mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2025-02-07 14:33:15 +00:00
0184a841d3
The coding style used here is not LLVM's style because this is modeled after a Boost interface and thus done in the style of a candidate C++ standard library interface. I'll probably end up proposing it as a standard C++ library if it proves to be reasonably portable and useful. This is just the most basic parts of the interface -- getting the process ID out of it. However, it helps sketch out some of the boiler plate such as the base class, derived class, shared code, and static factory function. It also introduces a unittest so that I can incrementally ensure this stuff works. However, I've not even compiled this code for Windows yet. I'll try to fix any Windows fallout from the bots, and if I can't fix it I'll revert and get someone on Windows to help out. There isn't a lot more that is mandatory, so soon I'll switch to just stubbing out the Windows side and get Michael Spencer to help with implementation as he can test it directly. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171289 91177308-0d34-0410-b5e6-96231b3b80d8
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
5. Multiple Implementations
6. Minimize Memory Allocation
7. No Virtual Methods