Rewrite the VS Integration Scripts

[zturner]

Summary

Not sure who knows MSBuild, so I'm adding several random people in hopes that someone can review this.

I expect this to need to go through a couple of iterations, but this represents a complete re-write of the Clang Visual Studio Integration. I'll try to summarize the high level differences between how this works now and how it used to work, as well as mention some future work I think we should do:

1. Previously we would install into %ProgramFiles%\MSBuild. At least with 2017, this no longer appears to be what you do. You now have to install to the VS instance. Rather than try to detect Installed VS Instances from a batch file, for now I just hardcode the path to the default installation path, and in follow-up patches we can port this to using a VSIX installer, which should handle all of this for us.

2. Previously we had separate .props and .targets files for every version of VS. This turns out to be unnecessary, so all of those have been removed and now there is just 1. The good news is that this means we should continue to work in subsequent versions of VS without any additional maintenance.

3. Previously would do a configure-style modification of the props and targets file to fill in with compile time values. The only one of these that's tricky is the LLVM Version number, the rest are already available via existing MSBuild substitutions. So all of those are fixed, and to handle the version number the installer is updated to write an additional value to the registry, which the MSBuild files pull. Decoupling these values from the particular build of LLVM opens the door for us to be able to package this in a VSIX and distribute it on the marketplace and update it independently of the actual toolchain.

4. An xml file is provided to present a custom view of compiler options (e.g. Project > Properties > C/C++). Options we don't support or ignore are grouped together under special tabs in the UI, while the settings we do support are in the original locations. This is done because we additionally will now warn (or error) on certain options which could have been enabled in a project prior to changing the toolset, and we like to be able to point the user exactly to which setting to change to silence the warning / error.

5. Previously we would copy clang-cl.exe to $(InstallDir)\bin\cl.exe because this is how MSBuild would find the compiler. This is now fixed so that it locates clang-cl.exe directly.

6. Options that we ignore are now not even passed to clang-cl. This might seem unimportant because if we ignore the option, there's no harm in passing it in. But some of these options trigger additional MSBuild logic that happens before the compiler even has a chance to run. For example, in llvm.org/pr36140, a user noted that using /Zi triggered a full rebuild every time, even if nothing changed. In any case, having smaller command lines makes for easier diagnostics. An additional side benefit of this is that whereas before you would get lots of -Wunused-command-line-argument warnings, now there will be no such warnings.

Future Work (in rough order of priority):

1. Wrap this all in a VSIX so that it can be properly installed, instead of relying on batch file hackery.
2. Expose all of clang warnings through a custom UI page.
3. Expose all of clang optimizations through a custom UI page.
4. Replace link.exe with lld-link.exe similar to how we currently replace cl.exe with clang-cl.exe
5. Install a clang platform (in additional to a platform toolset), so that we have Clang (x86) and Clang (x64) platforms for people to enable building side-by-side configurations.
6. Add a Clang (Cross-Platform) platform that exposes the clang++ driver in all of its glory and allows the user to set the target triple.

[zturner]

+asmith

[hans]

llvm/tools/msbuild/Clang.Cpp.Common.props

41

As I mentioned before, separating the toolset config from the actual toolchain installation makes me a little nervous.

But if we're doing it, the version checks below should probably include the .1 versions too, i.e. at least 5.0.1 and 6.0.1.

49

It's embarrassing that we didn't figure this out before :-)

With this, we can remove

if (MSVC)
   list(APPEND CLANG_LINKS_TO_CREATE ../msbuild-bin/cl)
 endif()

from Clang's tools/driver/CMakeLists.txt

llvm/tools/msbuild/LLVM.props

8

Hmm, we previously intentionally called the toolset "LLVM" with the thinking that it would eventually include lld and designated the complete llvm toolchain, not just Clang. And is the "for Windows" part necessary?

llvm/tools/msbuild/Toolset.targets

38

This seems to duplicate a lot of logic from clang-cl. It's nice to provide a good UI for the user, but maintaining this seems a lot of work. Are you not concerned that this will rot?

46

But maybe we want clang-cl to map this to -flto one day. Now we need to update two places. And with the toolset/toolchain install split, the two places may be installed separately :-/

73

Comment copy-paste-o?

83

Keeping up with all these flags seems like a huge amount of work. Why not just let clang-cl ignore it?

[hans]

llvm/tools/msbuild/Toolset.targets

111

Maybe it will one day. The OpenMP folks claim their runtime works on Windows and we've shipped it for some releases. It seems better to keep this logic tied to the toolchain?

128

More stuff to keep in sync with MSVC's options and clang-cl :-/

166

I guess we'll need to update the fork with each VS release (but still stay compatible with old versions?)

llvm/tools/msbuild/clang-cl.xml

1

Maybe add a short top-level comment about what this file is.

343

This seems like a huge amount of stuff to keep in sync with MSVC and clang-cl's flags.

llvm/tools/msbuild/install.bat

10

Don't we want to support at least 2015 too?

20

This should probably have quotes just to be safe.

[zturner]

llvm/tools/msbuild/Clang.Cpp.Common.props

41

Unless we're going to release the full thing including the compiler, linker, etc through the marketplace I don't see an alternative. In any case, I actually think this it's preferable this way. There's nothing really about the two that benefits from having them coupled together, as far as I can see. I'm willing to be convinced though, if we can figure out how to to do it so that we can still ship it on the marketplace.

llvm/tools/msbuild/LLVM.props

8

Do you think there's any value in having a toolset that does Clang+Link and a second one that does Clang+LLD? Or do you think we should stick with only a single one? I can change the name to LLVM though.

llvm/tools/msbuild/Toolset.targets

38

I don't think it will. Maybe I'm being overly optimistic here, but the only case we would ever need to maintain this again is if we started supporting these options. Fiber Safe Optimizations, for example, I'm pretty sure we will never support. If MSVC ever removes the option, for example, we can do nothing and continue to work.

We could also just silently ignore them and just pass the option through to clang-cl, but these are pretty unusual options with pretty specialized use cases, so I feel like if I had gone out of my way to enable such a strange option I would want to know if the compiler was not going to respect it.

46

That's even better then. All we have to do is change this xml, push a new build to the market place, and the VS UI will update their extension for them.

Note that we could do the mapping at the MSBuild level, in this file down below where we have an ItemGroup. Just add a line that says <AdditionalOptions Condition="%(ClCompile.WholeProgramOptimization)' == 'true'>-flto=thin %(AdditionalOptions)</AdditionalOptions>

and we can do this without touching clang.

83

See the large comment at the top of the file. For some options, we could probably get by with this. Maybe even this one, I debated on this particular one.

My bar was "If the option fundamentally changes assumptions about the way code could be compiled, we should generate an error. If it changes the behavior of the language in a way we don't support, changes the way we generate code in a meaningful way, or causes specialized output files to be written, warn, and if it's an option we ignore then drop it"

The last category there we could probably just pass through in some cases, but in that comment I also mentioned a case where setting an option that clang-cl ignores impacts MSBuild's ability to figure out dependencies and ends up causing a full rebuild every time even when nothing changed.

We can scour the entire cl build tasks and try to discover if any other ones have unintended consequences, but I think it's easier to just turn them off at the MSBuild level. And as a side benefit, the user gets shorter command lines, which is always nice.

As for maintenance, this all looks like zero-maintenance code to me. Did you have an example in mind of where we'd need to update this? Whether it be a new VS version, or VS dropping support for one of these options or deprecating them, I don't think we'd have to do anything.

111

I can put some conditions that only cause it to error if clang version is less than or equal to 7, but that seems higher maintenance because we'll probably have many new releases before that ever happens. Even if we do tie it to the toolchain, the user is still going to have an error in their code if they have /openmp on, they'll just have to spend more time figuring out that the underlying cause is we don't currently support this option. I'd rather err on the side of improving the user experience today and worrying about what we might do in the future when it happens.

Even if we do have to push a new version of the extension every so often, that's less trouble for the user than downloading a new installer because they get auto-updated through the VS Extension Manager.

128

Mentioned before, but I dont' think we have to do anything to keep this in sync with MSVC. All of these lines should be able to remain forever, regardless of what MSVC does.

166

I don't think it would be necessary to update every release unless they fundamentally change the way the UI looks. The logic didn't change between 2015 and 2017 for example. Unless they redesign the entire Project Settings dialog, I think we should be future proof.

llvm/tools/msbuild/clang-cl.xml

343

This stuff almost never changes though. Most of these options have been here since at least VS 2010, which is about as far back as I can remember. The only one that wasn't here in 2015 is /diagonstics

llvm/tools/msbuild/install.bat

10

Mentioned in the other review, but the install.bat file shouldn't really be used anymore except for during development. The VSIX supports both 2015 and 2017 (I tested it in both and confirmed it works)

[hans]

llvm/tools/msbuild/Clang.Cpp.Common.props

41

"There's nothing really about the two that benefits from having them coupled together,"

The toolset needs to know at least where to find the toolchain and how to invoke it. If we decouple them, there needs to be an interface between them that can't change: in this case the LLVM path and version number in the registry.

But at the same time you're baking in all this logic in the toolset about how to invoke the toolchain, what flags are supported, etc. Those things are strongly dependent on the toolchain, which in this de-coupled world seems problematic. It seems like you're actually making the coupling tighter in that way, except you still want to ship the two parts separately.

Are there restrictions in the marketplace about how big a vsix can be? Because if not, I think we could just package up clang+headers+runtime into a vsix and ship the whole thing, and maybe that would be the best thing.

Or we could just stick to the current installer version and make it a little smarter about finding VS2017. Maybe instead of the batch files we write an actual program that finds the installation and copies the files.

llvm/tools/msbuild/LLVM.props

8

The best would be to only have one, but where the user could select between the two linkers, I think.

llvm/tools/msbuild/Toolset.targets

38

I feel pretty strongly that we should handle this clang-cl side. If a flag is not supported, either we should ignore it, or if it's something the user would want to know about us not supporting, we should warn. That's what clang-cl tries to do currently, and if there are flags we don't get right, we should fix it.

And we do move flags from the unsupported to supported category now and then, so the "only case we would ever need to maintain this again is if we started supporting these options" scenario is real.

46

But the toolset is decoupled from the toolchain in your proposal.

Not only would we need to update both clang-cl and this file, but this file would need to handle clang-cl versions both before and after.

83

The maintenance would come from when clang-cl changes how it handles some option, or when VS adds new options.

llvm/tools/msbuild/install.bat

10

Hmm, but then we should delete it, or at least take it out of the installer, and we need a replacement. As it is now, if we land this, it breaks the installer for versions before 2017.

[zturner]

1. Removed the option remapping. I will be adding this back in a follow up patch. The clang-cl specific "limited options view" is still here.
2. Removed the dependency on writing the version number to the registry. This was originally done so that we could add the clang resource dir to the include path, but clang can always figure out its own resource path anyway, so it turns out this was unnecessary. This has the nice property that it will automatically work with all past, present, and future clang versions without modification.
3. Changed "clang" to "llvm"
4. Merged D42769 into this patch.
5. Remove the batch files (and for that matter all other files as well) from being installed by CMake. The vsix is now the installer, which we can publish on the marketplace.

[zturner]

Don't install the batch files for real. The previous patch didn't copy them to the output directory on install, but it failed to remove the invocation of install.bat and uninstall.bat from the actual installer.

[hans]

llvm/CMakeLists.txt

234

Now that the LLVM toolchain installer no longer includes the VS integration, is there some way we could point the user to the marketplace to install the integration, or could we include the vsix in the installer and launch it for them?

llvm/tools/msbuild/LLVM.Cpp.Common.props

1 ↗

(On Diff #132645)

Do we know what other versions this works with besides VS 2017?

47 ↗

(On Diff #132645)

Is there a way for the user to point to another LLVM installation? This was one of the reasons for separating the toolset from the toolchain, right?

llvm/tools/msbuild/clang-cl.xml

2

I thought you were going to leave the flag logic out of this patch?

llvm/tools/msbuild/install.bat

1

I thought you meant to delete this file? I can see that it's still useful for development, but maybe then we should rename it or put a comment on the top or something explaining what it does, since its purpose is now changing from what it was before.

llvm/tools/msbuild/license.txt

1 ↗

(On Diff #132645)

Can't we use the old file? Checking in another copy seems unfortunate.

llvm/tools/msbuild/llvm.sln

1 ↗

(On Diff #132645)

Should we have a cmake build target to build this vsix, similar to what we do for the clang-format one, which gets built by the "clang_format_vsix" target?

[zturner]

llvm/CMakeLists.txt

234

Do we have a Release Notes file that we install? That could be a good place to include a link to the marketplace?

Although, we'd probably want to wait until it's actually published on the marketplace before we do anything.

llvm/tools/msbuild/LLVM.Cpp.Common.props

47 ↗

(On Diff #132645)

At the moment, you can do this by changing the registry key. In subsequent patches I can add a UI setting under C/C++ > General.

llvm/tools/msbuild/clang-cl.xml

2

I thought Nico said to only separate out the option remapping into another patch. I took all of that out.

llvm/tools/msbuild/license.txt

1 ↗

(On Diff #132645)

I copied this one from the clang-format vs integration folder. The one at the top level llvm directory has some extra stuff at the bottom which doesn't apply to this, but I don't know if it would still work just as well even with all that extra stuff in it.

llvm/tools/msbuild/llvm.sln

1 ↗

(On Diff #132645)

Yea that seems reasonable. I'll look into how that works.

[hans]

llvm/tools/msbuild/LLVM.Cpp.Common.props

47 ↗

(On Diff #132645)

Is it hard to add, or can you add it to this patch? Changing the registry isn't very good UI and is also global.

llvm/tools/msbuild/clang-cl.xml

2

This file still attempts to duplicate the logic of what flags clang-cl supports, which are ignored, etc. I'd prefer if we didn't do that.

To repeat my concerns:

1. This list of flags would need to be maintained, and I expect it will always end up being incomplete or inaccurate in some other way. The only way to keep it accurate would be if it's auto-generated from clang-cl's tablegen file. But that ties it to a specific clang-cl version, which is the next problem

2. It ties it to a particular clang-cl version, which goes against the point of decoupling the VS integration from the toolchain. As a concrete example, your file is missing /arch:AVX512 and /arch:AVX512F, so those should be added, but only when the user is using a Clang >= r323433. Of course the user could them manually, but why should some flags be listed and some not? And maybe we could handle this with version logic, but now we're getting into *really* hairy maintenance.

llvm/tools/msbuild/license.txt

1 ↗

(On Diff #132645)

Right, the clang-format one is my fault :-) It's formated to fit better in the vsix installer window. Could we make the build system copy it instead of checking in another copy? If that's not easy, never mind this is not important obviously.

[zturner]

llvm/tools/msbuild/LLVM.Cpp.Common.props

47 ↗

(On Diff #132645)

I can add it to this patch, but there's also no way to do this without forking the UI file, which gets to your next comment.

llvm/tools/msbuild/clang-cl.xml

2

I can move this to another patch if you want, but I have to say that presenting a clang-cl tailored UI of the options is something that I feel very strongly about. In fact, the main reason I volunteered to take on this effort is specifically because I wanted to make sure we do this.

