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963162cab0
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>
57 lines
2.2 KiB
C
57 lines
2.2 KiB
C
/** @file
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The PRM Module Discovery library provides functionality to discover PRM modules installed by platform firmware.
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Copyright (c) Microsoft Corporation
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SPDX-License-Identifier: BSD-2-Clause-Patent
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**/
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#pragma once
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#include <Base.h>
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#include <PrmContextBuffer.h>
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#include <PrmModuleImageContext.h>
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#include <Uefi.h>
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/**
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Gets the next PRM module discovered after the given PRM module.
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@param[in,out] ModuleImageContext A pointer to a pointer to a PRM module image context structure.
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@retval EFI_SUCCESS The next PRM module was found successfully.
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@retval EFI_INVALID_PARAMETER The given ModuleImageContext structure is invalid or the pointer is NULL.
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@retval EFI_NOT_FOUND The next PRM module was not found.
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**/
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EFI_STATUS
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EFIAPI
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GetNextPrmModuleEntry (
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IN OUT PRM_MODULE_IMAGE_CONTEXT **ModuleImageContext
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);
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/**
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Discovers all PRM Modules loaded during boot.
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Each PRM Module discovered is placed into a linked list so the list can br processsed in the future.
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@param[out] ModuleCount An optional pointer parameter that, if provided, is set to the number
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of PRM modules discovered.
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@param[out] HandlerCount An optional pointer parameter that, if provided, is set to the number
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of PRM handlers discovered.
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@retval EFI_SUCCESS All PRM Modules were discovered successfully.
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@retval EFI_INVALID_PARAMETER An actual pointer parameter was passed as NULL.
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@retval EFI_NOT_FOUND The gEfiLoadedImageProtocolGuid protocol could not be found.
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@retval EFI_OUT_OF_RESOURCES Insufficient memory resources to allocate the new PRM Context
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linked list nodes.
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@retval EFI_ALREADY_STARTED The function was called previously and already discovered the PRM modules
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loaded on this boot.
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**/
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EFI_STATUS
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EFIAPI
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DiscoverPrmModules (
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OUT UINTN *ModuleCount OPTIONAL,
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OUT UINTN *HandlerCount OPTIONAL
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);
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