llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-11-04 22:07:27 +00:00

History

Jeffrey Yasskin f28411f732 Tell Valgrind when we modify already-executed machine code so it knows to re-instrument the code. We depend on the system valgrind.h to avoid adding a new license. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98529 91177308-0d34-0410-b5e6-96231b3b80d8		2010-03-15 04:57:55 +00:00
..
Unix	don't forget to close a FD on an error condition, found by	2010-03-14 23:16:45 +00:00
Win32	Remove superfluous NULL assignment	2010-03-12 14:17:24 +00:00
Alarm.cpp
Atomic.cpp
CMakeLists.txt	Tell Valgrind when we modify already-executed machine code so it knows	2010-03-15 04:57:55 +00:00
Disassembler.cpp
DynamicLibrary.cpp	Make clang bootstrap happier on OSX 10.5 by reducing the number of headers	2010-03-11 06:14:32 +00:00
Errno.cpp
Host.cpp
IncludeFile.cpp
Makefile
Memory.cpp	Tell Valgrind when we modify already-executed machine code so it knows	2010-03-15 04:57:55 +00:00
Mutex.cpp
Path.cpp
Process.cpp
Program.cpp
README.txt
RWMutex.cpp
SearchForAddressOfSpecialSymbol.cpp	Make clang bootstrap happier on OSX 10.5 by reducing the number of headers	2010-03-11 06:14:32 +00:00
Signals.cpp
Threading.cpp
ThreadLocal.cpp
TimeValue.cpp
Valgrind.cpp	Tell Valgrind when we modify already-executed machine code so it knows	2010-03-15 04:57:55 +00:00

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