llvm/System at 22f35ace4599f28f50159cf0e19436e755669340 - llvm

RPCSX/llvm

mirror of https://github.com/RPCSX/llvm.git synced 2024-12-03 09:21:13 +00:00

History

Duncan Sands 3429c5e153 Using a signal handler that does nothing should be equivalent to SIG_IGN. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81144 91177308-0d34-0410-b5e6-96231b3b80d8		2009-09-07 05:58:25 +00:00
..
Unix	Using a signal handler that does nothing should be	2009-09-07 05:58:25 +00:00
Win32	Prune #includes from llvm/Linker.h and llvm/System/Path.h,	2009-08-23 22:45:37 +00:00
Alarm.cpp
Atomic.cpp
CMakeLists.txt	CMake: make sure that the *.inc files for libSystem show up in the resulting	2009-07-27 17:55:55 +00:00
Disassembler.cpp	This void is implicit in C++.	2009-08-12 22:10:57 +00:00
DynamicLibrary.cpp	Fix ExplicitSymbols leak.	2009-08-31 16:12:29 +00:00
Errno.cpp
Host.cpp
IncludeFile.cpp
Makefile
Memory.cpp
Mutex.cpp	Tweak code into an equivalent form for which icc	2009-09-06 10:53:22 +00:00
Path.cpp	Prune #includes from llvm/Linker.h and llvm/System/Path.h,	2009-08-23 22:45:37 +00:00
Process.cpp
Program.cpp	Remove duplication in Program::Execute{And,No}Wait.	2009-07-18 21:43:12 +00:00
README.txt
RWMutex.cpp	Tweak code into an equivalent form for which icc	2009-09-06 10:53:22 +00:00
Signals.cpp
Threading.cpp	No need to double-include config.h	2009-07-06 21:24:37 +00:00
ThreadLocal.cpp
TimeValue.cpp

README.txt

Design Of lib/System
====================

The software in this directory is designed to completely shield LLVM from any
and all operating system specific functionality. It is not intended to be a
complete operating system wrapper (such as ACE), but only to provide the
functionality necessary to support LLVM.

The software located here, of necessity, has very specific and stringent design
rules. Violation of these rules means that cracks in the shield could form and
the primary goal of the library is defeated. By consistently using this library,
LLVM becomes more easily ported to new platforms since the only thing requiring 
porting is this library.

Complete documentation for the library can be found in the file:
  llvm/docs/SystemLibrary.html 
or at this URL:
  http://llvm.org/docs/SystemLibrary.html

While we recommend that you read the more detailed documentation, for the 
impatient, here's a high level summary of the library's requirements.

 1. No system header files are to be exposed through the interface.
 2. Std C++ and Std C header files are okay to be exposed through the interface.
 3. No exposed system-specific functions.
 4. No exposed system-specific data.
 5. Data in lib/System classes must use only simple C++ intrinsic types.
 6. Errors are handled by returning "true" and setting an optional std::string
 7. Library must not throw any exceptions, period.
 8. Interface functions must not have throw() specifications.
 9. No duplicate function impementations are permitted within an operating
    system class.

To accomplish these requirements, the library has numerous design criteria that 
must be satisfied. Here's a high level summary of the library's design criteria:

 1. No unused functionality (only what LLVM needs)
 2. High-Level Interfaces
 3. Use Opaque Classes
 4. Common Implementations</a></li>
 5. Multiple Implementations</a></li>
 6. Minimize Memory Allocation</a></li>
 7. No Virtual Methods