Use absolute label for DW_AT_stmt_list if a target does not prefer offset here.

This patch was developed on top of original patch by Artur Pietrek.

llvm-svn: 112678

include/llvm/MC/MCAsmInfo.h

@@ -255,6 +255,10 @@ namespace llvm {
     /// DwarfSectionOffsetDirective - Special section offset directive.
     const char* DwarfSectionOffsetDirective; // Defaults to NULL
     
+    /// DwarfUsesAbsoluteLabelForStmtList - True if DW_AT_stmt_list needs 
+    /// absolute label instead of offset.
+    bool DwarfUsesAbsoluteLabelForStmtList;  // Defaults to true;
+
     //===--- CBE Asm Translation Table -----------------------------------===//
 
     const char *const *AsmTransCBE;          // Defaults to empty
@@ -417,6 +421,9 @@ namespace llvm {
     const char *getDwarfSectionOffsetDirective() const {
       return DwarfSectionOffsetDirective;
     }
+    bool doesDwarfUsesAbsoluteLabelForStmtList() const {
+      return DwarfUsesAbsoluteLabelForStmtList;
+    }
     const char *const *getAsmCBE() const {
       return AsmTransCBE;
     }

lib/CodeGen/AsmPrinter/DwarfDebug.cpp

@@ -1815,7 +1815,11 @@ void DwarfDebug::constructCompileUnit(const MDNode *N) {
   addUInt(Die, dwarf::DW_AT_entry_pc, dwarf::DW_FORM_addr, 0);
   // DW_AT_stmt_list is a offset of line number information for this
   // compile unit in debug_line section.
-  addUInt(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4, 0);
+  if (Asm->MAI->doesDwarfUsesAbsoluteLabelForStmtList())
+    addLabel(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_addr,
+             Asm->GetTempSymbol("section_line"));
+  else
+    addUInt(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4, 0);
 
   if (!Dir.empty())
     addString(Die, dwarf::DW_AT_comp_dir, dwarf::DW_FORM_string, Dir);

lib/MC/MCAsmInfo.cpp

@@ -68,6 +68,7 @@ MCAsmInfo::MCAsmInfo() {
   ExceptionsType = ExceptionHandling::None;
   DwarfRequiresFrameSection = true;
   DwarfUsesInlineInfoSection = false;
+  DwarfUsesAbsoluteLabelForStmtList = true;
   DwarfSectionOffsetDirective = 0;
   HasMicrosoftFastStdCallMangling = false;
 

lib/MC/MCAsmInfoDarwin.cpp

@@ -44,5 +44,7 @@ MCAsmInfoDarwin::MCAsmInfoDarwin() {
   
   HasDotTypeDotSizeDirective = false;
   HasNoDeadStrip = true;
+
+  DwarfUsesAbsoluteLabelForStmtList = false;
 }