Add some support for dealing with an object pointer on arguments.

Part of rdar://9797999

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163667 91177308-0d34-0410-b5e6-96231b3b80d8

7 files changed, 130 insertions, 1 deletions

diff --git a/include/llvm/DIBuilder.h b/include/llvm/DIBuilder.h
index dd4ea96..2610ce1 100644
--- a/include/llvm/DIBuilder.h
+++ b/include/llvm/DIBuilder.h
@@ -347,6 +347,10 @@ namespace llvm {
     /// createArtificialType - Create a new DIType with "artificial" flag set.
     DIType createArtificialType(DIType Ty);
 
+    /// createObjectPointerType - Create a new DIType with the "object pointer"
+    /// flag set.
+    DIType createObjectPointerType(DIType Ty);
+
     /// createTemporaryType - Create a temporary forward-declared type.
     DIType createTemporaryType();
     DIType createTemporaryType(DIFile F);
diff --git a/include/llvm/DebugInfo.h b/include/llvm/DebugInfo.h
index 618220f..4c1d045 100644
--- a/include/llvm/DebugInfo.h
+++ b/include/llvm/DebugInfo.h
@@ -60,7 +60,8 @@ namespace llvm {
       FlagArtificial         = 1 << 6,
       FlagExplicit           = 1 << 7,
       FlagPrototyped         = 1 << 8,
-      FlagObjcClassComplete  = 1 << 9
+      FlagObjcClassComplete  = 1 << 9,
+      FlagObjectPointer      = 1 << 10
     };
   protected:
     const MDNode *DbgNode;
@@ -287,6 +288,9 @@ namespace llvm {
     bool isArtificial() const {
       return (getFlags() & FlagArtificial) != 0;
     }
+    bool isObjectPointer() const {
+      return (getFlags() & FlagObjectPointer) != 0;
+    }
     bool isObjcClassComplete() const {
       return (getFlags() & FlagObjcClassComplete) != 0;
     }
@@ -644,6 +648,10 @@ namespace llvm {
       return (getUnsignedField(6) & FlagArtificial) != 0;
     }
 
+    bool isObjectPointer() const {
+      return (getUnsignedField(6) & FlagObjectPointer) != 0;
+    }
+
     /// getInlinedAt - If this variable is inlined then return inline location.
     MDNode *getInlinedAt() const;
 
diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 0007f13..4b65a9b 100644
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -1109,6 +1109,8 @@ DIE *CompileUnit::getOrCreateSubprogramDIE(DISubprogram SP) {
         addType(Arg, ATy);
         if (ATy.isArtificial())
           addFlag(Arg, dwarf::DW_AT_artificial);
+        if (ATy.isObjectPointer())
+          addFlag(Arg, dwarf::DW_AT_object_pointer);
         SPDie->addChild(Arg);
       }
   }
@@ -1348,6 +1350,8 @@ DIE *CompileUnit::constructVariableDIE(DbgVariable *DV, bool isScopeAbstract) {
 
   if (DV->isArtificial())
     addFlag(VariableDie, dwarf::DW_AT_artificial);
+  if (DV->isObjectPointer())
+    addFlag(VariableDie, dwarf::DW_AT_object_pointer);
 
   if (isScopeAbstract) {
     DV->setDIE(VariableDie);
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 0fface1..b1f0212 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -330,6 +330,8 @@ DIE *DwarfDebug::updateSubprogramScopeDIE(CompileUnit *SPCU,
           SPCU->addType(Arg, ATy);
           if (ATy.isArtificial())
             SPCU->addFlag(Arg, dwarf::DW_AT_artificial);
+          if (ATy.isObjectPointer())
+            SPCU->addFlag(Arg, dwarf::DW_AT_object_pointer);
           SPDie->addChild(Arg);
         }
       DIE *SPDeclDie = SPDie;
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.h b/lib/CodeGen/AsmPrinter/DwarfDebug.h
index d662ead..d5ae468 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -164,6 +164,16 @@ public:
       return true;
     return false;
   }
+
+  bool isObjectPointer()             const {
+    if (Var.isObjectPointer())
+      return true;
+    if (Var.getTag() == dwarf::DW_TAG_arg_variable
+        && getType().isObjectPointer())
+      return true;
+    return false;
+  }
+  
   bool variableHasComplexAddress()   const {
     assert(Var.Verify() && "Invalid complex DbgVariable!");
     return Var.hasComplexAddress();
diff --git a/lib/VMCore/DIBuilder.cpp b/lib/VMCore/DIBuilder.cpp
index f5894e9..6a29a02 100644
--- a/lib/VMCore/DIBuilder.cpp
+++ b/lib/VMCore/DIBuilder.cpp
@@ -640,6 +640,30 @@ DIType DIBuilder::createArtificialType(DIType Ty) {
   return DIType(MDNode::get(VMContext, Elts));
 }
 
