Toolset update: VS 2022 17.1 Preview 4, ARM64EC

[StephanTLavavej]

• Rename tools/move_only_function_specializations to tools/scripts.
  • Now we can add other scripts to this directory, and it avoids repeating the filename move_only_function_specializations.py.
  • Update the comment in <functional> accordingly.
  • Add a comment to move_only_function_specializations.py explaining what it does - even though the filename and code are fairly self-explanatory, as we accumulate scripts, it will be helpful for each of them to briefly mention what they do, so we don't need to deduce their intent from their code.
• Add tools/scripts/print_failures.py.
  • This automates the process of searching through test logs to find FAIL and XPASS tests, then decoding their JSON with search-and-replace (replacing CRLFs and LFs with newlines, unescaping double quotes and backslashes).
• Remove workaround for VSO-1460046 in P0220R1_optional/test.cpp.
  • This was "EDG rejects hash<optional<const B>> called with optional<B>".
• Remove compiler workaround in subrange.
• Remove workaround for VSO-1433873 in <format>.
  • This was "Standard Library Header Units: Adding template <int = 0> to vformat() emits warnings C4265 and C4365".
• Fix C4365 sign conversion warnings in <format>'s use of fill_n.
  • Filling with '0' can convert char to wchar_t. _CharT{'0'} forms the same type, avoiding the warning.
• Perma-workaround VSO-1464637 C4365 sign conversion warnings in <format>.
  • This is "Standard Library Header Units: #pragma warning doesn't always suppress warnings in templates", which @cdacamar has fixed in VS 2022 17.2 Preview 2.
  • Instead of copying char to char/wchar_t and silencing the warnings, we can use a function object to transform() with a static_cast. This is more elegant than silencing warnings, and should result in identical release codegen. (Debug mode has more function calls, but avoiding them isn't all-important.)
• Followup simplification: ranges::transform() can directly take string_view.
• create-vmss.ps1: Allow QUIC, renumber priorities.
  • QUIC was standardized as the transport layer for HTTP/3, and will presumably be used by tools in the future. Let's permit outbound connections now.
  • Priority values are arbitrary - New-AzNetworkSecurityRuleConfig documentation says that a priority needs to be "An integer between 100 and 4096." To make future changes a bit easier, I'm following the QBASIC pattern for Allow rules (1000, 1010, 1020), and leaving lots of room before the Deny rule at 2000.
• Add 'Microsoft.VisualStudio.Component.VC.Tools.ARM64EC' for Add arm64EC pipeline. Disable all SSE usage for ARM64EC #2491.
• Python 3.10.2.
• create-vmss.ps1: Also set the Azure CLI subscription.
  • This is the robust thing to do (although I haven't seen issues with the subscription getting set to something else, I realized that it was a potential issue).
  • Long-term, I'll investigate whether we can replace our usage of Azure CLI with Azure PowerShell as I've learned more.
• create-vmss.ps1: Use member enumeration and the -in containment operator, making Find-ResourceGroupNameCollision unnecessary.
• Add 'THHmm' to VMSS names.
  • This is a quality of life improvement when frequently creating and deleting resource groups, as it generates unique names with unique logs in the Azure portal.
  • I've kept the -1, -2, etc. suffix logic as it's theoretically needed, although in practice it should never appear. (Note that I tested the suffix logic changes before adding these timestamp changes.)
• Fix VMSS diagnostics.
  • I discovered that the diagnostics extension was failing (by logging into the VMs through Azure Bastion), apparently due to SAS token parsing. Through extensive searching, I found VM diagnostics Azure/azure-cli#8108 (comment) which helped me understand this. That issue resulted in an update to the az vm diagnostics documentation - we're using az vmss diagnostics whose documentation wasn't updated, but it's equally applicable.
  • I've updated the Checklist for Toolset Updates accordingly, simplifying it - we don't need to manually prepare vmss-config.json and vmss-protected.json anymore!
  • This limits the permissions etc. for the SAS token, and adds --https-only, exactly following the documentation. (I think --https-only might have been the actual fix, but I didn't confirm that.)
  • This also replaces '__DIAGNOSTIC_STORAGE_ACCOUNT__' and '__VM_OR_VMSS_RESOURCE_ID__' in vmss-config.json, following the documentation. (I wasn't previously instructed that this was necessary, but in retrospect these strings are obviously placeholders.)
  • We can pass JSON directly to --protected-settings, avoiding saving the SAS token to disk. I'm leaving /azure-devops/vmss-protected.json mentioned in .gitignore.
  • Note that vmss-config.json is too big to pass on the command line, so it must be saved to a file.
  • The documentation doesn't depict the leading question mark being added to the SAS token in the JSON, but I believe that's a mistake, so I am adding it.
• create-vmss.ps1: Use Out-Null instead of ignored variables.
  • I just learned this existed.
• Use 2022-datacenter-g2, fixing the problems we've had with preparing toolset updates.
  • Thanks to @BillyONeal for mentioning that vcpkg had successfully performed a toolset update recently, which led me to think about any potential differences between our setups.
  • I've updated the Checklist for Toolset Updates accordingly, simplifying the displayed SKU/version information with my increased knowledge of Azure PowerShell.
• New pool: VS 2022 17.1 Preview 4, ARM64EC, Server.
• Mention VS 2022 17.1 Preview 4 in README.md.

[barcharcraz]

format stuff looks good (as do other changes, however I spent more attention on format stuff)

[StephanTLavavej]

I'm mirroring this to the MSVC-internal repo - please notify me if any further changes are pushed.