From 7a0103c30d2f423c78527aeeeebc7915e3bc9ee9 Mon Sep 17 00:00:00 2001
From: Eric Christopher <echristo@gmail.com>
Date: Thu, 7 Feb 2013 21:19:50 +0000
Subject: [PATCH] "Clean up" line section symbol emission by emitting the
 section syms before constructing the compile units so we're not emitting
 section references to sections not there already.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174663 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 18 +++++++++++-------
 lib/CodeGen/AsmPrinter/DwarfDebug.h   |  2 +-
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 3b8bebea16a..5d19a8d765e 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -165,7 +165,7 @@ DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
 
   DwarfInfoSectionSym = DwarfAbbrevSectionSym = 0;
   DwarfStrSectionSym = TextSectionSym = 0;
-  DwarfDebugRangeSectionSym = DwarfDebugLocSectionSym = 0;
+  DwarfDebugRangeSectionSym = DwarfDebugLocSectionSym = DwarfLineSectionSym = 0;
   DwarfAbbrevDWOSectionSym = DwarfStrDWOSectionSym = 0;
   FunctionBeginSym = FunctionEndSym = 0;
 
@@ -677,7 +677,7 @@ CompileUnit *DwarfDebug::constructCompileUnit(const MDNode *N) {
     NewCU->addUInt(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4, 0);
   else
     NewCU->addDelta(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4,
-                    LineTableStartSym, Asm->GetTempSymbol("section_line"));
+                    LineTableStartSym, DwarfLineSectionSym);
 
   if (!CompilationDir.empty())
     NewCU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
@@ -782,6 +782,9 @@ bool DwarfDebug::collectLegacyDebugInfo(const Module *M) {
   }
   if (!HasDebugInfo) return false;
 
+  // Emit initial sections so we can refer to them later.
+  emitSectionLabels();
+
   // Create all the compile unit DIEs.
   for (DebugInfoFinder::iterator I = DbgFinder.compile_unit_begin(),
          E = DbgFinder.compile_unit_end(); I != E; ++I)
@@ -819,6 +822,9 @@ void DwarfDebug::beginModule() {
   // module using debug info finder to collect debug info.
   NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
   if (CU_Nodes) {
+    // Emit initial sections so we can reference labels later.
+    emitSectionLabels();
+
     for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
       DICompileUnit CUNode(CU_Nodes->getOperand(i));
       CompileUnit *CU = constructCompileUnit(CUNode);
@@ -951,9 +957,6 @@ void DwarfDebug::endModule() {
   // Finalize the debug info for the module.
   finalizeModuleInfo();
 
-  // Emit initial sections.
-  emitSectionLabels();
-
   if (!useSplitDwarf()) {
     // Emit all the DIEs into a debug info section.
     emitDebugInfo();
@@ -1775,7 +1778,8 @@ void DwarfDebug::emitSectionLabels() {
   if (const MCSection *MacroInfo = TLOF.getDwarfMacroInfoSection())
     emitSectionSym(Asm, MacroInfo);
 
-  emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
+  DwarfLineSectionSym =
+    emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
   emitSectionSym(Asm, TLOF.getDwarfLocSection());
   emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
   DwarfStrSectionSym =
@@ -2489,7 +2493,7 @@ CompileUnit *DwarfDebug::constructSkeletonCU(const MDNode *N) {
   // compile unit in debug_line section.
   if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
     NewCU->addLabel(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_sec_offset,
-                    Asm->GetTempSymbol("section_line"));
+                    DwarfLineSectionSym);
   else
     NewCU->addUInt(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_sec_offset, 0);
 
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.h b/lib/CodeGen/AsmPrinter/DwarfDebug.h
index fb9020291ef..7d57a829af4 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -386,7 +386,7 @@ class DwarfDebug {
   // section offsets and are created by EmitSectionLabels.
   MCSymbol *DwarfInfoSectionSym, *DwarfAbbrevSectionSym;
   MCSymbol *DwarfStrSectionSym, *TextSectionSym, *DwarfDebugRangeSectionSym;
-  MCSymbol *DwarfDebugLocSectionSym;
+  MCSymbol *DwarfDebugLocSectionSym, *DwarfLineSectionSym;
   MCSymbol *FunctionBeginSym, *FunctionEndSym;
   MCSymbol *DwarfAbbrevDWOSectionSym, *DwarfStrDWOSectionSym;
 
-- 
2.34.1