+/// createArtificialType - Create a new DIType with "artificial" flag set.
+DIType DIBuilder::createObjectPointerType(DIType Ty) {
+  if (Ty.isObjectPointer())
+    return Ty;
+
+  SmallVector<Value *, 9> Elts;
+  MDNode *N = Ty;
+  assert (N && "Unexpected input DIType!");
+  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
+    if (Value *V = N->getOperand(i))
+      Elts.push_back(V);
+    else
+      Elts.push_back(Constant::getNullValue(Type::getInt32Ty(VMContext)));
+  }
+
+  unsigned CurFlags = Ty.getFlags();
+  CurFlags = CurFlags | (DIType::FlagObjectPointer | DIType::FlagArtificial);
+
+  // Flags are stored at this slot.
+  Elts[8] = ConstantInt::get(Type::getInt32Ty(VMContext), CurFlags);
+
+  return DIType(MDNode::get(VMContext, Elts));
+}
+
 /// retainType - Retain DIType in a module even if it is not referenced
 /// through debug info anchors.
 void DIBuilder::retainType(DIType T) {
diff --git a/test/DebugInfo/X86/DW_AT_object_pointer.ll b/test/DebugInfo/X86/DW_AT_object_pointer.ll
new file mode 100644
index 0000000..11587ef1
--- /dev/null
+++ b/test/DebugInfo/X86/DW_AT_object_pointer.ll
@@ -0,0 +1,77 @@
+; RUN: llc -mtriple=x86_64-apple-darwin %s -o %t -filetype=obj
+; RUN: llvm-dwarfdump %t | FileCheck %s
+
+; CHECK: DW_AT_object_pointer [DW_FORM_flag] (0x01)
+
+%class.A = type { i32 }
+
+define i32 @_Z3foov() nounwind uwtable ssp {
+entry:
+  %a = alloca %class.A, align 4
+  call void @llvm.dbg.declare(metadata !{%class.A* %a}, metadata !21), !dbg !23
+  call void @_ZN1AC1Ev(%class.A* %a), !dbg !24
+  %m_a = getelementptr inbounds %class.A* %a, i32 0, i32 0, !dbg !25
+  %0 = load i32* %m_a, align 4, !dbg !25
+  ret i32 %0, !dbg !25
+}
+
+declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
+
+define linkonce_odr void @_ZN1AC1Ev(%class.A* %this) unnamed_addr nounwind uwtable ssp align 2 {
+entry:
+  %this.addr = alloca %class.A*, align 8
+  store %class.A* %this, %class.A** %this.addr, align 8
+  call void @llvm.dbg.declare(metadata !{%class.A** %this.addr}, metadata !26), !dbg !28
+  %this1 = load %class.A** %this.addr
+  call void @_ZN1AC2Ev(%class.A* %this1), !dbg !29
+  ret void, !dbg !29
+}
+
+define linkonce_odr void @_ZN1AC2Ev(%class.A* %this) unnamed_addr nounwind uwtable ssp align 2 {
+entry:
+  %this.addr = alloca %class.A*, align 8
+  store %class.A* %this, %class.A** %this.addr, align 8
+  call void @llvm.dbg.declare(metadata !{%class.A** %this.addr}, metadata !30), !dbg !31
+  %this1 = load %class.A** %this.addr
+  %m_a = getelementptr inbounds %class.A* %this1, i32 0, i32 0, !dbg !32
+  store i32 0, i32* %m_a, align 4, !dbg !32
+  ret void, !dbg !34
+}
+
+!llvm.dbg.cu = !{!0}
+
+!0 = metadata !{i32 786449, i32 0, i32 4, metadata !"bar.cpp", metadata !"/Users/echristo/debug-tests", metadata !"clang version 3.2 (trunk 163586) (llvm/trunk 163570)", i1 true, i1 false, metadata !"", i32 0, metadata !1, metadata !1, metadata !3, metadata !1} ; [ DW_TAG_compile_unit ] [/Users/echristo/debug-tests/bar.cpp] [DW_LANG_C_plus_plus]
+!1 = metadata !{metadata !2}
+!2 = metadata !{i32 0}
+!3 = metadata !{metadata !4}
+!4 = metadata !{metadata !5, metadata !10, metadata !20}
+!5 = metadata !{i32 786478, i32 0, metadata !6, metadata !"foo", metadata !"foo", metadata !"_Z3foov", metadata !6, i32 7, metadata !7, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, i32 ()* @_Z3foov, null, null, metadata !1, i32 7} ; [ DW_TAG_subprogram ] [line 7] [def] [foo]
+!6 = metadata !{i32 786473, metadata !"bar.cpp", metadata !"/Users/echristo/debug-tests", null} ; [ DW_TAG_file_type ]
