Zachary Turner c504ae3cef Resubmit r301986 and r301987 "Add codeview::StringTable"
This was reverted due to a "missing" file, but in reality
what happened was that I renamed a file, and then due to
a merge conflict both the old file and the new file got
added to the repository.  This led to an unused cpp file
being in the repo and not referenced by any CMakeLists.txt
but #including a .h file that wasn't in the repo.  In an
even more unfortunate coincidence, CMake didn't report the
unused cpp file because it was in a subdirectory of the
folder with the CMakeLists.txt, and not in the same directory
as any CMakeLists.txt.

The presence of the unused file was then breaking certain
tools that determine file lists by globbing rather than
by what's specified in CMakeLists.txt

In any case, the fix is to just remove the unused file from
the patch set.

llvm-svn: 302042
2017-05-03 15:58:37 +00:00
..
2016-09-14 08:55:18 +00:00
2016-11-29 17:32:43 +00:00
2017-01-04 19:47:10 +00:00
2017-04-18 01:04:05 +00:00
2016-11-23 03:58:12 +00:00
2017-01-28 02:02:38 +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
 5. Multiple Implementations
 6. Minimize Memory Allocation
 7. No Virtual Methods