We can get into how it would have to be maintained etc, but all of that is irrelevant IMO because I'm approaching this from the perspective of the user. As someone who has used VS pretty heavily for close to 20 years, this is absolutely a large value-add for the user.

To re-iterate though, I don't see where the perceived maintenance comes from. You're already suggesting that I do nothing, which means that the user will already have to manually add options anyway if the version of VS doesn't match up with the version of clang-cl exactly. So what I'm doing here is imperfect (as is the alternative of doing nothing), but is strictly better. I don't see how that could be perceived as anything other than a win.

Version logic isn't even that hairy of maintenance. Every time we ship a new LLVM release (which seems to be about once a year), we copy the file and make the 1 or 2 necessary modifications to the copied file.

[hans]

llvm/tools/msbuild/LLVM.Cpp.Common.props

47 ↗

(On Diff #132645)

Aww :-(

llvm/tools/msbuild/clang-cl.xml

2

I think a clang-cl tailored UI would be really nice, but I don't think it's sustainable to maintain this file by hand. If we want to expose clang-cl's options this way, I think we need to auto-generate it from the .td file, and that it needs to be tied to the clang-cl version whose options are being exposed.

We ship a major release twice a year, typically two more stable (x.0.1) releases per year, and in addition to that I ship snapshots about once or twice a month. If we're going to present clang-cl's options here, I think the file needs to stay in sync with clang-cl's options.

[zturner]

llvm/tools/msbuild/clang-cl.xml

2

Having it be auto-generated from the .td file is a good idea, but it's quite a bit of extra work and it may not be possible to do it in a useful way (for example, MSVC's UI displays the options in categories, which are defined just below this comment in Phab. Having the auto-generated options be correctly categorized seems difficult / impossible).

It's worth trying, and if we can do it then I agree it would be worth doing, but in the meantime I think the approach here is still strictly better than doing nothing, even if this file were never touched again (which is unlikely).

[hans]

llvm/tools/msbuild/clang-cl.xml

2

We can add categories to the flags in the .td file.

The "doing nothing" that we currently do is expose Visual Studio's choice of flags and then let clang-cl handle them. I don't think that's terribly bad.

[zturner]

llvm/tools/msbuild/clang-cl.xml

2

Sure, it's not terribly bad. But I'd like to do something better than just "not terribly bad". :)

There are other issues with auto-generating the file from the td as well. When an option takes multiple values (such as /arch:), the specific values it takes are not always present in the TD file. You mentioned /arch:AVX512 earlier, but that value is not in the td file anywhere.

That doesn't mean it's impossible, we can probably address all of the various issues to get the td file to a point where this file could be auto-generated. But I don't think that work should hold this up, as I still maintain that the solution here is strictly better from the user's perspective than the old method of doing nothing.

[• olgaark]

llvm/tools/msbuild/Clang.Cpp.Common.props

49

Yes, you can redefine CLToolExe/Path if you want to use 'cl' task, but have you looked at using 'ClangCompile' task instead (see Microsoft.Cpp.Clang.props & targets, as well as clang c2 toolset)? Would it work better for you? If not, we'll interested to know why.

llvm/tools/msbuild/LLVM.props

8

I believe the debugging is different for LLD produced binaries, so if this is the case, I'd recommend creating separate msbuild toolsets for Clang+Link and Clang+LLD.

VS has extensibility to support different debugging and it is expected that when toolset changes the set of available debuggers can change, but not when some arbitrary property is changed.

llvm/tools/msbuild/Toolset.targets

38

There is a way currently to extend a rule (not override it) where you can add/remove properties, but I am not sure it will make it better from maintenance perspective for clang-cl rule. You might want to use it for ConfigGeneral page though.

https://github.com/Microsoft/VSProjectSystem/commit/3e2e9c7ea2f3155de9932ab53d9ec37b6bdafa17

Also, if you decide to use ClangCompile task, clang.xml it the one which is matching it.

166

If you don't need to remove rules added by default and want just replace some of them (like cl one with clang-cl) you can allow default rules to be added and then include yours, If several rules in the list have the same name, the last one will be used.

So if you name your rule as "CL" (instead of "clang-cl") and make sure you include it to PropertyPageSchema items after importing MS targets which add 'real' cl rule, your rule will be used instead.

[zturner]

llvm/tools/msbuild/Clang.Cpp.Common.props

49

My understanding of the ClangCompile task is that it invokes clang.exe or clang++.exe and that it passes gcc style command line options (for example, clang.xml looks like it passes all gcc style options such as -fno-exceptions, etc.

The clang cl driver (clang-cl.exe) is designed to be a drop in replacement for cl.exe, and accepts MSVC style command line arguments. It's also the only supported way to produce native Windows exes (that's not to say you can't construct a clang++.exe command line that will do it, just that we only support it via the cl driver).

[zturner]

llvm/tools/msbuild/LLVM.props

8

Recent versions of LLD produce PDBs that are supposed to be completely compatible with link.exe PDBs. So, debugging should not change (we don't support managed debugging and certain other things like that, but on the other hand we don't generate managed code either, so it should be fine).

[zturner]

Question for @olgaark. Is there any way to get a page that looks like PageTemplate="generic" (i.e. with the expanding categories, such as the General page), but as a subpage of a PageTemplate="tool" page? For example, imagine you click Properties > C/C++ > Warnings, and then when you click the warnings page, I'd like that page to look like PageTemplate="generic". Is that possible?

[rnk]

llvm/tools/msbuild/clang-cl.xml

2

I don't think we'd get much value from table generating them. This file contains a lot of information and organization that we'd have to encode in tablegen. Every option would need its property sheet category, name, and display name, none of which we currently encode.

If we did want to automatically fill in undescribed options somehow, I'd suggest storing the property sheet information separately kind of like we currently do for the attribute documentation, and then "joining" the two files in tablegen to make this XML file. I just don't think it's worth it, though.

[rnk]

llvm/tools/msbuild/clang-cl.xml

2

I think part of the reason why I don't like the idea of loading this all into tablegen is that editing tablegen files sucks. We have all these ad-hoc conventions for adding line breaks, but there's no editor support for them or anything. I think if they were YAML files, it would be a lot easier to add new fields to options to help us auto-generate property sheets like this or even full HTML command line reference, something we sorely lack today.

Maybe this is just dreaming, but I expect YAML would also make it easier to automatically parse enum values to options, like /arch:avx512 etc. We could do that today, but it requires hacking on and extending this janky Record abstraction that's not well understood. Or maybe it just requires effort and motivation.

[zturner]

Added a UI setting that allows the user to choose a custom path to clang. It defaults to $(LLVMInstallDir)bin\clang-cl.exe. I added this to the general page of the UI. I then initialize the value of $(CLToolExe) with the value of this setting in the .targets file. And since I'm mucking with that page anyway, removed some settings that don't apply to clang-cl, surrounding managed code and App Store stuff.

Also fixed a bug where DebuggerFlavor wasn't being initialized in the .props file, the effect of which was that you couldn't debug unless you explicitly went to the debugger page and chose Local Windows Debugger.

[• olgaark]

llvm/tools/msbuild/Clang.Cpp.Common.props

49

Ok, it makes sense to use 'cl' task then

[hans]

llvm/tools/msbuild/clang-cl.xml

2

But this file is effectively duplicating the information about what flags clang-cl supports. Am I the only one that's concerned about how to maintain that, and the two getting out of sync?

Olga mentioned (https://reviews.llvm.org/D42762?id=132243#inline-375127) something about extending rules rather than overwriting them. Would that be an option for us, i.e. just exposing the regular cl options and maybe do a few tweaks where really necessary?

[rnk]

llvm/tools/msbuild/clang-cl.xml

2

I am concerned about the duplication, but I think encoding the information in this XML into TableGen is going to be really ugly. Even if we stored this info outside the tablegen, we'd need some way to "join" the property sheet data with the .td data, which effectively duplicates the list of flags, or at least the supported flags with documentation and display names, similar to the way the attribute reference docs work.

Re: Olga's comment, maybe that would work, but I suspect we won't have as much control over the organization.

[zturner]

llvm/tools/msbuild/clang-cl.xml

2

extending a rules file only works when you want to add a new category or option, not when you want to remove some options but keep others. So it's not going to save us from the duplication. Personally though I'm not at all concerned about the duplication. If we take the duplicated file as it exists in this CL, and never touch it or maintain it ever again, we would still be providing a better user experience than doing nothing and relying on whatever version happens to ship with Visual Studio.

It's extremely unlikely that we would never touch it again, however. And in the worst case scenario, if we do ultimately find out that it's too much maintenance, we can change 4 or 5 lines of xml to disable our custom rules file, push an update to the marketplace, and people will automatically get updated to the new version.

[hans]

llvm/tools/msbuild/clang-cl.xml

2

"If we take the duplicated file as it exists in this CL, and never touch it or maintain it ever again, we would still be providing a better user experience than doing nothing and relying on whatever version happens to ship with Visual Studio."

I'm not sure I agree, but I think this has been reviewed to exhaustion. Go ahead and submit, please publish under the [e-mail] account, and I guess we'll see how it works out.

[rnk]

lgtm, thanks for revamping the VS integration!

[chandlerc]

FYI, Andrew Pardoe from Microsoft and I were talking and he wanted to express really strong support for getting this in and deployed. He's also offered any help that would be useful to sorting this out so there is a solid installer for VS 2017.

Anything this is waiting on (since it already got an LGTM some time ago)?

[zturner]

In D42762#1041034, @chandlerc wrote:

FYI, Andrew Pardoe from Microsoft and I were talking and he wanted to express really strong support for getting this in and deployed. He's also offered any help that would be useful to sorting this out so there is a solid installer for VS 2017.

Anything this is waiting on (since it already got an LGTM some time ago)?

I think the biggest reason I've been dragging my feet on this is that there was never really a strong consensus that this was the right direction, and I don't feel great about committing without consensus. I guess I was subconsciously hoping someone else would show up and chime in with their opinion. Part of the problem is that there's not many LLVM developers who are also VS users, and of the ones that actually are, most are VS users of CMake generated projects as opposed to VS users of hand-maintained projects. And that is ultimately who we are targeting with this VS integration, so it would be good to have their feedback.

But since it looks like that probably isn't gonna happen, I guess I can wait until the end of this week and see if the discussion magically picks up again. If not, I suppose I can commit as-is at the end of the week.

[smeenai]

Any updates here?

[zturner]

I've got a new version of the VS integration here. Below I'll outline the changes from the previous iteration. Most of this is based on feedback from David Tarditi (who I'm now adding as a reviewer) and Hans. But I also added something new that was my own idea.

1. We no longer present a custom UI of the options. We do not change the layout of any builtin Microsoft UI page in any way.

2. We now silently discard certain command line options before passing them to clang-cl. We only do this for options that generate -Wunused-command-line warnings and for which we never plan to support the option anyway (for example Fiber Safe Optimizations).

3. We hard-error on options that fundamentally change the assumptions about the way in which code should be compiled. For example, /clr. These types of options would result in an error anyway because clang wouldn't understand the code, but at least now the user has a more meaningful error message.

4. We remap /ZI and /Zi to /Z7. See the comment in LLVM.Cpp.Common.Targets for a longer explanation.

5. Previously we let the user specify the Path to clang-cl.exe in the General page. We did this by forking the general page and adding a field to it. While this is arguably a "cleaner" user experience, it's more maintenance for us (and requires us to change a builtin UI page, which point #1 explains that we are no longer doing), and it may not continue to be a cleaner experience if we ever want to add more than just 1 field here (for example, path to lld-link.exe if/when we update the extension to support LLD). So I made a separate page called LLVM. This page appears whenever the LLVM Platform Toolset is selected. For now it only contains one option (path to clang-cl.exe), but in the future it could contain other options such as "Use clang-cl (True/False)", "Path to clang-cl.exe", "Use LLD", "Path to lld-link.exe", and maybe some other ones we could come up with.

Hopefully this is a nice middle ground and addresses all of the issues we were discussing earlier in the thread.

[smeenai]

llvm/tools/msbuild/LLVM.Cpp.Common.props

6 ↗

(On Diff #155494)

I think this should say LLVM.Cpp.Common.props instead of Clang.Cpp.Common.props?

42 ↗

(On Diff #155494)

Is there a way to add some sort of error here if LLVMInstallDir is still empty? Is it worth it?

72 ↗

(On Diff #155494)

Not that it really matters right now, but this wouldn't do the right thing for arm or arm64, right?

llvm/tools/msbuild/LLVM.Cpp.Common.targets

56 ↗

(On Diff #155494)

If users want to use LTO with clang-cl + lld-link, are they just expected to set the appropriate compiler and linker options manually?

85 ↗

(On Diff #155494)

This comment is swapped...

90 ↗

(On Diff #155494)

...with this.

118 ↗

(On Diff #155494)

I think it's more accurate to describe this as not supporting C++/CX, since clang does support WinRT using straight up COM.

[zturner]

Fixed issues pointed out by @smeenai

[zturner]

llvm/tools/msbuild/LLVM.Cpp.Common.props

42 ↗

(On Diff #155494)

I'm not sure it's worth it. We could maybe warn when the project is loaded if the path is invalid, but I don't think we should do anything special for $(LLVMInstallDir) specifically, because ultimately the user can just change this to something else, so having a valid install dir is not even necessary. So for a user that never wants to install LLVM and just set the path to clang, they might get annoyed by constantly seeing a warning which they don't care about. If they do try to use it, they'll get an error pretty quickly along the lines of Unable to find path file \bin\clang-cl.exe so hopefully that's a sufficient clue? I could probably try to catch this in BeforeClCompile and print a better error message if you think the standard error message isn't clear enough.

72 ↗

(On Diff #155494)

Right, we'd need something else here for arm.

llvm/tools/msbuild/LLVM.Cpp.Common.targets

56 ↗

(On Diff #155494)

For now yes. Even though they are conceptually the same thing, they are incompatible with each other from an implementation standpoint. So, for example, you couldn't use MSVC WPO object files with lld-link, for example, or vice versa. This VS integration right now, for example, doesn't even add support for using lld-link (only clang-cl), so use of this option right now would break the build, as link.exe would be trying to link llvm bitcode files. So I think it makes sense to (eventually) provide a separate UI option for LLVM LTO, perhaps under the new LLVM UI page.

[zturner]

Deleted clang-cl.xml. We no longer modify the existing settings UI so this file was stale. Also fixed the csproj to properly refer to llvm-general.xml.

[rnk]

I think that addresses @hans's concerns of duplicating all our options, so let's go ahead and land this.

[hans]

Thanks for pushing this through!

Will you upload the vsix to the marketplace? (Use the [e-mail] account, which despite the name is also used for the clang-format vs plugin etc.)

