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>
1. Add DebugAgentPei driver to initialize Debug Agent in PEI phase.
Add DebugAgentDxe driver to initialize Debug Agent in DXE phase.
DebugAgentDxe driver could be loaded and unloaded in shell.
2. Update the SourceLevelDebugPkg so that the debug agent can be initialized in any phase: SEC, PEI or DXE.
3. Add an enhanced retry algorithm that provides a robust connection when data loss happens in the debug channel.
4. Clear DR7 register in exception handler.
5. Set the default serial port parameter to 0 instead of PCDs.
6. Build pointer of Mailbox in HOB instead of Mailbox itself, since HOB may be moved at DXE entry point function.
7. Raise TPL to prevent recursion from EFI timer interrupts in SerialIo.c.
8. Add one spin lock for accessing Mailbox when MP debugging supported.
9. Use more non-NULL library instances in SourceLevelDebugPkg DSC file, thus DebugAgentDxe.efi built from SourceLevelDebugPkg could work in shell.
10.Separate all operations about IDT table entry from SecDebugAgentLib.c into DebugAgent\DebugAgentCommon's arch sub-directory.
11.Enhance Debug Agent to avoid breaking by hardware SMI during DXE debugging phase.
12.Add supporting on mode switch code debugging.
13.Remove reset Host Controller operation in DebugCommunicationLibUsb.c to avoid impacting EDKII usb stack.
14.Fix debug timer interrupt missing issue after back from legacy code.
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
Signed-off-by: Feng Tian <feng.tian@intel.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@14083 6f19259b-4bc3-4df7-8a09-765794883524
Michael Kubackiandmergify[bot]
Michael D Kinney
vanjeff