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>
There are duplicate library function names between 2 Unit Test libraries
(UnitTestPeiServicesTablePointerLib and UnitTestUefiBootServicesTableLib).
There are 3 functions (UnitTestAllocatePages, UnitTestAllocatePool and
UnitTestFreePage). This update avoids the duplication and prevents a build
error when building a Unit Test application that links the libraries based
on UnitTestFrameworkPkg.
Signed-off-by: Phil Noh <Phil.Noh@amd.com>
This library supports a PeiServicesTablePointerLib implementation
that allows code dependent upon PeiServicesTable to operate in an
isolated execution environment such as within the context of a
host-based unit test framework.
The unit test should initialize the PeiServicesTable database with
any required elements (e.g. PPIs, Hob etc.) prior to the services
being invoked by code under test.
It is strongly recommended to clean any global databases by using
EFI_PEI_SERVICES.ResetSystem2 after every unit test so the tests
execute in a predictable manner from a clean state.
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Michael Kubacki <mikuback@linux.microsoft.com>
Cc: Sean Brogan <sean.brogan@microsoft.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Signed-off-by: Zhiguang Liu <zhiguang.liu@intel.com>
