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01f75b3927
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>
48 lines
1.4 KiB
C
48 lines
1.4 KiB
C
/** @file
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Copyright (c) 2020, Arm Limited. All rights reserved.<BR>
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SPDX-License-Identifier: BSD-2-Clause-Patent
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@par Glossary:
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- Cm or CM - Configuration Manager
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- Obj or OBJ - Object
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- Std or STD - Standard
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@par Reference(s):
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- Arm CoreLink CMN-600 Coherent Mesh Network Technical Reference Manual r3p0
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- Generic ACPI for Arm Components 1.0 Platform Design Document
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**/
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#pragma once
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/** PeriphBase maximum address length is 256MB (0x10000000)
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for a (X >= 4) || (Y >= 4) dimensions mesh.
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*/
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#define PERIPHBASE_MAX_ADDRESS_LENGTH SIZE_256MB
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/** PeriphBase minimum address length is 64MB (0x04000000)
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for a (X < 4) && (Y < 4) dimensions mesh.
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*/
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#define PERIPHBASE_MIN_ADDRESS_LENGTH SIZE_64MB
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/** RootNodeBase address length is 16KB (0x00004000).
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*/
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#define ROOTNODEBASE_ADDRESS_LENGTH SIZE_16KB
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/** Maximum number of CMN-600 Debug and Trace Logic Controllers (DTC).
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*/
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#define MAX_DTC_COUNT 4
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/** Starting value for the UID to represent the CMN600 devices.
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*/
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#define CMN600_DEVICE_START_UID 0
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/** Maximum CMN-600 devices supported by this generator.
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This generator supports a maximum of 16 CMN-600 devices.
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Note: This is not a hard limitation and can be extended if needed.
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Corresponding changes would be needed to support the Name and
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UID fields describing the serial port.
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*/
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#define MAX_CMN600_DEVICES_SUPPORTED 16
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