Move the C++ data formatters to the C++ language plugin

llvm-svn: 246873

1 files changed, 370 insertions, 0 deletions

diff --git a/lldb/source/Plugins/Language/CPlusPlus/LibCxxList.cpp b/lldb/source/Plugins/Language/CPlusPlus/LibCxxList.cpp
new file mode 100644
index 00000000000..7da1b7a128f
--- /dev/null
+++ b/lldb/source/Plugins/Language/CPlusPlus/LibCxxList.cpp
@@ -0,0 +1,370 @@
+//===-- LibCxxList.cpp -------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LibCxx.h"
+
+#include "lldb/Core/DataBufferHeap.h"
+#include "lldb/Core/Error.h"
+#include "lldb/Core/Stream.h"
+#include "lldb/Core/ValueObject.h"
+#include "lldb/Core/ValueObjectConstResult.h"
+#include "lldb/DataFormatters/FormattersHelpers.h"
+#include "lldb/Host/Endian.h"
+#include "lldb/Symbol/ClangASTContext.h"
+#include "lldb/Target/Target.h"
+
+using namespace lldb;
+using namespace lldb_private;
+using namespace lldb_private::formatters;
+
+namespace lldb_private {
+    namespace formatters {
+        class LibcxxStdListSyntheticFrontEnd : public SyntheticChildrenFrontEnd
+        {
+        public:
+            LibcxxStdListSyntheticFrontEnd (lldb::ValueObjectSP valobj_sp);
+            
+            virtual size_t
+            CalculateNumChildren ();
+            
+            virtual lldb::ValueObjectSP
+            GetChildAtIndex (size_t idx);
+            
+            virtual bool
+            Update();
+            
+            virtual bool
+            MightHaveChildren ();
+            
+            virtual size_t
+            GetIndexOfChildWithName (const ConstString &name);
+            
+            virtual
+            ~LibcxxStdListSyntheticFrontEnd ();
+        private:
+            bool
+            HasLoop(size_t);
+            
+            size_t m_list_capping_size;
+            static const bool g_use_loop_detect = true;
+            size_t m_loop_detected;
+            lldb::addr_t m_node_address;
+            ValueObject* m_head;
+            ValueObject* m_tail;
+            CompilerType m_element_type;
+            size_t m_count;
+            std::map<size_t,lldb::ValueObjectSP> m_children;
+        };
+    }
+}
+
+class ListEntry
+{
+public:
+    ListEntry () {}
+    ListEntry (ValueObjectSP entry_sp) : m_entry_sp(entry_sp) {}
+    ListEntry (const ListEntry& rhs) : m_entry_sp(rhs.m_entry_sp) {}
+    ListEntry (ValueObject* entry) : m_entry_sp(entry ? entry->GetSP() : ValueObjectSP()) {}
+    
+    ListEntry
+    next ()
+    {
+        if (!m_entry_sp)
+            return ListEntry();
+        return ListEntry(m_entry_sp->GetChildMemberWithName(ConstString("__next_"), true));
+    }
+    
+    ListEntry
+    prev ()
+    {
+        if (!m_entry_sp)
+            return ListEntry();
+        return ListEntry(m_entry_sp->GetChildMemberWithName(ConstString("__prev_"), true));
+    }
+    
+    uint64_t
+    value ()
+    {
+        if (!m_entry_sp)
+            return 0;
+        return m_entry_sp->GetValueAsUnsigned(0);
+    }
+
+    bool
+    null()
+    {
+        return (value() == 0);
+    }
+    
+    explicit operator bool ()
+    {
+        return GetEntry().get() != nullptr && null() == false;
+    }
+    
+    ValueObjectSP
+    GetEntry ()
+    {
+        return m_entry_sp;
+    }
+    
+    void
+    SetEntry (ValueObjectSP entry)
+    {
+        m_entry_sp = entry;
+    }
+    
+    bool
+    operator == (const ListEntry& rhs) const
+    {
+        return (rhs.m_entry_sp.get() == m_entry_sp.get());
+    }
+    
+private:
