From 48b380c9613318b888473aa6f178d06de3f21e7e Mon Sep 17 00:00:00 2001 From: Craig Scott Date: Sun, 11 Sep 2022 17:54:57 +1000 Subject: FetchContent: Ignore EXACT for redirected find_package() calls When FetchContent_MakeAvailable() populates a dependency for which find_package() integration is enabled, all future calls to find_package() MUST succeed using the contents of the redirection directory. The generated config version file was not handling calls where the EXACT keyword was given, resulting in such calls rejecting the redirection directory's contents and continuing its search. It is not allowed to do that. Fix the generated file to also set PACKAGE_VERSION_EXACT to true so that calls with EXACT now accept it, as was originally intended. Fixes: #23950 --- Modules/FetchContent.cmake | 9 ++++++--- Modules/FetchContent/package-config-version.cmake.in | 5 ++++- .../RunCMake/FetchContent_find_package/PreferFetchContent.cmake | 4 ++++ 3 files changed, 14 insertions(+), 4 deletions(-) diff --git a/Modules/FetchContent.cmake b/Modules/FetchContent.cmake index 20f0bd2..09a1512 100644 --- a/Modules/FetchContent.cmake +++ b/Modules/FetchContent.cmake @@ -303,13 +303,16 @@ Commands ``-extra.cmake`` or ``Extra.cmake`` file with the ``OPTIONAL`` flag (so the files can be missing and won't generate a warning). Similarly, if no config version file exists, a very simple - one will be written which sets ``PACKAGE_VERSION_COMPATIBLE`` to true. + one will be written which sets ``PACKAGE_VERSION_COMPATIBLE`` and + ``PACKAGE_VERSION_EXACT`` to true. This ensures all future calls to + :command:`find_package()` for the dependency will use the redirected + config file, regardless of any version requirements. CMake cannot automatically determine an arbitrary dependency's version, - so it cannot set ``PACKAGE_VERSION`` or ``PACKAGE_VERSION_EXACT``. + so it cannot set ``PACKAGE_VERSION``. When a dependency is pulled in via :command:`add_subdirectory` in the next step, it may choose to overwrite the generated config version file in :variable:`CMAKE_FIND_PACKAGE_REDIRECTS_DIR` with one that also sets - ``PACKAGE_VERSION``, and if appropriate, ``PACKAGE_VERSION_EXACT``. + ``PACKAGE_VERSION``. The dependency may also write a ``-extra.cmake`` or ``Extra.cmake`` file to perform custom processing or define any variables that their normal (installed) package config file would diff --git a/Modules/FetchContent/package-config-version.cmake.in b/Modules/FetchContent/package-config-version.cmake.in index 7f19094..9fcade7 100644 --- a/Modules/FetchContent/package-config-version.cmake.in +++ b/Modules/FetchContent/package-config-version.cmake.in @@ -1,5 +1,8 @@ # Automatically generated by CMake's FetchContent module. # Do not edit this file, it will be regenerated every time CMake runs. -# Version not available, assuming it is compatible +# Version not available, assuming it is compatible. We must also say it is an +# exact match to ensure find_package() calls with the EXACT keyword still get +# redirected. set(PACKAGE_VERSION_COMPATIBLE TRUE) +set(PACKAGE_VERSION_EXACT TRUE) diff --git a/Tests/RunCMake/FetchContent_find_package/PreferFetchContent.cmake b/Tests/RunCMake/FetchContent_find_package/PreferFetchContent.cmake index c1030fb..4943f9e 100644 --- a/Tests/RunCMake/FetchContent_find_package/PreferFetchContent.cmake +++ b/Tests/RunCMake/FetchContent_find_package/PreferFetchContent.cmake @@ -18,3 +18,7 @@ message(STATUS "Lowercase extra file was read") # This is expected to be re-routed to a FetchContent_MakeAvailable() call find_package(AddedProject REQUIRED) + +# Verify that find_package() version constraints are fully ignored by the +# default-generated config version file +find_package(AddedProject 1.2.3 EXACT REQUIRED) -- cgit v0.12