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 ShellPkg 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: Ray Ni <ray.ni@intel.com>
"Compress.h" declares the Compress() function as EFIAPI, but the
definition in "Compress.c" lacks EFIAPI.
GCC toolchains without LTO do not catch this error because "Compress.c"
does not include "Compress.h"; i.e. the declaration used by callers such
as "EfiCompress.c" is not actually matched against the function definition
at build time.
With LTO enabled, the mismatch is found -- however, as a warning only, due
to commit f8d0b96629 ("BaseTools GCC5: disable warnings-as-errors for
now", 2016-08-03).
Include the header in the C file (which turns the issue into a hard build
error on all GCC toolchains), plus sync the declaration from the header
file to the C file. Finally, remove EFIAPI from both declaration and
definition -- this was the original intent of commit c4e74e9b81
("ShellPkg/UefiShellDebug1CommandsLib: Remove unnecessary EFIAPI",
2016-10-09), but it missed the header file.
(Gary meant to address that omission in Oct 2017:
[edk2] [PATCH] ShellPkg/UefiShellDebug1CommandsLib: Remove EFIAPI from
Compress()
http://mid.mail-archive.com/20171026065329.32311-1-glin@suse.com
and Ray reviewed the patch, but then the patch was never committed.)
So do the sync and drop EFIAPI now.
This happens to fix the EFICOMPRESS shell command, when built with GCC for
X64.
Cc: Gary Lin <glin@suse.com>
Cc: Jaben Carsey <jaben.carsey@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Fixes: c4e74e9b81
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Gary Lin <glin@suse.com>
Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>
