CMake: Allow opting out of building examples as ExternalProjects

We default to configuring examples as separate ExternalProjects when using a developer / non-prefix Qt build. This ensures we test that the examples configure successfully without the pollution of the main Qt build (e.g. already found packages). One down-side of this is that a developer's IDE doesn't see these example targets, unless each project is loaded into the IDE separately. This is cumbersome to do when refactoring or renaming code across multiple example projects. Allow configuring the example projects as part of the main Qt build by setting QT_BUILD_EXAMPLES_AS_EXTERNAL to FALSE when configuring Qt. Save the value of the variable in QtBuildInternalsExtra.cmake.in so it's propagated to leaf repositories as well. Amends dab8f64 Amends d97fd7a Task-number: QTBUG-90820 Task-number: QTBUG-94608 Task-number: QTBUG-96232 Task-number: QTCREATORBUG-26168 Pick-to: 6.2 Change-Id: Ie1f724f74365b3a788b04c3fffe9eb2d0611dd50 Reviewed-by: Craig Scott <[email protected]> Reviewed-by: Qt CI Bot <[email protected]>
fwcd · Sep 6, 2021 · c8dbb17 · c8dbb17
1 parent 25feb2f
commit c8dbb17
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Showing 3 changed files with 16 additions and 2 deletions.
diff --git a/cmake/QtBuildInternals/QtBuildInternalsConfig.cmake b/cmake/QtBuildInternals/QtBuildInternalsConfig.cmake
@@ -669,8 +669,8 @@ macro(qt_examples_build_begin)
 
     cmake_parse_arguments(arg "${options}" "${singleOpts}" "${multiOpts}" ${ARGN})
 
-    # FIXME: Support prefix builds as well
-    if(arg_EXTERNAL_BUILD AND NOT QT_WILL_INSTALL)
+    # FIXME: Support prefix builds as well QTBUG-96232
+    if(arg_EXTERNAL_BUILD AND QT_BUILD_EXAMPLES_AS_EXTERNAL)
         # Examples will be built using ExternalProject.
         # We always depend on all plugins so as to prevent opportunities for
         # weird errors associated with loading out-of-date plugins from

diff --git a/cmake/QtBuildInternalsExtra.cmake.in b/cmake/QtBuildInternalsExtra.cmake.in
@@ -69,6 +69,9 @@ set(QT_BUILD_EXAMPLES_BY_DEFAULT @QT_BUILD_EXAMPLES_BY_DEFAULT@ CACHE BOOL
 set(QT_BUILD_TOOLS_BY_DEFAULT @QT_BUILD_TOOLS_BY_DEFAULT@ CACHE BOOL
     "Should tools be built as part of the default 'all' target.")
 
+set(QT_BUILD_EXAMPLES_AS_EXTERNAL "@QT_BUILD_EXAMPLES_AS_EXTERNAL@" CACHE BOOL
+    "Should examples be built as ExternalProjects.")
+
 # Propagate usage of ccache.
 set(QT_USE_CCACHE @QT_USE_CCACHE@ CACHE BOOL "Enable the use of ccache")
 

diff --git a/cmake/QtSetup.cmake b/cmake/QtSetup.cmake
@@ -174,6 +174,17 @@ enable_testing()
 option(QT_BUILD_EXAMPLES "Build Qt examples" OFF)
 option(QT_BUILD_EXAMPLES_BY_DEFAULT "Should examples be built as part of the default 'all' target." ON)
 
+
+# FIXME: Support prefix builds as well QTBUG-96232
+if(QT_WILL_INSTALL)
+    set(_qt_build_examples_as_external OFF)
+else()
+    set(_qt_build_examples_as_external ON)
+endif()
+option(QT_BUILD_EXAMPLES_AS_EXTERNAL "Should examples be built as ExternalProjects."
+       ${_qt_build_examples_as_external})
+unset(_qt_build_examples_as_external)
+
 option(QT_BUILD_MANUAL_TESTS "Build Qt manual tests" OFF)
 option(QT_BUILD_MINIMAL_STATIC_TESTS "Build minimal subset of tests for static Qt builds" OFF)