+!7 = metadata !{i32 786453, i32 0, metadata !"", i32 0, i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !8, i32 0, i32 0} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!8 = metadata !{metadata !9}
+!9 = metadata !{i32 786468, null, metadata !"int", null, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
+!10 = metadata !{i32 786478, i32 0, null, metadata !"A", metadata !"A", metadata !"_ZN1AC1Ev", metadata !6, i32 3, metadata !11, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, void (%class.A*)* @_ZN1AC1Ev, null, metadata !17, metadata !1, i32 3} ; [ DW_TAG_subprogram ] [line 3] [def] [A]
+!11 = metadata !{i32 786453, i32 0, metadata !"", i32 0, i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !12, i32 0, i32 0} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!12 = metadata !{null, metadata !13}
+!13 = metadata !{i32 786447, i32 0, metadata !"", i32 0, i32 0, i64 64, i64 64, i64 0, i32 1088, metadata !14} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [from A]
+!14 = metadata !{i32 786434, null, metadata !"A", metadata !6, i32 1, i64 32, i64 32, i32 0, i32 0, null, metadata !15, i32 0, null, null} ; [ DW_TAG_class_type ] [A] [line 1, size 32, align 32, offset 0] [from ]
+!15 = metadata !{metadata !16, metadata !17}
+!16 = metadata !{i32 786445, metadata !14, metadata !"m_a", metadata !6, i32 4, i64 32, i64 32, i64 0, i32 0, metadata !9} ; [ DW_TAG_member ] [m_a] [line 4, size 32, align 32, offset 0] [from int]
+!17 = metadata !{i32 786478, i32 0, metadata !14, metadata !"A", metadata !"A", metadata !"", metadata !6, i32 3, metadata !11, i1 false, i1 false, i32 0, i32 0, null, i32 256, i1 false, null, null, i32 0, metadata !18, i32 3} ; [ DW_TAG_subprogram ] [line 3] [A]
+!18 = metadata !{metadata !19}
+!19 = metadata !{i32 786468}                      ; [ DW_TAG_base_type ] [line 0, size 0, align 0, offset 0]
+!20 = metadata !{i32 786478, i32 0, null, metadata !"A", metadata !"A", metadata !"_ZN1AC2Ev", metadata !6, i32 3, metadata !11, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, void (%class.A*)* @_ZN1AC2Ev, null, metadata !17, metadata !1, i32 3} ; [ DW_TAG_subprogram ] [line 3] [def] [A]
+!21 = metadata !{i32 786688, metadata !22, metadata !"a", metadata !6, i32 8, metadata !14, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [a] [line 8]
+!22 = metadata !{i32 786443, metadata !5, i32 7, i32 11, metadata !6, i32 0} ; [ DW_TAG_lexical_block ] [/Users/echristo/debug-tests/bar.cpp]
+!23 = metadata !{i32 8, i32 5, metadata !22, null}
+!24 = metadata !{i32 8, i32 6, metadata !22, null}
+!25 = metadata !{i32 9, i32 3, metadata !22, null}
+!26 = metadata !{i32 786689, metadata !10, metadata !"this", metadata !6, i32 16777219, metadata !27, i32 1088, i32 0} ; [ DW_TAG_arg_variable ] [this] [line 3]
+!27 = metadata !{i32 786447, null, metadata !"", null, i32 0, i64 64, i64 64, i64 0, i32 0, metadata !14} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [from A]
+!28 = metadata !{i32 3, i32 3, metadata !10, null}
+!29 = metadata !{i32 3, i32 18, metadata !10, null}
+!30 = metadata !{i32 786689, metadata !20, metadata !"this", metadata !6, i32 16777219, metadata !27, i32 1088, i32 0} ; [ DW_TAG_arg_variable ] [this] [line 3]
+!31 = metadata !{i32 3, i32 3, metadata !20, null}
+!32 = metadata !{i32 3, i32 9, metadata !33, null}
+!33 = metadata !{i32 786443, metadata !20, i32 3, i32 7, metadata !6, i32 1} ; [ DW_TAG_lexical_block ] [/Users/echristo/debug-tests/bar.cpp]
+!34 = metadata !{i32 3, i32 18, metadata !33, null}