RedfishPkg: Replace include guards with #pragma once

Replace traditional `#ifndef`/`#define`/`#endif` include guards with
`#pragma` once.

`#pragma once` is a widely supported preprocessor directive that
prevents header files from being included multiple times. It is
supported by all toolchains used to build edk2: GCC, Clang/LLVM, and
MSVC.

Compared to macro-based include guards, `#pragma once`:

- Eliminates the risk of macro name collisions or copy/paste errors
  where two headers inadvertently use the same guard macro.
- Eliminate inconsistency in the way include guard macros are named
  (e.g., some files use `__FILE_H__`, others use `FILE_H_`, etc.).
- Reduces boilerplate (three lines replaced by one).
- Avoids polluting the macro namespace with guard symbols.
- Can improve build times as the preprocessor can skip re-opening the
  file entirely, rather than re-reading it to find the matching
  `#endif` ("multiple-include optimization").
  - Note that some compilers may already optimize traditional include
    guards, by recognzining the idiomatic pattern.

This change is made acknowledging that overall portability of the
code will technically be reduced, as `#pragma once` is not part of the
C/C++ standards.

However, this is considered acceptable given:

1. edk2 already defines a subset of supported compilers in
   BaseTools/Conf/tools_def.template, all of which have supported
   `#pragma once` for over two decades.
2. There have been concerns raised to the project about inconsistent
   include guard naming and potential macro collisions.

Approximate compiler support dates:

- MSVC: Supported since Visual C++ 4.2 (1996)
- GCC: Supported since 3.4 (2004)
  (http://gnu.ist.utl.pt/software/gcc/gcc-3.4/changes.html)
- Clang (LLVM based): Since initial release in 2007

Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>

RedfishPkg/Include/IndustryStandard/RedfishHostInterface.h

@@ -8,8 +8,7 @@
   SPDX-License-Identifier: BSD-2-Clause-Patent
 **/
 
-#ifndef REDFISH_HOST_INTERFACE_
-#define REDFISH_HOST_INTERFACE_
+#pragma once
 
 #include <IndustryStandard/SmBios.h>
 
@@ -187,5 +186,3 @@ typedef struct {
 } REDFISH_OVER_IP_PROTOCOL_DATA;
 
 #pragma pack()
-
-#endif

RedfishPkg/Include/IndustryStandard/RedfishHostInterfaceIpmi.h

@@ -5,8 +5,7 @@
   SPDX-License-Identifier: BSD-2-Clause-Patent
 **/
 
-#ifndef REDFISH_HOST_INTERFACE_IPMI_H_
-#define REDFISH_HOST_INTERFACE_IPMI_H_
+#pragma once
 
 #include <Uefi.h>
 #include <IndustryStandard/IpmiNetFnGroupExtension.h>
@@ -47,5 +46,3 @@ typedef struct {
 } IPMI_BOOTSTRAP_CREDENTIALS_RESULT_RESPONSE;
 
 #pragma pack()
-
-#endif

RedfishPkg/Include/Library/BaseUcs2Utf8Lib.h

@@ -8,8 +8,7 @@
 
 **/
 
-#ifndef BASE_UCS2UTF8_LIB_H_
-#define BASE_UCS2UTF8_LIB_H_
+#pragma once
 
 ///
 ///  L"\u0000"
@@ -57,5 +56,3 @@ UTF8StrToUCS2 (
   IN  CHAR8   *Utf8Str,
   OUT CHAR16  **Ucs2StrAddr
   );
-
-#endif

RedfishPkg/Include/Library/HiiUtilityLib.h

@@ -9,8 +9,7 @@
 
 **/
 
-#ifndef HII_UTILITY_LIB_
-#define HII_UTILITY_LIB_
+#pragma once
 
 #include <Protocol/DisplayProtocol.h>
 #include <Protocol/HiiConfigAccess.h>
@@ -1200,5 +1199,3 @@ EvaluateExpressionList (
   IN HII_FORMSET          *FormSet OPTIONAL,
   IN HII_FORM             *Form OPTIONAL
   );
-
-#endif // HII_UTILITY_LIB_

RedfishPkg/Include/Library/JsonLib.h

@@ -9,8 +9,7 @@
 
 **/
 
-#ifndef JSON_LIB_H_
-#define JSON_LIB_H_
+#pragma once
 
 typedef    VOID  *EDKII_JSON_VALUE;
 typedef    VOID  *EDKII_JSON_ARRAY;
@@ -944,5 +943,3 @@ EFIAPI
 JsonGetType (
   IN EDKII_JSON_VALUE  JsonValue
   );
-
-#endif

