Previously the `CMAKE_GENERATOR_INSTANCE` value was used only to filter
the instances reported by the Visual Studio Installer tool. If the
specified install location is not known to the VS Installer, but the
user provided a `version=` field, check for the installation directly
on disk.
Fixes: #21639, #22197
#pragma once is a widely supported compiler pragma, even though it is
not part of the C++ standard. Many of the issues keeping #pragma once
from being standardized (distributed filesystems, build farms, hard
links, etc.) do not apply to CMake - it is easy to build CMake on a
single machine. CMake also does not install any header files which can
be consumed by other projects (though cmCPluginAPI.h has been
deliberately omitted from this conversion in case anyone is still using
it.) Finally, #pragma once has been required to build CMake since at
least August 2017 (7f29bbe6 enabled server mode unconditionally, which
had been using #pragma once since September 2016 (b13d3e0d)). The fact
that we now require C++11 filters out old compilers, and it is unlikely
that there is a compiler which supports C++11 but does not support
#pragma once.
Fix the SmartBSTR copy constructor and copy assignment operator added by
commit 18c8278b62 (VS: Add helper class to interact with Visual Studio
Installer, 2016-12-14, v3.8.0-rc1~93^2~4) to use the string from the
source of the copy.
Issue: #19610
Run the `clang-format.bash` script to update all our C and C++ code to a
new style defined by `.clang-format`. Use `clang-format` version 6.0.
* If you reached this commit for a line in `git blame`, re-run the blame
operation starting at the parent of this commit to see older history
for the content.
* See the parent commit for instructions to rebase a change across this
style transition commit.
The `Microsoft.VisualStudio.Component.VC.Tools.x86.x64` component is
not the only way a VS instance may provide the `cl` compiler tool.
For example, VS 2017 Express Edition does not install that component.
Instead search for the tools directly on disk within an instance.
Suggested-by: Rich Chiodo <rchiodo@microsoft.com>
Fixes: #17349
VS 2017 exports a COM component which can be queried to find if VS 2017
is installed and also other components such as VC toolset and Windows
SDKs. Add a helper class to interact with this interface.
