[lldb] Improve breakpoint management for interactive scripted process

This patch improves breakpoint management when doing interactive
scripted process debugging.

In other to know which process set a breakpoint, we need to do some book
keeping on the multiplexer scripted process. When initializing the
multiplexer, we will first copy breakpoints that are already set on the
driving target.

Everytime we launch or resume, we should copy breakpoints from the
multiplexer to the driving process.

When creating a breakpoint from a child process, it needs to be set both
on the multiplexer and on the driving process. We also tag the created
breakpoint with the name and pid of the originator process.

This patch also implements all the requirement to achieve proper
breakpoint management. That involves:

- Adding python interator for breakpoints and watchpoints in SBTarget
- Add a new `ScriptedProcess.create_breakpoint` python method

Differential Revision: https://reviews.llvm.org/D148548

Signed-off-by: Med Ismail Bennani <[email protected]>
(cherry picked from commit e31d0c2)

Author: medismailben

lldb/bindings/interface/SBTargetExtensions.i

@@ -88,7 +88,7 @@ STRING_EXTENSION_LEVEL_OUTSIDE(SBTarget, lldb::eDescriptionLevelBrief)
 
         def get_modules_access_object(self):
             '''An accessor function that returns a modules_access() object which allows lazy module access from a lldb.SBTarget object.'''
-            return self.modules_access (self)
+            return self.modules_access(self)
 
         def get_modules_array(self):
             '''An accessor function that returns a list() that contains all modules in a lldb.SBTarget object.'''
@@ -107,18 +107,80 @@ STRING_EXTENSION_LEVEL_OUTSIDE(SBTarget, lldb::eDescriptionLevelBrief)
             object.'''
             return lldb_iter(self, 'GetNumBreakpoints', 'GetBreakpointAtIndex')
 
+        class bkpts_access(object):
+            '''A helper object that will lazily hand out bkpts for a target when supplied an index.'''
+            def __init__(self, sbtarget):
+                self.sbtarget = sbtarget
+
+            def __len__(self):
+                if self.sbtarget:
+                    return int(self.sbtarget.GetNumBreakpoints())
+                return 0
+
+            def __getitem__(self, key):
+                if isinstance(key, int):
+                    count = len(self)
+                    if -count <= key < count:
+                        key %= count
+                        return self.sbtarget.GetBreakpointAtIndex(key)
+                return None
+
+        def get_bkpts_access_object(self):
+            '''An accessor function that returns a bkpts_access() object which allows lazy bkpt access from a lldb.SBtarget object.'''
+            return self.bkpts_access(self)
+
+        def get_target_bkpts(self):
+            '''An accessor function that returns a list() that contains all bkpts in a lldb.SBtarget object.'''
+            bkpts = []
+            for idx in range(self.GetNumBreakpoints()):
+                bkpts.append(self.GetBreakpointAtIndex(idx))
+            return bkpts
+
         def watchpoint_iter(self):
             '''Returns an iterator over all watchpoints in a lldb.SBTarget
             object.'''
             return lldb_iter(self, 'GetNumWatchpoints', 'GetWatchpointAtIndex')
 
+        class watchpoints_access(object):
+            '''A helper object that will lazily hand out watchpoints for a target when supplied an index.'''
+            def __init__(self, sbtarget):
+                self.sbtarget = sbtarget
+
+            def __len__(self):
+                if self.sbtarget:
+                    return int(self.sbtarget.GetNumWatchpoints())
+                return 0
+
+            def __getitem__(self, key):
+                if isinstance(key, int):
+                    count = len(self)
+                    if -count <= key < count:
+                        key %= count
+                        return self.sbtarget.GetWatchpointAtIndex(key)
+                return None
+
+        def get_watchpoints_access_object(self):
+            '''An accessor function that returns a watchpoints_access() object which allows lazy watchpoint access from a lldb.SBtarget object.'''
+            return self.watchpoints_access(self)
+
+        def get_target_watchpoints(self):
+            '''An accessor function that returns a list() that contains all watchpoints in a lldb.SBtarget object.'''
+            watchpoints = []
+            for idx in range(self.GetNumWatchpoints()):
+                bkpts.append(self.GetWatchpointAtIndex(idx))
+            return watchpoints
+
         modules = property(get_modules_array, None, doc='''A read only property that returns a list() of lldb.SBModule objects contained in this target. This list is a list all modules that the target currently is tracking (the main executable and all dependent shared libraries).''')
         module = property(get_modules_access_object, None, doc=r'''A read only property that returns an object that implements python operator overloading with the square brackets().\n    target.module[<int>] allows array access to any modules.\n    target.module[<str>] allows access to modules by basename, full path, or uuid string value.\n    target.module[uuid.UUID()] allows module access by UUID.\n    target.module[re] allows module access using a regular expression that matches the module full path.''')
         process = property(GetProcess, None, doc='''A read only property that returns an lldb object that represents the process (lldb.SBProcess) that this target owns.''')
         executable = property(GetExecutable, None, doc='''A read only property that returns an lldb object that represents the main executable module (lldb.SBModule) for this target.''')
         debugger = property(GetDebugger, None, doc='''A read only property that returns an lldb object that represents the debugger (lldb.SBDebugger) that owns this target.''')
         num_breakpoints = property(GetNumBreakpoints, None, doc='''A read only property that returns the number of breakpoints that this target has as an integer.''')
+        breakpoints = property(get_target_bkpts, None, doc='''A read only property that returns a list() of lldb.SBBreakpoint objects for all breakpoints in this target.''')
+        breakpoint = property(get_bkpts_access_object, None, doc='''A read only property that returns an object that can be used to access breakpoints as an array ("bkpt_12 = lldb.target.bkpt[12]").''')
         num_watchpoints = property(GetNumWatchpoints, None, doc='''A read only property that returns the number of watchpoints that this target has as an integer.''')
+        watchpoints = property(get_target_watchpoints, None, doc='''A read only property that returns a list() of lldb.SBwatchpoint objects for all watchpoints in this target.''')
+        watchpoint = property(get_watchpoints_access_object, None, doc='''A read only property that returns an object that can be used to access watchpoints as an array ("watchpoint_12 = lldb.target.watchpoint[12]").''')
         broadcaster = property(GetBroadcaster, None, doc='''A read only property that an lldb object that represents the broadcaster (lldb.SBBroadcaster) for this target.''')
         byte_order = property(GetByteOrder, None, doc='''A read only property that returns an lldb enumeration value (lldb.eByteOrderLittle, lldb.eByteOrderBig, lldb.eByteOrderInvalid) that represents the byte order for this target.''')
         addr_size = property(GetAddressByteSize, None, doc='''A read only property that returns the size in bytes of an address for this target.''')