+    ValueObjectSP m_entry_sp;
+};
+
+class ListIterator
+{
+public:
+    ListIterator () {}
+    ListIterator (ListEntry entry) : m_entry(entry) {}
+    ListIterator (ValueObjectSP entry) : m_entry(entry) {}
+    ListIterator (const ListIterator& rhs) : m_entry(rhs.m_entry) {}
+    ListIterator (ValueObject* entry) : m_entry(entry) {}
+
+    ValueObjectSP
+    value ()
+    {
+        return m_entry.GetEntry();
+    }
+    
+    ValueObjectSP
+    advance (size_t count)
+    {
+        if (count == 0)
+            return m_entry.GetEntry();
+        if (count == 1)
+        {
+            next ();
+            return m_entry.GetEntry();
+        }
+        while (count > 0)
+        {
+            next ();
+            count--;
+            if (m_entry.null())
+                return lldb::ValueObjectSP();
+        }
+        return m_entry.GetEntry();
+    }
+    
+    bool
+    operator == (const ListIterator& rhs) const
+    {
+        return (rhs.m_entry == m_entry);
+    }
+    
+protected:
+    void
+    next ()
+    {
+        m_entry = m_entry.next();
+    }
+    
+    void
+    prev ()
+    {
+        m_entry = m_entry.prev();
+    }
+private:
+    ListEntry m_entry;
+};
+
+lldb_private::formatters::LibcxxStdListSyntheticFrontEnd::LibcxxStdListSyntheticFrontEnd (lldb::ValueObjectSP valobj_sp) :
+SyntheticChildrenFrontEnd(*valobj_sp.get()),
+m_list_capping_size(0),
+m_loop_detected(0),
+m_node_address(),
+m_head(NULL),
+m_tail(NULL),
+m_element_type(),
+m_count(UINT32_MAX),
+m_children()
+{
+    if (valobj_sp)
+        Update();
+}
+
+bool
+lldb_private::formatters::LibcxxStdListSyntheticFrontEnd::HasLoop(size_t count)
+{
+    if (g_use_loop_detect == false)
+        return false;
+    // don't bother checking for a loop if we won't actually need to jump nodes
+    if (m_count < 2)
+        return false;
+    auto steps_left = std::min(count,m_count);
+    auto steps_left_save = steps_left;
+    ListEntry slow(m_head);
+    ListEntry fast(m_head);
+    while (steps_left-- > 0)
+    {
+        slow = slow.next();
+        fast = fast.next();
+        if (fast.next())
+            fast = fast.next().next();
+        else
+            fast = nullptr;
+        if (!slow || !fast)
+            return false;
+        if (slow == fast)
+            return true;
+    }
+    m_loop_detected = steps_left_save;
+    return false;
+}
+
+size_t
+lldb_private::formatters::LibcxxStdListSyntheticFrontEnd::CalculateNumChildren ()
+{
+    if (m_count != UINT32_MAX)
+        return m_count;
+    if (!m_head || !m_tail || m_node_address == 0)
+        return 0;
+    ValueObjectSP size_alloc(m_backend.GetChildMemberWithName(ConstString("__size_alloc_"), true));
+    if (size_alloc)
+    {
+        ValueObjectSP first(size_alloc->GetChildMemberWithName(ConstString("__first_"), true));
+        if (first)
+        {
+            m_count = first->GetValueAsUnsigned(UINT32_MAX);
+        }
+    }
+    if (m_count != UINT32_MAX)
+    {
+        return m_count;
+    }
+    else
+    {
+        uint64_t next_val = m_head->GetValueAsUnsigned(0);
+        uint64_t prev_val = m_tail->GetValueAsUnsigned(0);
+        if (next_val == 0 || prev_val == 0)
+            return 0;
+        if (next_val == m_node_address)
+            return 0;
+        if (next_val == prev_val)
+            return 1;
+        uint64_t size = 2;
+        ListEntry current(m_head);
+        while (current.next() && current.next().value() != m_node_address)
+        {
+            size++;
