Consolidate pragma section (#23374)

* add text for existing issues

There are two existing issues in this section of content. This commit fixes both.

* combine all files.

* first pass at formatting.

* restore F1 and helpviewer keywords.

* fix build warnings.

* organize by scenario, not keyword.

* first pass edit.

* finish proofreading.

* fix warning

* run clean-repo to replace links

First run: replace redirected file links.

* Replace relative links

Run clean repo to replace absolute links (introduced in the previous run) with relative links.

* Revert "Replace relative links"

This reverts commit d3c931e.

* run with the new cleanrepo build

This way, forward slashes aren't replaced with backslashes.

* Apply suggestions from code review

Co-authored-by: Tom Dykstra <[email protected]>

* respond to code review comments.

Co-authored-by: Tom Dykstra <[email protected]>

Author: BillWagner

.openpublishing.redirection.json

@@ -1570,6 +1570,71 @@
             "source_path": "docs/csharp/language-reference/operators/xor-operator.md",
             "redirect_url": "/dotnet/csharp/language-reference/operators/boolean-logical-operators#logical-exclusive-or-operator-"
         },
+        {
+            "source_path": "docs/csharp/language-reference/preprocessor-directives/index.md",
+            "redirect_url": "/dotnet/csharp/language-reference/preprocessor-directives",
+            "redirect_document_id":true
+        },
+        {
+            "source_path": "docs/csharp/language-reference/preprocessor-directives/preprocessor-define.md",
+            "redirect_url": "/dotnet/csharp/language-reference/preprocessor-directives"
+        },
+        {
+            "source_path": "docs/csharp/language-reference/preprocessor-directives/preprocessor-else.md",
+            "redirect_url": "/dotnet/csharp/language-reference/preprocessor-directives"
+        },
+        {
+            "source_path": "docs/csharp/language-reference/preprocessor-directives/preprocessor-elif.md",
+            "redirect_url": "/dotnet/csharp/language-reference/preprocessor-directives"
+        },
+        {
+            "source_path": "docs/csharp/language-reference/preprocessor-directives/preprocessor-endif.md",
+            "redirect_url": "/dotnet/csharp/language-reference/preprocessor-directives"
+        },
+        {
+            "source_path": "docs/csharp/language-reference/preprocessor-directives/preprocessor-endregion.md",
+            "redirect_url": "/dotnet/csharp/language-reference/preprocessor-directives"
+        },
+        {
+            "source_path": "docs/csharp/language-reference/preprocessor-directives/preprocessor-error.md",
+            "redirect_url": "/dotnet/csharp/language-reference/preprocessor-directives"
+        },
+        {
+            "source_path": "docs/csharp/language-reference/preprocessor-directives/preprocessor-if.md",
+            "redirect_url": "/dotnet/csharp/language-reference/preprocessor-directives"
+        },
+        {
+            "source_path": "docs/csharp/language-reference/preprocessor-directives/preprocessor-line.md",
+            "redirect_url": "/dotnet/csharp/language-reference/preprocessor-directives"
+        },
+        {
+            "source_path": "docs/csharp/language-reference/preprocessor-directives/preprocessor-nullable.md",
+            "redirect_url": "/dotnet/csharp/language-reference/preprocessor-directives"
+        },
+        {
+            "source_path": "docs/csharp/language-reference/preprocessor-directives/preprocessor-pragma.md",
+            "redirect_url": "/dotnet/csharp/language-reference/preprocessor-directives"
+        },
+        {
+            "source_path": "docs/csharp/language-reference/preprocessor-directives/preprocessor-pragma-checksum.md",
+            "redirect_url": "/dotnet/csharp/language-reference/preprocessor-directives"
+        },
+        {
+            "source_path": "docs/csharp/language-reference/preprocessor-directives/preprocessor-pragma-warning.md",
+            "redirect_url": "/dotnet/csharp/language-reference/preprocessor-directives"
+        },
+        {
+            "source_path": "docs/csharp/language-reference/preprocessor-directives/preprocessor-region.md",
+            "redirect_url": "/dotnet/csharp/language-reference/preprocessor-directives"
+        },
+        {
+            "source_path": "docs/csharp/language-reference/preprocessor-directives/preprocessor-undef.md",
+            "redirect_url": "/dotnet/csharp/language-reference/preprocessor-directives"
+        },
+        {
+            "source_path": "docs/csharp/language-reference/preprocessor-directives/preprocessor-warning.md",
+            "redirect_url": "/dotnet/csharp/language-reference/preprocessor-directives"
+        },
         {
             "source_path": "docs/csharp/language-reference/proposals/csharp-7.0/index.md",
             "redirect_url": "/dotnet/csharp/language-reference/proposals/csharp-7.0/pattern-matching"

docs/architecture/porting-existing-aspnet-apps/strategies-migrating-in-production.md

@@ -37,7 +37,7 @@ Once the facade is in place, you can route part of it to a new ASP.NET Core app.
 
