llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-11-06 05:06:45 +00:00

History

Owen Anderson 0d1ea255d9 Get rid of a helgrind warning. If this is _actually_ a performance problem, we can find a way to cache the answer that isn't racy. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79472 91177308-0d34-0410-b5e6-96231b3b80d8		2009-08-19 21:48:34 +00:00
..
Unix	Get rid of a helgrind warning. If this is _actually_ a performance problem,	2009-08-19 21:48:34 +00:00
Win32	improve win32 path support, patch by Baptiste Lepilleur!	2009-08-12 17:47:06 +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
Errno.cpp
Host.cpp
IncludeFile.cpp
Makefile
Memory.cpp
Mutex.cpp
Path.cpp
Process.cpp
Program.cpp	Remove duplication in Program::Execute{And,No}Wait.	2009-07-18 21:43:12 +00:00
README.txt
RWMutex.cpp
Signals.cpp
Threading.cpp
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