Merge pull request #6174 from MicrosoftDocs/main

Auto Publish – main to live - 2025-12-04 06:00 UTC

Author: learn-build-service-prod[bot]

docs/build/reference/rtc-run-time-error-checks.md

@@ -42,7 +42,7 @@ int main() {
 }
 ```
 
-Because **`/RTCc`** rejects code that conforms to the standard, it's not supported by the C++ Standard Library. Code that uses **`/RTCc`** and the C++ Standard Library may cause compiler error [C1189](../../error-messages/compiler-errors-1/fatal-error-c1189.md). You can define `_ALLOW_RTCc_IN_STL` to silence the warning and use the **`/RTCc`** option.
+Because **`/RTCc`** rejects code that conforms to the standard, it's not supported by the C++ Standard Library. Code that uses **`/RTCc`** and the C++ Standard Library may cause compiler error [C1189](../../error-messages/compiler-errors-1/fatal-error-c1189.md) or [C2338](../../error-messages/compiler-errors-1/compiler-error-c2338.md). Remove the **`/RTCc`** option to use the C++ Standard Library.
 
 **`/RTCs`**<br/>
 Enables stack frame run-time error checking, as follows:

docs/overview/how-to-report-a-problem-with-the-visual-cpp-toolset.md

@@ -311,6 +311,20 @@ After you generate the preprocessed files, it's a good idea to make sure the pro
 
 Finally, attach the preprocessed repro files (*filename*.i and *modulename*.i) along with the .ifc output to your report.
 
+#### To generate a module trace file
+
+When issues involve C++ modules, provide a module trace file along with the preprocessed repro improves diagnostic quality to reduce turnaround time. A module trace file records detailed information about module operations during compilation.
+
+It's ideal if the example can be condensed to a single source code file, without reference to any user headers. 
+
+Reducing the amount of code we have to consider as a possible contributor to the problem is enormously helpful to us. Using **/MP** or multi-source invocations can cause the trace to represent only the last compiled file or be incomplete. If you can't reduce the problem to a single source file, package your code into a .zip file or similar, or consider using an IDE project repro. For more information, see [Other repros](#other-repros).
+
+1. Open the **Developer Command Prompt** that matches the Visual Studio version and configuration architecture used to build your project.
+1. Enter the command `cl /d1module:enableLogging`*trace.json* [*other-args*] *filename.cpp*. For *trace.json*, specify the desired output file name for the module trace. There can't be a space between `/d1module:enableLogging` and the output file name. For [*other-args*], include any additional compilation arguments. For *filename.cpp*, specify the source file that reproduces the problem.
+1. If multiple translation units are involved in the problem, run separate single-file invocations to collect a trace for the specific file that reproduces the problem. You can collect traces for additional relevant files if needed.
+
+Finally, attach the generated *trace.json* file along with the preprocessed repro to your report.
+
 ### Link repros
 
 A *link repro* is the linker-generated contents of a directory, specified either by the **link\_repro** environment variable, or as an argument to the [/LINKREPRO](../build/reference/linkrepro.md) linker option. It contains build artifacts that collectively demonstrate a problem that occurs at link time. Examples include a backend crash involving Link-Time Code Generation (LTCG), or a linker crash. These build artifacts are the ones needed as linker input so the problem can be reproduced. A link repro can be created easily by using this environment variable. It enables the linker's built-in repro generation capability.

docs/windows/latest-supported-vc-redist.md

@@ -1,7 +1,7 @@
 ---
 title: "Latest supported Visual C++ Redistributable downloads"
 description: "This article provides download links for the latest Visual C++ Redistributable packages."
-ms.date: 11/03/2025
+ms.date: 12/03/2025
 helpviewer_keywords:
   [
     "redist",
@@ -58,12 +58,13 @@ Download other versions, including long term servicing release channel (LTSC) ve
 
 - Some of the downloads that are mentioned in this article are currently available on [my.visualstudio.com](https://my.visualstudio.com/). Log in using a Visual Studio Subscription account so that you can access the download links. If you're asked for credentials, use your existing Visual Studio subscription account. Or, create a free account by choosing the [**No account? Create one!**](https://my.visualstudio.com/).
 - The Visual C++ v14 Redistributable doesn't have separate packages for different languages. License terms for different languages are available at [https://aka.ms/VCRedistLicense](https://aka.ms/VCRedistLicense).
-- Visual Studio 2017 and later share the same Redistributable files. Any apps built by Microsoft C++ (MSVC) Build Tools v14.* available in Visual Studio 2017, 2019, 2022, or 2026 can use the latest Visual C++ v14 Redistributable. However, the version of the redistributable installed on the machine must be the same or higher than the version of the MSVC Build Tools used to create your application. For more information about which version of the Redistributable to install, see [Determining which DLLs to redistribute](determining-which-dlls-to-redistribute.md). For more information about binary compatibility, see [C++ binary compatibility between Visual Studio versions](../porting/binary-compat-2015-2017.md).
+- Visual Studio 2017 and later share the same Redistributable files. Any apps built by Microsoft C++ (MSVC) Build Tools v14.* available in Visual Studio 2017, 2019, 2022, or 2026 can use the latest Visual C++ v14 Redistributable. The version of the redistributable installed on the machine must be the same or higher than the version of the MSVC Build Tools used to create your application. For more information about which version of the Redistributable to install, see [Determining which DLLs to redistribute](determining-which-dlls-to-redistribute.md). For more information about binary compatibility, see [C++ binary compatibility between Visual Studio versions](../porting/binary-compat-2015-2017.md).
 - The latest version of the Visual C++ v14 Redistributable included with Visual Studio 2026 only supports the following operating systems:
   * Windows 10 and 11
   * Windows Server 2016, 2019, 2022, and 2025
 - Support for Visual Studio 2015 ended on October 15, 2025. Because support for the Visual C++ Redistributable is connected to the version of Visual Studio in which it first ships, support for Visual C++ 2015 Redistributable (version 14.0.24212) also ended October 15, 2025. See [Visual Studio 2015 (VC++ 14.0)](#visual-studio-2015-vc-140-no-longer-supported) section below for the latest available version.<br/>
-When Visual Studio 2015 support ended, the v14 runtime was binary compatible with applications built using the VS 2015 MSVC Build Tools. Since VS 2015 is no longer supported, we recommend updating your projects to use a supported MSVC Build Tools version and the latest v14 runtime.
+When Visual Studio 2015 support ended, the v14 runtime was binary compatible with applications built using the VS 2015 MSVC Build Tools. Since VS 2015 is no longer supported, we recommend updating your projects to use a supported MSVC Build Tools version and the latest v14 runtime. The Visual C++ Redistributable for 2017, and later, in-place upgrade the Visual C++ 2015 Redistributable (14.0.24212.0). Redistributables for 2013 and earlier remain installed side-by-side.
+
 -  The Visual C++ Redistributable supports several command-line options. For more information, see [Command-line options for the Redistributable packages](./redistributing-visual-cpp-files.md#command-line-options-for-the-redistributable-packages).
 
 ## Unsupported legacy versions