Then I can update the docs to point at it.

llvm/CMakeLists.txt

 if(WIN32 AND NOT UNIX)
   set(CPACK_PACKAGE_INSTALL_REGISTRY_KEY "LLVM")
   set(CPACK_PACKAGE_ICON "${CMAKE_CURRENT_SOURCE_DIR}\\\\cmake\\\\nsis_logo.bmp")
   set(CPACK_NSIS_MUI_ICON "${CMAKE_CURRENT_SOURCE_DIR}\\\\cmake\\\\nsis_icon.ico")
   set(CPACK_NSIS_MUI_UNIICON "${CMAKE_CURRENT_SOURCE_DIR}\\\\cmake\\\\nsis_icon.ico")
   set(CPACK_NSIS_MODIFY_PATH "ON")
   set(CPACK_NSIS_ENABLE_UNINSTALL_BEFORE_INSTALL "ON")
   set(CPACK_NSIS_EXTRA_INSTALL_COMMANDS
-    "ExecWait '$INSTDIR/tools/msbuild/install.bat'")
+    "ExecWait '$INSTDIR/tools/msbuild/install.bat'
+     WriteRegStr HKLM 'Software\\\\${CPACK_PACKAGE_INSTALL_REGISTRY_KEY}' 'Version' '${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR}.${LLVM_VERSION_PATCH}'
+    ")
   set(CPACK_NSIS_EXTRA_UNINSTALL_COMMANDS
     "ExecWait '$INSTDIR/tools/msbuild/uninstall.bat'")
   if( CMAKE_CL_64 )
     set(CPACK_NSIS_INSTALL_ROOT "$PROGRAMFILES64")
   endif()
 endif()
 include(CPack)
 
 # Sanity check our source directory to make sure that we are not trying to
 # generate an in-source build (unless on MSVC_IDE, where it is ok), and to make

llvm/tools/msbuild/CMakeLists.txt

 if (MSVC)
-  # CPack will install a registry key in this format that we wish to reference.
-  set(REG_KEY "${CPACK_PACKAGE_INSTALL_REGISTRY_KEY}")
-  set(LIB_PATH_VERSION "${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR}")
+  install(FILES "${CMAKE_CURRENT_SOURCE_DIR}/clang-cl.xml" DESTINATION tools/msbuild)
+  install(FILES "${CMAKE_CURRENT_SOURCE_DIR}/LLVM.props" DESTINATION tools/msbuild)
+  install(FILES "${CMAKE_CURRENT_SOURCE_DIR}/Toolset.props" DESTINATION tools/msbuild)
+  install(FILES "${CMAKE_CURRENT_SOURCE_DIR}/Toolset.targets" DESTINATION tools/msbuild)
 
-  foreach (platform "Win32" "x64")
-    set(prop_file_in "Microsoft.Cpp.Win32.llvm.props.in")
-    set(prop_file_v100 "Microsoft.Cpp.${platform}.LLVM-vs2010.props")
-    set(prop_file_v110 "Microsoft.Cpp.${platform}.LLVM-vs2012.props")
-    set(prop_file_v110_xp "Microsoft.Cpp.${platform}.LLVM-vs2012_xp.props")
-    set(prop_file_v120 "toolset-vs2013.props")
-    set(prop_file_v120_xp "toolset-vs2013_xp.props")
-    set(prop_file_v140 "toolset-vs2014.props")
-    set(prop_file_v140_xp "toolset-vs2014_xp.props")
-
-    if (platform STREQUAL "Win32")
-      set(mflag "m32")
-    else()
-      set(mflag "m64")
-    endif()
-    set(VS_VERSION "v100")
-    set(MSC_VERSION "1600")
-    configure_file(${prop_file_in} ${platform}/${prop_file_v100})
-    set(VS_VERSION "v110")
-    set(MSC_VERSION "1700")
-    configure_file(${prop_file_in} ${platform}/${prop_file_v110})
-    set(VS_VERSION "v110_xp")
-    configure_file(${prop_file_in} ${platform}/${prop_file_v110_xp})
-    set(VS_VERSION "v120")
-    set(MSC_VERSION "1800")
-    configure_file(${prop_file_in} ${platform}/${prop_file_v120})
-    set(VS_VERSION "v120_xp")
-    configure_file(${prop_file_in} ${platform}/${prop_file_v120_xp})
-    set(VS_VERSION "v140")
-    set(MSC_VERSION "1900")
-    configure_file(${prop_file_in} ${platform}/${prop_file_v140})
-    set(VS_VERSION "v140_xp")
-    configure_file(${prop_file_in} ${platform}/${prop_file_v140_xp})
-    set(VS_VERSION)
-    set(MSC_VERSION)
-    set(mflag)
-
-    install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${platform}/${prop_file_v100}" DESTINATION tools/msbuild/${platform})
-    install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${platform}/${prop_file_v110}" DESTINATION tools/msbuild/${platform})
-    install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${platform}/${prop_file_v110_xp}" DESTINATION tools/msbuild/${platform})
-    install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${platform}/${prop_file_v120}" DESTINATION tools/msbuild/${platform})
-    install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${platform}/${prop_file_v120_xp}" DESTINATION tools/msbuild/${platform})
-    install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${platform}/${prop_file_v140}" DESTINATION tools/msbuild/${platform})
-    install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${platform}/${prop_file_v140_xp}" DESTINATION tools/msbuild/${platform})
-
-    install(FILES "Microsoft.Cpp.Win32.LLVM-vs2010.targets" DESTINATION "tools/msbuild/${platform}" RENAME "Microsoft.Cpp.${platform}.LLVM-vs2010.targets")
-    install(FILES "Microsoft.Cpp.Win32.LLVM-vs2012.targets" DESTINATION "tools/msbuild/${platform}" RENAME "Microsoft.Cpp.${platform}.LLVM-vs2012.targets")
-    install(FILES "Microsoft.Cpp.Win32.LLVM-vs2012_xp.targets" DESTINATION "tools/msbuild/${platform}" RENAME "Microsoft.Cpp.${platform}.LLVM-vs2012_xp.targets")
-    install(FILES "toolset-vs2013.targets" DESTINATION "tools/msbuild/${platform}")
-    install(FILES "toolset-vs2013_xp.targets" DESTINATION "tools/msbuild/${platform}")
-    install(FILES "toolset-vs2014.targets" DESTINATION "tools/msbuild/${platform}")
-    install(FILES "toolset-vs2014_xp.targets" DESTINATION "tools/msbuild/${platform}")
-  endforeach()
-
-  set(LIB_PATH_VERSION)
-  set(REG_KEY)
-
-  install(DIRECTORY .
-    DESTINATION tools/msbuild
-    FILES_MATCHING
-    PATTERN "*.bat"
-    PATTERN ".svn" EXCLUDE
-    )
+  install(FILES "${CMAKE_CURRENT_SOURCE_DIR}/install.bat" DESTINATION tools/msbuild)
+  install(FILES "${CMAKE_CURRENT_SOURCE_DIR}/uninstall.bat" DESTINATION tools/msbuild)
 endif()

llvm/tools/msbuild/Clang.Cpp.Common.props

+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <!-- The general order of executing an MSBuild file is roughly:
+       1) vcxproj file
+       2) ├─ Import Microsoft.Cpp.props
+       3) │  └─ Import Toolset specific props (e.g. $(VCTargets)Platforms\Win32\PlatformToolsets\llvm\Toolset.props)
+       4) │     └─ Import This File (Clang.Cpp.Common.props)
+       5) │─ Core logic of vcxproj (define files, override properties, etc)
+       6) └─ Import Microsoft.Cpp.targets
+       7)    │─ Import Toolset specific targets file (e.g. $(VCTargets)Platforms\Win32\PlatformToolsets\llvm\Toolset.targets)
+       8)    └─ Run the compiler.
+       The important thing is that we have hooks at 3, 4, and 7.  3 and 4 give
+       us the ability to provide initial values for toolchain settings (where
+       is the compiler, what values are considered "default" for a given
+       setting, etc), 7 gives us the ability to act on anything that the user
+       has overridden (such as warning or erroring on incompatible settings,
+       mapping settings to other settings, etc).
+       -->
+  
+  <PropertyGroup>
+    <!-- This initializes the values in Properties > General > Output Directory.
+       Builds will fail without this. -->
+    <OutDirWasSpecified Condition=" '$(OutDir)'!='' AND '$(OutDirWasSpecified)'=='' ">true</OutDirWasSpecified>
+    <OutDirWasSpecified Condition=" '$(OutDir)'=='' AND '$(OutDirWasSpecified)'=='' ">false</OutDirWasSpecified>
+
+    <IntDir Condition="'$(IntDir)'=='' AND '$(IntermediateOutputPath)'!=''">$(IntermediateOutputPath)</IntDir>
+    <IntDir Condition="'$(IntDir)'=='' AND '$(IntermediateOutputPath)'==''">$(Configuration)\</IntDir>
+    <OutDir Condition="'$(OutDir)'=='' AND '$(SolutionDir)' != ''">$(SolutionDir)$(Configuration)\</OutDir>
+    <OutDir Condition="'$(OutDir)'=='' AND '$(SolutionDir)' == ''">$(IntDir)</OutDir>
+  </PropertyGroup>
+  
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.WindowsSDK.props" Condition="Exists('$(VCTargetsPath)\Microsoft.Cpp.WindowsSDK.props')"/>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Common.props" />
+
+  <PropertyGroup>
+    <!-- Find an installed LLVM. -->
+    <LLVMInstallDir>$(Registry:HKEY_LOCAL_MACHINE\SOFTWARE\LLVM@LLVM)</LLVMInstallDir>
+    <LLVMInstallDir Condition="'$(LLVMInstallDir)' == ''">$(Registry:HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\LLVM@LLVM)</LLVMInstallDir>
+    <LLVMVersion>$(Registry:HKEY_LOCAL_MACHINE\SOFTWARE\LLVM@Version)</LLVMVersion>
+    <LLVMVersion Condition="'$(LLVMVersion)' == ''">$(Registry:HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\LLVM@Version)</LLVMVersion>
+    
+    <!-- The registry key may not be set if it's an old installer, try the newest version that exists -->
+    <LLVMVersion Condition="'$(LLVMVersion)' == '' and Exists('$(LLVMInstallDir)\lib\clang\7.0.0')">7.0.0</LLVMVersion>
+    <LLVMVersion Condition="'$(LLVMVersion)' == '' and Exists('$(LLVMInstallDir)\lib\clang\6.0.0')">6.0.0</LLVMVersion>
+    <LLVMVersion Condition="'$(LLVMVersion)' == '' and Exists('$(LLVMInstallDir)\lib\clang\5.0.0')">5.0.0</LLVMVersion>
+
+    <LLVMLibDir>$(LLVMInstallDir)lib\clang\$(LLVMVersion)</LLVMLibDir>
+    <!-- Tell MSBuild that instead of invoking cl.exe, it should invoke clang-cl.exe from the install dir. -->
+    <CLToolExe>clang-cl.exe</CLToolExe>
+    <CLToolPath>$(LLVMInstallDir)bin</CLToolPath>
+
+    <!-- Set some paths (such as include paths) that are common to all platforms.  This is mostly the same
+         as what the default paths for cl will use, except that we add $(LLVMLibDir)include, which contains
+         clang system header files.
+         -->
+    <IncludePath Condition="'$(IncludePath)' == ''">$(LLVMLibDir)include;$(IncludePath);$(VC_IncludePath);$(WindowsSDK_IncludePath);</IncludePath>
+    <LibraryWPath Condition="'$(LibraryWPath)' == ''">$(WindowsSDK_MetadataPath);</LibraryWPath>
+    <SourcePath Condition="'$(SourcePath)' == ''">$(VC_SourcePath);</SourcePath>
+  </PropertyGroup>
+
+
+  <!-- Set values which are reflected in the property UI by default.  The user can override these
+       by editing the vcxproj file (or making changes via the UI, which has the same effect).  There
+       are some additional settings which we want to override *after* the user has a chance to set them
+       as well.  Those are handled in the .targets file, since that gets imported at the end of the
+       .vcxproj.
+       -->
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <!-- Set this to "Default" (which means not passing any /RTC option) so that any other value will
+           be treated as having been overridden by the user.  This Serves as a hint to the user that
+           Default is the value we support, and other values will generate a warning.  It also means
+           that if the user simply creates a new project in MSVC (which uses /RTCu by default), then
+           switches the toolset to Clang, we will still treat the value as default (which for us is to
+           not pass the option).  Only if the user explicitly overrode this setting in a project to use
+           /RTCu would we see the warning. -->
+      <BasicRuntimeChecks>Default</BasicRuntimeChecks>
+
+      <AdditionalOptions>-m$(PlatformArchitecture) %(AdditionalOptions)</AdditionalOptions>
+    </ClCompile>
+  </ItemDefinitionGroup>
+</Project>

llvm/tools/msbuild/Clang.Toolset.x64.props

+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(VCTargetsPath)\Clang.Cpp.Common.props"/>
+
+  <PropertyGroup>
+    <ExecutablePath Condition="'$(ExecutablePath)' == ''">$(VC_ExecutablePath_x64);$(WindowsSDK_ExecutablePath);$(VS_ExecutablePath);$(MSBuild_ExecutablePath);$(FxCopDir);$(PATH);</ExecutablePath>
+    <ReferencePath Condition="'$(ReferencePath)' == ''">$(VC_ReferencesPath_x64);</ReferencePath>
+    <LibraryPath Condition="'$(LibraryPath)' == ''">$(VC_LibraryPath_x64);$(WindowsSDK_LibraryPath_x64);$(NETFXKitsDir)Lib\um\x64</LibraryPath>
+    <ExcludePath Condition="'$(ExcludePath)' == ''">$(VC_IncludePath);$(WindowsSDK_IncludePath);$(MSBuild_ExecutablePath);$(VC_LibraryPath_x64);</ExcludePath>
+    <DebugCppRuntimeFilesPath Condition="'$(DebugCppRuntimeFilesPath)' == ''">$(VCToolsInstallDir)redist\Debug_NonRedist\x64</DebugCppRuntimeFilesPath>
+  </PropertyGroup>
+</Project>

llvm/tools/msbuild/Clang.Toolset.x86.props

+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(VCTargetsPath)\Clang.Cpp.Common.props"/>
+
+  <PropertyGroup>
+    <ExecutablePath Condition="'$(ExecutablePath)' == ''">$(VC_ExecutablePath_x86);$(WindowsSDK_ExecutablePath);$(VS_ExecutablePath);$(MSBuild_ExecutablePath);$(SystemRoot)\SysWow64;$(FxCopDir);$(PATH);</ExecutablePath>
+    <ReferencePath Condition="'$(ReferencePath)' == ''">$(VC_ReferencesPath_x86);</ReferencePath>
+    <LibraryPath Condition="'$(LibraryPath)' == ''">$(VC_LibraryPath_x86);$(WindowsSDK_LibraryPath_x86);$(NETFXKitsDir)Lib\um\x86</LibraryPath>
+    <ExcludePath Condition="'$(ExcludePath)' == ''">$(VC_IncludePath);$(WindowsSDK_IncludePath);$(MSBuild_ExecutablePath);$(VC_LibraryPath_x86);</ExcludePath>
+    <DebugCppRuntimeFilesPath Condition="'$(DebugCppRuntimeFilesPath)' == ''">$(VCToolsInstallDir)redist\Debug_NonRedist\x86</DebugCppRuntimeFilesPath>
+  </PropertyGroup>
+</Project>

