Zachary Turner 98638f07f1 [Windows] Implement PrintStackTrace(FILE*)
llvm::sys::PrintBacktrace(FILE*) is supposed to print a backtrace
of the current thread given the current PC.  This function was
unimplemented on Windows, and instead the only time we could
print a backtrace was as the result of an exception through
LLVMUnhandledExceptionFilter.

This patch implements backtracing of self by using
RtlCaptureContext to get a CONTEXT for the current thread, and
moving the printing and StackWalk64 code to a common method that
printing own stack trace and printing stack trace of an exception
can use.

Differential Revision: http://reviews.llvm.org/D8068
Reviewed by: Reid Kleckner

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231382 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-05 17:47:52 +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