From 62fdfb5fa7efdfd61339e4abe6fd87e60e939e58 Mon Sep 17 00:00:00 2001
From: David Blaikie <dblaikie@gmail.com>
Date: Mon, 7 Jan 2013 05:51:15 +0000
Subject: PR14759: Debug info support for C++ member pointers.

This works fine with GDB for member variable pointers, but GDB's support for
member function pointers seems to be quite unrelated to
DW_TAG_ptr_to_member_type. (see GDB bug 14998 for details)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171698 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp |  3 +++
 lib/IR/DIBuilder.cpp                        | 18 ++++++++++++++++++
 lib/IR/DebugInfo.cpp                        |  2 ++
 3 files changed, 23 insertions(+)

(limited to 'lib')

diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 5dbf74d3f7..854d82c2c5 100644
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -784,6 +784,9 @@ void CompileUnit::constructTypeDIE(DIE &Buffer, DIDerivedType DTy) {
   if (Size && Tag != dwarf::DW_TAG_pointer_type)
     addUInt(&Buffer, dwarf::DW_AT_byte_size, 0, Size);
 
+  if (Tag == dwarf::DW_TAG_ptr_to_member_type)
+      addDIEEntry(&Buffer, dwarf::DW_AT_containing_type, dwarf::DW_FORM_ref4,
+                  getOrCreateTypeDIE(DTy.getClassType()));
   // Add source line info if available and TyDesc is not a forward declaration.
   if (!DTy.isForwardDecl())
     addSourceLine(&Buffer, DTy);
diff --git a/lib/IR/DIBuilder.cpp b/lib/IR/DIBuilder.cpp
index 802c33289c..9fd0cd8683 100644
--- a/lib/IR/DIBuilder.cpp
+++ b/lib/IR/DIBuilder.cpp
@@ -229,6 +229,24 @@ DIType DIBuilder::createPointerType(DIType PointeeTy, uint64_t SizeInBits,
   return DIType(MDNode::get(VMContext, Elts));
 }
 
+DIType DIBuilder::createMemberPointerType(DIType PointeeTy, DIType Base) {
+  // Pointer types are encoded in DIDerivedType format.
+  Value *Elts[] = {
+    GetTagConstant(VMContext, dwarf::DW_TAG_ptr_to_member_type),
+    NULL, //TheCU,
+    NULL,
+    NULL, // Filename
+    ConstantInt::get(Type::getInt32Ty(VMContext), 0), // Line
+    ConstantInt::get(Type::getInt64Ty(VMContext), 0),
+    ConstantInt::get(Type::getInt64Ty(VMContext), 0),
+    ConstantInt::get(Type::getInt64Ty(VMContext), 0), // Offset
+    ConstantInt::get(Type::getInt32Ty(VMContext), 0), // Flags
+    PointeeTy,
+    Base
+  };
+  return DIType(MDNode::get(VMContext, Elts));
+}
+
 /// createReferenceType - Create debugging information entry for a reference
 /// type.
 DIType DIBuilder::createReferenceType(unsigned Tag, DIType RTy) {
diff --git a/lib/IR/DebugInfo.cpp b/lib/IR/DebugInfo.cpp
index 5dd9dd1c9d..b5e1d177df 100644
--- a/lib/IR/DebugInfo.cpp
+++ b/lib/IR/DebugInfo.cpp
@@ -172,6 +172,7 @@ bool DIDescriptor::isDerivedType() const {
   switch (getTag()) {
   case dwarf::DW_TAG_typedef:
   case dwarf::DW_TAG_pointer_type:
+  case dwarf::DW_TAG_ptr_to_member_type:
   case dwarf::DW_TAG_reference_type:
   case dwarf::DW_TAG_rvalue_reference_type:
   case dwarf::DW_TAG_const_type:
@@ -423,6 +424,7 @@ bool DIType::Verify() const {
   unsigned Tag = getTag();
   if (!isBasicType() && Tag != dwarf::DW_TAG_const_type &&
       Tag != dwarf::DW_TAG_volatile_type && Tag != dwarf::DW_TAG_pointer_type &&
+      Tag != dwarf::DW_TAG_ptr_to_member_type &&
       Tag != dwarf::DW_TAG_reference_type &&
       Tag != dwarf::DW_TAG_rvalue_reference_type &&
       Tag != dwarf::DW_TAG_restrict_type && Tag != dwarf::DW_TAG_vector_type &&
-- 
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