llvm/tools/msbuild/LLVM.props

+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003" TreatAsLocalProperty="Platform">
+
+  <PropertyGroup>
+    <!-- Short names for platform toolsets (added to project name in Solution Explorer) -->
+    <_PlatformToolsetShortNameFor_llvm Condition="'$(_PlatformToolsetShortNameFor_llvm)' == ''">clang-cl</_PlatformToolsetShortNameFor_llvm>
+
+    <!-- Friendly names added to the PlatformToolset in the property pages. -->
+    <_PlatformToolsetFriendlyNameFor_llvm Condition="'$(_PlatformToolsetFriendlyNameFor_llvm)' == ''">Clang for Windows</_PlatformToolsetFriendlyNameFor_llvm>
+  </PropertyGroup>
+
+</Project>

llvm/tools/msbuild/Microsoft.Cpp.Win32.LLVM-vs2010.targets

-<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-</Project>

llvm/tools/msbuild/Microsoft.Cpp.Win32.LLVM-vs2012.targets

-<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(VCTargetsPath)\Microsoft.CppCommon.targets" />
-</Project>

llvm/tools/msbuild/Microsoft.Cpp.Win32.LLVM-vs2012_xp.targets

-<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <!-- Force TargetFrameworkVersion to v4.0 to support XP-->
-  <PropertyGroup>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
-    <BeforeClCompileTargets>NoSupportCodeAnalysisXP;$(BeforeClCompileTargets)</BeforeClCompileTargets>
-  </PropertyGroup>
-
-  <Import Project="$(VCTargetsPath)\Microsoft.CppCommon.targets" />
-
-  <Target Name="NoSupportCodeAnalysisXP" Condition="'$(ErrorNoSupportCodeAnalysisXP)' != 'false'">
-    <VCMessage Condition="'$(DesignTimeBuild)' != 'true' and '@(ClCompile->AnyHaveMetadataValue('EnablePREfast', 'true'))'=='true'" Code="MSB8026" Type="Error"/>
-  </Target>
-
-  <PropertyGroup>
-    <PrepareForBuildDependsOn>CheckWindowsSDK71A;$(PrepareForBuildDependsOn)</PrepareForBuildDependsOn>
-  </PropertyGroup>
-
-  <Target Name="CheckWindowsSDK71A">
-    <VCMessage Code="MSB8003" Type="Warning" Arguments="WindowsSdkDir_71A" Condition="'$(WindowsSdkDir_71A)'=='' and '$(UseEnv)' != 'true'" />
-  </Target>
-</Project>

llvm/tools/msbuild/Microsoft.Cpp.Win32.llvm.props.in

-<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">  
-  <Import Project="$(VCTargetsPath)\Platforms\$(Platform)\PlatformToolsets\@VS_VERSION@\Microsoft.Cpp.$(Platform).@VS_VERSION@.props" Condition="Exists('$(VCTargetsPath)\Platforms\$(Platform)\PlatformToolsets\@VS_VERSION@\Microsoft.Cpp.$(Platform).@VS_VERSION@.props')"/>
-  <Import Project="$(VCTargetsPath)\Platforms\$(Platform)\PlatformToolsets\@VS_VERSION@\Toolset.props" Condition="Exists('$(VCTargetsPath)\Platforms\$(Platform)\PlatformToolsets\@VS_VERSION@\Toolset.props')"/>
-
-  <PropertyGroup>
-    <LLVMInstallDir>$(Registry:HKEY_LOCAL_MACHINE\SOFTWARE\LLVM\@REG_KEY@)</LLVMInstallDir>
-    <LLVMInstallDir Condition="'$(LLVMInstallDir)' == ''">$(Registry:HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\LLVM\@REG_KEY@)</LLVMInstallDir>
-    <ExecutablePath>$(LLVMInstallDir)\msbuild-bin;$(ExecutablePath)</ExecutablePath>
-    <LibraryPath>$(LLVMInstallDir)\lib\clang\@LIB_PATH_VERSION@\lib\windows;$(LibraryPath)</LibraryPath>
-  </PropertyGroup>
-
-  <ItemDefinitionGroup>
-    <ClCompile>
-      <!-- Set the value of _MSC_VER to claim for compatibility -->
-      <AdditionalOptions>-@mflag@ -fmsc-version=@MSC_VERSION@ %(AdditionalOptions)</AdditionalOptions>
-    </ClCompile>
-  </ItemDefinitionGroup>
-</Project>

llvm/tools/msbuild/Toolset.targets

+<!-- This file exists to replace the compiler and linker UI pages.  The code in here is forked
+     from VCTargets/Microsoft.CppBuild.targets with only the compiler and linker pages replaced.
+-->
+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(MSBuildThisFileDirectory)ImportBefore\*.targets" Condition="Exists('$(MSBuildThisFileDirectory)ImportBefore')" />
+
+  <Import Project="$(VCTargetsPath)\Microsoft.CppCommon.targets" />
+
+  <!-- We hook up a target to run every time ClCompile is about to run, the purpose of which is to
+       sanitize the command line before it gets passed to the compiler.  Some options we silently
+       discard, other options we warn on and then discard, and other options we generate a hard
+       error.
+       
+       We try to keep hard errors to a minimum and reserve it for cases where the option implies
+       fundamentally different assumptions about the way code should be compiled.  This code would
+       probably generate an error anyway, but at least this way we give the user a more useful message
+       about what the actual problem is, rather than relying on some obscure compilation error.
+       
+       For any options that clang-cl discards, we would prefer to not even pass them in on the command
+       line.  Even though we expose only a limited set of options through the UI, we re-use the existing
+       ClCompile task infrastructure.  So if a user starts with a cl projects and changes the toolset to
+       clang, they could have set options such as /Gm (minimal rebuild), /sdl (Security Checks), etc.
+       The ClCompile task would then notice this and pass these through to clang-cl.exe.  Clang would of
+       course ignore them, but in some cases (such as /Gm), they would generate -Wunused-command-line-argument
+       warnings, so it's better if we can just strip them from the command line entirely.  This also has the
+       side benefit of making command lines shorter which is always nice when trying to look at the tool
+       output.
+      -->
+  <Target Name="BeforeClCompile" BeforeTargets="ClCompile">
+    <!-- Warn on /Zi and /ZI, then map them both to /Z7. -->
+    <Warning Condition="'%(ClCompile.DebugInformationFormat)' == 'ProgramDatabase'"
+             File="@(ClCompile)(0,0)"
+             Text="clang-cl does not support /Zi (Program Database).  The file will be compiled as if /Z7 (C7 Compatible Debug Info) had been passed.  Update the Debug Information Format in project settings to silence this warning."/>
+    <Warning Condition="'%(ClCompile.DebugInformationFormat)' == 'EditAndContinue'"
+             File="@(ClCompile)(0,0)"
+           Text="clang-cl does not support /ZI (Program Database for Edit and Continue).  The file will be compiled as if /Z7 (C7 Compatible Debug Info) had been passed.  Update the Debug Information Format in project settings to silence this warning."/>
+    
+    <!-- Warn if Fiber Safe Optimizations are enabled, and then ignore them. -->
+    <Warning Condition="'%(ClCompile.EnableFiberSafeOptimizations)' == 'true'"
+             File="@(ClCompile)(0,0)"
+             Text="clang-cl does not support fiber safe optimizations (/GT).  Disable this option in compatibility settings to silence this warning."/>
+    
+    <!-- Warn if Whole Program Optimization is enabled, and then ignore it. -->
+    <Warning Condition="'%(ClCompile.WholeProgramOptimization)' == 'true'"
+             File="@(ClCompile)(0,0)"
+             Text="clang-cl does not support MSVC Link Time Optimization.  Disable this option in compatibility settings to silence this warning."/>
+
+    <!-- Warn if Ignore Standard Include Paths is non-empty, then ignore it. -->
+    <Warning Condition="'%(ClCompile.IgnoreStandardIncludePath)' == 'true'"
+             File="@(ClCompile)(0,0)"
+             Text="clang-cl does not support Ignore Standard Include Path (/X).  Disable this option in compatibility settings to silence this warning."/>
+    
+    <!-- Warn if Smaller Type Check is enabled, then ignore it.-->
+    <Warning Condition="'%(ClCompile.SmallerTypeCheck)' == 'true'"
+             File="@(ClCompile)(0,0)"
+             Text="clang-cl does not support Smaller Type Check (/RTCc).  Disable this option in compatibility settings to silence this warning."/>
+
+    <!-- Warn if Runtime Checks are enabled, then ignore them.-->
+    <Warning Condition="'%(ClCompile.BasicRuntimeChecks)' != 'Default'"
+             File="@(ClCompile)(0,0)"
+             Text="clang-cl does not support Basic Runtime Checks (/RTCu, /RTC1, /RTCs).  Disable this option in compatibility settings to silence this warning."/>
+
+    <!-- Warn if parallel code generation on #pragma loop is enabled, then ignore. -->
+    <Warning Condition="'(ClCompile.EnableParallelCodeGeneration)' == 'true'"
+             File="@(ClCompile)(0,0)"
+             Text="clang-cl does not support parallel code generation with #pragma loop(hint) (/Qpar).  Disable this option in compatibility settings to silence this warning."/>
+    
+    <!-- Warn if hotpatchable images are turned on -->
+    <Warning Condition="'%(ClCompile.CreateHotpatchableImage)' == 'true'"
+             File="@(ClCompile)(0,0)"
+             Text="clang-cl does not support creating hotpatchable images (/hotpatch).  Disable this option in compatibility settings to silence this warning."/>
+
+    <!-- Warn if /Zc:wchar_t- is specified, and then ignore it. -->
+    <Warning Condition="'%(ClCompile.ForceConformanceInForLoopScope)' == 'false'"
+             File="@(ClCompile)(0,0)"
+             Text="clang-cl does not support disabling for loop scope conformance (/Zc:forScope-).  Disable this option in compatibility settings to silence this warning."/>
+
+    <!-- Warn if /Zc:forScope- is specified, and then ignore it. -->
+    <Warning Condition="'%(ClCompile.TreatWChar_tAsBuiltInType)' == 'false'"
+             File="@(ClCompile)(0,0)"
+             Text="clang-cl does not support treating wchar_t as a non builtin type (/Zc:wchar_t-).  Disable this option in compatibility settings to silence this warning."/>
+    
+    <!-- Warn if XML Documentation is generated, and then ignore it. -->
+    <Warning Condition="'%(ClCompile.GenerateXMLDocumentationFiles)' == 'true'"
+             File="@(ClCompile)(0,0)"
+             Text="clang-cl does not support generating xml documentation comment files (/doc).  Disable this option in compatibility settings to silence this warning."/>
+
+    <!-- Warn if Browse Information is generated, and then ignore it. -->
+    <Warning Condition="'%(ClCompile.BrowseInformation)' == 'true'"
+             File="@(ClCompile)(0,0)"
+             Text="clang-cl does not support generating browse information (/FR).  Disable this option in compatibility settings to silence this warning."/>
+    
+    <!-- Warn if /analyze is passed, then ignore it. -->
+    <Warning Condition="'%(ClCompile.EnablePREfast)' == 'true'"
+             File="@(ClCompile)(0,0)"
+             Text="clang-cl does not support MSVC code analysis functionality (/analyze).  Disable this option in compatibility settings to silence this warning."/>
+
+    <!-- Error if they're trying to compile this file as managed code. -->
+    <Error Condition="('%(ClCompile.CompileAsManaged)' != 'false') AND ('%(ClCompile.CompileAsManaged)' != '')"
+           File="@(ClCompile)(0,0)"
+           Text="clang-cl does not support the /clr option.  This file cannot be compiled."/>
+
+    <!-- Error if WinRT is being used. -->
+    <Error Condition="('%(ClCompile.CompileAsWinRT)' == 'true') OR ('%(ClCompile.WinRTNoStdLib)' == 'true')"
+           File="@(ClCompile)(0,0)"
+           Text="clang-cl does not support WinRT (/ZW, /ZW:nostdlib).  This file cannot be compiled."/>
+
+    <!-- Error if OpenMP language extensions are enabled. -->
+    <Error Condition="'%(ClCompile.OpenMPSupport)' == 'true'"
+           File="@(ClCompile)(0,0)"
+           Text="clang-cl does not support OpenMP (/openmp).  This file cannot be compiled."/>
+    
+    <!-- Error if C++ Modules are enabled.  Clang has its own notion of modules that are not compatible. -->
+    <Error Condition="'%(ClCompile.EnableModules)' == 'true'"
+           File="@(ClCompile)(0,0)"
+           Text="clang-cl does not support MSVC Modules (/experimental:module).  This file cannot be compiled."/>
+    
+    <ItemGroup>
+      <ClCompile>
+        <!-- Map /ZI and /Zi to /Z7 -->
+        <DebugInformationFormat Condition="'%(ClCompile.DebugInformationFormat)' == 'ProgramDatabase'">OldStyle</DebugInformationFormat>
+        <DebugInformationFormat Condition="'%(ClCompile.DebugInformationFormat)' == 'EditAndContinue'">OldStyle</DebugInformationFormat>
+        
+        <!-- Unset any options that we either silently ignore or warn about due to compatibility.
+             Generally when an option is set to no value, that means "Don't pass an option to the
+             compiler at all."
+             -->
+        <WholeProgramOptimization/>
+        <EnableFiberSafeOptimizations/>
+        <IgnoreStandardIncludePath/>
+        <EnableParallelCodeGeneration/>
+        <ForceConformanceInForLoopScope/>
+        <TreatWChar_tAsBuiltInType/>
+        <SDLCheck/>
+        <CreateHotpatchableImage/>
+        <GenerateXMLDocumentationFiles/>
+        <BrowseInformation/>
+        <EnablePREfast/>
+        <MinimalRebuild/>
+        <StringPooling/>
+        <ExpandAttributedSource/>
+        <DiagnosticsFormat/>
+        <EnforceTypeConversionRules/>
+        <ErrorReporting/>
+        <DisableLanguageExtensions/>
+        <ProgramDataBaseFileName/>
+        <DisableSpecificWarnings/>
+        <TreatSpecificWarningsAsErrors/>
+        <ForcedUsingFiles/>
+        <PREfastLog/>
+        <PREfastAdditionalOptions/>
+        <PREfastAdditionalPlugins/>
+        <MultiProcessorCompilation/>
+        <UseFullPaths/>
+        <RemoveUnreferencedCodeData/>
+
+        <!-- We can't just unset BasicRuntimeChecks, as that will pass /RTCu to the compiler.
+             We have to explicitly set it to 'Default' to avoid passing anything. -->
+        <BasicRuntimeChecks>Default</BasicRuntimeChecks>
+      </ClCompile>
+    </ItemGroup>
+  </Target>
+  
+  <!-- By default MSBuild will add its own settings UI.  Disable this and use our forked version
+       instead.  The code below is mostly a straight fork from the common Microsoft build file,
+       with only cl.xml replaced with clang-cl.xml. -->
+  <PropertyGroup>
+    <UseDefaultProjectTools>false</UseDefaultProjectTools>
+    <UseDefaultPropertyPageSchemas>false</UseDefaultPropertyPageSchemas>
+    <UseDefaultGeneralPropertyPageSchema>false</UseDefaultGeneralPropertyPageSchema>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <!-- Property pages that always apply -->
+    <PropertyPageSchema Include="
+      $(VCTargetsPath)$(LangID)\ProjectItemsSchema.xml;
+      $(VCTargetsPath)$(LangID)\midl.xml;
+      $(VCTargetsPath)$(LangID)\build_events.xml;
+      $(VCTargetsPath)$(LangID)\custom_build_tool.xml;
+      $(VCTargetsPath)$(LangID)\custom_build_step.xml;
+  "/>
+    <PropertyPageSchema Include="$(VCTargetsPath)$(LangID)\general_file.xml">
+      <Context>File</Context>
+    </PropertyPageSchema>
+
+    <DesktopDebuggerPages Include="$(VCTargetsPath)$(LangID)\debugger_local_windows.xml" />
+
+    <!-- Debuggers -->
+    <DebuggerPages Condition="'$(_ApplicableDebuggers)' == 'Desktop'" Include="@(DesktopDebuggerPages)" />
+
+    <!-- We always need debuggers general page as soon as we have at least one debugger -->
+    <PropertyPageSchema Condition="'@(DebuggerPages)' != ''" Include="$(VCTargetsPath)$(LangID)\debugger_general.xml" />
+    <PropertyPageSchema Include="@(DebuggerPages)" />
+
+    <!-- Property sheet specific property pages -->
+    <PropertyPageSchema Include="$(VCTargetsPath)$(LangID)\usermacros.xml">
+      <Context>PropertySheet</Context>
+    </PropertyPageSchema>
+
+    <!-- Switch view between project property based directories and environment variables -->
+    <PropertyPageSchema Condition="'$(UseEnv)' != 'true'" Include="$(VCTargetsPath)$(LangID)\directories.xml" />
+    <PropertyPageSchema Condition="'$(UseEnv)' == 'true'" Include="$(VCTargetsPath)$(LangID)\envvars.xml" />
+
+    <!-- Non-Utility project property pages -->
+    <PropertyPageSchema Condition="'$(ConfigurationType)' != 'Utility'" Include="$(VCTargetsPath)$(LangID)\mt.xml;">
+      <Context>Project;PropertySheet</Context>
+    </PropertyPageSchema>
+
+    <PropertyPageSchema Condition="'$(ConfigurationType)' != 'Utility'" Include="$(VCTargetsPath)$(LangID)\clang-cl.xml"/>
+    <PropertyPageSchema Condition="'$(ConfigurationType)' != 'Utility'" Include="$(VCTargetsPath)$(LangID)\link.xml"/>
+    <PropertyPageSchema Condition="'$(ConfigurationType)' != 'Utility'" Include="$(VCTargetsPath)$(LangID)\lib.xml"/>
+
+    <PropertyPageSchema Condition="'$(ConfigurationType)' != 'Utility'" Include="
+      $(VCTargetsPath)$(LangID)\alink.xml;
+      $(VCTargetsPath)$(LangID)\rc.xml;
+      $(VCTargetsPath)$(LangID)\resgen.xml;
+  "/>
+  </ItemGroup>
+
+  <ItemGroup>
+    <PropertyPageSchema Include="$(VCTargetsPath)$(LangID)\general.xml">
+      <Context>Project</Context>
+    </PropertyPageSchema>
+    <PropertyPageSchema Include="$(VCTargetsPath)$(LangID)\general_ps.xml">
+      <Context>PropertySheet</Context>
+    </PropertyPageSchema>
+    <PropertyPageSchema Include="$(VCTargetsPath)$(LangID)\folder.xml">
+      <Context>File;BrowseObject</Context>
+    </PropertyPageSchema>
+  </ItemGroup>
+
+  <ItemGroup Condition="('$(ConfigurationType)' == 'Application' or '$(ConfigurationType)' == 'DynamicLibrary')">
+    <ProjectTools Include="Link"/>
+    <ProjectTools Include="CustomBuildStep"/>
+  </ItemGroup>
+
+  <!-- Tools that show up in the IDE property pages for lib project-->
+  <ItemGroup Condition="'$(ConfigurationType)' == 'StaticLibrary'">
+    <ProjectTools Include="Lib"/>
+    <ProjectTools Include="CustomBuildStep"/>
+  </ItemGroup>
+
+  <Import Project="$(MSBuildThisFileDirectory)ImportAfter\*.targets" Condition="Exists('$(MSBuildThisFileDirectory)ImportAfter')" />
+
+</Project>
 No newline at end of file

