anything without accessing it

[MVoz]

-- Fixing pkgconfig --- finished
CMake Error at scripts/cmake/vcpkg_fixup_pkgconfig.cmake:245 (set):
set given invalid arguments for CACHE mode.

[MVoz]

when there are dependencies, the script does not work, and outputs an error without pointing to the package.
I performed validation of all files

removed under comment
# vcpkg_fixup_pkgconfig_check_libraries("DEBUG" _contents "${_vfpkg_SYSTEM_LIBRARIES}" "${_vfpkg_SYSTEM_PACKAGES}")
# vcpkg_fixup_pkgconfig_check_libraries("RELEASE" _contents "${_vfpkg_SYSTEM_LIBRARIES}" "${_vfpkg_SYSTEM_PACKAGES}")

[Neumann-A]

Could you add the *.pc file which failed?
I am not going to comment vcpkg_fixup_pkgconfig_check_libraries out since its intention is too make sure that all required packages and libraries are available.

[MVoz]

I am not suggesting that you comment on this line \ function
I removed it under the comment (at itself), so that the build was successful until I find out the reason for the error

collected the glib(MESON) package,*.pc everything from vcpkg, all pass validation manually
I don't know what the reason is, there is no debugging information

[Neumann-A]

until I find out the reason for the error
an error without pointing to the package.

So the reason for the error was that one package was missing but the error did not point to the missing package? Or am I misunderstanding it again?

[MVoz]

all packages were found and the build was made successfully, the script after the build can not work out some system files
which ones, I have no idea, I got the error without explanation

пакеты все найдены и сборка была произведена успешно, скрипт после сборки не может отработать некие системные файлы
какие именно, я без понятия, вывела ошибку без пояснения

specifically these lines

# vcpkg_fixup_pkgconfig_check_libraries("DEBUG" _contents "${_vfpkg_SYSTEM_LIBRARIES}" "${_vfpkg_SYSTEM_PACKAGES}")
# vcpkg_fixup_pkgconfig_check_libraries("RELEASE" _contents "${_vfpkg_SYSTEM_LIBRARIES}" "${_vfpkg_SYSTEM_PACKAGES}")

[JackBoosY]

/azp run

[Neumann-A]

TODO:
#10731 (comment)
Make prefix use ${pcfiledir}/../..

Done

[JackBoosY]

LGTM.
@ras0219-msft Could you review this PR?

Thanks.

[MVoz]

@Neumann-A
still would such a feature to implement, naturally in another request

example

# Templates release\debug.pc.cmake \\ RELEASE and DEBUG

prefix=@CMAKE_INSTALL_PREFIX@ ### @CURRENT_INSTALLED_DIR@ ???
exec_prefix=${prefix}
libdir=${exec_prefix}/@LIB_INSTALL_DIR@
includedir=${prefix}/include ### ${exec_prefix}/@INCLUDE_INSTALL_DIR@ ???

Name: @PORT@
URL: @PORT_HOMEPAGE@
Description: @PORT_DESCRIPTION@ ### error /n
Version: @PORT_VERSION@ ### ???
Requires: @PORT_REQUIRES_RELEASE@

Libs: -L${libdir} @PORT_LIBS_RELEASE@ ### -lexample
Cflags: -I${includedir}


# Generate and Install Pkgconfig

configure_file(${scripts}/templates/release.pc.cmake ${PROJECT_BINARY_DIR}//@PORT@.pc @ONLY) ### ${PROJECT_BINARY_DIR} ???
install(FILES ${PROJECT_BINARY_DIR}/@PORT@.pc DESTINATION "${CMAKE_INSTALL_LIBDIR}/pkgconfig") ### ${CMAKE_INSTALL_LIBDIR} ???

[MVoz]

@ras0219-msft merge this PR

Thanks.

[strega-nil]

LGTM! Thanks @Neumann-A :)