Adding support for fetching the Dynamic Value for ObjC Objects.

llvm-svn: 130701
diff --git a/lldb/source/Plugins/LanguageRuntime/CPlusPlus/ItaniumABI/ItaniumABILanguageRuntime.cpp b/lldb/source/Plugins/LanguageRuntime/CPlusPlus/ItaniumABI/ItaniumABILanguageRuntime.cpp
index fb4c98d..20b608e 100644
--- a/lldb/source/Plugins/LanguageRuntime/CPlusPlus/ItaniumABI/ItaniumABILanguageRuntime.cpp
+++ b/lldb/source/Plugins/LanguageRuntime/CPlusPlus/ItaniumABI/ItaniumABILanguageRuntime.cpp
@@ -41,7 +41,7 @@
 }
 
 bool
-ItaniumABILanguageRuntime::GetDynamicValue (ValueObject &in_value, lldb::TypeSP &dynamic_type_sp, Address &dynamic_address)
+ItaniumABILanguageRuntime::GetDynamicTypeAndAddress (ValueObject &in_value, TypeAndOrName &class_type_or_name, Address &dynamic_address)
 {
     // For Itanium, if the type has a vtable pointer in the object, it will be at offset 0
     // in the object.  That will point to the "address point" within the vtable (not the beginning of the
@@ -104,6 +104,7 @@
                     {
                          // We are a C++ class, that's good.  Get the class name and look it up:
                         const char *class_name = name + strlen(vtable_demangled_prefix);
+                        class_type_or_name.SetName (class_name);
                         TypeList class_types;
                         uint32_t num_matches = target->GetImages().FindTypes (sc, 
                                                                               ConstString(class_name),
@@ -112,14 +113,40 @@
                                                                               class_types);
                         if (num_matches == 1)
                         {
-                            dynamic_type_sp = class_types.GetTypeAtIndex(0);
+                            class_type_or_name.SetTypeSP(class_types.GetTypeAtIndex(0));
                         }
                         else if (num_matches > 1)
                         {
-                            // How to sort out which of the type matches to pick?
+                            for (size_t i = 0; i < num_matches; i++)
+                            {
+                                lldb::TypeSP this_type(class_types.GetTypeAtIndex(i));
+                                if (this_type)
+                                {
+                                    if (ClangASTContext::IsCXXClassType(this_type->GetClangFullType()))
+                                    {
+                                        // There can only be one type with a given name,
+                                        // so we've just found duplicate definitions, and this
+                                        // one will do as well as any other.
+                                        // We don't consider something to have a dynamic type if
+                                        // it is the same as the static type.  So compare against
+                                        // the value we were handed:
+                                        
+                                        clang::ASTContext *in_ast_ctx = in_value.GetClangAST ();
+                                        clang::ASTContext *this_ast_ctx = this_type->GetClangAST ();
+                                        if (in_ast_ctx != this_ast_ctx
+                                            || !ClangASTContext::AreTypesSame (in_ast_ctx, 
+                                                                               in_value.GetClangType(),
+                                                                               this_type->GetClangFullType()))
+                                        {
+                                            class_type_or_name.SetTypeSP (this_type);
+                                            return true;
+                                        }
+                                        return false;
+                                    }
+                                }
+                            }
                         }
-                        
-                        if (!dynamic_type_sp)
+                        else
                             return false;
                             
                         // The offset_to_top is two pointers above the address.
diff --git a/lldb/source/Plugins/LanguageRuntime/CPlusPlus/ItaniumABI/ItaniumABILanguageRuntime.h b/lldb/source/Plugins/LanguageRuntime/CPlusPlus/ItaniumABI/ItaniumABILanguageRuntime.h
index 421ac12..966090d 100644
--- a/lldb/source/Plugins/LanguageRuntime/CPlusPlus/ItaniumABI/ItaniumABILanguageRuntime.h
+++ b/lldb/source/Plugins/LanguageRuntime/CPlusPlus/ItaniumABI/ItaniumABILanguageRuntime.h
@@ -31,7 +31,7 @@
         IsVTableName (const char *name);
         
         virtual bool
-        GetDynamicValue (ValueObject &in_value, lldb::TypeSP &type_sp, Address &address);
+        GetDynamicTypeAndAddress (ValueObject &in_value, TypeAndOrName &class_type_or_name, Address &address);
         
         virtual bool
         CouldHaveDynamicValue (ValueObject &in_value);
diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntime.cpp b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntime.cpp
index 08af0b6..62eac38 100644
--- a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntime.cpp
+++ b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntime.cpp
@@ -198,7 +198,7 @@
 }
 
