From ef5da25931100de4f824d9609d25b2f0434d46d0 Mon Sep 17 00:00:00 2001
From: Alexandru Croitor <alexandru.croitor@qt.io>
Date: Thu, 16 Dec 2021 12:55:07 +0100
Subject: [PATCH] CMake: Allow installing examples outside of the Qt prefix
MIME-Version: 1.0
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Introduce a new QT_INTERNAL_CUSTOM_INSTALL_DIR variable to
allow specifying an 'examples install dir' outside of the Qt prefix.

It will be used in a follow-up change to ensure we don't package
the example binaries in our CI artifacts (thus saving space).

This will be even more important when the examples will contain code
to deploy Qt libraries alongside each deployed example (which would
significantly increase the package size).

Task-number: QTBUG-90820
Task-number: QTBUG-96232
Change-Id: I06b4a8f9e8c57a712a356bca0f5c351a9362bc30
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
(cherry picked from commit 1031fa15472bba3f20691cda2305e0821391c5db)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 cmake/QtBuildInternals/QtBuildInternalsConfig.cmake | 9 ++++++++-
 cmake/QtPostProcessHelpers.cmake                    | 6 ++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/cmake/QtBuildInternals/QtBuildInternalsConfig.cmake b/cmake/QtBuildInternals/QtBuildInternalsConfig.cmake
index ae7f8ec0dbe..87dd783e4c4 100644
--- a/cmake/QtBuildInternals/QtBuildInternalsConfig.cmake
+++ b/cmake/QtBuildInternals/QtBuildInternalsConfig.cmake
@@ -1063,6 +1063,7 @@ function(qt_internal_add_example_external_project subdir)
     # E.g. ensure qtbase/examples/widgets/widgets/wiggly is installed to
     # $qt_example_install_prefix/examples/widgets/widgets/wiggly/wiggly.exe
     # $qt_example_install_prefix defaults to ${CMAKE_INSTALL_PREFIX}/${INSTALL_EXAMPLEDIR}
+    # but can also be set to a custom location.
     # This needs to work both:
     #  - when using ExternalProject to build examples
     #  - when examples are built in-tree as part of Qt (no ExternalProject).
@@ -1089,7 +1090,13 @@ function(qt_internal_add_example_external_project subdir)
     #    example_source_dir, use _qt_internal_override_example_install_dir_to_dot to ensure
     #    INSTALL_EXAMPLEDIR does not interfere.
 
-    set(qt_example_install_prefix "${CMAKE_INSTALL_PREFIX}/${INSTALL_EXAMPLESDIR}")
+    # Allow installing somewhere under the build dir.
+    if(QT_INTERNAL_CUSTOM_INSTALL_DIR)
+        set(qt_example_install_prefix "${QT_INTERNAL_CUSTOM_INSTALL_DIR}")
+    else()
+        set(qt_example_install_prefix "${CMAKE_INSTALL_PREFIX}/${INSTALL_EXAMPLESDIR}")
+    endif()
+
     set(example_install_prefix "${qt_example_install_prefix}/${example_rel_path}")
 
     set(ep_binary_dir    "${CMAKE_CURRENT_BINARY_DIR}/${subdir}")
diff --git a/cmake/QtPostProcessHelpers.cmake b/cmake/QtPostProcessHelpers.cmake
index 60a745c0f54..12e44113b29 100644
--- a/cmake/QtPostProcessHelpers.cmake
+++ b/cmake/QtPostProcessHelpers.cmake
@@ -596,6 +596,12 @@ endif()\n")
                 "set(QT_BUILD_TOOLS_WHEN_CROSSCOMPILING \"TRUE\" CACHE BOOL \"\" FORCE)\n")
         endif()
 
+        if(QT_INTERNAL_CUSTOM_INSTALL_DIR)
+            file(TO_CMAKE_PATH "${QT_INTERNAL_CUSTOM_INSTALL_DIR}" qt_internal_custom_install_dir)
+            string(APPEND QT_EXTRA_BUILD_INTERNALS_VARS
+                "set(QT_INTERNAL_CUSTOM_INSTALL_DIR \"${qt_internal_custom_install_dir}\" CACHE STRING \"\")\n")
+        endif()
+
         # Save the default qpa platform.
         # Used by qtwayland/src/plugins/platforms/qwayland-generic/CMakeLists.txt. Otherwise
         # the DEFAULT_IF condition is evaluated incorrectly.