llvm/tools/msbuild/clang-cl.xml

+<?xml version="1.0" encoding="utf-8"?>
+<Rule Name="clang-cl" PageTemplate="tool" DisplayName="C/C++" SwitchPrefix="/" Order="10" xmlns="http://schemas.microsoft.com/build/2009/properties" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:sys="clr-namespace:System;assembly=mscorlib">
+  <Rule.Categories>
+    <Category Name="Incompatible" DisplayName="MSVC (Incompatible)"/>
+    <Category Name="Ignored" DisplayName="MSVC (Ignored)"/>
+    <Category Name="General" DisplayName="General" />
+    <Category Name="Optimization" DisplayName="Optimization" />
+    <Category Name="Preprocessor" DisplayName="Preprocessor" />
+    <Category Name="Code Generation" DisplayName="Code Generation" />
+    <Category Name="Language" DisplayName="Language" />
+    <Category Name="Precompiled Headers" DisplayName="Precompiled Headers" />
+    <Category Name="Output Files" DisplayName="Output Files" />
+    <Category Name="Advanced" DisplayName="Advanced" />
+    <Category Name="All Options" DisplayName="All Options" Subtype="Search" />
+    <Category Name="Command Line" DisplayName="Command Line" Subtype="CommandLine" />
+  </Rule.Categories>
+  <Rule.DataSource>
+    <DataSource Persistence="ProjectFile" ItemType="ClCompile" Label="" HasConfigurationCondition="true" />
+  </Rule.DataSource>
+  <StringListProperty Subtype="folder" Name="AdditionalIncludeDirectories" DisplayName="Additional Include Directories" Description="Specifies one or more directories to add to the include path; separate with semi-colons if more than one.     (/I[path])" Category="General" Switch="I" F1Keyword="VC.Project.VCCLCompilerTool.AdditionalIncludeDirectories">
+  </StringListProperty>
+  <EnumProperty Name="DebugInformationFormat" DisplayName="Debug Information Format" Description="Specifies the type of debugging information generated by the compiler.  This requires compatible linker settings.  (/Z7)" Category="General" F1Keyword="VC.Project.VCCLCompilerTool.DebugInformationFormat">
+    <EnumValue Name="None" Switch="" DisplayName="None" Description="Produces no debugging information, so compilation may be faster.">
+    </EnumValue>
+    <EnumValue Name="OldStyle" Switch="Z7" DisplayName="C7 compatible" Description="Select the type of debugging information created for your program and whether this information is kept in object (.obj) files or in a program database (PDB).">
+    </EnumValue>
+  </EnumProperty>
+  <BoolProperty Name="SuppressStartupBanner" DisplayName="Suppress Startup Banner" Description="Suppresses the display of the sign-on banner when the compiler starts up and display of informational messages during compiling." Category="General" Switch="nologo" F1Keyword="VC.Project.VCCLCompilerTool.SuppressStartupBanner">
+  </BoolProperty>
+  <EnumProperty Name="WarningLevel" DisplayName="Warning Level" Description="Select how strict you want the compiler to be about code errors.     (/W0 - /W4)" Category="General" F1Keyword="VC.Project.VCCLCompilerTool.WarningLevel">
+    <EnumValue Name="TurnOffAllWarnings" Switch="W0" DisplayName="Turn Off All Warnings" Description="Level 0 disables all warnings.">
+    </EnumValue>
+    <EnumValue Name="Level1" Switch="W1" DisplayName="Level1" Description="Level 1 displays severe warnings. Level 1 is the default warning level at the command line.">
+    </EnumValue>
+    <EnumValue Name="Level2" Switch="W2" DisplayName="Level2" Description="Level 2 displays all level 1 warnings and warnings less severe than level 1.">
+    </EnumValue>
+    <EnumValue Name="Level3" Switch="W3" DisplayName="Level3" Description="Level 3 displays all level 2 warnings and all other warnings recommended for production purposes.">
+    </EnumValue>
+    <EnumValue Name="Level4" Switch="W4" DisplayName="Level4" Description="Level 4 displays all level 3 warnings plus informational warnings, which in most cases can be safely ignored.">
+    </EnumValue>
+    <EnumValue Name="EnableAllWarnings" Switch="Wall" DisplayName="EnableAllWarnings" Description="Enables all warnings, including those disabled by default.">
+    </EnumValue>
+  </EnumProperty>
+  <BoolProperty ReverseSwitch="WX-" Name="TreatWarningAsError" DisplayName="Treat Warnings As Errors" Description="Treats all compiler warnings as errors. For a new project, it may be best to use /WX in all compilations; resolving all warnings will ensure the fewest possible hard-to-find code defects." Category="General" Switch="WX" F1Keyword="VC.Project.VCCLCompilerTool.WarnAsError">
+  </BoolProperty>
+  <StringProperty Subtype="folder" Name="TrackerLogDirectory" DisplayName="Tracker Log Directory" Description="Tracker Log Directory." Category="General" IncludeInCommandLine="false" Visible="false">
+  </StringProperty>
+  <EnumProperty Name="Optimization" DisplayName="Optimization" Description="Select option for code optimization; choose Custom to use specific optimization options.     (/Od, /O1, /O2, /Ox)" Category="Optimization" F1Keyword="VC.Project.VCCLCompilerTool.Optimization">
+    <EnumValue Name="Custom" Switch="" DisplayName="Custom" Description="Custom optimization.">
+    </EnumValue>
+    <EnumValue Name="Disabled" Switch="Od" DisplayName="Disabled" Description="Disable optimization.">
+    </EnumValue>
+    <EnumValue Name="MinSpace" Switch="O1" DisplayName="Minimize Size" Description="Equivalent to /Og /Os /Oy /Ob2 /Gs /GF /Gy">
+    </EnumValue>
+    <EnumValue Name="MaxSpeed" Switch="O2" DisplayName="Maximize Speed" Description="Equivalent to /Og /Oi /Ot /Oy /Ob2 /Gs /GF /Gy">
+    </EnumValue>
+    <EnumValue Name="Full" Switch="Ox" DisplayName="Full Optimization" Description="Equivalent to /Og /Oi /Ot /Oy /Ob2">
+    </EnumValue>
+  </EnumProperty>
+  <EnumProperty Name="InlineFunctionExpansion" DisplayName="Inline Function Expansion" Description="Select the level of inline function expansion for the build.     (/Ob1, /Ob2)" Category="Optimization" F1Keyword="VC.Project.VCCLCompilerTool.InlineFunctionExpansion">
+    <EnumValue Name="Default" Switch="" DisplayName="Default">
+    </EnumValue>
+    <EnumValue Name="Disabled" Switch="Ob0" DisplayName="Disabled" Description="Disables inline expansion, which is on by default.">
+    </EnumValue>
+    <EnumValue Name="OnlyExplicitInline" Switch="Ob1" DisplayName="Only __inline" Description="Expands only functions marked as inline, __inline, __forceinline or __inline or, in a C++ member function, defined within a class declaration.">
+    </EnumValue>
+    <EnumValue Name="AnySuitable" Switch="Ob2" DisplayName="Any Suitable" Description="Expands functions marked as inline or __inline and any other function that the compiler chooses (expansion occurs at the compiler's discretion, often referred to as auto-inlining).">
+    </EnumValue>
+  </EnumProperty>
+  <BoolProperty Name="IntrinsicFunctions" DisplayName="Enable Intrinsic Functions" Description="Enables intrinsic functions.  Using intrinsic functions generates faster, but possibly larger, code.     (/Oi)" Category="Optimization" Switch="Oi" F1Keyword="VC.Project.VCCLCompilerTool.EnableIntrinsicFunctions">
+  </BoolProperty>
+  <EnumProperty Name="FavorSizeOrSpeed" DisplayName="Favor Size Or Speed" Description="Whether to favor code size or code speed; 'Global Optimization' must be turned on.     (/Ot, /Os)" Category="Optimization" F1Keyword="VC.Project.VCCLCompilerTool.FavorSizeOrSpeed">
+    <EnumValue Name="Size" Switch="Os" DisplayName="Favor small code" Description="Favor Small Code. Minimizes the size of EXEs and DLLs by instructing the compiler to favor size over speed.">
+    </EnumValue>
+    <EnumValue Name="Speed" Switch="Ot" DisplayName="Favor fast code" Description="Favor Fast Code. Maximizes the speed of EXEs and DLLs by instructing the compiler to favor speed over size. (This is the default.) ">
+    </EnumValue>
+    <EnumValue Name="Neither" Switch="" DisplayName="Neither" Description="No size nor speed optimization.">
+    </EnumValue>
+  </EnumProperty>
+  <StringListProperty Name="PreprocessorDefinitions" DisplayName="Preprocessor Definitions" Description="Defines a preprocessing symbols for your source file." Category="Preprocessor" Switch="D " F1Keyword="VC.Project.VCCLCompilerTool.PreprocessorDefinitions">
+  </StringListProperty>
+  <StringListProperty Name="UndefinePreprocessorDefinitions" DisplayName="Undefine Preprocessor Definitions" Description="Specifies one or more preprocessor undefines.     (/U[macro])" Category="Preprocessor" Switch="U" F1Keyword="VC.Project.VCCLCompilerTool.UndefinePreprocessorDefinitions">
+  </StringListProperty>
+  <BoolProperty Name="UndefineAllPreprocessorDefinitions" DisplayName="Undefine All Preprocessor Definitions" Description="Undefine all previously defined preprocessor values.     (/u)" Category="Preprocessor" Switch="u" F1Keyword="VC.Project.VCCLCompilerTool.UndefineAllPreprocessorDefinitions">
+  </BoolProperty>
+  <BoolProperty Name="PreprocessToFile" DisplayName="Preprocess to a File" Description="Preprocesses C and C++ source files and writes the preprocessed output to a file. This option suppresses compilation, thus it does not produce an .obj file." Category="Preprocessor" Switch="P" F1Keyword="VC.Project.VCCLCompilerTool.GeneratePreprocessedFile">
+  </BoolProperty>
+  <StringProperty Name="PreprocessOutputPath" DisplayName="Preprocess Output Path" Description="Specify the output path for the preprocesser. The default location is the same as the source file(s)." Category="Preprocessor" Switch="Fi" Visible="false">
+  </StringProperty>
+  <BoolProperty Name="PreprocessSuppressLineNumbers" DisplayName="Preprocess Suppress Line Numbers" Description="Preprocess without #line directives." Category="Preprocessor" Switch="EP" F1Keyword="VC.Project.VCCLCompilerTool.GeneratePreprocessedFileNoLines">
+  </BoolProperty>
+  <BoolProperty Name="PreprocessKeepComments" DisplayName="Keep Comments" Description="Suppresses comment strip from source code; requires that one of the 'Preprocessing' options be set.     (/C)" Category="Preprocessor" Switch="C" F1Keyword="VC.Project.VCCLCompilerTool.KeepComments">
+  </BoolProperty>
+  <EnumProperty Name="ExceptionHandling" DisplayName="Enable C++ Exceptions" Description="Specifies the model of exception handling to be used by the compiler." Category="Code Generation" F1Keyword="VC.Project.VCCLCompilerTool.ExceptionHandling">
+    <EnumValue Name="Async" Switch="EHa" DisplayName="Yes with SEH Exceptions" Description="The exception-handling model that catches asynchronous (structured) and synchronous (C++) exceptions. (/EHa)">
+    </EnumValue>
+    <EnumValue Name="Sync" Switch="EHsc" DisplayName="Yes" Description="The exception-handling model that catches C++ exceptions only and tells the compiler to assume that extern C functions never throw a C++ exception. (/EHsc)">
+    </EnumValue>
+    <EnumValue Name="SyncCThrow" Switch="EHs" DisplayName="Yes with Extern C functions" Description="The exception-handling model that catches C++ exceptions only and tells the compiler to assume that extern C functions do throw an exception. (/EHs)">
+    </EnumValue>
+    <EnumValue Name="false" Switch="" DisplayName="No" Description="No exception handling.">
+    </EnumValue>
+  </EnumProperty>
+  <EnumProperty Name="RuntimeLibrary" DisplayName="Runtime Library" Description="Specify runtime library for linking.     (/MT, /MTd, /MD, /MDd)" Category="Code Generation" F1Keyword="VC.Project.VCCLCompilerTool.RuntimeLibrary">
+    <EnumValue Name="MultiThreaded" Switch="MT" DisplayName="Multi-threaded" Description="Causes your application to use the multithread, static version of the run-time library.">
+    </EnumValue>
+    <EnumValue Name="MultiThreadedDebug" Switch="MTd" DisplayName="Multi-threaded Debug" Description="Defines _DEBUG and _MT. This option also causes the compiler to place the library name LIBCMTD.lib into the .obj file so that the linker will use LIBCMTD.lib to resolve external symbols.">
+    </EnumValue>
+    <EnumValue Name="MultiThreadedDLL" Switch="MD" DisplayName="Multi-threaded DLL" Description="Causes your application to use the multithread- and DLL-specific version of the run-time library. Defines _MT and _DLL and causes the compiler to place the library name MSVCRT.lib into the .obj file.">
+    </EnumValue>
+    <EnumValue Name="MultiThreadedDebugDLL" Switch="MDd" DisplayName="Multi-threaded Debug DLL" Description="Defines _DEBUG, _MT, and _DLL and causes your application to use the debug multithread- and DLL-specific version of the run-time library. It also causes the compiler to place the library name MSVCRTD.lib into the .obj file.">
+    </EnumValue>
+  </EnumProperty>
+  <EnumProperty Name="StructMemberAlignment" DisplayName="Struct Member Alignment" Description="Specifies 1, 2, 4, or 8-byte boundaries for struct member alignment.     (/Zp[num])" Category="Code Generation" F1Keyword="VC.Project.VCCLCompilerTool.StructMemberAlignment">
+    <EnumValue Name="1Byte" Switch="Zp1" DisplayName="1 Byte" Description="Packs structures on 1-byte boundaries. Same as /Zp.">
+    </EnumValue>
+    <EnumValue Name="2Bytes" Switch="Zp2" DisplayName="2 Bytes" Description="Packs structures on 2-byte boundaries.">
+    </EnumValue>
+    <EnumValue Name="4Bytes" Switch="Zp4" DisplayName="4 Byte" Description="Packs structures on 4-byte boundaries.">
+    </EnumValue>
+    <EnumValue Name="8Bytes" Switch="Zp8" DisplayName="8 Bytes" Description="Packs structures on 8-byte boundaries (default).">
+    </EnumValue>
+    <EnumValue Name="16Bytes" Switch="Zp16" DisplayName="16 Bytes" Description="Packs structures on 16-byte boundaries.">
