This patch provides a set of formatters for most of the commonly used Cocoa classes.

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

1 files changed, 302 insertions, 0 deletions

diff --git a/lldb/examples/summaries/cocoa/CFString.py b/lldb/examples/summaries/cocoa/CFString.py
new file mode 100644
index 00000000000..478f972e529
--- /dev/null
+++ b/lldb/examples/summaries/cocoa/CFString.py
@@ -0,0 +1,302 @@
+# synthetic children and summary provider for CFString
+# (and related NSString class)
+import lldb
+
+def CFString_SummaryProvider (valobj,dict):
+	provider = CFStringSynthProvider(valobj,dict);
+	if provider.invalid == False:
+	    try:
+	        summary = provider.get_child_at_index(provider.get_child_index("content")).GetSummary();
+	    except:
+	        summary = None
+	    if summary == None:
+	        summary = 'no valid string here'
+	    return '@'+summary
+	return ''
+
+def CFAttributedString_SummaryProvider (valobj,dict):
+	offset = valobj.GetTarget().GetProcess().GetAddressByteSize()
+	pointee = valobj.GetValueAsUnsigned(0)
+	summary = 'no valid string here'
+	if pointee != None and pointee != 0:
+		pointee = pointee + offset
+		child_ptr = valobj.CreateValueFromAddress("string_ptr",pointee,valobj.GetType())
+		child = child_ptr.CreateValueFromAddress("string_data",child_ptr.GetValueAsUnsigned(),valobj.GetType()).AddressOf()
+		provider = CFStringSynthProvider(child,dict);
+		if provider.invalid == False:
+			try:
+				summary = provider.get_child_at_index(provider.get_child_index("content")).GetSummary();
+			except:
+				summary = 'no valid string here'
+	if summary == None:
+		summary = 'no valid string here'
+	return '@'+summary
+
+
+def __lldb_init_module(debugger,dict):
+	debugger.HandleCommand("type summary add -F CFString.CFString_SummaryProvider NSString CFStringRef CFMutableStringRef")
+	debugger.HandleCommand("type summary add -F CFString.CFAttributedString_SummaryProvider NSAttributedString")
+
+class CFStringSynthProvider:
+	def __init__(self,valobj,dict):
+		self.valobj = valobj;
+		self.update()
+
+	# children other than "content" are for debugging only and must not be used in production code
+	def num_children(self):
+		if self.invalid:
+			return 0;
+		return 6;
+
+	def read_unicode(self, pointer):
+		process = self.valobj.GetTarget().GetProcess()
+		error = lldb.SBError()
+		pystr = u''
+		# cannot do the read at once because the length value has
+		# a weird encoding. better play it safe here
+		while True:
+			content = process.ReadMemory(pointer, 2, error)
+			new_bytes = bytearray(content)
+			b0 = new_bytes[0]
+			b1 = new_bytes[1]
+			pointer = pointer + 2
+			if b0 == 0 and b1 == 0:
+				break
+			# rearrange bytes depending on endianness
+			# (do we really need this or is Cocoa going to
+			#  use Windows-compatible little-endian even
+			#  if the target is big endian?)
+			if self.is_little:
+				value = b1 * 256 + b0
+			else:
+				value = b0 * 256 + b1
+			pystr = pystr + unichr(value)
+		return pystr
+
+	# handle the special case strings
+	# only use the custom code for the tested LP64 case
+	def handle_special(self):
+		if self.lp64 == False:
+			# for 32bit targets, use safe ObjC code
+			return self.handle_unicode_string_safe()
+		offset = 12
+		pointer = self.valobj.GetValueAsUnsigned(0) + offset
+		pystr = self.read_unicode(pointer)
+		return self.valobj.CreateValueFromExpression("content",
+			"(char*)\"" + pystr.encode('utf-8') + "\"")
+
+	# last resort call, use ObjC code to read; the final aim is to
+	# be able to strip this call away entirely and only do the read
+	# ourselves
+	def handle_unicode_string_safe(self):
+		return self.valobj.CreateValueFromExpression("content",
+			"(char*)\"" + self.valobj.GetObjectDescription() + "\"");
+
+	def handle_unicode_string(self):
+		# step 1: find offset
+		if self.inline:
+			pointer = self.valobj.GetValueAsUnsigned(0) + self.size_of_cfruntime_base();
+			if self.explicit == False:
+				# untested, use the safe code path
+				return self.handle_unicode_string_safe();
+			else:
+				# not sure why 8 bytes are skipped here
+				# (lldb) mem read -c 50 0x00000001001154f0
+				# 0x1001154f0: 98 1a 85 71 ff 7f 00 00 90 07 00 00 01 00 00 00  ...q?...........