 bool
-AppleObjCRuntime::GetDynamicValue (ValueObject &in_value, lldb::TypeSP &type_sp, Address &address)
+AppleObjCRuntime::GetDynamicTypeAndAddress (ValueObject &in_value, TypeAndOrName &class_type_or_name, Address &address)
 {
     return false;
 }
diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntime.h b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntime.h
index e7e0f71..f3eb074 100644
--- a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntime.h
+++ b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntime.h
@@ -41,7 +41,7 @@
     CouldHaveDynamicValue (ValueObject &in_value);
     
     virtual bool
-    GetDynamicValue (ValueObject &in_value, lldb::TypeSP &type_sp, Address &address);
+    GetDynamicTypeAndAddress (ValueObject &in_value, TypeAndOrName &class_type_or_name, Address &address);
 
     // These are the ObjC specific functions.
     
diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.cpp b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.cpp
index 000f14e..fe29b62 100644
--- a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.cpp
+++ b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.cpp
@@ -41,7 +41,7 @@
 static const char *pluginShort = "language.apple.objc.v1";
 
 bool
-AppleObjCRuntimeV1::GetDynamicValue (ValueObject &in_value, lldb::TypeSP &type_sp, Address &address)
+AppleObjCRuntimeV1::GetDynamicTypeAndAddress (ValueObject &in_value, TypeAndOrName &class_type_or_name, Address &address)
 {
     return false;
 }
diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.h b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.h
index 975c018..7a43ca3 100644
--- a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.h
+++ b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.h
@@ -32,7 +32,7 @@
     
     // These are generic runtime functions:
     virtual bool
-    GetDynamicValue (ValueObject &in_value, lldb::TypeSP &type_sp, Address &address);
+    GetDynamicTypeAndAddress (ValueObject &in_value, TypeAndOrName &class_type_or_name, Address &address);
 
     virtual ClangUtilityFunction *
     CreateObjectChecker (const char *);
diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
index c6e3533..42e7aee 100644
--- a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
+++ b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
@@ -40,15 +40,359 @@
 static const char *pluginDesc = "Apple Objective C Language Runtime - Version 2";
 static const char *pluginShort = "language.apple.objc.v2";
 
+
+const char *AppleObjCRuntimeV2::g_find_class_name_function_name = "__lldb_apple_objc_v2_find_class_name";
+const char *AppleObjCRuntimeV2::g_find_class_name_function_body = "                               \n\
+extern \"C\"                                                                                      \n\
+{                                                                                                 \n\
+    extern void *gdb_class_getClass (void *objc_class);                                           \n\
+    extern void *class_getName(void *objc_class);                                                 \n\
+    extern int printf(const char *format, ...);                                                   \n\
+}                                                                                                 \n\
+                                                                                                  \n\
+struct __lldb_objc_object {                                                                       \n\
+    void *isa;                                                                                    \n\
+};                                                                                                \n\
+                                                                                                  \n\
+extern \"C\" void *__lldb_apple_objc_v2_find_class_name (                                         \n\
+                                                          __lldb_objc_object *object_ptr,         \n\
+                                                          int debug)                              \n\
+{                                                                                                 \n\
+    void *name = 0;                                                                               \n\
+    if (debug)                                                                                    \n\
+        printf (\"\\n*** Called in v2_find_class_name with object: 0x%p\\n\", object_ptr);        \n\
+    // Call gdb_class_getClass so we can tell if the class is good.                               \n\
+    void *objc_class = gdb_class_getClass (object_ptr->isa);                                      \n\
+    if (objc_class)                                                                               \n\
+    {                                                                                             \n\
+        void *actual_class = (void *) [(id) object_ptr class];                                    \n\
+        if (actual_class != 0)                                                                    \n\
+            name = class_getName((void *) actual_class);                                          \n\
+        if (debug)                                                                                \n\
+            printf (\"\\n*** Found name: %s\\n\", name ? name : \"<NOT FOUND>\");                 \n\
+    }                                                                                             \n\
+    else if (debug)                                                                               \n\
+        printf (\"\\n*** gdb_class_getClass returned NULL\\n\");                                  \n\
+    return name;                                                                                  \n\
+}                                                                                                 \n\
+";
+
+const char *AppleObjCRuntimeV2::g_objc_class_symbol_prefix = "OBJC_CLASS_$_";
+const char *AppleObjCRuntimeV2::g_objc_class_data_section_name = "__objc_data";
+
 AppleObjCRuntimeV2::AppleObjCRuntimeV2 (Process *process, ModuleSP &objc_module_sp) : 
-    lldb_private::AppleObjCRuntime (process)
+    lldb_private::AppleObjCRuntime (process),
+    m_get_class_name_args(LLDB_INVALID_ADDRESS),
+    m_get_class_name_args_mutex(Mutex::eMutexTypeNormal)
 {
     m_has_object_getClass = (objc_module_sp->FindFirstSymbolWithNameAndType(ConstString("gdb_object_getClass")) != NULL);
 }
 