+    </EnumValue>
+    <EnumValue Name="Default" Switch="" DisplayName="Default" Description="Default alignment settings.">
+    </EnumValue>
+  </EnumProperty>
+  <EnumProperty Name="BufferSecurityCheck" DisplayName="Security Check" Description="The Security Check helps detect stack-buffer over-runs, a common attempted attack upon a program's security.  .  (/GS-, /GS)" Category="Code Generation" F1Keyword="VC.Project.VCCLCompilerTool.BufferSecurityCheck">
+    <EnumValue Name="false" Switch="GS-" DisplayName="Disable Security Check" Description="Disable Security Check. (/GS-)">
+    </EnumValue>
+    <EnumValue Name="true" Switch="GS" DisplayName="Enable Security Check" Description="Enable Security Check. (/GS)">
+    </EnumValue>
+  </EnumProperty>
+  <EnumProperty Name="ControlFlowGuard" DisplayName="Control Flow Guard" Description="Guard security check helps detect attempts to dispatch to illegal block of code. (/guard:cf)" Category="Code Generation" F1Keyword="VC.Project.VCCLCompilerTool.ControlFlowGuard">
+    <EnumValue Name="Guard" Switch="guard:cf" DisplayName="Yes" Description="Enable Security Check with Guard (/guard:cf)">
+    </EnumValue>
+    <EnumValue Name="false" Switch="" DisplayName="No">
+    </EnumValue>
+  </EnumProperty>
+  <BoolProperty ReverseSwitch="Gy-" Name="FunctionLevelLinking" DisplayName="Enable Function-Level Linking" Description="Allows the compiler to package individual functions in the form of packaged functions (COMDATs). Required for edit and continue to work.     (/Gy)" Category="Code Generation" Switch="Gy" F1Keyword="VC.Project.VCCLCompilerTool.EnableFunctionLevelLinking">
+  </BoolProperty>
+  <EnumProperty Name="EnableEnhancedInstructionSet" DisplayName="Enable Enhanced Instruction Set" Description="Enable use of instructions found on processors that support enhanced instruction sets, e.g., the SSE, SSE2, AVX, and AVX2 enhancements to IA-32; AVX and AVX2 to x64. Currently /arch:SSE and /arch:SSE2 are only available when building for the x86 architecture. If no option is specified, the compiler will use instructions found on processors that support SSE2. Use of enhanced instructions can be disabled with /arch:IA32.   (/arch:SSE, /arch:SSE2, /arch:AVX, /arch:AVX2, /arch:IA32)" Category="Code Generation" F1Keyword="VC.Project.VCCLCompilerTool.EnableEnhancedInstructionSet">
+    <EnumValue Name="StreamingSIMDExtensions" Switch="arch:SSE" DisplayName="Streaming SIMD Extensions" Description="Streaming SIMD Extensions. (/arch:SSE)">
+    </EnumValue>
+    <EnumValue Name="StreamingSIMDExtensions2" Switch="arch:SSE2" DisplayName="Streaming SIMD Extensions 2" Description="Streaming SIMD Extensions 2. (/arch:SSE2)">
+    </EnumValue>
+    <EnumValue Name="AdvancedVectorExtensions" Switch="arch:AVX" DisplayName="Advanced Vector Extensions" Description="Advanced Vector Extensions. (/arch:AVX)">
+    </EnumValue>
+    <EnumValue Name="AdvancedVectorExtensions2" Switch="arch:AVX2" DisplayName="Advanced Vector Extensions 2" Description="Advanced Vector Extensions 2. (/arch:AVX2)">
+    </EnumValue>
+    <EnumValue Name="NoExtensions" Switch="arch:IA32" DisplayName="No Enhanced Instructions" Description="No Enhanced Instructions. (/arch:IA32)">
+    </EnumValue>
+    <EnumValue Name="NotSet" Switch="" DisplayName="Not Set" Description="Not Set.">
+    </EnumValue>
+  </EnumProperty>
+  <EnumProperty Name="FloatingPointModel" DisplayName="Floating Point Model" Description="Sets the floating point model.     (/fp:precise, /fp:strict, /fp:fast)" Category="Code Generation" F1Keyword="VC.Project.VCCLCompilerTool.floatingPointModel">
+    <EnumValue Name="Precise" Switch="fp:precise" DisplayName="Precise" Description="Default. Improves the consistency of floating-point tests for equality and inequality.">
+    </EnumValue>
+    <EnumValue Name="Strict" Switch="fp:strict" DisplayName="Strict" Description="The strictest floating-point model. /fp:strict causes fp_contract to be OFF and fenv_access to be ON. /fp:except is implied and can be disabled by explicitly specifying /fp:except-. When used with /fp:except-, /fp:strict enforces strict floating-point semantics but without respect for exceptional events.">
+    </EnumValue>
+    <EnumValue Name="Fast" Switch="fp:fast" DisplayName="Fast" Description="Creates the fastest code in the majority of cases. ">
+    </EnumValue>
+  </EnumProperty>
+  <BoolProperty ReverseSwitch="fp:except-" Name="FloatingPointExceptions" DisplayName="Enable Floating Point Exceptions" Description="Reliable floating-point exception model. Exceptions will be raised immediately after they are triggered.      (/fp:except)" Category="Code Generation" Switch="fp:except" F1Keyword="VC.Project.VCCLCompilerTool.FloatingPointExceptions">
+  </BoolProperty>
+  <BoolProperty ReverseSwitch="GR-" Name="RuntimeTypeInfo" DisplayName="Enable Run-Time Type Information" Description="Adds code for checking C++ object types at run time (runtime type information).     (/GR, /GR-)" Category="Language" Switch="GR" F1Keyword="VC.Project.VCCLCompilerTool.RuntimeTypeInfo">
+  </BoolProperty>
+  <EnumProperty Name="LanguageStandard" DisplayName="C++ Language Standard" Description="Determines the C++ language standard.     (/std:c++14, /std:c++17, /std:c++latest)" Category="Language" F1Keyword="VC.Project.VCCLCompilerTool.CppLanguageStandard">
+    <EnumValue Name="stdcpp14" Switch="std:c++14" DisplayName="ISO C++14 Standard">
+    </EnumValue>
+    <EnumValue Name="stdcpp17" Switch="std:c++17" DisplayName="ISO C++17 Standard">
+    </EnumValue>
+    <EnumValue Name="stdcpplatest" Switch="std:c++latest" DisplayName="ISO C++ Latest Draft Standard">
+    </EnumValue>
+  </EnumProperty>
+  <EnumProperty Name="PrecompiledHeader" DisplayName="Precompiled Header" Description="Create/Use Precompiled Header : Enables creation or use of a precompiled header during the build.     (/Yc, /Yu)" Category="Precompiled Headers" F1Keyword="VC.Project.VCCLCompilerTool.UsePrecompiledHeader">
+    <EnumValue Name="Create" Switch="Yc" DisplayName="Create" Description="Instructs the compiler to create a precompiled header (.pch) file that represents the state of compilation at a certain point.">
+      <Argument Property="PrecompiledHeaderFile" IsRequired="false" />
+    </EnumValue>
+    <EnumValue Name="Use" Switch="Yu" DisplayName="Use" Description="Instructs the compiler to use an existing precompiled header (.pch) file in the current compilation.">
+      <Argument Property="PrecompiledHeaderFile" IsRequired="false" />
+    </EnumValue>
+    <EnumValue Name="NotUsing" Switch="" DisplayName="Not Using Precompiled Headers" Description="Not using precompiled headers. ">
+    </EnumValue>
+  </EnumProperty>
+  <StringProperty Subtype="file" Name="PrecompiledHeaderFile" DisplayName="Precompiled Header File" Description="Specifies header file name to use when creating or using a precompiled header file. (/Yc[name], /Yu[name])" Category="Precompiled Headers" F1Keyword="VC.Project.VCCLCompilerTool.PrecompiledHeaderThrough">
+  </StringProperty>
+  <StringProperty Subtype="file" Name="PrecompiledHeaderOutputFile" DisplayName="Precompiled Header Output File" Description="Specifies the path and/or name of the generated precompiled header file. (/Fp[name])" Category="Precompiled Headers" Switch="Fp" F1Keyword="VC.Project.VCCLCompilerTool.PrecompiledHeaderFile">
+  </StringProperty>
+  <EnumProperty Name="AssemblerOutput" DisplayName="Assembler Output" Description="Specifies the contents of assembly language output file.     (/FA, /FAc, /FAs, /FAcs)" Category="Output Files" F1Keyword="VC.Project.VCCLCompilerTool.AssemblerOutput">
+    <EnumValue Name="NoListing" Switch="" DisplayName="No Listing" Description="No listing. ">
+    </EnumValue>
+    <EnumValue Name="AssemblyCode" Switch="FA" DisplayName="Assembly-Only Listing" Description="Assembly code; .asm">
+    </EnumValue>
+    <EnumValue Name="AssemblyAndMachineCode" Switch="FAc" DisplayName="Assembly With Machine Code" Description="Machine and assembly code; .cod">
+    </EnumValue>
+    <EnumValue Name="AssemblyAndSourceCode" Switch="FAs" DisplayName="Assembly With Source Code" Description="Source and assembly code; .asm">
+    </EnumValue>
+    <EnumValue Name="All" Switch="FAcs" DisplayName="Assembly, Machine Code and Source" Description="Assembly, machine code and source code; .cod">
+    </EnumValue>
+  </EnumProperty>
+  <BoolProperty Name="UseUnicodeForAssemblerListing" DisplayName="Use Unicode For Assembler Listing" Description="Causes the output file to be created in UTF-8 format. " Category="Output Files" Switch="FAu" F1Keyword="VC.Project.VCCLCompilerTool.UseUnicodeForAssemblerListing">
+  </BoolProperty>
+  <StringProperty Subtype="file" Name="AssemblerListingLocation" DisplayName="ASM List Location" Description="Specifies relative path and/or name for ASM listing file; can be file or directory name.     (/Fa[name])" Category="Output Files" Switch="Fa" F1Keyword="VC.Project.VCCLCompilerTool.AssemblerListingLocation">
+  </StringProperty>
+  <StringProperty Subtype="file" Name="ObjectFileName" DisplayName="Object File Name" Description="Specifies a name to override the default object file name; can be file or directory name.     (/Fo[name])" Category="Output Files" Switch="Fo" F1Keyword="VC.Project.VCCLCompilerTool.ObjectFile">
+  </StringProperty>
+  <EnumProperty Name="CallingConvention" DisplayName="Calling Convention" Description="Select the default calling convention for your application (can be overridden by function).     (/Gd, /Gr, /Gz, /Gv)" Category="Advanced" F1Keyword="VC.Project.VCCLCompilerTool.CallingConvention">
+    <EnumValue Name="Cdecl" Switch="Gd" DisplayName="__cdecl" Description="Specifies the __cdecl calling convention for all functions except C++ member functions and functions marked __stdcall or __fastcall.">
+    </EnumValue>
+    <EnumValue Name="FastCall" Switch="Gr" DisplayName="__fastcall" Description="Specifies the __fastcall calling convention for all functions except C++ member sfunctions and functions marked __cdecl or __stdcall. All __fastcall functions must have prototypes.">
+    </EnumValue>
+    <EnumValue Name="StdCall" Switch="Gz" DisplayName="__stdcall" Description="Specifies the __stdcall calling convention for all functions except C++ member functions and functions marked __cdecl or __fastcall. All __stdcall functions must have prototypes.">
+    </EnumValue>
+    <EnumValue Name="VectorCall" Switch="Gv" DisplayName="__vectorcall" Description="Specifies the __vectorcall calling convention for all functions except C++ member functions and functions marked __cdecl, __fastcall, or __stdcall. All __vectorcall functions must have prototypes.">
+    </EnumValue>
+  </EnumProperty>
+  <EnumProperty Name="CompileAs" DisplayName="Compile As" Description="Select compile language option for .c and .cpp files.     (/TC, /TP)" Category="Advanced" F1Keyword="VC.Project.VCCLCompilerTool.CompileAs">
+    <EnumValue Name="Default" Switch="" DisplayName="Default" Description="Default.">
+    </EnumValue>
+    <EnumValue Name="CompileAsC" Switch="TC" DisplayName="Compile as C Code" Description="Compile as C Code.">
+    </EnumValue>
+    <EnumValue Name="CompileAsCpp" Switch="TP" DisplayName="Compile as C++ Code" Description="Compile as C++ Code.">
+    </EnumValue>
+  </EnumProperty>
+  <StringListProperty Subtype="file" Name="ForcedIncludeFiles" DisplayName="Forced Include File" Description="one or more forced include files.     (/FI[name])" Category="Advanced" Switch="FI" F1Keyword="VC.Project.VCCLCompilerTool.ForcedIncludeFiles">
+  </StringListProperty>
+  <BoolProperty Name="ShowIncludes" DisplayName="Show Includes" Description="Generates a list of include files with compiler output.     (/showIncludes)" Category="Advanced" Switch="showIncludes" F1Keyword="VC.Project.VCCLCompilerTool.ShowIncludes">
+  </BoolProperty>
+  <BoolProperty Name="OmitDefaultLibName" DisplayName="Omit Default Library Name" Description="Do not include default library names in .obj files.     (/Zl)" Category="Advanced" Switch="Zl" F1Keyword="VC.Project.VCCLCompilerTool.OmitDefaultLibName">
+  </BoolProperty>
+  <StringProperty Name="AdditionalOptions" DisplayName="Additional Options" Description="Additional Options." Category="Command Line" F1Keyword="vc.project.AdditionalOptionsPage">
+  </StringProperty>
+  <BoolProperty Name="BuildingInIde" Visible="false">
+  </BoolProperty>
+
+  <!-- Silently discarded options go here -->
+  <StringListProperty Subtype="folder" Name="AdditionalUsingDirectories" DisplayName="Additional #using Directories" Description="This option is silently discarded by clang-cl.  (/AI[path])" Category="Ignored" Switch="AI" F1Keyword="VC.Project.VCCLCompilerTool.AdditionalUsingDirectories">
+  </StringListProperty>
+  <BoolProperty Name="WinRTNoStdLib" DisplayName="No Standard WinRT Libraries" Description="This option is silently discarded by clang-cl.  (/ZW:nostdlib)" Category="Ignored" Switch="ZW:nostdlib" Visible="false">
+  </BoolProperty>
+  <StringProperty Name="WarningVersion" DisplayName="Warning Version" Description="This option is silently discarded by clang-cl.  (/Wv:)" Category="Ignored" Switch="Wv:" F1Keyword="VC.Project.VCCLCompilerTool.WarningVersion">
+  </StringProperty>
+  <EnumProperty Name="DiagnosticsFormat" DisplayName="Diagnostics Format" Description="This option is silently discarded by clang-cl.  (/diagnostics:)" Category="Ignored" F1Keyword="VC.Project.VCCLCompilerTool.DiagnosticsFormat">
