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| author | Alexandru Croitor <alexandru.croitor@qt.io> | 2025-07-30 16:38:47 +0200 |
|---|---|---|
| committer | Alexandru Croitor <alexandru.croitor@qt.io> | 2025-08-01 16:36:43 +0200 |
| commit | 26f8dff7daeb6538b9308d2bef77ecea8bd2a80e (patch) | |
| tree | ba8b28235bef5f2e124e8326b7f4718ca3618d2f /src | |
| parent | 346a748ffe5571e05b01a02ddbd3131c336ca433 (diff) | |
CMake: Add warnings as errors support for example builds
We want to ensure we don't introduce new build warnings in examples.
We have a mechanism to enable warnings as errors for qt targets like
modules or plugins, but not for targets in example projects.
To enable this, we introduce a new internal target
PlatformExampleInternal, which is linked to all targets created
by qt_add_executable and qt_add_library-like functions in projects
in the <repo>/examples subdirectory.
The detection of targets in example projects is done by checking the
QT_INTERNAL_IS_EXAMPLE_EP_BUILD variable or the
QT_INTERNAL_IS_EXAMPLE_IN_TREE_BUILD variable. These are set either by
ExternalProject_Add in the case of external example projects, or by
qt_examples_build_begin in the case of in-tree example projects.
The PlatformExampleInternal target gets the same warnings as errors
flags as the other Platform*Internal targets.
To enable gradual adoption, the new feature is opt-in rather than
opt-out, on a per-repo basis. The QT_REPO_EXAMPLES_WARNINGS_CLEAN
variable can be set to TRUE in a repo's '.cmake.conf' file.
The warnings as errors behavior is controlled as usual by configuring
qt with -DWARNINGS_ARE_ERRORS=ON.
Pick-to: 6.8 6.9 6.10
Task-number: QTBUG-108448
Change-Id: If62b47b205c111f2a1fec791e5bb6502f5b64f9c
Reviewed-by: Alexey Edelev <alexey.edelev@qt.io>
Diffstat (limited to 'src')
| -rw-r--r-- | src/corelib/Qt6CoreMacros.cmake | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/src/corelib/Qt6CoreMacros.cmake b/src/corelib/Qt6CoreMacros.cmake index 46283381a42..dd6108066b6 100644 --- a/src/corelib/Qt6CoreMacros.cmake +++ b/src/corelib/Qt6CoreMacros.cmake @@ -695,6 +695,31 @@ function(_qt_internal_disable_autorcc_zstd_when_not_supported target) endif() endfunction() +# Link given target to PlatformExampleInternal when the target is part of an example build. +function(_qt_internal_link_to_platform_example_internal target) + # The first variable is set when examples are built using ExternalProject_Add. + # The second is set when examples are built in-tree, the scope is in the <repo>/examples subdir. + if(QT_INTERNAL_IS_EXAMPLE_EP_BUILD + OR QT_INTERNAL_IS_EXAMPLE_IN_TREE_BUILD) + target_link_libraries("${target}" PRIVATE + ${QT_CMAKE_EXPORT_NAMESPACE}::PlatformExampleInternal) + endif() +endfunction() + +# Set up warnings as errors for targets built in example projects. +function(_qt_internal_setup_warnings_are_errors_for_example_target target) + # Only enable warnings as errors when the global variable is enabled and the repo is known + # to have clean examples. + if(QT_INTERNAL_IS_EXAMPLE_EP_BUILD + OR QT_INTERNAL_IS_EXAMPLE_IN_TREE_BUILD) + if(WARNINGS_ARE_ERRORS AND QT_REPO_EXAMPLES_WARNINGS_CLEAN) + _qt_internal_set_skip_warnings_are_errors("${target}" FALSE) + else() + _qt_internal_set_skip_warnings_are_errors("${target}" TRUE) + endif() + endif() +endfunction() + function(_qt_internal_create_executable target) if(ANDROID) list(REMOVE_ITEM ARGN "WIN32" "MACOSX_BUNDLE") @@ -727,6 +752,8 @@ function(_qt_internal_create_executable target) endif() _qt_internal_disable_autorcc_zstd_when_not_supported("${target}") + _qt_internal_link_to_platform_example_internal("${target}") + _qt_internal_setup_warnings_are_errors_for_example_target("${target}") _qt_internal_set_up_static_runtime_library("${target}") endfunction() @@ -2834,6 +2861,8 @@ function(_qt_internal_add_library target) cmake_policy(POP) _qt_internal_disable_autorcc_zstd_when_not_supported("${target}") + _qt_internal_link_to_platform_example_internal("${target}") + _qt_internal_setup_warnings_are_errors_for_example_target("${target}") _qt_internal_set_up_static_runtime_library(${target}) if(NOT type_to_create STREQUAL "INTERFACE" AND NOT type_to_create STREQUAL "OBJECT") |