llvm-6502/lib/System
Douglas Gregor 01746745f1 Add terminal width detection to llvm::sys::Process. This is needed to
fix Clang PRs 4148 and 4183.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71448 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-11 18:05:52 +00:00
..
Unix Add terminal width detection to llvm::sys::Process. This is needed to 2009-05-11 18:05:52 +00:00
Win32 Add terminal width detection to llvm::sys::Process. This is needed to 2009-05-11 18:05:52 +00:00
Alarm.cpp
CMakeLists.txt CMake: when bulding shared libraries on non-WIN32 systems, link dl to 2008-11-12 20:40:56 +00:00
Disassembler.cpp
DynamicLibrary.cpp Fix PR3424, a static constructor ordering issue. Patch by Robert Schuster! 2009-01-29 04:43:42 +00:00
Host.cpp
IncludeFile.cpp
LICENSE.TXT
Makefile Removed trailing whitespace from Makefiles. 2009-01-09 16:44:42 +00:00
Memory.cpp ARM / Mac OS X also wants to invalidate icache after jitting. 2008-11-14 02:33:17 +00:00
Mutex.cpp plug leakage of mutex data. pthread_mutex_destroy() doesnt free our malloc'ed memory. 2008-11-06 16:21:49 +00:00
Path.cpp Fix g++-4.4.0 warning, it was causing llvm-nm to fail on wrapped BC files: 2009-04-25 10:25:12 +00:00
Process.cpp
Program.cpp
README.txt
Signals.cpp
TimeValue.cpp

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