Merge pull request #3133 from corob-msft/docs/corob/20200501-Elnar-mail

Update preprocessor content per Elnar mail

Author: v-dihans

docs/build/reference/experimental-preprocessor.md

@@ -1,31 +1,31 @@
 ---
 title: "/experimental:preprocessor (Enable preprocessor conformance mode)"
 description: "Use the /experimental:preprocessor compiler option to enable experimental compiler support for a standard conforming preprocessor."
-ms.date: "10/31/2019"
+ms.date: 09/10/2020
 f1_keywords: ["preprocessor", "/experimental:preprocessor"]
 helpviewer_keywords: ["preprocessor conformance", "/experimental:preprocessor", "Enable preprocessor conformance mode"]
 ---
-# /experimental:preprocessor (Enable preprocessor conformance mode)
+# `/experimental:preprocessor` (Enable preprocessor conformance mode)
 
-This option enables an experimental, token-based preprocessor that more closely conforms to C++11 standards, including C99 preprocessor features. For more information, see [MSVC experimental preprocessor overview](../../preprocessor/preprocessor-experimental-overview.md).
+This option is obsolete starting in Visual Studio 2019 version 16.5, replaced by the [`/Zc:preprocessor`](zc-preprocessor.md) compiler option. **`/experimental:preprocessor`** enables an experimental, token-based preprocessor that more closely conforms to C++11 standards, including C99 preprocessor features. For more information, see [MSVC new preprocessor overview](../../preprocessor/preprocessor-experimental-overview.md).
 
 ## Syntax
 
-> **/experimental:preprocessor**[**-**]
+> **`/experimental:preprocessor`**\[**`-`**]
 
 ## Remarks
 
-Use the **/experimental:preprocessor** compiler option to enable the experimental conforming preprocessor. You can use **/experimental:preprocessor-** option to explicitly specify the traditional preprocessor.
+Use the **`/experimental:preprocessor`** compiler option to enable the experimental conforming preprocessor. You can use **`/experimental:preprocessor-`** option to explicitly specify the traditional preprocessor.
 
-The **/experimental:preprocessor** option is available starting in Visual Studio 2017 version 15.8.
+The **`/experimental:preprocessor`** option is available starting in Visual Studio 2017 version 15.8. Starting in Visual Studio 2019 version 16.5, the new preprocessor is complete, and available under the [`/Zc:preprocessor`](zc-preprocessor.md) compiler option.
 
 ### To set this compiler option in the Visual Studio development environment
 
 1. Open the project's **Property Pages** dialog box. For details, see [Set C++ compiler and build properties in Visual Studio](../working-with-project-properties.md).
 
 1. Select the **Configuration Properties** > **C/C++** > **Command Line** property page.
 
-1. Modify the **Additional Options** property to include **/experimental:preprocessor** and then choose **OK**.
+1. Modify the **Additional Options** property to include *`/experimental:preprocessor`* and then choose **OK**.
 
 ## See also
 

docs/build/reference/zc-conformance.md

@@ -1,6 +1,7 @@
 ---
 title: "/Zc (Conformance)"
-ms.date: "03/06/2018"
+description: "The /Zc conformance compiler options enable or disable support for conforming or backward-compatible behavior."
+ms.date: 09/10/2020
 helpviewer_keywords: ["/Zc compiler options [C++]", "-Zc compiler options [C++]", "Conformance compiler options", "Zc compiler options [C++]"]
 ms.assetid: db1cc175-6e93-4a2e-9396-c3725d2d8f71
 ---
@@ -28,6 +29,7 @@ These are the **`/Zc`** compiler options:
 | [`/ZcimplicitNoexcept`](zc-implicitnoexcept-implicit-exception-specifiers.md) | Enable implicit **`noexcept`** on required functions (on by default). |
 | [`/Zc:inline`](zc-inline-remove-unreferenced-comdat.md) | Remove unreferenced function or data if it is COMDAT or has internal linkage only (off by default). |
 | [`/Zc:noexceptTypes`](zc-noexcepttypes.md) | Enforce C++17 **`noexcept`** rules (on by default in C++17 or later). |
+| [`/Zc:preprocessor`](zc-preprocessor.md) | Use the new conforming preprocessor (off by default, except in C11/C17). |
 | [`/Zc:referenceBinding`](zc-referencebinding-enforce-reference-binding-rules.md) | A UDT temporary will not bind to an non-const lvalue reference (off by default). |
 | [`/Zc:rvalueCast`](zc-rvaluecast-enforce-type-conversion-rules.md) | Enforce Standard C++ explicit type conversion rules (off by default). |
 | [`/Zc:sizedDealloc`](zc-sizeddealloc-enable-global-sized-dealloc-functions.md) | Enable C++14 global sized deallocation functions (on by default). |

