[DebugInfo] Introduce DIEExpr variant of DIEValue to hold MCExpr values

This partially reverts r185202 and restores DIELabel to hold plain
MCSymbol references.  Instead, we add a new subclass DIEExpr of
DIEValue that can hold generic MCExpr references.

This is in preparation for supporting debug info for TLS variables
on PowerPC, where we need to describe the variable location using
a more complex expression than just MCSymbolRefExpr.

llvm-svn: 185458

1 files changed, 12 insertions, 9 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index f42a33eb774..398718dc175 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -136,7 +136,7 @@ void CompileUnit::addString(DIE *Die, unsigned Attribute, StringRef String) {
     MCSymbol *Symb = DU->getStringPoolEntry(String);
     DIEValue *Value;
     if (Asm->needsRelocationsForDwarfStringPool())
-      Value = new (DIEValueAllocator) DIELabel(Symb, Asm->OutContext);
+      Value = new (DIEValueAllocator) DIELabel(Symb);
     else {
       MCSymbol *StringPool = DU->getStringPoolSym();
       Value = new (DIEValueAllocator) DIEDelta(Symb, StringPool);
@@ -156,7 +156,7 @@ void CompileUnit::addLocalString(DIE *Die, unsigned Attribute,
   MCSymbol *Symb = DU->getStringPoolEntry(String);
   DIEValue *Value;
   if (Asm->needsRelocationsForDwarfStringPool())
-    Value = new (DIEValueAllocator) DIELabel(Symb, Asm->OutContext);
+    Value = new (DIEValueAllocator) DIELabel(Symb);
   else {
     MCSymbol *StringPool = DU->getStringPoolSym();
     Value = new (DIEValueAllocator) DIEDelta(Symb, StringPool);
@@ -164,17 +164,20 @@ void CompileUnit::addLocalString(DIE *Die, unsigned Attribute,
   Die->addValue(Attribute, dwarf::DW_FORM_strp, Value);
 }
 
-/// addLabel - Add a Dwarf label attribute data and value.
+/// addExpr - Add a Dwarf expression attribute data and value.
 ///
-void CompileUnit::addLabel(DIE *Die, unsigned Attribute, unsigned Form,
-                           const MCSymbolRefExpr *Label) {
-  DIEValue *Value = new (DIEValueAllocator) DIELabel(Label);
+void CompileUnit::addExpr(DIE *Die, unsigned Attribute, unsigned Form,
+                          const MCExpr *Expr) {
+  DIEValue *Value = new (DIEValueAllocator) DIEExpr(Expr);
   Die->addValue(Attribute, Form, Value);
 }
 
+/// addLabel - Add a Dwarf label attribute data and value.
+///
 void CompileUnit::addLabel(DIE *Die, unsigned Attribute, unsigned Form,
                            const MCSymbol *Label) {
-  addLabel(Die, Attribute, Form, MCSymbolRefExpr::Create(Label, Asm->OutContext));
+  DIEValue *Value = new (DIEValueAllocator) DIELabel(Label);
+  Die->addValue(Attribute, Form, Value);
 }
 
 /// addLabelAddress - Add a dwarf label attribute data and value using
@@ -184,7 +187,7 @@ void CompileUnit::addLabelAddress(DIE *Die, unsigned Attribute,
                                   MCSymbol *Label) {
   if (!DD->useSplitDwarf()) {
     if (Label != NULL) {
-      DIEValue *Value = new (DIEValueAllocator) DIELabel(Label, Asm->OutContext);
+      DIEValue *Value = new (DIEValueAllocator) DIELabel(Label);
       Die->addValue(Attribute, dwarf::DW_FORM_addr, Value);
     } else {
       DIEValue *Value = new (DIEValueAllocator) DIEInteger(0);
@@ -1363,7 +1366,7 @@ void CompileUnit::createGlobalVariableDIE(const MDNode *N) {
         addUInt(Block, 0, dwarf::DW_FORM_data1,
                 PointerSize == 4 ? dwarf::DW_OP_const4u : dwarf::DW_OP_const8u);
         // 2) containing the (relocated) address of the TLS variable
-        addLabel(Block, 0, dwarf::DW_FORM_udata, Ref);
+        addExpr(Block, 0, dwarf::DW_FORM_udata, Ref);
       } else {
         addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_const_index);
         addUInt(Block, 0, dwarf::DW_FORM_udata, DU->getAddrPoolIndex(Ref));