Tianocore/edk2.git/DynamicTablesPkg/Library/Common/AmlLib/Parser/AmlMethodParser.h, branch master

DynamicTablesPkg: Replace include guards with #pragma once

2026-02-23T21:01:28+00:00

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

DynamicTablesPkg: Apply uncrustify changes

2021-12-07T17:24:28+00:00

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3737 Apply uncrustify changes to .c/.h files in the DynamicTablesPkg package Cc: Andrew Fish Cc: Leif Lindholm Cc: Michael D Kinney Signed-off-by: Michael Kubacki Reviewed-by: Sami Mujawar

DynamicTablesPkg: AML Method parser

2020-08-13T18:00:06+00:00

The AML language allows a Definition Block to implement methods that an Operating System can invoke at runtime. Although Dynamic AML does not provide interfaces to modify AML methods; an AML template code may contain methods and/or method invocations. Method definitions have an opcode defined in the AML encoding and can be easily parsed. However, the language does not define an opcode for method invocation. Method invocations are represented as a NameString followed by the arguments to the method. This poses a significant challenge for the AML parser as it has to determine if a NameString appearing in the AML byte stream is a method invocation and if it is a method invocation, then how many arguments follow. This also means the Method definition must occur prior to the method invocation in the AML byte stream. This is a hard requirement for the AML parser. The AML method parser maintains a NameSpaceRefList that keeps a track of every namespace node and its raw AML absolute path. The AmlIsMethodInvocation() searches the NameSpaceRefList to determine if a NameString matches a Method definition. A pseudo opcode has been defined in the AML encoding to represent the Method invocation in the AML tree. The AML encoding for method invocations in the ACPI specification 6.3 is: MethodInvocation := NameString TermArgList The AmlLib library redefines this as: MethodInvocation := MethodInvocationOp NameString ArgumentCount TermArgList ArgumentCount := ByteData Where MethodInvocationOp is the pseudo opcode and ArgumentCount is the number of arguments passed to the method. NOTE: The AmlLib library's definition for a method invocation only applies to the representation of method invocation node in the AML tree. When computing the size of a tree or serialising it, the additional data is not taken into account i.e. the MethodInvocationOp and the ArgumentCount are stripped before serialising. Method invocation nodes have the AML_METHOD_INVOVATION attribute set in the AmlLib library's representation of the AML encoding. Signed-off-by: Pierre Gondois Signed-off-by: Sami Mujawar Reviewed-by: Alexei Fedorov