 ## Multi-targeting approaches
 
-Large apps that target .NET Framework may be migrated to ASP.NET Core over time by using multi-targeting and separate code paths for each framework. For example, code that must run in both environments could be modified with [preprocessor `#if`](../../csharp/language-reference/preprocessor-directives/preprocessor-if.md) directives to implement different functionality or use different dependencies when run in .NET Framework versus .NET Core. Another option is to modify project files to include different sets of files based on which framework is being targeted. Project files can use different globbing patterns, such as `*.core.cs`, to include different sets of source files depending on the framework being targeted.
+Large apps that target .NET Framework may be migrated to ASP.NET Core over time by using multi-targeting and separate code paths for each framework. For example, code that must run in both environments could be modified with [preprocessor `#if`](../../csharp/language-reference/preprocessor-directives.md) directives to implement different functionality or use different dependencies when run in .NET Framework versus .NET Core. Another option is to modify project files to include different sets of files based on which framework is being targeted. Project files can use different globbing patterns, such as `*.core.cs`, to include different sets of source files depending on the framework being targeted.
 
 These techniques allow a single common codebase to be maintained while new functionality is added and (parts of) the app are ported to use .NET Core.
 

docs/csharp/language-reference/builtin-types/built-in-types.md

@@ -36,7 +36,7 @@ The following table lists the C# built-in [reference](../keywords/reference-type
 |[`string`](reference-types.md#the-string-type)|<xref:System.String?displayProperty=nameWithType>|
 |[`dynamic`](reference-types.md#the-dynamic-type)|<xref:System.Object?displayProperty=nameWithType>|
 
-In the preceding tables, each C# type keyword from the left column (except [nint and nuint](nint-nuint.md) and [dynamic](using-type-dynamic.md)) is an alias for the corresponding .NET type. They are interchangeable. For example, the following declarations declare variables of the same type:
+In the preceding tables, each C# type keyword from the left column (except [nint and nuint](nint-nuint.md) and [dynamic](reference-types.md#the-dynamic-type)) is an alias for the corresponding .NET type. They are interchangeable. For example, the following declarations declare variables of the same type:
 
 ```csharp
 int a = 123;

docs/csharp/language-reference/compiler-messages/cs0420.md

@@ -12,7 +12,7 @@ ms.assetid: 0f52f508-286e-493d-9151-180e05397bf9
 
 'identifier': a reference to a volatile field will not be treated as volatile  
 
- A volatile field should not normally be passed using a `ref` or **out** parameter, since it will not be treated as volatile within the scope of the function. There are exceptions to this, such as when calling an interlocked API. As with any warning, you may use the [#pragma warning](../preprocessor-directives/preprocessor-pragma-warning.md) to disable this warning in those rare cases where you are intentionally using a volatile field as a reference parameter.  
+ A volatile field should not normally be passed using a `ref` or **out** parameter, since it will not be treated as volatile within the scope of the function. There are exceptions to this, such as when calling an interlocked API. As with any warning, you may use the [#pragma warning](../preprocessor-directives.md) to disable this warning in those rare cases where you are intentionally using a volatile field as a reference parameter.  
 
  The following sample generates CS0420:  
 

docs/csharp/language-reference/compiler-messages/cs1029.md

@@ -12,7 +12,7 @@ ms.assetid: 61bd4d44-9bfc-42bb-a9f0-a0683da53640
 
 \#error: 'text'
 
-Displays the text of an error defined with the [#error](../preprocessor-directives/preprocessor-error.md) directive.
+Displays the text of an error defined with the [#error](../preprocessor-directives.md) directive.
 
 The following sample shows how to create a user-defined error:
 

docs/csharp/language-reference/compiler-messages/cs1691.md

@@ -12,7 +12,7 @@ ms.assetid: 7f0fea4d-4215-446c-a249-57daa7e967d2
 
 'number' is not a valid warning number  
 
- A number that was passed to the [#pragma warning](../preprocessor-directives/preprocessor-pragma-warning.md) preprocessor directive was not a valid warning number. Verify that the number represents a warning, not an error or another sequence of characters.  
+ A number that was passed to the [#pragma warning](../preprocessor-directives.md) preprocessor directive was not a valid warning number. Verify that the number represents a warning, not an error or another sequence of characters.  
 
 ## Example  
 

docs/csharp/language-reference/compiler-messages/cs4014.md

@@ -74,7 +74,7 @@ Exiting the Click event handler.
     Task.Delay is finished--returning from called method.
 ```
 
-You can also suppress compiler warnings by using [#pragma warning](../preprocessor-directives/preprocessor-pragma-warning.md) directives.
+You can also suppress compiler warnings by using [#pragma warning](../preprocessor-directives.md) directives.
 