+				# 0x100115500: 03 00 00 00 00 00 00 00 *c3 03 78 00 78 00 00 00  ........?.x.x...
+				# 0x100115510: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
+				# 0x100115520: 00 00                                            ..
+				# content begins at * (i.e. 8 bytes into variants, skipping void* buffer in
+				# __notInlineImmutable1 entirely, while the length byte is correctly located
+				# for an inline string)
+				pointer = pointer + 8;
+		else:
+			pointer = self.valobj.GetValueAsUnsigned(0) + self.size_of_cfruntime_base();
+			# read 8 bytes here and make an address out of them
+			try:
+			    vopointer = self.valobj.CreateChildAtOffset("dummy",
+				pointer,self.valobj.GetType().GetBasicType(lldb.eBasicTypeChar).GetPointerType());
+			    pointer = vopointer.GetValueAsUnsigned(0)
+			except:
+			    return self.valobj.CreateValueFromExpression("content",
+                                                             '(char*)"@\"invalid NSString\""')
+		# step 2: read Unicode data at pointer
+		pystr = self.read_unicode(pointer)
+		# step 3: return it
+		return self.valobj.CreateValueFromExpression("content",
+			"(char*)\"" + pystr.encode('utf-8') + "\"")
+
+	def handle_inline_explicit(self):
+		if self.lp64:
+			offset = 24
+		else:
+			offset = 12
+		offset = offset + self.valobj.GetValueAsUnsigned(0)
+		return self.valobj.CreateValueFromExpression("content",
+				"(char*)(" + str(offset) + ")")
+
+	def handle_mutable_string(self):
+		if self.lp64:
+			offset = 16
+		else:
+			offset = 8
+		data = self.valobj.CreateChildAtOffset("content",
+			offset, self.valobj.GetType().GetBasicType(lldb.eBasicTypeChar).GetPointerType());
+		data_value = data.GetValueAsUnsigned(0)
+		data_value = data_value + 1
+		return self.valobj.CreateValueFromExpression("content", "(char*)(" + str(data_value) + ")")
+
+	def handle_UTF8_inline(self):
+		offset = self.valobj.GetValueAsUnsigned(0) + self.size_of_cfruntime_base();
+		if self.explicit == False:
+			offset = offset + 1;
+		return self.valobj.CreateValueFromAddress("content",
+				offset, self.valobj.GetType().GetBasicType(lldb.eBasicTypeChar)).AddressOf();
+
+	def handle_UTF8_not_inline(self):
+		offset = self.size_of_cfruntime_base();
+		return self.valobj.CreateChildAtOffset("content",
+				offset,self.valobj.GetType().GetBasicType(lldb.eBasicTypeChar).GetPointerType());
+
+	def get_child_at_index(self,index):
+		if index == 0:
+			return self.valobj.CreateValueFromExpression("mutable",
+				str(int(self.mutable)));
+		if index == 1:
+			return self.valobj.CreateValueFromExpression("inline",
+				str(int(self.inline)));
+		if index == 2:
+			return self.valobj.CreateValueFromExpression("explicit",
+				str(int(self.explicit)));
+		if index == 3:
+			return self.valobj.CreateValueFromExpression("unicode",
+				str(int(self.unicode)));
+		if index == 4:
+			return self.valobj.CreateValueFromExpression("special",
+				str(int(self.special)));
+		if index == 5:
+			# we are handling the several possible combinations of flags.
