diff options
Diffstat (limited to 'lldb/examples/synthetic/CFString.py')
| -rw-r--r-- | lldb/examples/synthetic/CFString.py | 41 |
1 files changed, 29 insertions, 12 deletions
diff --git a/lldb/examples/synthetic/CFString.py b/lldb/examples/synthetic/CFString.py index 0e39b73ae57..7d3a43ae98e 100644 --- a/lldb/examples/synthetic/CFString.py +++ b/lldb/examples/synthetic/CFString.py @@ -1,15 +1,18 @@ # synthetic children provider for CFString # (and related NSString class) import lldb + 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() @@ -34,6 +37,7 @@ class CFStringSynthProvider: 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): @@ -45,12 +49,14 @@ class CFStringSynthProvider: 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: @@ -80,6 +86,7 @@ class CFStringSynthProvider: # step 3: return it return self.valobj.CreateValueFromExpression("content", "(char*)\"" + pystr.encode('utf-8') + "\"") + # we read at "the right place" into the __CFString object instead of running code # we are replicating the functionality of __CFStrContents in CFString.c here def handle_UTF8_inline(self): @@ -88,10 +95,12 @@ class CFStringSynthProvider: offset = offset + 1; return self.valobj.CreateValueFromAddress("content", offset, self.valobj.GetType().GetBasicType(lldb.eBasicTypeChar)); + 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", @@ -117,6 +126,7 @@ class CFStringSynthProvider: 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; @@ -130,17 +140,13 @@ class CFStringSynthProvider: return 3; if name == "special": return 4; + def is_64bit(self): - if self.valobj.GetTarget().GetProcess().GetAddressByteSize() == 8: - return True; - else: - return False; + return self.valobj.GetTarget().GetProcess().GetAddressByteSize() == 8 + def is_little_endian(self): - # 4 is eByteOrderLittle - if self.valobj.GetTarget().GetProcess().GetByteOrder() == 4: - return True; - else: - return False; + 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 @@ -150,6 +156,7 @@ class CFStringSynthProvider: 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 @@ -163,6 +170,7 @@ class CFStringSynthProvider: 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(), @@ -175,30 +183,37 @@ class CFStringSynthProvider: 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): @@ -210,12 +225,14 @@ class CFStringSynthProvider: 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(); + def CFString_SummaryProvider (valobj,dict): provider = CFStringSynthProvider(valobj,dict); - if provider.invalid == True: - return "<invalid object>"; - return provider.get_child_at_index(provider.get_child_index("content")).GetSummary(); + if provider.invalid == False: + return provider.get_child_at_index(provider.get_child_index("content")).GetSummary(); + return '' |
