CMake: Allow building bundled 3rd party libraries in qtbase

A few things are needed to accomplish that:

- the python scripts do not ignore certain system_foo features anymore
  (it is a hardcoded list for now just to be safe)

- configurejson2cmake now outputs
  qt_find_package(WrapSystemFoo) calls for bundled libraries
  (see below)

- the harfbuzz .pro file is modified to accommodate pro2cmake
  not being able to correctly parse some conditional scopes

- the freetype .pro file is modified to make sure linking of the
  library succeeds without duplicate symbol errors, which qmake
  doesn't encounter due to magical exclusion of cpp files that are
  included in other cpp files (presumably for include moc_foo.cpp
  support)

- feature evaluation for Core, Gui, Network now happens in the
  qtbase/src directory, so that bundled libraries can be conditionally
  built

- for each bundled library there are now two FindWrap scripts:
  - FindWrapSystemFoo which finds an installed library in the system
  - FindWrapFoo which either uses the system installed library or
    the built bundled one depending on a condition

- projects that intend to use bundled libraries need to link against
  WrapFoo::WrapFoo instead of WrapSystemFoo::WrapSystemFoo targets
  (this is handled by pro2cmake).
  Unfortunately manually added qt_find_package(WrapFoo) calls might
  still be needed as is the case for WrapFreetype and others.

- a new cmake/QtFindWrapHelper.cmake file is added that provides
  a macro to simplify creation of WrapFoo targets that link against
  a bundled or system library. The implementation is fairly ugly
  due to CMake macro constraints, but it was deemed better than
  copy-pasting a bunch of almost identical code across all
  FindWrapFoo.cmake files.

- a qtzlib header-only module is now created when using bundled
  zlib, to provide public syncqt created headers for consumers
  that need them. These are projects that have
  'QT_PRIVATE += zlib-private' in their .pro files
  (e.g. qtimageformats, qtlocation, qt3d, etc.)
  This is unfortunately needed due to QtNetwork using zlib
  types in its private C++ API.

The change includes support for building the following bundled
libraries:
- zlib
- libpng
- libjpeg
- Freetype
- Harfbuzz-ng
- PCRE2

The following 3rd party libraries are still using an old
implementation within the CMake build system, and should be migrated
to the new one in the near future:
- double-conversion
- Old harfbuzz

The are a few libraries that are not yet ported:
- system-sqlite
- systemxcb
- maybe others

Among other things, this change allows building qtbase on Windows
without requiring vcpkg.

Task-number: QTBUG-82167
Change-Id: I35ecea0d832f66c1943c82e618de4a51440971a5
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
Reviewed-by: Leander Beernaert <leander.beernaert@qt.io>

1 files changed, 40 insertions, 7 deletions

diff --git a/src/gui/configure.cmake b/src/gui/configure.cmake
index aac73e8bc2..7b3cd14ce4 100644
--- a/src/gui/configure.cmake
+++ b/src/gui/configure.cmake
@@ -26,14 +26,14 @@ qt_find_package(ATSPI2 PROVIDED_TARGETS PkgConfig::ATSPI2)
 qt_find_package(DirectFB PROVIDED_TARGETS PkgConfig::DirectFB)
 qt_find_package(Libdrm PROVIDED_TARGETS Libdrm::Libdrm)
 qt_find_package(EGL PROVIDED_TARGETS EGL::EGL)
-qt_find_package(WrapFreetype PROVIDED_TARGETS WrapFreetype::WrapFreetype)
+qt_find_package(WrapSystemFreetype PROVIDED_TARGETS WrapSystemFreetype::WrapSystemFreetype)
 set_package_properties(WrapFreetype PROPERTIES TYPE REQUIRED)
 qt_find_package(Fontconfig PROVIDED_TARGETS Fontconfig::Fontconfig)
 qt_find_package(gbm PROVIDED_TARGETS gbm::gbm)
-qt_find_package(WrapHarfbuzz PROVIDED_TARGETS WrapHarfbuzz::WrapHarfbuzz)
+qt_find_package(WrapSystemHarfbuzz PROVIDED_TARGETS WrapSystemHarfbuzz::WrapSystemHarfbuzz)
 qt_find_package(Libinput PROVIDED_TARGETS Libinput::Libinput)
 qt_find_package(JPEG PROVIDED_TARGETS JPEG::JPEG)
-qt_find_package(PNG PROVIDED_TARGETS PNG::PNG)
+qt_find_package(WrapSystemPNG PROVIDED_TARGETS WrapSystemPNG::WrapSystemPNG)
 qt_find_package(Mtdev PROVIDED_TARGETS PkgConfig::Mtdev)
 qt_find_package(OpenGL PROVIDED_TARGETS OpenGL::GL)
 qt_find_package(GLESv2 PROVIDED_TARGETS GLESv2::GLESv2)
@@ -43,7 +43,7 @@ if((LINUX) OR QT_FIND_ALL_PACKAGES_ALWAYS)
     qt_find_package(Wayland PROVIDED_TARGETS Wayland::Server)
 endif()
 if((LINUX) OR QT_FIND_ALL_PACKAGES_ALWAYS)
-    qt_find_package(X11 PROVIDED_TARGETS X11::XCB)
+    qt_find_package(X11 PROVIDED_TARGETS X11::X11)
 endif()
 if((LINUX) OR QT_FIND_ALL_PACKAGES_ALWAYS)
     qt_find_package(X11 PROVIDED_TARGETS ${X11_SM_LIB} ${X11_ICE_LIB})
@@ -82,6 +82,9 @@ if((LINUX) OR QT_FIND_ALL_PACKAGES_ALWAYS)
     qt_find_package(XCB COMPONENTS XINERAMA PROVIDED_TARGETS XCB::XINERAMA)
 endif()
 if((LINUX) OR QT_FIND_ALL_PACKAGES_ALWAYS)
+    qt_find_package(X11_XCB PROVIDED_TARGETS X11::XCB)
+endif()
+if((LINUX) OR QT_FIND_ALL_PACKAGES_ALWAYS)
     qt_find_package(XCB COMPONENTS XKB PROVIDED_TARGETS XCB::XKB)
 endif()
 if((LINUX) OR QT_FIND_ALL_PACKAGES_ALWAYS)
@@ -97,6 +100,9 @@ if((LINUX) OR QT_FIND_ALL_PACKAGES_ALWAYS)
     qt_find_package(XKB 0.4.1 PROVIDED_TARGETS XKB::XKB)
 endif()
 if((LINUX) OR QT_FIND_ALL_PACKAGES_ALWAYS)
+    qt_find_package(XKB_COMMON_X11 0.4.1 PROVIDED_TARGETS PkgConfig::XKB_COMMON_X11)
+endif()
+if((LINUX) OR QT_FIND_ALL_PACKAGES_ALWAYS)
     qt_find_package(XRender PROVIDED_TARGETS PkgConfig::XRender)
 endif()
 