docs/build/reference/zc-preprocessor.md

@@ -0,0 +1,32 @@
+---
+title: "/Zc:preprocessor (Enable preprocessor conformance mode)"
+description: "Use the /Zc:preprocessor compiler option to enable compiler support for a standard conforming preprocessor."
+ms.date: 09/10/2020
+f1_keywords: ["preprocessor", "/Zc:preprocessor"]
+helpviewer_keywords: ["preprocessor conformance", "/Zc:preprocessor", "Enable preprocessor conformance mode"]
+---
+# `/Zc:preprocessor` (Enable preprocessor conformance mode)
+
+This option enables a token-based preprocessor that conforms to C99 and C++11 and later standards. For more information, see [MSVC new preprocessor overview](../../preprocessor/preprocessor-experimental-overview.md).
+
+## Syntax
+
+> **`/Zc:preprocessor`**[**-**]
+
+## Remarks
+
+Use the **`/Zc:preprocessor`** compiler option to enable the conforming preprocessor. You can use **`/Zc:preprocessor-`** option to explicitly specify the traditional (non-conforming) preprocessor.
+
+The **`/Zc:preprocessor`** option is available starting in Visual Studio 2019 version 16.5. An earlier, incomplete version of the new preprocessor option is available in versions of Visual Studio starting in Visual Studio 2017 version 15.8. For more information, see [`/experimental:preprocessor`](experimental-preprocessor.md).
+
+### To set this compiler option in the Visual Studio development environment
+
+1. Open the project's **Property Pages** dialog box. For details, see [Set C++ compiler and build properties in Visual Studio](../working-with-project-properties.md).
+
+1. Select the **Configuration Properties** > **C/C++** > **Command Line** property page.
+
+1. Modify the **Additional Options** property to include *`/Zc:preprocessor`* and then choose **OK**.
+
+## See also
+
+[/Zc (Conformance)](zc-conformance.md)

docs/build/toc.yml

@@ -744,6 +744,8 @@
                       href: ../build/reference/zc-inline-remove-unreferenced-comdat.md
                     - name: "/Zc:noexceptTypes (C++17 noexcept rules)"
                       href: ../build/reference/zc-noexcepttypes.md
+                    - name: "/Zc:preprocessor (Enable preprocessor conformance mode)"
+                      href: ../build/reference/zc-preprocessor.md
                     - name: "/Zc:referenceBinding (Enforce reference binding rules)"
                       href: ../build/reference/zc-referencebinding-enforce-reference-binding-rules.md
                     - name: "/Zc:rvalueCast (Enforce type conversion rules)"

docs/overview/cpp-conformance-improvements.md

@@ -738,7 +738,7 @@ int main() {
 
 ### Preprocessor output preserves newlines
 
-The experimental preprocessor now preserves newlines and whitespace when using **`/P`** or **`/E`** with **`/experimental:preprocessor`**. This change can be disabled by using **`/d1experimental:preprocessor:oldWhitespace`**.
+The experimental preprocessor now preserves newlines and whitespace when using **`/P`** or **`/E`** with **`/experimental:preprocessor`**.
 
 Given this example source,
 

docs/overview/what-s-new-for-visual-cpp-in-visual-studio.md

@@ -1,5 +1,6 @@
 ---
 title: "What's new for C++ in Visual Studio"
+description: "The new features and fixes in the Microsoft C/C++ compiler and tools in Visual Studio."
 ms.date: "05/19/2020"
 ms.technology: "cpp-ide"
 ms.assetid: 8801dbdb-ca0b-491f-9e33-01618bff5ae9
@@ -251,7 +252,7 @@ The MSVC compiler toolset in Visual Studio version 15.7 now conforms with the C+
 
 ##### Visual Studio 2017 version 15.8
 
-The [`/experimental:preprocessor`](../build/reference/experimental-preprocessor.md) compiler switch enables the new experimental MSVC preprocessor that will eventually conform to all applicable C and C++ standards. For more information, see [MSVC experimental preprocessor overview](../preprocessor/preprocessor-experimental-overview.md).
+The [`/experimental:preprocessor`](../build/reference/experimental-preprocessor.md) compiler switch enables the new experimental MSVC preprocessor that will eventually conform to all applicable C and C++ standards. For more information, see [MSVC new preprocessor overview](../preprocessor/preprocessor-experimental-overview.md).
 
