Since commit b8626261e9 (Precompile headers: Add methods to generate PCH
sources, 2019-07-13, v3.16.0-rc1~182^2~4) we look up source files for a
target using an upper-case configuration even though an original-case
name is sufficient. Since commit 36ded610af (PCH: Generate sources
during Compute step, 2019-10-05, v3.16.0-rc1~2^2) the source file lookup
is the first time we compute many on-demand structures that depend on
the configuration name. This caused the `$<CONFIG>` generator
expression to evaluate to the upper-case configuration name in some
cases where we used original-case before.
Fix this by switching the source file lookup to the original-case config
name. Add a test covering the symptom that led to the discovery of this
problem.
Fixes: #20517
CMake Tests Directory
*********************
This directory contains the CMake test suite.
See also the `CMake Source Code Guide`_.
.. _`CMake Source Code Guide`: ../Help/dev/source.rst
Many tests exist as immediate subdirectories, but some tests
are organized as follows.
* ``CMakeLib/``:
Source code, used for tests, that links to the ``CMakeLib`` library
defined over in ``Source/``.
* ``CMakeOnly/``:
Deprecated. Tests that run CMake to generate a project but not build it.
Superseded by ``Tests/RunCMake/``.
* ``Find*/``:
Tests for specific find modules that can only be run on machines with
the corresponding packages installed. They are enabled in
``CMakeLists.txt`` by undocumented options used on CI builds.
* ``Module/``:
Tests for specific CMake modules.
* ``RunCMake/``:
Tests that run CMake and/or other tools while precisely checking
their return code and stdout/stderr content. Useful for testing
error cases and diagnostic output.