[Lldb-commits] [lldb] r346708 - [lldb] Add synthetic frontend for _NSCallStackArray

[Kuba Mracek via lldb-commits]

Author: kuba.brecka
Date: Mon Nov 12 13:26:03 2018
New Revision: 346708

URL: http://llvm.org/viewvc/llvm-project?rev=346708&view=rev
Log:
[lldb] Add synthetic frontend for _NSCallStackArray

An Obj-C array type _NSCallStackArray is used in NSException backtraces. This patch adds a synthetic frontend for _NSCallStackArray, which now correctly returns frame PCs.

Differential Revision: https://reviews.llvm.org/D44081


Modified:
    lldb/trunk/packages/Python/lldbsuite/test/lang/objc/exceptions/TestObjCExceptions.py
    lldb/trunk/source/Plugins/Language/ObjC/NSArray.cpp
    lldb/trunk/source/Plugins/Language/ObjC/ObjCLanguage.cpp

Modified: lldb/trunk/packages/Python/lldbsuite/test/lang/objc/exceptions/TestObjCExceptions.py
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/packages/Python/lldbsuite/test/lang/objc/exceptions/TestObjCExceptions.py?rev=346708&r1=346707&r2=346708&view=diff
==============================================================================
--- lldb/trunk/packages/Python/lldbsuite/test/lang/objc/exceptions/TestObjCExceptions.py (original)
+++ lldb/trunk/packages/Python/lldbsuite/test/lang/objc/exceptions/TestObjCExceptions.py Mon Nov 12 13:26:03 2018
@@ -28,7 +28,8 @@ class ObjCExceptionsTestCase(TestBase):
         self.expect("thread list", STOPPED_DUE_TO_BREAKPOINT,
                     substrs=['stopped', 'stop reason = breakpoint'])
 
-        thread = self.dbg.GetSelectedTarget().GetProcess().GetSelectedThread()
+        target = self.dbg.GetSelectedTarget()
+        thread = target.GetProcess().GetSelectedThread()
         frame = thread.GetSelectedFrame()
 
         self.expect(
@@ -87,4 +88,13 @@ class ObjCExceptionsTestCase(TestBase):
         self.assertEqual(userInfo.summary, "1 key/value pair")
         self.assertEqual(userInfo.GetChildAtIndex(0).GetChildAtIndex(0).description, "some_key")
         self.assertEqual(userInfo.GetChildAtIndex(0).GetChildAtIndex(1).description, "some_value")
-        self.assertGreater(e2.GetChildMemberWithName("reserved").dynamic.num_children, 0)
+        reserved = e2.GetChildMemberWithName("reserved").dynamic
+        self.assertGreater(reserved.num_children, 0)
+        callStackReturnAddresses = [reserved.GetChildAtIndex(i).GetChildAtIndex(1) for i in range(0, reserved.GetNumChildren())
+                if reserved.GetChildAtIndex(i).GetChildAtIndex(0).description == "callStackReturnAddresses"][0].dynamic
+        children = [callStackReturnAddresses.GetChildAtIndex(i) for i in range(0, callStackReturnAddresses.num_children)]
+
+        pcs = [i.unsigned for i in children]
+        names = [target.ResolveSymbolContextForAddress(lldb.SBAddress(pc, target), lldb.eSymbolContextSymbol).GetSymbol().name for pc in pcs]
+        for n in ["objc_exception_throw", "foo", "main"]:
+            self.assertTrue(n in names, "%s is in the exception backtrace (%s)" % (n, names))

Modified: lldb/trunk/source/Plugins/Language/ObjC/NSArray.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Language/ObjC/NSArray.cpp?rev=346708&r1=346707&r2=346708&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Language/ObjC/NSArray.cpp (original)
+++ lldb/trunk/source/Plugins/Language/ObjC/NSArray.cpp Mon Nov 12 13:26:03 2018
@@ -214,6 +214,25 @@ namespace Foundation1437 {
 
