[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, 28 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DIE.cpp b/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
index 81bab336475..4b6698e374e 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
@@ -247,13 +247,39 @@ void DIEInteger::print(raw_ostream &O) const {
 #endif
 
 //===----------------------------------------------------------------------===//
+// DIEExpr Implementation
+//===----------------------------------------------------------------------===//
+
+/// EmitValue - Emit expression value.
+///
+void DIEExpr::EmitValue(AsmPrinter *AP, unsigned Form) const {
+  AP->OutStreamer.EmitValue(Expr, SizeOf(AP, Form));
+}
+
+/// SizeOf - Determine size of expression value in bytes.
+///
+unsigned DIEExpr::SizeOf(AsmPrinter *AP, unsigned Form) const {
+  if (Form == dwarf::DW_FORM_data4) return 4;
+  if (Form == dwarf::DW_FORM_sec_offset) return 4;
+  if (Form == dwarf::DW_FORM_strp) return 4;
+  return AP->getDataLayout().getPointerSize();
+}
+
+#ifndef NDEBUG
+void DIEExpr::print(raw_ostream &O) const {
+  O << "Expr: ";
+  Expr->print(O);
+}
+#endif
+
+//===----------------------------------------------------------------------===//
 // DIELabel Implementation
 //===----------------------------------------------------------------------===//
 
 /// EmitValue - Emit label value.
 ///
 void DIELabel::EmitValue(AsmPrinter *AP, unsigned Form) const {
-  AP->OutStreamer.EmitValue(Label, SizeOf(AP, Form));
+  AP->EmitLabelReference(Label, SizeOf(AP, Form));
 }
 
 /// SizeOf - Determine size of label value in bytes.
@@ -267,7 +293,7 @@ unsigned DIELabel::SizeOf(AsmPrinter *AP, unsigned Form) const {
 
 #ifndef NDEBUG
 void DIELabel::print(raw_ostream &O) const {
-  O << "Lbl: " << Label->getSymbol().getName();
+  O << "Lbl: " << Label->getName();
 }
 #endif