Refactor. Global variables are part of compile unit so let CompileUnit create new global variable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137621 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 109 insertions, 0 deletions

diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 81a3d1cc2e..60ca1fb359 100644
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -16,7 +16,10 @@
 #include "DwarfCompileUnit.h"
 #include "DwarfDebug.h"
 #include "llvm/Constants.h"
+#include "llvm/GlobalVariable.h"
+#include "llvm/Instructions.h"
 #include "llvm/Analysis/DIBuilder.h"
+#include "llvm/Target/Mangler.h"
 #include "llvm/Target/TargetData.h"
 #include "llvm/Target/TargetFrameLowering.h"
 #include "llvm/Target/TargetMachine.h"
@@ -994,6 +997,112 @@ DIE *CompileUnit::getOrCreateSubprogramDIE(DISubprogram SP) {
   return SPDie;
 }
 
+// Return const expression if value is a GEP to access merged global
+// constant. e.g.
+// i8* getelementptr ({ i8, i8, i8, i8 }* @_MergedGlobals, i32 0, i32 0)
+static const ConstantExpr *getMergedGlobalExpr(const Value *V) {
+  const ConstantExpr *CE = dyn_cast_or_null<ConstantExpr>(V);
+  if (!CE || CE->getNumOperands() != 3 ||
+      CE->getOpcode() != Instruction::GetElementPtr)
+    return NULL;
+
+  // First operand points to a global struct.
+  Value *Ptr = CE->getOperand(0);
+  if (!isa<GlobalValue>(Ptr) ||
+      !isa<StructType>(cast<PointerType>(Ptr->getType())->getElementType()))
+    return NULL;
+
+  // Second operand is zero.
+  const ConstantInt *CI = dyn_cast_or_null<ConstantInt>(CE->getOperand(1));
+  if (!CI || !CI->isZero())
+    return NULL;
+
+  // Third operand is offset.
+  if (!isa<ConstantInt>(CE->getOperand(2)))
+    return NULL;
+
+  return CE;
+}
+
+/// createGlobalVariableDIE - create global variable DIE.
+void CompileUnit::createGlobalVariableDIE(const MDNode *N) {
+  DIGlobalVariable GV(N);
+
+  // Check for pre-existence.
+  if (getDIE(GV))
+    return;
+
+  DIType GTy = GV.getType();
+  DIE *VariableDIE = new DIE(GV.getTag());
+
+  bool isGlobalVariable = GV.getGlobal() != NULL;
+
+  // Add name.
+  addString(VariableDIE, dwarf::DW_AT_name, dwarf::DW_FORM_string,
+                   GV.getDisplayName());
+  StringRef LinkageName = GV.getLinkageName();
+  if (!LinkageName.empty() && isGlobalVariable)
+    addString(VariableDIE, dwarf::DW_AT_MIPS_linkage_name, 
+                     dwarf::DW_FORM_string,
+                     getRealLinkageName(LinkageName));
+  // Add type.
+  addType(VariableDIE, GTy);
+
+  // Add scoping info.
+  if (!GV.isLocalToUnit()) {
+    addUInt(VariableDIE, dwarf::DW_AT_external, dwarf::DW_FORM_flag, 1);
+    // Expose as global. 
+    addGlobal(GV.getName(), VariableDIE);
+  }
+  // Add line number info.
+  addSourceLine(VariableDIE, GV);
+  // Add to map.
+  insertDIE(N, VariableDIE);
+  // Add to context owner.
+  DIDescriptor GVContext = GV.getContext();
+  addToContextOwner(VariableDIE, GVContext);
+  // Add location.
+  if (isGlobalVariable) {
+    DIEBlock *Block = new (DIEValueAllocator) DIEBlock();
+    addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_addr);
+    addLabel(Block, 0, dwarf::DW_FORM_udata,
+             Asm->Mang->getSymbol(GV.getGlobal()));
+    // Do not create specification DIE if context is either compile unit
+    // or a subprogram.
+    if (GV.isDefinition() && !GVContext.isCompileUnit() &&
+        !GVContext.isFile() && !isSubprogramContext(GVContext)) {
+      // Create specification DIE.
+      DIE *VariableSpecDIE = new DIE(dwarf::DW_TAG_variable);
+      addDIEEntry(VariableSpecDIE, dwarf::DW_AT_specification,
+                  dwarf::DW_FORM_ref4, VariableDIE);
+      addBlock(VariableSpecDIE, dwarf::DW_AT_location, 0, Block);
+      addUInt(VariableDIE, dwarf::DW_AT_declaration, dwarf::DW_FORM_flag,
+                     1);
+      addDie(VariableSpecDIE);
+    } else {
+      addBlock(VariableDIE, dwarf::DW_AT_location, 0, Block);
+    } 
+  } else if (const ConstantInt *CI = 
+             dyn_cast_or_null<ConstantInt>(GV.getConstant()))
+    addConstantValue(VariableDIE, CI, GTy.isUnsignedDIType());
+  else if (const ConstantExpr *CE = getMergedGlobalExpr(N->getOperand(11))) {
+    // GV is a merged global.
+    DIEBlock *Block = new (DIEValueAllocator) DIEBlock();
+    Value *Ptr = CE->getOperand(0);
+    addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_addr);
+    addLabel(Block, 0, dwarf::DW_FORM_udata,
+                    Asm->Mang->getSymbol(cast<GlobalValue>(Ptr)));
+    addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
+    SmallVector<Value*, 3> Idx(CE->op_begin()+1, CE->op_end());
+    addUInt(Block, 0, dwarf::DW_FORM_udata, 
+                   Asm->getTargetData().getIndexedOffset(Ptr->getType(), Idx));
+    addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
+    addBlock(VariableDIE, dwarf::DW_AT_location, 0, Block);
+  }
+
+  return;
+}
+
 /// constructSubrangeDIE - Construct subrange DIE from DISubrange.
 void CompileUnit::constructSubrangeDIE(DIE &Buffer, DISubrange SR, DIE *IndexTy){
   DIE *DW_Subrange = new DIE(dwarf::DW_TAG_subrange_type);