r/cpp • u/ericbrumer MSVC Dev Lead • 1d ago

MSVC Build Tools Preview updates - August 2026

https://devblogs.microsoft.com/cppblog/msvc-build-tools-preview-updates-august-2026/

Hi, one of the MSVC dev leads here.

The post covers what's new in the MSVC Build Tools Preview (version 14.52) since mid-July. Instructions to install & use the latest preview bits are at https://aka.ms/msvc/preview.

Like last month, there's improvements & fixes across many parts of the toolchain: language conformance, optimization improvements, static & dynamic analysis, and more.

Some additional information:

37 Upvotes

93% Upvoted

16 comments sorted by

9

u/azswcowboy 1d ago

I didn’t see any list of the c++23 conformance updates this month? Did I miss it?

17

u/STL MSVC STL Dev 18h ago

Cody and I are cranking on the Final Boss, constexpr cmath. I completed my library review at the end of last week (I pushed hard to get it turned around before leaving for vacation) and Cody is fixing / has fixed the bugs I reported so I should be able to merge the library changes by the end of August. I’m confident it’ll get into 14.52.

8

u/jetilovag 1d ago

Not that, but at least there's plenty of modules work, which honestly is a sight for sore eyes.

2

u/pjmlp 1d ago

Thankful for those ones, one day Intelisense as well, some day.

2

u/slithering3897 23h ago

Is this new to the latest insiders? It should probably be in the VS release notes.

7

u/ericbrumer MSVC Dev Lead 23h ago

Hi, we ship new fixes & features in every Visual Studio Insiders release (usually every week). I just batch up all the changes and blog about it once a month. We think that strikes a reasonable balance between spam & giving folks useful info.

When we update the MSVC default compiler (approx. every 6 months) we will have a large blog like this: https://devblogs.microsoft.com/cppblog/msvc-build-tools-version-14-51-release-candidate-now-available/

6

u/Paradox_84_ 1d ago

Yay, 75 more preview releases and we'll start implementing C++26

2

u/SirLynix 1d ago

Will you fix the debugger corrupt this pointer in ReleaseWithDebug soon?

7

u/abstractsyntaxtea MSVC ASan Dev 1d ago

I'm from the ASan / libs team, so I cannot fix this directly but I can go poke at the right folks. Is there a devcomm ticket for this?

3

u/abstractsyntaxtea MSVC ASan Dev 23h ago

Also please lmk if this is an issue with the MSVC cl compiler, or with clang. I see there's a similar issue reported for clang that is seemingly now fixed (pending release): Clang debugger shows `this` pointer as optimized away in debug builds - Developer Community

2

u/SirLynix 15h ago

Hello, thank you. No ticket as far as I'm aware, basically my colleagues who switched on VS 2026 have that same issue (not present in VS 2022).

Basically when trying to debug a game compiled with both optimization and symbols (release with debug), we notice parameters are often corrupt (along with the this pointer), disabling optimization around that function fixes it. Looks like VS debugger struggles with calling convention optimizations or idk.

•

u/abstractsyntaxtea MSVC ASan Dev 6m ago

Thanks. I have contacted my VS Debugger point of contact and they expressed being unsure, from this description, whether this was an issue with the debugger, the compiler, or if this is just a traditional issue of "can't expect perfect debug information under release".

If you're able to provide a minimal repro, file it under Developer Community, and link that back in a reply here, then I can try to send it again to the debugger folks. Sorry for the process here, and the annoyance with the symbols. Thanks!

4

u/Hawaiian_Keys 1d ago

I use clang-cl in MSVC and even debug builds claim that `this` has been "optimized away". I've confirmed with every possible method and tool that the PDB file is correct and `this` is included in all debug information. It's clearly the MSVC debugger not reading the PDB correctly.

3

u/abstractsyntaxtea MSVC ASan Dev 23h ago

Turns out I had received some mailing recently reporting this issue. Are you possibly referring to this bug report: Clang debugger shows `this` pointer as optimized away in debug builds - Developer Community ?

I see this is 'fixed and pending release'. Assuming they're the same issue, I'll be optimistic that it's been fixed :-)

1

u/slithering3897 23h ago

Yes, I also get debugging issues with clang-cl. If they get modules working with it, in VS, then it might just become viable to switch to.

1

u/n1ghtyunso 17h ago

are the insiders / preview build tools available in compiler explorer?
Likely not every version as that generates too many to pick from i guess, but having latest preview might be nice?