RedfishPkg/Include/Library/RedfishContentCodingLib.h

@@ -7,8 +7,7 @@
 
 **/
 
-#ifndef REDFISH_CONTENT_CODING_LIB_H_
-#define REDFISH_CONTENT_CODING_LIB_H_
+#pragma once
 
 /**
   This is the function to encode the content use the
@@ -76,5 +75,3 @@ RedfishContentDecode (
   OUT VOID   **DecodedContentPointer,
   OUT UINTN  *DecodedLength
   );
-
-#endif

RedfishPkg/Include/Library/RedfishCredentialLib.h

@@ -7,8 +7,7 @@
 
 **/
 
-#ifndef REDFISH_CREDENTIAL_LIB_H_
-#define REDFISH_CREDENTIAL_LIB_H_
+#pragma once
 
 #include <Uefi.h>
 
@@ -89,5 +88,3 @@ LibStopRedfishService (
   IN     EDKII_REDFISH_CREDENTIAL_PROTOCOL           *This,
   IN     EDKII_REDFISH_CREDENTIAL_STOP_SERVICE_TYPE  ServiceStopType
   );
-
-#endif

RedfishPkg/Include/Library/RedfishCrtLib.h

@@ -8,8 +8,7 @@
 
 **/
 
-#ifndef REDFISH_CRT_LIB_H_
-#define REDFISH_CRT_LIB_H_
+#pragma once
 
 #include <Library/BaseLib.h>
 #include <Library/BaseMemoryLib.h>
@@ -405,5 +404,3 @@ time        (
 extern int  errno;
 
 #define ERANGE  34                 /* 34   Result too large */
-
-#endif

RedfishPkg/Include/Library/RedfishDebugLib.h

@@ -8,8 +8,7 @@
 
 **/
 
-#ifndef REDFISH_DEBUG_LIB_H_
-#define REDFISH_DEBUG_LIB_H_
+#pragma once
 
 #include <Uefi.h>
 #include <Library/DebugLib.h>
@@ -176,5 +175,3 @@ DumpBuffer (
   IN  UINT8  *Buffer,
   IN  UINTN  BufferSize
   );
-
-#endif

RedfishPkg/Include/Library/RedfishHostInterfaceLib.h

@@ -9,8 +9,7 @@
 
 **/
 
-#ifndef REDFISH_HOST_INTERFACE_LIB_H_
-#define REDFISH_HOST_INTERFACE_LIB_H_
+#pragma once
 
 #include <Uefi.h>
 #include <IndustryStandard/RedfishHostInterface.h>
@@ -87,5 +86,3 @@ EFI_STATUS
 RedfishPlatformHostInterfaceSerialNumber (
   OUT CHAR8  **SerialNumber
   );
-
-#endif

RedfishPkg/Include/Library/RedfishHttpLib.h

@@ -7,8 +7,7 @@
 
 **/
 
-#ifndef REDFISH_HTTP_LIB_H_
-#define REDFISH_HTTP_LIB_H_
+#pragma once
 
 #include <Protocol/EdkIIRedfishHttpProtocol.h>
 
@@ -322,5 +321,3 @@ RedfishHttpDeleteResourceEx (
   IN  CHAR8             *ContentType OPTIONAL,
   OUT REDFISH_RESPONSE  *Response
   );
-
-#endif

RedfishPkg/Include/Library/RedfishLib.h

@@ -67,8 +67,7 @@
 
 **/
 
-#ifndef REDFISH_LIB_H_
-#define REDFISH_LIB_H_
+#pragma once
 
 #include <RedfishServiceData.h>
 #include <Library/JsonLib.h>
@@ -736,5 +735,3 @@ RedfishBuildRedpathUseId (
   IN  CHAR8  *Id,
   OUT CHAR8  **Redpath
   );
-
-#endif

RedfishPkg/Include/Library/RedfishPlatformConfigLib.h

@@ -8,8 +8,7 @@
 
 **/
 
-#ifndef REDFISH_PLATFORM_CONFIG_LIB_H_
-#define REDFISH_PLATFORM_CONFIG_LIB_H_
+#pragma once
 
 #include <Protocol/EdkIIRedfishPlatformConfig.h>
 
@@ -139,5 +138,3 @@ RedfishPlatformConfigGetDefaultValue (
   IN     UINT16               DefaultClass,
   OUT    EDKII_REDFISH_VALUE  *Value
   );
-
-#endif

