llvm-6502/lib/System
Bill Wendling 40db5d4539 Follow-up to the reverting of r51218. This puts the checks out-of-line. Because
they aren't in the header file, systems with a <string> header file that isn't
64-bit clean shouldn't warn if #including Path.h and specifying
-Wshorten-64-to-32.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51393 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-21 21:20:07 +00:00
..
Unix Make PreVerifyID, IntSigsEnd, and KillSigsEnd const. 2008-05-14 00:42:30 +00:00
Win32 Make constructors target-specific. This fixes problems where the path would 2008-05-11 17:37:40 +00:00
Alarm.cpp Remove uses of llvm/System/IncludeFile.h that are no longer needed. 2008-05-06 01:32:53 +00:00
Disassembler.cpp Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
DynamicLibrary.cpp Remove uses of llvm/System/IncludeFile.h that are no longer needed. 2008-05-06 01:32:53 +00:00
IncludeFile.cpp Specialize FORCE_DEFINING_FILE_TO_BE_LINKED using a GCC trick 2008-03-21 23:38:23 +00:00
LICENSE.TXT
Makefile remove attribution from lib Makefiles. 2007-12-29 20:09:26 +00:00
Memory.cpp Remove uses of llvm/System/IncludeFile.h that are no longer needed. 2008-05-06 01:32:53 +00:00
Mutex.cpp Remove uses of llvm/System/IncludeFile.h that are no longer needed. 2008-05-06 01:32:53 +00:00
Path.cpp Follow-up to the reverting of r51218. This puts the checks out-of-line. Because 2008-05-21 21:20:07 +00:00
Process.cpp Remove uses of llvm/System/IncludeFile.h that are no longer needed. 2008-05-06 01:32:53 +00:00
Program.cpp Remove uses of llvm/System/IncludeFile.h that are no longer needed. 2008-05-06 01:32:53 +00:00
README.txt
Signals.cpp Remove uses of llvm/System/IncludeFile.h that are no longer needed. 2008-05-06 01:32:53 +00:00
TimeValue.cpp Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00

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