+    <EnumValue Name="Caret" Switch="diagnostics:caret" DisplayName="Caret" Description="Provides column information in the diagnostic message, as well as outputting the relevant line of source code with a caret indicating the offending column.">
+    </EnumValue>
+    <EnumValue Name="Column" Switch="diagnostics:column" DisplayName="Column Info" Description="Additionally provides the column number within the line where the diagnostic is issued, where applicable.">
+    </EnumValue>
+    <EnumValue Name="Classic" Switch="diagnostics:classic" DisplayName="Classic" Description="Retains the prior, concise diagnostic messages with the line number.">
+    </EnumValue>
+  </EnumProperty>
+  <BoolProperty Name="MultiProcessorCompilation" DisplayName="Multi-processor Compilation" Description="This option is silently discarded by clang-cl.  (/MP)" Category="Ignored" Switch="MP" F1Keyword="VC.Project.VCCLCompilerTool.MultiProcessorCompilation">
+  </BoolProperty>
+  <BoolProperty ReverseSwitch="Oy-" Name="OmitFramePointers" DisplayName="Omit Frame Pointers" Description="This option is silently discarded by clang-cl.  (/Oy)" Category="Ignored" Switch="Oy" F1Keyword="VC.Project.VCCLCompilerTool.OmitFramePointers">
+  </BoolProperty>
+  <BoolProperty Name="IgnoreStandardIncludePath" DisplayName="Ignore Standard Include Paths" Description="This option is silently discarded by clang-cl.  (/X)" Category="Ignored" Switch="X" F1Keyword="VC.Project.VCCLCompilerTool.IgnoreStandardIncludePath">
+  </BoolProperty>
+  <BoolProperty ReverseSwitch="GF-" Name="StringPooling" DisplayName="Enable String Pooling" Description="This option is silently discarded by clang-cl.  (/GF)" Category="Ignored" Switch="GF" F1Keyword="VC.Project.VCCLCompilerTool.StringPooling">
+  </BoolProperty>
+  <BoolProperty ReverseSwitch="Gm-" Name="MinimalRebuild" DisplayName="Enable Minimal Rebuild" Description="This option is silently discarded by clang-cl.  (/Gm)" Category="Ignored" Switch="Gm" F1Keyword="VC.Project.VCCLCompilerTool.MinimalRebuild">
+  </BoolProperty>
+  <BoolProperty Name="DisableLanguageExtensions" DisplayName="Disable Language Extensions" Description="This option is silently discarded by clang-cl.  (/Za)" Category="Ignored" Switch="Za" F1Keyword="VC.Project.VCCLCompilerTool.DisableLanguageExtensions">
+  </BoolProperty>
+  <BoolProperty Name="RemoveUnreferencedCodeData" DisplayName="Remove unreferenced code and data" Description="This option is silently discarded by clang-cl.  (/Zc:inline)" Category="Ignored" Switch="Zc:inline" F1Keyword="VC.Project.VCCLCompilerTool.RemoveUnreferencedCodeData">
+  </BoolProperty>
+  <BoolProperty ReverseSwitch="Zc:rvalueCast-" Name="EnforceTypeConversionRules" DisplayName="Enforce type conversion rules" Description="This option is silently discarded by clang-cl.  (/Zc:rvalueCast)" Category="Ignored" Switch="Zc:rvalueCast" F1Keyword="VC.Project.VCCLCompilerTool.EnforceTypeConversionRules">
+  </BoolProperty>
+  <BoolProperty Name="ExpandAttributedSource" DisplayName="Expand Attributed Source" Description="This option is silently discarded by clang-cl.  (/Fx)" Category="Ignored" Switch="Fx" F1Keyword="VC.Project.VCCLCompilerTool.ExpandAttributedSource">
+  </BoolProperty>
+  <StringProperty Subtype="file" Name="ProgramDataBaseFileName" DisplayName="Program Database File Name" Description="This option is silently discarded by clang-cl.  (/Fd[name])" Category="Ignored" Switch="Fd" F1Keyword="VC.Project.VCCLCompilerTool.ProgramDataBaseFileName">
+  </StringProperty>
+  <StringListProperty Name="DisableSpecificWarnings" DisplayName="Disable Specific Warnings" Description="This option is silently discarded by clang-cl.  (/wd)" Category="Ignored" Switch="wd" F1Keyword="VC.Project.VCCLCompilerTool.DisableSpecificWarnings">
+  </StringListProperty>
+  <StringListProperty Subtype="file" Name="ForcedUsingFiles" DisplayName="Forced #using File" Description="This option is silently discarded by clang-cl.  (/FU)" Category="Ignored" Switch="FU" F1Keyword="VC.Project.VCCLCompilerTool.ForcedUsingFiles">
+  </StringListProperty>
+  <StringProperty Subtype="file" Name="PREfastLog" DisplayName="Code Analysis Log" Description="This option is silently discarded by clang-cl.  (/analyze:log)" Category="Ignored" Switch="analyze:log " Visible="false" F1Keyword="VC.Project.VCCLCompilerTool.EnablePREfast">
+  </StringProperty>
+  <StringListProperty Name="PREfastAdditionalOptions" DisplayName="Additional Code Analysis Native options" Description="This option is silently discarded by clang-cl.  (/analyze:)" Category="Ignored" Switch="analyze:" Visible="false" F1Keyword="VC.Project.VCCLCompilerTool.PREfastAdditionalOptions">
+  </StringListProperty>
+  <StringListProperty Name="PREfastAdditionalPlugins" DisplayName="Additional Code Analysis Native plugins" Description="This option is silently discarded by clang-cl.  (/analyze:plugin)" Category="Ignored" Switch="analyze:plugin" Visible="false" F1Keyword="VC.Project.VCCLCompilerTool.PREfastAdditionalPlugins">
+  </StringListProperty>
+  <BoolProperty Name="UseFullPaths" DisplayName="Use Full Paths" Description="This option is silently discarded by clang-cl.  (/FC)" Category="Ignored" Switch="FC" F1Keyword="VC.Project.VCCLCompilerTool.UseFullPaths">
+  </BoolProperty>
+  <EnumProperty Name="ErrorReporting" DisplayName="Internal Compiler Error Reporting" Description="This option is silently discarded by clang-cl.  (/errorReport:)" Category="Ignored" F1Keyword="VC.Project.VCCLCompilerTool.ErrorReporting">
+    <EnumValue Name="None" Switch="errorReport:none" DisplayName="Do Not Send Report" Description="Reports about internal compiler errors will not be collected or sent to Microsoft.">
+    </EnumValue>
+    <EnumValue Name="Prompt" Switch="errorReport:prompt" DisplayName="Prompt Immediately" Description="Prompts you to send a report when you receive an internal compiler error.">
+    </EnumValue>
+    <EnumValue Name="Queue" Switch="errorReport:queue" DisplayName="Queue For Next Login" Description="Queues the error report. When you log in with administrator privileges, a pop-up window is displayed and allows you to report any failures since the last time you were logged in (you will not be prompted to send reports for failures more than once every three days). queue is the default when compiling an application at the command line.">
+    </EnumValue>
+    <EnumValue Name="Send" Switch="errorReport:send" DisplayName="Send Automatically" Description="Automatically sends reports of internal compiler errors to Microsoft. To enable this option, you must first agree to Microsoft%27s data collection policy. The first time you specify /errorReport:send on a computer, a compiler message will refer you to a website that contains Microsoft%27s data collection policy.">
+    </EnumValue>
+  </EnumProperty>
+  <StringListProperty Name="TreatSpecificWarningsAsErrors" DisplayName="Treat Specific Warnings As Errors" Description="This option is silently discarded by clang-cl.  (/we)" Category="Ignored" Switch="we" F1Keyword="VC.Project.VCCLCompilerTool.TreatSpecificWarningsAsErrors">
+  </StringListProperty>
+
+  <!-- Warn-and-ignore options go here -->
+  <BoolProperty Name="EnableFiberSafeOptimizations" DisplayName="Enable Fiber-Safe Optimizations" Description="This option is unsupported by clang-cl, and will generate a warning if enabled.  (/GT)" Category="Ignored" Switch="GT" F1Keyword="VC.Project.VCCLCompilerTool.EnableFiberSafeOptimizations">
+  </BoolProperty>
+  <BoolProperty Name="WholeProgramOptimization" DisplayName="Whole Program Optimization" Description="This option is unsupported by clang-cl, and will generate a warning if enabled.  (/GL)" Category="Ignored" Switch="GL" F1Keyword="VC.Project.VCCLWCECompilerTool.WholeProgramOptimization">
+  </BoolProperty>
+  <BoolProperty Name="SmallerTypeCheck" DisplayName="Smaller Type Check" Description="This option is unsupported by clang-cl, and will generate a warning if enabled.  (/RTCc)" Category="Ignored" Switch="RTCc" F1Keyword="VC.Project.VCCLCompilerTool.SmallerTypeCheck">
+  </BoolProperty>
+  <EnumProperty Name="BasicRuntimeChecks" DisplayName="Basic Runtime Checks" Description="This option is unsupported by clang-cl, and will generate a warning if enabled.  (/RTCs, /RTCu, /RTC1)" Category="Ignored" F1Keyword="VC.Project.VCCLCompilerTool.BasicRuntimeChecks">
+    <EnumValue Name="StackFrameRuntimeCheck" Switch="RTCs" DisplayName="Stack Frames" Description="Enables stack frame run-time error checking.">
+    </EnumValue>
+    <EnumValue Name="UninitializedLocalUsageCheck" Switch="RTCu" DisplayName="Uninitialized variables" Description="Reports when a variable is used without having been initialized.">
+    </EnumValue>
+    <EnumValue Name="EnableFastChecks" Switch="RTC1" DisplayName="Both (/RTC1, equiv. to /RTCsu)" Description="Equivalent of /RTCsu.">
+    </EnumValue>
+    <EnumValue Name="Default" Switch="" DisplayName="None" Description="Do not perform additional runtime checks.">
+    </EnumValue>
+  </EnumProperty>
+  <BoolProperty ReverseSwitch="Qpar-" Name="EnableParallelCodeGeneration" DisplayName="Enable Parallel Code Generation" Description="This option is unsupported by clang-cl, and will generate a warning if enabled.  (/Qpar)" Category="Ignored" Switch="Qpar" F1Keyword="VC.Project.VCCLCompilerTool.EnableParallelCodeGeneration">
+  </BoolProperty>
+  <BoolProperty Name="CreateHotpatchableImage" DisplayName="Create Hotpatchable Image" Description="This option is unsupported by clang-cl, and will generate a warning if enabled.  (/hotpatch)" Category="Ignored" Switch="hotpatch" F1Keyword="VC.Project.VCCLCompilerTool.CreateHotpatchableImage">
+  </BoolProperty>
+  <BoolProperty ReverseSwitch="Zc:wchar_t-" Name="TreatWChar_tAsBuiltInType" DisplayName="Treat WChar_t As Built in Type" Description="This option is unsupported by clang-cl, and will generate a warning if disabled.  (/Zc:wchar_t)" Category="Ignored" Switch="Zc:wchar_t" F1Keyword="VC.Project.VCCLCompilerTool.TreatWChar_tAsBuiltInType">
+  </BoolProperty>
+  <BoolProperty ReverseSwitch="Zc:forScope-" Name="ForceConformanceInForLoopScope" DisplayName="Force Conformance in For Loop Scope" Description="This option is unsupported by clang-cl, and will generate a warning if disabled.  (/Zc:forScope)" Category="Ignored" Switch="Zc:forScope" F1Keyword="VC.Project.VCCLCompilerTool.ForceConformanceInForLoopScope">
+  </BoolProperty>
+  <BoolProperty Name="GenerateXMLDocumentationFiles" DisplayName="Generate XML Documentation Files" Description="This option is unsupported by clang-cl, and will generate a warning if enabled.  (/doc)" Category="Ignored" Switch="doc" F1Keyword="VC.Project.VCCLCompilerTool.GenerateXMLDocumentationFiles">
+  </BoolProperty>
+  <BoolProperty Name="BrowseInformation" DisplayName="Enable Browse Information" Description="This option is unsupported by clang-cl, and will generate a warning if enabled.  (/FR)" Category="Ignored" Switch="FR" F1Keyword="VC.Project.VCCLCompilerTool.BrowseInformation">
+  </BoolProperty>
+  <BoolProperty ReverseSwitch="analyze-" Name="EnablePREfast" DisplayName="Enable Code Analysis" Description="This option is unsupported by clang-cl, and will generate a warning if enabled.  (/analyze)" Category="Ignored" Switch="analyze" Visible="false" F1Keyword="VC.Project.VCCLCompilerTool.EnablePREfast">
+  </BoolProperty>
+
+  <!-- Incompatible options go here -->
+  <EnumProperty Name="CompileAsManaged" DisplayName="Common Language RunTime Support" Description="This switch is incompatible with clang-cl and will generate an error if enabled.  (/clr)" Category="Incompatible" F1Keyword="VC.Project.VCCLCompilerTool.CompileAsManaged">
+    <EnumValue Name="false" Switch="" DisplayName="No Common Language RunTime Support" Description="No Common Language RunTime Support">
+    </EnumValue>
+    <EnumValue Name="true" Switch="clr" DisplayName="Common Language RunTime Support" Description="Creates metadata for your application that can be consumed by other CLR applications, and allows your application to consume types and data in the metadata of other CLR components.">
+    </EnumValue>
+    <EnumValue Name="Pure" Switch="clr:pure" DisplayName="Pure MSIL Common Language RunTime Support" Description="Produces an MSIL-only output file with no native executable code, although it can contain native types compiled to MSIL.">
+    </EnumValue>
+    <EnumValue Name="Safe" Switch="clr:safe" DisplayName="Safe MSIL Common Language RunTime Support" Description="Produces an MSIL-only (no native executable code) and verifiable output file.">
+    </EnumValue>
+  </EnumProperty>
+  <BoolProperty Name="CompileAsWinRT" DisplayName="Consume Windows Runtime Extension" Description="This switch is incompatible with clang-cl and will generate an error if set to true.  (/ZW)" Category="Incompatible" Switch="ZW" F1Keyword="VC.Project.VCCLCompilerTool.CompileAsWinRT">
+  </BoolProperty>
+  <BoolProperty ReverseSwitch="openmp-" Name="OpenMPSupport" DisplayName="Open MP Support" Description="This switch is incompatible with clang-cl and will generate an error if set to true.  (/openmp)" Category="Incompatible" Switch="openmp" F1Keyword="VC.Project.VCCLCompilerTool.OpenMP">
+  </BoolProperty>
+  <BoolProperty Name="EnableModules" DisplayName="Enable C++ Modules (experimental)" Description="This switch is incompatible with clang-cl and will generate an error if set to true.  (/experimental:module)" Category="Incompatible" Switch="experimental:module" F1Keyword="VC.Project.VCCLCompilerTool.ModulesSupport">
+  </BoolProperty>
+
+</Rule>
 No newline at end of file

