From 0dc623c2325ba1da8d64f5bc4ee7f0b81954410e Mon Sep 17 00:00:00 2001
From: David Blaikie <dblaikie@gmail.com>
Date: Fri, 24 Oct 2014 17:53:38 +0000
Subject: [PATCH] Remove DwarfDebug::FirstCU as it has no use

It was only being used as a flag to identify the lack of debug info from
within endModule - use the section labels for that instead.

llvm-svn: 220575
---
 llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 16 +++++-----------
 llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h   |  6 ------
 2 files changed, 5 insertions(+), 17 deletions(-)

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 5fcc28e..19c8c39 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -169,8 +169,7 @@ static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
     DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
 
 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
-    : Asm(A), MMI(Asm->MMI), FirstCU(nullptr), PrevLabel(nullptr),
-      GlobalRangeCount(0),
+    : Asm(A), MMI(Asm->MMI), PrevLabel(nullptr), GlobalRangeCount(0),
       InfoHolder(A, *this, "info_string", DIEValueAllocator),
       UsedNonDefaultText(false),
       SkeletonHolder(A, *this, "skel_string", DIEValueAllocator),
@@ -403,9 +402,6 @@ DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
     NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
                   dwarf::DW_FORM_data1, RVer);
 
-  if (!FirstCU)
-    FirstCU = &NewCU;
-
   if (useSplitDwarf()) {
     NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
                       DwarfInfoDWOSectionSym);
@@ -438,8 +434,6 @@ void DwarfDebug::beginModule() {
 
   FunctionDIs = makeSubprogramMap(*M);
 
-  // If module has named metadata anchors then use them, otherwise scan the
-  // module using debug info finder to collect debug info.
   NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
   if (!CU_Nodes)
     return;
@@ -687,7 +681,10 @@ void DwarfDebug::endModule() {
   assert(CurFn == nullptr);
   assert(CurMI == nullptr);
 
-  if (!FirstCU)
+  // If we aren't actually generating debug info (check beginModule -
+  // conditionalized on !DisableDebugInfoPrinting and the presence of the
+  // llvm.dbg.cu metadata node)
+  if (!DwarfInfoSectionSym)
     return;
 
   // End any existing sections.
@@ -741,9 +738,6 @@ void DwarfDebug::endModule() {
   // clean up.
   SPMap.clear();
   AbstractVariables.clear();
-
-  // Reset these for the next Module if we have one.
-  FirstCU = nullptr;
 }
 
 // Find abstract variable, if any, associated with Var.
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 9692213..2c7955d 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -164,12 +164,6 @@ class DwarfDebug : public AsmPrinterHandler {
   // All DIEValues are allocated through this allocator.
   BumpPtrAllocator DIEValueAllocator;
 
-  // Handle to the compile unit used for the inline extension handling,
-  // this is just so that the DIEValue allocator has a place to store
-  // the particular elements.
-  // FIXME: Store these off of DwarfDebug instead?
-  DwarfCompileUnit *FirstCU;
-
   // Maps MDNode with its corresponding DwarfCompileUnit.
   MapVector<const MDNode *, DwarfCompileUnit *> CUMap;
 
-- 
2.7.4