+            current = current.next();
+            if (size > m_list_capping_size)
+                break;
+        }
+        return m_count = (size-1);
+    }
+}
+
+lldb::ValueObjectSP
+lldb_private::formatters::LibcxxStdListSyntheticFrontEnd::GetChildAtIndex (size_t idx)
+{
+    if (idx >= CalculateNumChildren())
+        return lldb::ValueObjectSP();
+    
+    if (!m_head || !m_tail || m_node_address == 0)
+        return lldb::ValueObjectSP();
+    
+    auto cached = m_children.find(idx);
+    if (cached != m_children.end())
+        return cached->second;
+    
+    if (m_loop_detected <= idx)
+        if (HasLoop(idx))
+            return lldb::ValueObjectSP();
+        
+    ListIterator current(m_head);
+    ValueObjectSP current_sp(current.advance(idx));
+    if (!current_sp)
+        return lldb::ValueObjectSP();
+    current_sp = current_sp->GetChildMemberWithName(ConstString("__value_"), true);
+    if (!current_sp)
+        return lldb::ValueObjectSP();
+    // we need to copy current_sp into a new object otherwise we will end up with all items named __value_
+    DataExtractor data;
+    Error error;
+    current_sp->GetData(data, error);
+    if (error.Fail())
+        return lldb::ValueObjectSP();
+    
+    StreamString name;
+    name.Printf("[%" PRIu64 "]", (uint64_t)idx);
+    return (m_children[idx] = CreateValueObjectFromData(name.GetData(), data, m_backend.GetExecutionContextRef(), m_element_type));
+}
+
+bool
+lldb_private::formatters::LibcxxStdListSyntheticFrontEnd::Update()
+{
+    m_children.clear();
+    m_head = m_tail = NULL;
+    m_node_address = 0;
+    m_count = UINT32_MAX;
+    m_loop_detected = false;
+    Error err;
+    ValueObjectSP backend_addr(m_backend.AddressOf(err));
+    m_list_capping_size = 0;
+    if (m_backend.GetTargetSP())
+        m_list_capping_size = m_backend.GetTargetSP()->GetMaximumNumberOfChildrenToDisplay();
+    if (m_list_capping_size == 0)
+        m_list_capping_size = 255;
+    if (err.Fail() || backend_addr.get() == NULL)
+        return false;
+    m_node_address = backend_addr->GetValueAsUnsigned(0);
+    if (!m_node_address || m_node_address == LLDB_INVALID_ADDRESS)
+        return false;
+    ValueObjectSP impl_sp(m_backend.GetChildMemberWithName(ConstString("__end_"),true));
+    if (!impl_sp)
+        return false;
+    CompilerType list_type = m_backend.GetCompilerType();
+    if (list_type.IsReferenceType())
+        list_type = list_type.GetNonReferenceType();
+
+    if (list_type.GetNumTemplateArguments() == 0)
+        return false;
+    lldb::TemplateArgumentKind kind;
+    m_element_type = list_type.GetTemplateArgument(0, kind);
+    m_head = impl_sp->GetChildMemberWithName(ConstString("__next_"), true).get();
+    m_tail = impl_sp->GetChildMemberWithName(ConstString("__prev_"), true).get();
+    return false;
+}
+
+bool
+lldb_private::formatters::LibcxxStdListSyntheticFrontEnd::MightHaveChildren ()
+{
+    return true;
+}
+
+size_t
+lldb_private::formatters::LibcxxStdListSyntheticFrontEnd::GetIndexOfChildWithName (const ConstString &name)
+{
+    return ExtractIndexFromString(name.GetCString());
+}
+
+lldb_private::formatters::LibcxxStdListSyntheticFrontEnd::~LibcxxStdListSyntheticFrontEnd ()
+{}
+
+SyntheticChildrenFrontEnd*
+lldb_private::formatters::LibcxxStdListSyntheticFrontEndCreator (CXXSyntheticChildren*, lldb::ValueObjectSP valobj_sp)
+{
+    if (!valobj_sp)
+        return NULL;
+    return (new LibcxxStdListSyntheticFrontEnd(valobj_sp));
+}
+