@@ -148,7 +154,7 @@ qt_config_compile_test(egl_x11
     LABEL "EGL on X11"
     LIBRARIES
         EGL::EGL
-        X11::XCB
+        X11::X11
     CODE
 "// Check if EGL is compatible with X. Some EGL implementations, typically on
 // embedded devices, are not intended to be used together with X. EGL support
@@ -609,10 +615,17 @@ qt_feature("freetype" PUBLIC PRIVATE
     PURPOSE "Supports the FreeType 2 font engine (and its supported font formats)."
 )
 qt_feature_definition("freetype" "QT_NO_FREETYPE" NEGATE VALUE "1")
+qt_feature("system-freetype" PRIVATE
+    LABEL "  Using system FreeType"
+    AUTODETECT NOT MSVC
+    CONDITION QT_FEATURE_freetype AND WrapSystemFreetype_FOUND
+    ENABLE INPUT_freetype STREQUAL 'system'
+    DISABLE INPUT_freetype STREQUAL 'qt'
+)
 qt_feature("fontconfig" PUBLIC PRIVATE
     LABEL "Fontconfig"
     AUTODETECT NOT APPLE
-    CONDITION NOT MSVC AND ON AND FONTCONFIG_FOUND
+    CONDITION NOT MSVC AND QT_FEATURE_system_freetype AND FONTCONFIG_FOUND
 )
 qt_feature_definition("fontconfig" "QT_NO_FONTCONFIG" NEGATE VALUE "1")
 qt_feature("gbm"
@@ -625,6 +638,13 @@ qt_feature("harfbuzz" PUBLIC PRIVATE
     CONDITION harfbuzz_FOUND
 )
 qt_feature_definition("harfbuzz" "QT_NO_HARFBUZZ" NEGATE VALUE "1")
+qt_feature("system-harfbuzz" PRIVATE
+    LABEL "  Using system HarfBuzz"
+    AUTODETECT NOT APPLE AND NOT WIN32
+    CONDITION QT_FEATURE_harfbuzz AND WrapSystemHarfbuzz_FOUND
+    ENABLE INPUT_harfbuzz STREQUAL 'system'
+    DISABLE INPUT_harfbuzz STREQUAL 'qt'
+)
 qt_feature("qqnx_imf" PRIVATE
     LABEL "IMF"
     CONDITION libs.imf OR FIXME
@@ -810,11 +830,24 @@ qt_feature("jpeg" PRIVATE
     DISABLE INPUT_libjpeg STREQUAL 'no'
 )
 qt_feature_definition("jpeg" "QT_NO_IMAGEFORMAT_JPEG" NEGATE)
+qt_feature("system-jpeg" PRIVATE
+    LABEL "  Using system libjpeg"
+    CONDITION QT_FEATURE_jpeg AND JPEG_FOUND
+    ENABLE INPUT_libjpeg STREQUAL 'system'
+    DISABLE INPUT_libjpeg STREQUAL 'qt'
+)
 qt_feature("png" PRIVATE
     LABEL "PNG"
     DISABLE INPUT_libpng STREQUAL 'no'
 )
 qt_feature_definition("png" "QT_NO_IMAGEFORMAT_PNG" NEGATE)
+qt_feature("system-png" PRIVATE
+    LABEL "  Using system libpng"
+    AUTODETECT QT_FEATURE_system_zlib
+    CONDITION QT_FEATURE_png AND WrapSystemPNG_FOUND
+    ENABLE INPUT_libpng STREQUAL 'system'
+    DISABLE INPUT_libpng STREQUAL 'qt'
+)
 qt_feature("sessionmanager" PUBLIC
     SECTION "Kernel"
     LABEL "Session Management"
@@ -884,7 +917,7 @@ qt_feature("xkbcommon" PRIVATE
 )
 qt_feature("xkbcommon-x11" PRIVATE
     LABEL "xkbcommon-x11"
-    CONDITION QT_FEATURE_xkbcommon AND XKB_FOUND
+    CONDITION QT_FEATURE_xkbcommon AND XKB_COMMON_X11_FOUND
 )
 qt_feature("xlib" PRIVATE
     LABEL "XLib"