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7a934d0bef
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>
56 lines
1.7 KiB
C
56 lines
1.7 KiB
C
/** @file
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Universal Payload general definitions.
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Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
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SPDX-License-Identifier: BSD-2-Clause-Patent
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@par Revision Reference:
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- Universal Payload Specification 0.75 (https://universalpayload.github.io/documentation/)
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**/
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#pragma once
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/**
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Main entry point to Universal Payload.
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@param HobList Pointer to the beginning of the HOB List from boot loader.
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**/
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typedef VOID (EFIAPI *UNIVERSAL_PAYLOAD_ENTRY)(VOID *HobList);
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#define UNIVERSAL_PAYLOAD_IDENTIFIER SIGNATURE_32('P', 'L', 'D', 'H')
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#define UNIVERSAL_PAYLOAD_INFO_SEC_NAME ".upld_info"
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#define UNIVERSAL_PAYLOAD_EXTRA_SEC_NAME_PREFIX ".upld."
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#define UNIVERSAL_PAYLOAD_EXTRA_SEC_NAME_PREFIX_LENGTH (sizeof (UNIVERSAL_PAYLOAD_EXTRA_SEC_NAME_PREFIX) - 1)
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#pragma pack(1)
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typedef struct {
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UINT32 Identifier;
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UINT32 HeaderLength;
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UINT16 SpecRevision;
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UINT8 Reserved[2];
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UINT32 Revision;
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UINT32 Attribute;
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UINT32 Capability;
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CHAR8 ProducerId[16];
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CHAR8 ImageId[16];
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} UNIVERSAL_PAYLOAD_INFO_HEADER;
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typedef struct {
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UINT8 Revision;
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UINT8 Reserved;
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UINT16 Length;
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} UNIVERSAL_PAYLOAD_GENERIC_HEADER;
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#pragma pack()
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/**
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Returns the size of a structure of known type, up through and including a specified field.
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@param TYPE The name of the data structure that contains the field specified by Field.
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@param Field The name of the field in the data structure.
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@return size, in bytes.
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**/
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#define UNIVERSAL_PAYLOAD_SIZEOF_THROUGH_FIELD(TYPE, Field) (OFFSET_OF(TYPE, Field) + sizeof (((TYPE *) 0)->Field))
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