 }
 
+namespace CallStackArray {
+struct DataDescriptor_32 {
+  uint32_t _data;
+  uint32_t _used;
+  uint32_t _offset;
+  const uint32_t _size = 0;
+};
+
+struct DataDescriptor_64 {
+  uint64_t _data;
+  uint64_t _used;
+  uint64_t _offset;
+  const uint64_t _size = 0;
+};
+
+using NSCallStackArraySyntheticFrontEnd =
+    GenericNSArrayMSyntheticFrontEnd<DataDescriptor_32, DataDescriptor_64>;
+} // namespace CallStackArray
+
 template <typename D32, typename D64, bool Inline>
 class GenericNSArrayISyntheticFrontEnd : public SyntheticChildrenFrontEnd {
 public:
@@ -364,6 +383,7 @@ bool lldb_private::formatters::NSArraySu
   static const ConstString g_NSArrayCF("__NSCFArray");
   static const ConstString g_NSArrayMLegacy("__NSArrayM_Legacy");
   static const ConstString g_NSArrayMImmutable("__NSArrayM_Immutable");
+  static const ConstString g_NSCallStackArray("_NSCallStackArray");
 
   if (class_name.IsEmpty())
     return false;
@@ -413,7 +433,9 @@ bool lldb_private::formatters::NSArraySu
     value = 0;
   } else if (class_name == g_NSArray1) {
     value = 1;
-  } else if (class_name == g_NSArrayCF) {
+  } else if (class_name == g_NSArrayCF || class_name == g_NSCallStackArray) {
+    // __NSCFArray and _NSCallStackArray store the number of elements as a
+    // pointer-sized value at offset `2 * ptr_size`.
     Status error;
     value = process_sp->ReadUnsignedIntegerFromMemory(
         valobj_addr + 2 * ptr_size, ptr_size, 0, error);
@@ -813,6 +835,7 @@ lldb_private::formatters::NSArraySynthet
   static const ConstString g_NSArray1("__NSSingleObjectArrayI");
   static const ConstString g_NSArrayMLegacy("__NSArrayM_Legacy");
   static const ConstString g_NSArrayMImmutable("__NSArrayM_Immutable");
+  static const ConstString g_NSCallStackArray("_NSCallStackArray");
 
   if (class_name.IsEmpty())
     return nullptr;
@@ -842,6 +865,8 @@ lldb_private::formatters::NSArraySynthet
       return (new Foundation1010::NSArrayMSyntheticFrontEnd(valobj_sp));
     else
       return (new Foundation109::NSArrayMSyntheticFrontEnd(valobj_sp));
+  } else if (class_name == g_NSCallStackArray) {
+    return (new CallStackArray::NSCallStackArraySyntheticFrontEnd(valobj_sp));
   } else {
     auto &map(NSArray_Additionals::GetAdditionalSynthetics());
     auto iter = map.find(class_name), end = map.end();

Modified: lldb/trunk/source/Plugins/Language/ObjC/ObjCLanguage.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Language/ObjC/ObjCLanguage.cpp?rev=346708&r1=346707&r2=346708&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Language/ObjC/ObjCLanguage.cpp (original)
+++ lldb/trunk/source/Plugins/Language/ObjC/ObjCLanguage.cpp Mon Nov 12 13:26:03 2018
@@ -409,6 +409,9 @@ static void LoadObjCFormatters(TypeCateg
       "NSArray summary provider", ConstString("__NSCFArray"), appkit_flags);
   AddCXXSummary(
       objc_category_sp, lldb_private::formatters::NSArraySummaryProvider,
+      "NSArray summary provider", ConstString("_NSCallStackArray"), appkit_flags);
+  AddCXXSummary(
+      objc_category_sp, lldb_private::formatters::NSArraySummaryProvider,
       "NSArray summary provider", ConstString("CFArrayRef"), appkit_flags);
   AddCXXSummary(objc_category_sp,
                 lldb_private::formatters::NSArraySummaryProvider,
@@ -528,6 +531,10 @@ static void LoadObjCFormatters(TypeCateg
                   ScriptedSyntheticChildren::Flags());
   AddCXXSynthetic(objc_category_sp,
                   lldb_private::formatters::NSArraySyntheticFrontEndCreator,
+                  "NSArray synthetic children", ConstString("_NSCallStackArray"),
+                  ScriptedSyntheticChildren::Flags());
+  AddCXXSynthetic(objc_category_sp,
+                  lldb_private::formatters::NSArraySyntheticFrontEndCreator,
                   "NSArray synthetic children",
                   ConstString("CFMutableArrayRef"),
                   ScriptedSyntheticChildren::Flags());