 ### New compiler options
 

docs/porting/visual-cpp-porting-and-upgrading-guide.md

@@ -1,7 +1,7 @@
 ---
 title: "Microsoft C++ porting and upgrading guide"
 description: "Upgrade Microsoft C++ code to the latest version of Visual Studio."
-ms.date: "11/18/2019"
+ms.date: 09/10/2020
 ms.assetid: f5fbcc3d-aa72-41a6-ad9a-a706af2166fb
 ms.topic: "overview"
 ---
@@ -23,7 +23,7 @@ If a legacy application is running satisfactorily, in a secure environment, and
 
 - Build times are faster, because of performance improvements in the compiler and linker.
 
-- Better standards conformance. The [/permissive-](../build/reference/permissive-standards-conformance.md) compiler option helps you identify code that doesn't conform to the current C++ standard.
+- Better standards conformance. The [/permissive-](../build/reference/permissive-standards-conformance.md) compiler option helps you identify code that doesn't conform to the current C++ standard. The [new preprocessor](../preprocessor/preprocessor-experimental-overview.md) supports code conformance, too.
 
 - Better run-time security, including more secure [C Runtime library](../c-runtime-library/security-features-in-the-crt.md) features. And, compiler features such as [guard checking](../build/reference/guard-enable-guard-checks.md) and address sanitizers (new in Visual Studio 2019 version 16.4).
 

docs/preprocessor/c-cpp-preprocessor-reference.md

@@ -1,19 +1,20 @@
 ---
 title: "C/C++ preprocessor reference"
-ms.date: "10/31/2019"
+description: "Reference for the Microsoft C/C++ compiler preprocessor in Visual Studio."
+ms.date: 09/10/2020
 helpviewer_keywords: ["preprocessor", "preprocessor, reference overview"]
 ms.assetid: e4a52843-7016-4f6d-8b40-cb1ace18f805
 ---
 # C/C++ preprocessor reference
 
 The *C/C++ preprocessor reference* explains the preprocessor as it is implemented in Microsoft C/C++. The preprocessor performs preliminary operations on C and C++ files before they are passed to the compiler. You can use the preprocessor to conditionally compile code, insert files, specify compile-time error messages, and apply machine-specific rules to sections of code.
 
-In Visual Studio 2019 the [/experimental:preprocessor](../build/reference/experimental-preprocessor.md) compiler option enables a new implementation of the preprocessor. The new implementation is still in progress, and is therefore considered experimental. It is intended to eventually be conformant with C99, C11, and C++20. For more information, see [MSVC experimental preprocessor overview](preprocessor-experimental-overview.md).
+In Visual Studio 2019 the [/experimental:preprocessor](../build/reference/experimental-preprocessor.md) compiler option enables a new implementation of the preprocessor. The new implementation is still in progress, and is therefore considered experimental. It is intended to eventually be conformant with C99, C11, and C++20. For more information, see [MSVC new preprocessor overview](preprocessor-experimental-overview.md).
 
 ## In this section
 
 [Preprocessor](preprocessor.md)\
-Provides an overview of the traditional and new experimental preprocessors.
+Provides an overview of the traditional and new conforming preprocessors.
 
 [Preprocessor directives](../preprocessor/preprocessor-directives.md)\
 Describes directives, typically used to make source programs easy to change and easy to compile in different execution environments.
@@ -22,7 +23,7 @@ Describes directives, typically used to make source programs easy to change and
 Discusses the four preprocessor-specific operators used in the context of the `#define` directive.
 
 [Predefined macros](../preprocessor/predefined-macros.md)\
-Discusses predefined macros as specified by ANSI and Microsoft C++.
+Discusses predefined macros as specified by the C and C++ standards and by Microsoft C++.
 
 [Pragmas](../preprocessor/pragma-directives-and-the-pragma-keyword.md)\
 Discusses pragmas, which offer a way for each compiler to offer machine- and operating system-specific features while retaining overall compatibility with the C and C++ languages.