+			# for each known combination we have a function that knows how to
+			# go fetch the data from memory instead of running code. if a string is not
+			# correctly displayed, one should start by finding a combination of flags that
+			# makes it different from these known cases, and provide a new reader function
+			# if this is not possible, a new flag might have to be made up (like the "special" flag
+			# below, which is not a real flag in CFString), or alternatively one might need to use
+			# the ObjC runtime helper to detect the new class and deal with it accordingly
+			if self.mutable == True:
+				return self.handle_mutable_string()
+			elif self.inline == True and self.explicit == True and \
+			   self.unicode == False and self.special == False and \
+			   self.mutable == False:
+				return self.handle_inline_explicit()
+			elif self.unicode == True:
+				return self.handle_unicode_string();
+			elif self.special == True:
+				return self.handle_special();
+			elif self.inline == True:
+				return self.handle_UTF8_inline();
+			else:
+				return self.handle_UTF8_not_inline();
+
+	def get_child_index(self,name):
+		if name == "content":
+			return self.num_children() - 1;
+		if name == "mutable":
+			return 0;
+		if name == "inline":
+			return 1;
+		if name == "explicit":
+			return 2;
+		if name == "unicode":
+			return 3;
+		if name == "special":
+			return 4;
+
+	def is_64bit(self):
+		return self.valobj.GetTarget().GetProcess().GetAddressByteSize() == 8
+
+	def is_little_endian(self):
+		return self.valobj.GetTarget().GetProcess().GetByteOrder() == lldb.eByteOrderLittle
+
+	# CFRuntimeBase is defined as having an additional
+	# 4 bytes (padding?) on LP64 architectures
+	# to get its size we add up sizeof(pointer)+4
+	# and then add 4 more bytes if we are on a 64bit system
+	def size_of_cfruntime_base(self):
+		if self.lp64 == True:
+			return 8+4+4;
+		else:
+			return 4+4;
+
+	# the info bits are part of the CFRuntimeBase structure
+	# to get at them we have to skip a uintptr_t and then get
+	# at the least-significant byte of a 4 byte array. If we are
+	# on big-endian this means going to byte 3, if we are on
+	# little endian (OSX & iOS), this means reading byte 0
+	def offset_of_info_bits(self):
+		if self.lp64 == True:
+			offset = 8;
+		else:
+			offset = 4;
+		if self.is_little == False:
+			offset = offset + 3;
+		return offset;
+
+	def read_info_bits(self):
+		cfinfo = self.valobj.CreateChildAtOffset("cfinfo",
+					self.offset_of_info_bits(),
+					self.valobj.GetType().GetBasicType(lldb.eBasicTypeChar));
+		cfinfo.SetFormat(11)
+		info = cfinfo.GetValue();
+		if info != None:
+			self.invalid = False;
+			return int(info,0);
+		else:
+			self.invalid = True;
+			return None;
+
+	# calculating internal flag bits of the CFString object
+	# this stuff is defined and discussed in CFString.c
+	def is_mutable(self):
+		return (self.info_bits & 1) == 1;
+
+	def is_inline(self):
+		return (self.info_bits & 0x60) == 0;
+
+	# this flag's name is ambiguous, it turns out
+	# we must skip a length byte to get at the data
+	# when this flag is False
+	def has_explicit_length(self):
+		return (self.info_bits & (1 | 4)) != 4;
+
+	# probably a subclass of NSString. obtained this from [str pathExtension]
+	# here info_bits = 0 and Unicode data at the start of the padding word
+	# in the long run using the isa value might be safer as a way to identify this
+	# instead of reading the info_bits
+	def is_special_case(self):
+		return self.info_bits == 0;
+
+	def is_unicode(self):
+		return (self.info_bits & 0x10) == 0x10;
+
+	# preparing ourselves to read into memory
+	# by adjusting architecture-specific info
+	def adjust_for_architecture(self):
+		self.lp64 = self.is_64bit();
+		self.is_little = self.is_little_endian();
+
+	# reading info bits out of the CFString and computing
+	# useful values to get at the real data
+	def compute_flags(self):
+		self.info_bits = self.read_info_bits();
+		if self.info_bits == None:
+			return;
+		self.mutable = self.is_mutable();
+		self.inline = self.is_inline();
+		self.explicit = self.has_explicit_length();
+		self.unicode = self.is_unicode();
+		self.special = self.is_special_case();
+
+	def update(self):
+		self.adjust_for_architecture();
+		self.compute_flags();
\ No newline at end of file