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2026-02-24MdePkg: Replace include guards with #pragma onceMichael Kubacki1-4/+1
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>
2021-12-07MdePkg: Apply uncrustify changesMichael Kubacki1-31/+19
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3737 Apply uncrustify changes to .c/.h files in the MdePkg package Cc: Andrew Fish <afish@apple.com> Cc: Leif Lindholm <leif@nuviainc.com> Cc: Michael D Kinney <michael.d.kinney@intel.com> Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com> Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>
2019-04-09MdePkg: Replace BSD License with BSD+Patent LicenseMichael D Kinney1-7/+1
https://bugzilla.tianocore.org/show_bug.cgi?id=1373 Replace BSD 2-Clause License with BSD+Patent License. This change is based on the following emails: https://lists.01.org/pipermail/edk2-devel/2019-February/036260.html https://lists.01.org/pipermail/edk2-devel/2018-October/030385.html RFCs with detailed process for the license change: V3: https://lists.01.org/pipermail/edk2-devel/2019-March/038116.html V2: https://lists.01.org/pipermail/edk2-devel/2019-March/037669.html V1: https://lists.01.org/pipermail/edk2-devel/2019-March/037500.html Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com> Reviewed-by: Liming Gao <liming.gao@intel.com>
2018-09-25MdePkg/SynchronizationLib: fix Interlocked[De|In]crement return valueRuiyu Ni1-4/+2
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1197 Today's InterlockedIncrement()/InterlockedDecrement() guarantees to perform atomic increment/decrement but doesn't guarantee the return value equals to the new value. The patch fixes the behavior to use "XADD" instruction to guarantee the return value equals to the new value. The patch calls intrinsic functions for MSVC tool chain, calls the NASM implementation for INTEL tool chain and calls GCC inline assembly implementation (GccInline.c) for GCC tool chain. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com> Cc: Jiewen Yao <jiewen.yao@intel.com> Reviewed-by: Liming Gao <liming.gao@intel.com> Cc: Michael D Kinney <michael.d.kinney@intel.com>
2018-06-28MdePkg: Clean up source filesLiming Gao1-2/+2
1. Do not use tab characters 2. No trailing white space in one line 3. All files must end with CRLF Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Liming Gao <liming.gao@intel.com>
2016-11-18MdePkg/Include: Add volatile to SynchronizationLib parametersMichael Kinney1-7/+7
The SpinLock functions in the SynchronicationLib use volatile parameters to keep compiler from optimizing these functions too much. The volatile keyword is missing from the Interlocked*() functions in this same library class. Update the library class to consistently use volatile on all functions in this class. Cc: Liming Gao <liming.gao@intel.com> Cc: Laszlo Ersek <lersek@redhat.com> Cc: Andrew Fish <afish@apple.com> Cc: Jeff Fan <jeff.fan@intel.com> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Michael Kinney <michael.d.kinney@intel.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Liming Gao <liming.gao@intel.com>
2015-02-28MdePkg/BaseSynchronizationLib: Add InterlockedCompareExchange16Ard Biesheuvel1-0/+26
This implements the function InterlockedCompareExchange16 () for all architectures, using architecture and toolchain specific intrinsics or primitive assembler instructions. Contributed-under: TianoCore Contribution Agreement 1.0 Reviewed-by: Olivier Martin <olivier.martin@arm.com> Acked-by: Jordan Justen <jordan.l.justen@intel.com> Reviewed-by: Michael Kinney <michael.d.kinney@intel.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Laszlo Ersek <lersek@redhat.com> git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16966 6f19259b-4bc3-4df7-8a09-765794883524
2012-03-07Clarify alignment of GetSpinLockProperties() is byte alignment.lgao41-3/+3
Signed-off-by: lgao4 Reviewed-by: mdkinney git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13086 6f19259b-4bc3-4df7-8a09-765794883524
2010-04-23Update the copyright notice formathhtian1-2/+2
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@10403 6f19259b-4bc3-4df7-8a09-765794883524
2009-06-04Second set of changes based on a review of the code comments in the Include ↵pkandel1-4/+4
directory for typos, grammar issues, and language clarity. git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@8467 6f19259b-4bc3-4df7-8a09-765794883524
2009-01-30Split out Synchronization Library from Base Librarymdkinney1-0/+269
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@7377 6f19259b-4bc3-4df7-8a09-765794883524