 ## Example
 

docs/csharp/language-reference/compiler-options/language.md

@@ -49,7 +49,7 @@ The **DefineConstants** option defines symbols in all source code files of your
 <DefineConstants>name;name2</DefineConstants>
 ```
 
-This option specifies the names of one or more symbols that you want to define. The **DefineConstants** option has the same effect as the [#define](../preprocessor-directives/preprocessor-define.md) preprocessor directive except that the compiler option is in effect for all files in the project. A symbol remains defined in a source file until an [#undef](../preprocessor-directives/preprocessor-undef.md) directive in the source file removes the definition. When you use the `-define` option, an `#undef` directive in one file has no effect on other source code files in the project. You can use symbols created by this option with [#if](../preprocessor-directives/preprocessor-if.md), [#else](../preprocessor-directives/preprocessor-else.md), [#elif](../preprocessor-directives/preprocessor-elif.md), and [#endif](../preprocessor-directives/preprocessor-endif.md) to compile source files conditionally. The C# compiler itself defines no symbols or macros that you can use in your source code; all symbol definitions must be user-defined.
+This option specifies the names of one or more symbols that you want to define. The **DefineConstants** option has the same effect as the [#define](../preprocessor-directives.md) preprocessor directive except that the compiler option is in effect for all files in the project. A symbol remains defined in a source file until an [#undef](../preprocessor-directives.md) directive in the source file removes the definition. When you use the `-define` option, an `#undef` directive in one file has no effect on other source code files in the project. You can use symbols created by this option with [#if](../preprocessor-directives.md), [#else](../preprocessor-directives.md), [#elif](../preprocessor-directives.md), and [#endif](../preprocessor-directives.md) to compile source files conditionally. The C# compiler itself defines no symbols or macros that you can use in your source code; all symbol definitions must be user-defined.
 
 > [!NOTE]
 > The C# `#define` directive does not allow a symbol to be given a value, as in languages such as C++. For example, `#define` cannot be used to create a macro or to define a constant. If you need to define a constant, use an `enum` variable. If you want to create a C++ style macro, consider alternatives such as generics. Since macros are notoriously error-prone, C# disallows their use but provides safer alternatives.
@@ -146,4 +146,4 @@ Invocation of methods annotated with the following attributes will also affect f
 > 1. Start the file name with *TemporaryGeneratedFile_*
 > 1. End the file name with *.designer.cs*, *.generated.cs*, *.g.cs*, or *.g.i.cs*.
 >
-> Generators can opt-in using the [`#nullable`](../preprocessor-directives/preprocessor-nullable.md) preprocessor directive.
+> Generators can opt-in using the [`#nullable`](../preprocessor-directives.md) preprocessor directive.

docs/csharp/language-reference/compiler-options/output.md

@@ -32,7 +32,7 @@ The **DocumentationFile** option allows you to place documentation comments in a
 The source code file that contains Main or top-level statements is output first into the XML. You'll often want to use the generated .xml file with [IntelliSense](/visualstudio/ide/using-intellisense). The *.xml* filename must be the same as the assembly name. The *.xml* file must be in the same directory as the assembly. When the assembly is referenced in a Visual Studio project, the *.xml* file is found as well. For more information about generating code comments, see [Supplying Code Comments](/visualstudio/ide/reference/generate-xml-documentation-comments). Unless you compile with [`<TargetType:Module>`](#targettype), `file` will contain `<assembly>` and `</assembly>` tags specifying the name of the file containing the assembly manifest for the output file. For examples, see [How to use the XML documentation features](../../programming-guide/xmldoc/how-to-use-the-xml-documentation-features.md).
 
 > [!NOTE]
-> The **DocumentationFile** option applies to all files in the project. To disable warnings related to documentation comments for a specific file or section of code, use [#pragma warning](../preprocessor-directives/preprocessor-pragma-warning.md).
+> The **DocumentationFile** option applies to all files in the project. To disable warnings related to documentation comments for a specific file or section of code, use [#pragma warning](../preprocessor-directives.md).
 
 ## OutputAssembly
 

docs/csharp/language-reference/configure-language-version.md

@@ -48,7 +48,7 @@ If you must specify your C# version explicitly, you can do so in several ways:
 - Configure the [**LangVersion** compiler option](compiler-options/language.md#langversion).
 
 > [!TIP]
-> To know what language version you're currently using, put `#error version` (case sensitive) in your code. This makes the compiler report a compiler error, CS8304, with a message containing the compiler version being used and the current selected language version. See [#error (C# Reference)](preprocessor-directives/preprocessor-error.md) for more information.
+> To know what language version you're currently using, put `#error version` (case sensitive) in your code. This makes the compiler report a compiler error, CS8304, with a message containing the compiler version being used and the current selected language version. See [#error (C# Reference)](preprocessor-directives.md) for more information.
 
 ### Edit the project file