edk2/ShellPkg/Library/UefiShellDebug1CommandsLib/HexEdit/MainHexEditor.h
Michael Kubacki 8472271dae ShellPkg: 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>
2026-02-23 21:01:28 +00:00

66 lines
1.3 KiB
C

/** @file
Defines the Main Editor data type -
- Global variables
- Instances of the other objects of the editor
- Main Interfaces
Copyright (c) 2005 - 2018, Intel Corporation. All rights reserved. <BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#pragma once
#include "HexEditor.h"
/**
Init function for MainEditor
@retval EFI_SUCCESS The operation was successful.
@retval EFI_LOAD_ERROR A load error occurred.
**/
EFI_STATUS
HMainEditorInit (
VOID
);
/**
Cleanup function for MainEditor.
@retval EFI_SUCCESS The operation was successful.
@retval EFI_LOAD_ERROR A load error occurred.
**/
EFI_STATUS
HMainEditorCleanup (
VOID
);
/**
Refresh function for MainEditor.
@retval EFI_SUCCESS The operation was successful.
**/
EFI_STATUS
HMainEditorRefresh (
VOID
);
/**
Handle user key input. will route it to other components handle function.
@retval EFI_SUCCESS The operation was successful.
@retval EFI_OUT_OF_RESOURCES A memory allocation occurred.
@retval EFI_LOAD_ERROR A load error occurred.
**/
EFI_STATUS
HMainEditorKeyInput (
VOID
);
/**
Backup function for MainEditor.
**/
VOID
HMainEditorBackup (
VOID
);