llvm/tools/msbuild/install.bat

 @echo off
 
 echo Installing MSVC integration...
 set SUCCESS=0
 
 REM Change to the directory of this batch file.
 cd /d %~dp0
 
-REM Loop over the two platforms in awkward batch file fashion.
-set PLATFORM=None
-:PLATFORMLOOPHEAD
-IF %PLATFORM% == x64 GOTO PLATFORMLOOPEND
-IF %PLATFORM% == Win32 SET PLATFORM=x64
-IF %PLATFORM% == None SET PLATFORM=Win32
+REM Older versions of VS would look for these files in the Program Files\MSBuild directory
+REM but with VS2017 it seems to look for these directly in the Visual Studio instance.
+REM This means we'll need to do a little extra work to properly detect all the various
+REM instances, but in reality we can probably sidestep all of this by just wrapping this
+REM in a vsix and calling it a day, as that should handle everything for us.
+SET VCTargets=%ProgramFiles(x86)%\Microsoft Visual Studio\2017\Professional\Common7\IDE\VC\VCTargets
 
-REM Search for the MSBuild toolsets directory.
+ECHO Installing Common Files
+copy Clang.Cpp.Common.props "%VCTargets%"
 
-SET D="%ProgramFiles%\MSBuild\Microsoft.Cpp\v4.0\Platforms\%PLATFORM%\PlatformToolsets"
-IF EXIST %D% GOTO FOUND_V100
-SET D="%ProgramFiles(x86)%\MSBuild\Microsoft.Cpp\v4.0\Platforms\%PLATFORM%\PlatformToolsets"
-IF EXIST %D% GOTO FOUND_V100
-
-:TRY_V110
-SET D="%ProgramFiles%\MSBuild\Microsoft.Cpp\v4.0\V110\Platforms\%PLATFORM%\PlatformToolsets"
-IF EXIST %D% GOTO FOUND_V110
-SET D="%ProgramFiles(x86)%\MSBuild\Microsoft.Cpp\v4.0\V110\Platforms\%PLATFORM%\PlatformToolsets"
-IF EXIST %D% GOTO FOUND_V110
-
-:TRY_V120
-SET D="%ProgramFiles%\MSBuild\Microsoft.Cpp\v4.0\V120\Platforms\%PLATFORM%\PlatformToolsets"
-IF EXIST %D% GOTO FOUND_V120
-SET D="%ProgramFiles(x86)%\MSBuild\Microsoft.Cpp\v4.0\V120\Platforms\%PLATFORM%\PlatformToolsets"
-IF EXIST %D% GOTO FOUND_V120
-
-:TRY_V140
-SET D="%ProgramFiles%\MSBuild\Microsoft.Cpp\v4.0\V140\Platforms\%PLATFORM%\PlatformToolsets"
-IF EXIST %D% GOTO FOUND_V140
-SET D="%ProgramFiles(x86)%\MSBuild\Microsoft.Cpp\v4.0\V140\Platforms\%PLATFORM%\PlatformToolsets"
-IF EXIST %D% GOTO FOUND_V140
-
-:TRY_V150
-
-GOTO PLATFORMLOOPHEAD
-
-:PLATFORMLOOPEND
-IF %SUCCESS% == 1 goto DONE
-echo Failed to find MSBuild toolsets directory.
-goto FAILED
-
-
-:FOUND_V100
-REM Routine for installing v100 toolchain.
-IF NOT EXIST %D%\LLVM-vs2010 mkdir %D%\LLVM-vs2010
+ECHO Installing x64 Platform Toolset
+SET PlatformToolsets=%VCTargets%\Platforms\x64\PlatformToolsets
+IF NOT EXIST "%PlatformToolsets%\llvm" mkdir "%PlatformToolsets%\llvm"
 IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-copy %PLATFORM%\Microsoft.Cpp.%PLATFORM%.LLVM-vs2010.props %D%\LLVM-vs2010
+copy Clang.Toolset.x64.props "%PlatformToolsets%\llvm\Toolset.props"
 IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-copy %PLATFORM%\Microsoft.Cpp.%PLATFORM%.LLVM-vs2010.targets %D%\LLVM-vs2010
+copy Toolset.targets "%PlatformToolsets%\llvm"
 IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-set SUCCESS=1
-GOTO TRY_V110
 
-:FOUND_V110
-REM Routine for installing v110 toolchain.
-IF NOT EXIST %D%\LLVM-vs2012 mkdir %D%\LLVM-vs2012
-IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-copy %PLATFORM%\Microsoft.Cpp.%PLATFORM%.LLVM-vs2012.props %D%\LLVM-vs2012
-IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-copy %PLATFORM%\Microsoft.Cpp.%PLATFORM%.LLVM-vs2012.targets %D%\LLVM-vs2012
+ECHO Installing Win32 Platform Toolset
+SET PlatformToolsets=%VCTargets%\Platforms\Win32\PlatformToolsets
+IF NOT EXIST "%PlatformToolsets%\llvm" mkdir "%PlatformToolsets%\llvm"
 IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-IF NOT EXIST %D%\LLVM-vs2012_xp mkdir %D%\LLVM-vs2012_xp
+copy Clang.Toolset.x86.props "%PlatformToolsets%\llvm\Toolset.props"
 IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-copy %PLATFORM%\Microsoft.Cpp.%PLATFORM%.LLVM-vs2012_xp.props %D%\LLVM-vs2012_xp
+copy Toolset.targets "%PlatformToolsets%\llvm"
 IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-copy %PLATFORM%\Microsoft.Cpp.%PLATFORM%.LLVM-vs2012_xp.targets %D%\LLVM-vs2012_xp
-IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-set SUCCESS=1
-GOTO TRY_V120
 
-:FOUND_V120
-REM Routine for installing v120 toolchain.
-IF NOT EXIST %D%\LLVM-vs2013 mkdir %D%\LLVM-vs2013
-IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-copy %PLATFORM%\toolset-vs2013.props %D%\LLVM-vs2013\toolset.props
-IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-copy %PLATFORM%\toolset-vs2013.targets %D%\LLVM-vs2013\toolset.targets
-IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-IF NOT EXIST %D%\LLVM-vs2013_xp mkdir %D%\LLVM-vs2013_xp
-IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-copy %PLATFORM%\toolset-vs2013_xp.props %D%\LLVM-vs2013_xp\toolset.props
+ECHO Installing C++ Settings UI
+copy clang-cl.xml "%VCTargets%\1033"
 IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-copy %PLATFORM%\toolset-vs2013_xp.targets %D%\LLVM-vs2013_xp\toolset.targets
-IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-set SUCCESS=1
-GOTO TRY_V140
 
-:FOUND_V140
-REM Routine for installing v140 toolchain.
-IF NOT EXIST %D%\LLVM-vs2014 mkdir %D%\LLVM-vs2014
-IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-copy %PLATFORM%\toolset-vs2014.props %D%\LLVM-vs2014\toolset.props
-IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-copy %PLATFORM%\toolset-vs2014.targets %D%\LLVM-vs2014\toolset.targets
+ECHO Installing MSBuild Hooks
+IF NOT EXIST "%VCTargets%\ImportAfter" mkdir "%VCTargets%\ImportAfter"
 IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-IF NOT EXIST %D%\LLVM-vs2014_xp mkdir %D%\LLVM-vs2014_xp
+IF NOT EXIST "%VCTargets%\ImportAfter\Default" mkdir "%VCTargets%\ImportAfter\Default"
 IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-copy %PLATFORM%\toolset-vs2014_xp.props %D%\LLVM-vs2014_xp\toolset.props
+copy LLVM.props "%VCTargets%\ImportAfter\Default"
 IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-copy %PLATFORM%\toolset-vs2014_xp.targets %D%\LLVM-vs2014_xp\toolset.targets
-IF NOT %ERRORLEVEL% == 0 GOTO FAILED
-set SUCCESS=1
-GOTO TRY_V150
-
 
 :DONE
 echo Done!
 goto END
 
 :FAILED
 echo MSVC integration install failed.
 pause
 goto END
 
 :END

llvm/tools/msbuild/toolset-vs2013.targets

-<Project ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(VCTargetsPath)\Microsoft.CppCommon.targets" />
-</Project>

llvm/tools/msbuild/toolset-vs2013_xp.targets

-<Project ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <!-- Force TargetFrameworkVersion to v4.0 to support XP-->
-  <PropertyGroup>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
-    <BeforeClCompileTargets>NoSupportCodeAnalysisXP;$(BeforeClCompileTargets)</BeforeClCompileTargets>
-  </PropertyGroup>
-
-  <Import Project="$(VCTargetsPath)\Microsoft.CppCommon.targets" />
-
-  <Target Name="NoSupportCodeAnalysisXP" Condition="'$(ErrorNoSupportCodeAnalysisXP)' != 'false'">
-    <VCMessage Condition="'$(DesignTimeBuild)' != 'true' and '@(ClCompile->AnyHaveMetadataValue('EnablePREfast', 'true'))'=='true'" Code="MSB8026" Type="Error"/>
-  </Target>
-
-  <PropertyGroup>
-    <PrepareForBuildDependsOn>CheckWindowsSDK71A;$(PrepareForBuildDependsOn)</PrepareForBuildDependsOn>
-  </PropertyGroup>
-
-  <Target Name="CheckWindowsSDK71A">
-    <VCMessage Code="MSB8003" Type="Warning" Arguments="WindowsSdkDir_71A" Condition="'$(WindowsSdkDir_71A)'=='' and '$(UseEnv)' != 'true'" />
-  </Target>
-</Project>

llvm/tools/msbuild/toolset-vs2014.targets

-<Project ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(VCTargetsPath)\Microsoft.CppCommon.targets" />
-</Project>

llvm/tools/msbuild/toolset-vs2014_xp.targets

-<Project ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <!-- Force TargetFrameworkVersion to v4.0 to support XP-->
-  <PropertyGroup>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
-    <BeforeClCompileTargets>NoSupportCodeAnalysisXP;$(BeforeClCompileTargets)</BeforeClCompileTargets>
-  </PropertyGroup>
-
-  <Import Project="$(VCTargetsPath)\Microsoft.CppCommon.targets" />
-
-  <Target Name="NoSupportCodeAnalysisXP" Condition="'$(ErrorNoSupportCodeAnalysisXP)' != 'false'">
-    <VCMessage Condition="'$(DesignTimeBuild)' != 'true' and '@(ClCompile->AnyHaveMetadataValue('EnablePREfast', 'true'))'=='true'" Code="MSB8026" Type="Error"/>
-  </Target>
-
-  <PropertyGroup>
-    <PrepareForBuildDependsOn>CheckWindowsSDK71A;$(PrepareForBuildDependsOn)</PrepareForBuildDependsOn>
-  </PropertyGroup>
-
-  <Target Name="CheckWindowsSDK71A">
-    <VCMessage Code="MSB8003" Type="Warning" Arguments="WindowsSdkDir_71A" Condition="'$(WindowsSdkDir_71A)'=='' and '$(UseEnv)' != 'true'" />
-  </Target>
-</Project>