 bool
-AppleObjCRuntimeV2::GetDynamicValue (ValueObject &in_value, lldb::TypeSP &type_sp, Address &address)
+AppleObjCRuntimeV2::RunFunctionToFindClassName(lldb::addr_t object_addr, Thread *thread, char *name_dst, size_t max_name_len)
 {
+    // Since we are going to run code we have to make sure only one thread at a time gets to try this.
+    Mutex::Locker (m_get_class_name_args_mutex);
+    
+    StreamString errors;
+    
+    LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));  // FIXME - a more appropriate log channel?
+    
+    int32_t debug;
+    if (log)
+        debug = 1;
+    else
+        debug = 0;
+
+    ValueList dispatch_values;
+    
+    Value void_ptr_value;
+    ClangASTContext *clang_ast_context = m_process->GetTarget().GetScratchClangASTContext();
+    
+    lldb::clang_type_t clang_void_ptr_type = clang_ast_context->GetVoidPtrType(false);
+    void_ptr_value.SetValueType (Value::eValueTypeScalar);
+    void_ptr_value.SetContext (Value::eContextTypeClangType, clang_void_ptr_type);
+    void_ptr_value.GetScalar() = object_addr;
+        
+    dispatch_values.PushValue (void_ptr_value);
+    
+    Value int_value;
+    lldb::clang_type_t clang_int_type = clang_ast_context->GetBuiltinTypeForEncodingAndBitSize(lldb::eEncodingSint, 32);
+    int_value.SetValueType (Value::eValueTypeScalar);
+    int_value.SetContext (Value::eContextTypeClangType, clang_int_type);
+    int_value.GetScalar() = debug;
+    
+    dispatch_values.PushValue (int_value);
+    
+    ExecutionContext exe_ctx;
+    thread->CalculateExecutionContext(exe_ctx);
+    
+    Address find_class_name_address;
+    
+    if (!m_get_class_name_code.get())
+    {
+        m_get_class_name_code.reset (new ClangUtilityFunction (g_find_class_name_function_body,
+                                                               g_find_class_name_function_name));
+                                                               
+        if (!m_get_class_name_code->Install(errors, exe_ctx))
+        {
+            if (log)
+                log->Printf ("Failed to install implementation lookup: %s.", errors.GetData());
+            m_get_class_name_code.reset();
+            return false;
+        }
+        find_class_name_address.Clear();
+        find_class_name_address.SetOffset(m_get_class_name_code->StartAddress());
+    }
+    else
+    {
+        find_class_name_address.Clear();
+        find_class_name_address.SetOffset(m_get_class_name_code->StartAddress());
+    }
+
+    // Next make the runner function for our implementation utility function.
+    if (!m_get_class_name_function.get())
+    {
+         m_get_class_name_function.reset(new ClangFunction (*m_process,
+                                                  clang_ast_context, 
+                                                  clang_void_ptr_type, 
+                                                  find_class_name_address, 
+                                                  dispatch_values));
+        
+        errors.Clear();        
+        unsigned num_errors = m_get_class_name_function->CompileFunction(errors);
+        if (num_errors)
+        {
+            if (log)
+                log->Printf ("Error compiling function: \"%s\".", errors.GetData());
+            return false;
+        }
+        
+        errors.Clear();
+        if (!m_get_class_name_function->WriteFunctionWrapper(exe_ctx, errors))
+        {
+            if (log)
+                log->Printf ("Error Inserting function: \"%s\".", errors.GetData());
+            return false;
+        }
+    }
+
+    if (m_get_class_name_code.get() == NULL || m_get_class_name_function.get() == NULL)
+        return false;
+
+    // Finally, write down the arguments, and call the function.  Note that we will re-use the same space in the target
+    // for the args.  We're locking this to ensure that only one thread at a time gets to call this function, so we don't
+    // have to worry about overwriting the arguments.
+    
+    if (!m_get_class_name_function->WriteFunctionArguments (exe_ctx, m_get_class_name_args, find_class_name_address, dispatch_values, errors))
+        return false;
+    
+    bool stop_others = true;
+    bool try_all_threads = true;
+    bool unwind_on_error = true;
+    
+    ExecutionResults results = m_get_class_name_function->ExecuteFunction (exe_ctx, 
+                                                     &m_get_class_name_args, 
+                                                     errors, 
+                                                     stop_others, 
+                                                     1000000, 
+                                                     try_all_threads, 
+                                                     unwind_on_error, 
+                                                     void_ptr_value);
+                                                     
+    if (results != eExecutionCompleted)
+    {
+        if (log)
+        log->Printf("Error evaluating our find class name function: %d.\n", results);
+        return false;
+    }
+    
+    lldb::addr_t result_ptr = void_ptr_value.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
+    size_t chars_read = m_process->ReadCStringFromMemory (result_ptr, name_dst, max_name_len);
+    
+    // If we exhausted our buffer before finding a NULL we're probably off in the weeds somewhere...
+    if (chars_read == max_name_len)
+        return false;
+    else
+        return true;
+       
+}
+
+bool
+AppleObjCRuntimeV2::GetDynamicTypeAndAddress (ValueObject &in_value, TypeAndOrName &class_type_or_name, Address &address)
+{
+    // The Runtime is attached to a particular process, you shouldn't pass in a value from another process.
+    assert (in_value.GetUpdatePoint().GetProcess() == m_process);
+    
+    // Make sure we can have a dynamic value before starting...
+    if (CouldHaveDynamicValue (in_value))
+    {
+        // First job, pull out the address at 0 offset from the object  That will be the ISA pointer.
+        AddressType address_type;
+        lldb::addr_t original_ptr = in_value.GetPointerValue(address_type, true);
+        
+        // ObjC only has single inheritance, so the objects all start at the same pointer value.
+        address.SetSection (NULL);
+        address.SetOffset (original_ptr);
+
+        if (original_ptr == LLDB_INVALID_ADDRESS)
+            return false;
+            
+        Target *target = m_process->CalculateTarget();
+
+        char memory_buffer[16];
+        DataExtractor data(memory_buffer, sizeof(memory_buffer), 