RedfishPkg/Include/Library/RedfishPlatformWantedDeviceLib.h

@@ -7,8 +7,7 @@
 
 **/
 
-#ifndef REDFISH_PLATFORM_WANTED_DEVICE_LIB_H_
-#define REDFISH_PLATFORM_WANTED_DEVICE_LIB_H_
+#pragma once
 
 #include <Uefi.h>
 
@@ -33,5 +32,3 @@ IsPlatformWantedDevice (
   IN EFI_HANDLE                ControllerHandle,
   IN EFI_DEVICE_PATH_PROTOCOL  *RemainingDevicePath OPTIONAL
   );
-
-#endif

RedfishPkg/Include/Library/RestExLib.h

@@ -8,8 +8,7 @@
 
 **/
 
-#ifndef REST_EX_LIB_H_
-#define REST_EX_LIB_H_
+#pragma once
 
 #include <Protocol/RestEx.h>
 
@@ -41,5 +40,3 @@ RestExLibCreateChild (
   IN EFI_REST_EX_SERVICE_TYPE         ServiceType,
   OUT EFI_HANDLE                      *ChildInstanceHandle
   );
-
-#endif

RedfishPkg/Include/Pcd/RestExServiceDevicePath.h

@@ -10,8 +10,7 @@
 
 **/
 
-#ifndef REST_EX_SERVICE_DEVICE_PATH_H_
-#define REST_EX_SERVICE_DEVICE_PATH_H_
+#pragma once
 
 #include <Protocol/DevicePath.h>
 
@@ -37,5 +36,3 @@ typedef struct {
   //
   EFI_DEVICE_PATH_PROTOCOL    DevicePath[MAX_DEVICE_PATH_NODE];
 } REST_EX_SERVICE_DEVICE_PATH_DATA;
-
-#endif

RedfishPkg/Include/Protocol/EdkIIRedfishConfigHandler.h

@@ -8,8 +8,7 @@
 
 **/
 
-#ifndef EDKII_REDFISH_CONFIG_HANDLER_H_
-#define EDKII_REDFISH_CONFIG_HANDLER_H_
+#pragma once
 
 typedef struct _EDKII_REDFISH_CONFIG_HANDLER_PROTOCOL EDKII_REDFISH_CONFIG_HANDLER_PROTOCOL;
 
@@ -73,5 +72,3 @@ struct _EDKII_REDFISH_CONFIG_HANDLER_PROTOCOL {
 };
 
 extern EFI_GUID  gdkIIRedfishConfigHandlerProtocolGuid;
-
-#endif

RedfishPkg/Include/Protocol/EdkIIRedfishCredential.h

@@ -8,8 +8,7 @@
 
 **/
 
-#ifndef EDKII_REDFISH_CREDENTIAL_H_
-#define EDKII_REDFISH_CREDENTIAL_H_
+#pragma once
 
 typedef struct _EDKII_REDFISH_CREDENTIAL_PROTOCOL EDKII_REDFISH_CREDENTIAL_PROTOCOL;
 
@@ -96,5 +95,3 @@ struct _EDKII_REDFISH_CREDENTIAL_PROTOCOL {
 };
 
 extern EFI_GUID  gEdkIIRedfishCredentialProtocolGuid;
-
-#endif

RedfishPkg/Include/Protocol/EdkIIRedfishCredential2.h

@@ -9,8 +9,7 @@
 
 **/
 
-#ifndef EDKII_REDFISH_CREDENTIAL2_H_
-#define EDKII_REDFISH_CREDENTIAL2_H_
+#pragma once
 
 #include <Protocol/EdkIIRedfishCredential.h>
 #include <RedfishServiceData.h>
@@ -124,5 +123,3 @@ struct _EDKII_REDFISH_CREDENTIAL2_PROTOCOL {
 };
 
 extern EFI_GUID  gEdkIIRedfishCredential2ProtocolGuid;
-
-#endif

RedfishPkg/Include/Protocol/EdkIIRedfishHttpProtocol.h

@@ -7,8 +7,7 @@
 
 **/
 
-#ifndef EDKII_REDFISH_HTTP_PROTOCOL_H_
-#define EDKII_REDFISH_HTTP_PROTOCOL_H_
+#pragma once
 
 #include <RedfishServiceData.h>
 #include <Library/JsonLib.h>
@@ -304,5 +303,3 @@ struct _EDKII_REDFISH_HTTP_PROTOCOL {
 #define EDKII_REDFISH_HTTP_PROTOCOL_REVISION  0x00001000
 
 extern EFI_GUID  gEdkIIRedfishHttpProtocolGuid;
-
-#endif