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>
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>
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>
The BaseNull instance of S3BootScriptLib obviously doesn't care about the
type of the S3BootScriptSaveMemPoll() function's LoopTimes parameter; this
lib instance doesn't do anything with the parameters received in
S3BootScriptSaveMemPoll().
The PiDxe instance saves the LoopTimes parameter in
EFI_BOOT_SCRIPT_MEM_POLL.LoopTimes. This target field already has UINT64
type. Furthermore, the BootScriptExecuteMemPoll() function in the same
library instance already uses a local UINT64 variable called LoopTimes to
count up to EFI_BOOT_SCRIPT_MEM_POLL.LoopTimes. This means that the the
UINTN type for S3BootScriptSaveMemPoll()'s LoopTimes parameter is an
unnecessary restriction.
The callers of S3BootScriptSaveMemPoll() will be updated in the next
patches, functionally. At this stage, they will continue to compile, since
UINT64 parameters can accept UINTN arguments.
Cc: Feng Tian <feng.tian@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: "Yao, Jiewen" <jiewen.yao@intel.com>
Reviewed-by: Michael Kinney <michael.d.kinney@intel.com>
