cmake: Don't give plugins PUBLIC usage requirements

The pro2cmake.py conversion script faithfully reproduced the .pro files
for the plugins, which specified the libraries as public. But in CMake,
the implications of this are that public usage requirements should then
be propagated to consumers. We don't expect any consumers, since a
plugin is created as a MODULE library in CMake, so for Windows we don't
even have an import library to link with. The only exception to this is
for static builds where plugins are created as STATIC libraries
instead, but only in certain controlled situations do we then link to
plugins. Even then, usage requirements are not expected to propagate to
the consumers, so these relationships should always be specified as
private.

This change warns on any PUBLIC usage requirements specified for a
plugin. This check is disabled by default to avoid spamming CI builds
for repos that haven't been fixed yet. The check can be enabled by a
CMake cache option, which is intended for developers to use locally
when fixing this issue in other repos (all plugins in qtbase should
not trigger this warning as a result of changes in this commit).

Task-number: QTBUG-90819
Pick-to: 6.1
Change-Id: I09f2c8da77db1193ad3370f85d367dfc6ab7b9a6
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

7 files changed, 7 insertions, 7 deletions

diff --git a/src/plugins/generic/evdevkeyboard/CMakeLists.txt b/src/plugins/generic/evdevkeyboard/CMakeLists.txt
index c6411cd76a..7134a2d858 100644
--- a/src/plugins/generic/evdevkeyboard/CMakeLists.txt
+++ b/src/plugins/generic/evdevkeyboard/CMakeLists.txt
@@ -10,7 +10,7 @@ qt_internal_add_plugin(QEvdevKeyboardPlugin
     DEFAULT_IF FALSE
     SOURCES
         main.cpp
-    PUBLIC_LIBRARIES
+    LIBRARIES
         Qt::Core
         Qt::CorePrivate
         Qt::Gui
diff --git a/src/plugins/generic/evdevmouse/CMakeLists.txt b/src/plugins/generic/evdevmouse/CMakeLists.txt
index 39741fbe25..78cf80f588 100644
--- a/src/plugins/generic/evdevmouse/CMakeLists.txt
+++ b/src/plugins/generic/evdevmouse/CMakeLists.txt
@@ -10,7 +10,7 @@ qt_internal_add_plugin(QEvdevMousePlugin
     DEFAULT_IF FALSE
     SOURCES
         main.cpp
-    PUBLIC_LIBRARIES
+    LIBRARIES
         Qt::Core
         Qt::CorePrivate
         Qt::Gui
diff --git a/src/plugins/generic/evdevtablet/CMakeLists.txt b/src/plugins/generic/evdevtablet/CMakeLists.txt
index da553f9b47..880090dd02 100644
--- a/src/plugins/generic/evdevtablet/CMakeLists.txt
+++ b/src/plugins/generic/evdevtablet/CMakeLists.txt
@@ -10,7 +10,7 @@ qt_internal_add_plugin(QEvdevTabletPlugin
     DEFAULT_IF FALSE
     SOURCES
         main.cpp
-    PUBLIC_LIBRARIES
+    LIBRARIES
         Qt::Core
         Qt::CorePrivate
         Qt::Gui
diff --git a/src/plugins/generic/evdevtouch/CMakeLists.txt b/src/plugins/generic/evdevtouch/CMakeLists.txt
index ce0b931e9c..d15367c6c2 100644
--- a/src/plugins/generic/evdevtouch/CMakeLists.txt
+++ b/src/plugins/generic/evdevtouch/CMakeLists.txt
@@ -10,7 +10,7 @@ qt_internal_add_plugin(QEvdevTouchScreenPlugin
     DEFAULT_IF FALSE
     SOURCES
         main.cpp
-    PUBLIC_LIBRARIES
+    LIBRARIES
         Qt::Core
         Qt::CorePrivate
         Qt::Gui
diff --git a/src/plugins/generic/libinput/CMakeLists.txt b/src/plugins/generic/libinput/CMakeLists.txt
index a37b898d5a..79da268510 100644
--- a/src/plugins/generic/libinput/CMakeLists.txt
+++ b/src/plugins/generic/libinput/CMakeLists.txt
@@ -10,7 +10,7 @@ qt_internal_add_plugin(QLibInputPlugin
     DEFAULT_IF FALSE
     SOURCES
         main.cpp
-    PUBLIC_LIBRARIES
+    LIBRARIES
         Qt::Core
         Qt::CorePrivate
         Qt::Gui
diff --git a/src/plugins/generic/tslib/CMakeLists.txt b/src/plugins/generic/tslib/CMakeLists.txt
index b151805108..9a6e368825 100644
--- a/src/plugins/generic/tslib/CMakeLists.txt
+++ b/src/plugins/generic/tslib/CMakeLists.txt
@@ -12,7 +12,7 @@ qt_internal_add_plugin(QTsLibPlugin
     DEFAULT_IF FALSE
     SOURCES
         main.cpp
-    PUBLIC_LIBRARIES
+    LIBRARIES
         PkgConfig::Tslib
         Qt::Core
         Qt::CorePrivate
diff --git a/src/plugins/generic/tuiotouch/CMakeLists.txt b/src/plugins/generic/tuiotouch/CMakeLists.txt
index ede5c5408a..b572b140b4 100644
--- a/src/plugins/generic/tuiotouch/CMakeLists.txt
+++ b/src/plugins/generic/tuiotouch/CMakeLists.txt
@@ -17,7 +17,7 @@ qt_internal_add_plugin(QTuioTouchPlugin
         qtuiotoken_p.h
     DEFINES
         QT_NO_FOREACH
-    PUBLIC_LIBRARIES
+    LIBRARIES
         Qt::Core
         Qt::CorePrivate
         Qt::Gui