+                           m_process->GetByteOrder(), 
+                           m_process->GetAddressByteSize());
+        size_t address_byte_size = m_process->GetAddressByteSize();
+        Error error;
+        size_t bytes_read = m_process->ReadMemory (original_ptr, 
+                                                   memory_buffer, 
+                                                   address_byte_size, 
+                                                   error);
+        if (!error.Success() || (bytes_read != address_byte_size))
+        {
+            return false;
+        }
+        
+        uint32_t offset_ptr = 0;
+        lldb::addr_t isa_addr = data.GetAddress (&offset_ptr);
+            
+        if (offset_ptr == 0)
+            return false;
+            
+        // Make sure the class address is readable, otherwise this is not a good object:
+        bytes_read = m_process->ReadMemory (isa_addr, 
+                                            memory_buffer, 
+                                            address_byte_size, 
+                                            error);
+        if (bytes_read != address_byte_size)
+            return false;
+        
+        // First check the cache...
+        
+        SymbolContext sc;
+            
+        class_type_or_name = LookupInClassNameCache (isa_addr);
+        
+        if (!class_type_or_name.IsEmpty())
+        {
+            if (class_type_or_name.GetTypeSP() != NULL)
+                return true;
+            else
+                return false;
+        }
+
+        const char *class_name = NULL;
+        Address isa_address;
+        target->GetSectionLoadList().ResolveLoadAddress (isa_addr, isa_address);
+        
+        if (isa_address.IsValid())
+        {
+            // If the ISA pointer points to one of the sections in the binary, then see if we can
+            // get the class name from the symbols.
+        
+            const Section *section = isa_address.GetSection();
+
+            if (section)
+            {
+                // If this points to a section that we know about, then this is
+                // some static class or nothing.  See if it is in the right section 
+                // and if its name is the right form.
+                ConstString section_name = section->GetName();
+                if (section_name == ConstString(g_objc_class_data_section_name))
+                {
+                    isa_address.CalculateSymbolContext(&sc);
+                    if (sc.symbol)
+                    {
+                        class_name = sc.symbol->GetName().AsCString();
+                        if (strstr (class_name, g_objc_class_symbol_prefix) == class_name)
+                            class_name += strlen (g_objc_class_symbol_prefix);
+                        else
+                            return false;
+                    }
+                }
+            }
+        }
+        
+        char class_buffer[1024];
+        if (class_name == NULL)
+        {
+            // If the class address didn't point into the binary, or
+            // it points into the right section but there wasn't a symbol
+            // there, try to look it up by calling the class method in the target.
+            ExecutionContextScope *exe_scope = in_value.GetUpdatePoint().GetExecutionContextScope();
+            Thread *thread_to_use;
+            if (exe_scope)
+                thread_to_use = exe_scope->CalculateThread();
+            
+            if (thread_to_use == NULL)
+                thread_to_use = m_process->GetThreadList().GetSelectedThread().get();
+                
+            if (thread_to_use == NULL)
+                return false;
+                
+            if (!RunFunctionToFindClassName (original_ptr, thread_to_use, class_buffer, 1024))
+                return false;
+                
+             class_name = class_buffer;   
+            
+        }
+        
+        if (class_name != NULL && *class_name != '\0')
+        {
+            class_type_or_name.SetName (class_name);
+            
+            TypeList class_types;
+            uint32_t num_matches = target->GetImages().FindTypes (sc, 
+                                                                  class_type_or_name.GetName(),
+                                                                  true,
+                                                                  UINT32_MAX,
+                                                                  class_types);
+            if (num_matches == 1)
+            {
+                class_type_or_name.SetTypeSP (class_types.GetTypeAtIndex(0));
+                return true;
+            }
+            else
+            {
+                for (size_t i  = 0; i < num_matches; i++)
+                {
+                    lldb::TypeSP this_type(class_types.GetTypeAtIndex(i));
+                    if (this_type)
+                    {
+                        if (ClangASTContext::IsObjCClassType(this_type->GetClangFullType()))
+                        {
+                            // There can only be one type with a given name,
+                            // so we've just found duplicate definitions, and this
+                            // one will do as well as any other.
+                            // We don't consider something to have a dynamic type if
+                            // it is the same as the static type.  So compare against
+                            // the value we were handed:
+                            
+                            clang::ASTContext *in_ast_ctx = in_value.GetClangAST ();
+                            clang::ASTContext *this_ast_ctx = this_type->GetClangAST ();
+                            if (in_ast_ctx != this_ast_ctx
+                                || !ClangASTContext::AreTypesSame (in_ast_ctx, 
+                                                                   in_value.GetClangType(),
+                                                                   this_type->GetClangFullType()))
+                            {
+                                class_type_or_name.SetTypeSP (this_type);
+                            }
+                            break;
+                        }
+                    }
+                }
+            }
+            
+            AddToClassNameCache (isa_addr, class_type_or_name);
+            if (class_type_or_name.GetTypeSP())
+                return true;
+            else
+                return false;
+        }
+    }
+    
     return false;
 }
 
diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.h b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.h
index 0015dd2..93395ff 100644
--- a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.h
+++ b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.h
@@ -23,7 +23,7 @@
 #include "AppleThreadPlanStepThroughObjCTrampoline.h"
 
 namespace lldb_private {
-    
+
 class AppleObjCRuntimeV2 :
         public AppleObjCRuntime
 {
@@ -32,7 +32,7 @@
     
     // These are generic runtime functions:
     virtual bool
-    GetDynamicValue (ValueObject &in_value, lldb::TypeSP &type_sp, Address &address);
+    GetDynamicTypeAndAddress (ValueObject &in_value, TypeAndOrName &class_type_or_name, Address &address);
     
     virtual ClangUtilityFunction *
     CreateObjectChecker (const char *);
@@ -76,7 +76,18 @@
 private:
     AppleObjCRuntimeV2(Process *process, ModuleSP &objc_module_sp);
     
-    bool m_has_object_getClass;
+    bool RunFunctionToFindClassName (lldb::addr_t class_addr, Thread *thread, char *name_dst, size_t max_name_len);
+    
+    bool                                m_has_object_getClass;
+    std::auto_ptr<ClangFunction>        m_get_class_name_function;
+    std::auto_ptr<ClangUtilityFunction> m_get_class_name_code;
+    lldb::addr_t                        m_get_class_name_args;
+    Mutex                               m_get_class_name_args_mutex;
+    
+    static const char *g_find_class_name_function_name;
+    static const char *g_find_class_name_function_body;
+    static const char *g_objc_class_symbol_prefix;
+    static const char *g_objc_class_data_section_name;
 };
     
 } // namespace lldb_private