Fixing a whole class of crashers and potential crashers related to data formatters eating up all the stack when an unknown class has to be summarized ; this should make the whole Objective-C summaries more stable

llvm-svn: 153712

The Cocoa formatters now provide error messages for many of the common things-went-wrong situations. Previously they would say nothing or log failures to the Python console

llvm-svn: 152673

Changed several of the Cocoa formatters to match the output style that Xcode uses internally to provide summaries
This has been done for those summaries where the difference is only cosmetic (e.g. naming things as items instead of values, ...)
The LLDB output style has been preserved when it provides more information (e.g. telling the type as well as the value of an NSNumber)

Test cases have been updated to reflect the updated output style where necessary

llvm-svn: 152592

 (a) the SystemParameters object is now passed around to the formatters; doing so enables the formatters to reuse computed values for things such as pointer-size and endianness
     instead of repeatedly computing these on their own
 (b) replacing the global ISA cache with a per-process one
 (c) providing a per-process types cache where each formatter can store the types it needs to operate, and be sure to find them the next time without recalculating them
     this also enables formatters to share types if they agree on a local naming convention
 (d) lazy fetching of data from Objective-C runtime data structures
     data is fetched as needed and we stop reading as soon as we determine that an ISA is actually garbage

llvm-svn: 152052

 a) adds a Python summary provider for NSDate
 b) changes the initialization for ScriptInterpreter so that we are not passing a bulk of Python-specific function pointers around
 c) provides a new ScriptInterpreterObject class that allows for ref-count safe wrapping of scripting objects on the C++ side
 d) contains much needed performance improvements:
    1) the pointer to the Python function generating a scripted summary is now cached instead of looked up every time
    2) redundant memory reads in the Python ObjC runtime wrapper are eliminated
    3) summaries now use the m_summary_str in ValueObject to store their data instead of passing around ( == copying) an std::string object
 e) contains other minor fixes, such as adding descriptive error messages for some cases of summary generation failure

llvm-svn: 151703

The formatter for NSString is an improved version of the one previously shipped as an example, the others are new in design and implementation.
A more robust and OO-compliant Objective-C runtime wrapper is provided for runtime versions 1 and 2 on 32 and 64 bit.
The formatters are contained in a category named "AppKit", which is not enabled at startup.

llvm-svn: 151300