From 93f3fed999e039988deca64d19cbf122d46cdd59 Mon Sep 17 00:00:00 2001
From: Eric Christopher <echristo@gmail.com>
Date: Mon, 6 May 2013 17:50:42 +0000
Subject: [PATCH] Don't emit .dwo sections unless they exist.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181224 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/DebugInfo/DWARFContext.cpp | 54 +++++++++++++++++++---------------
 1 file changed, 30 insertions(+), 24 deletions(-)

diff --git a/lib/DebugInfo/DWARFContext.cpp b/lib/DebugInfo/DWARFContext.cpp
index e5daf55982f..4ce8f7a4d79 100644
--- a/lib/DebugInfo/DWARFContext.cpp
+++ b/lib/DebugInfo/DWARFContext.cpp
@@ -110,36 +110,42 @@ void DWARFContext::dump(raw_ostream &OS, DIDumpType DumpType) {
   }
 
   if (DumpType == DIDT_All || DumpType == DIDT_AbbrevDwo) {
-    OS << "\n.debug_abbrev.dwo contents:\n";
-    getDebugAbbrevDWO()->dump(OS);
+    const DWARFDebugAbbrev *D = getDebugAbbrevDWO();
+    if (D) {
+      OS << "\n.debug_abbrev.dwo contents:\n";
+      getDebugAbbrevDWO()->dump(OS);
+    }
   }
 
-  if (DumpType == DIDT_All || DumpType == DIDT_InfoDwo) {
-    OS << "\n.debug_info.dwo contents:\n";
-    for (unsigned i = 0, e = getNumDWOCompileUnits(); i != e; ++i)
-      getDWOCompileUnitAtIndex(i)->dump(OS);
-  }
+  if (DumpType == DIDT_All || DumpType == DIDT_InfoDwo)
+    if (getNumDWOCompileUnits()) {
+      OS << "\n.debug_info.dwo contents:\n";
+      for (unsigned i = 0, e = getNumDWOCompileUnits(); i != e; ++i)
+	getDWOCompileUnitAtIndex(i)->dump(OS);
+    }
 
-  if (DumpType == DIDT_All || DumpType == DIDT_StrDwo) {
-    OS << "\n.debug_str.dwo contents:\n";
-    DataExtractor strDWOData(getStringDWOSection(), isLittleEndian(), 0);
-    offset = 0;
-    uint32_t strDWOOffset = 0;
-    while (const char *s = strDWOData.getCStr(&offset)) {
-      OS << format("0x%8.8x: \"%s\"\n", strDWOOffset, s);
-      strDWOOffset = offset;
+  if (DumpType == DIDT_All || DumpType == DIDT_StrDwo)
+    if (!getStringDWOSection().empty()) {
+      OS << "\n.debug_str.dwo contents:\n";
+      DataExtractor strDWOData(getStringDWOSection(), isLittleEndian(), 0);
+      offset = 0;
+      uint32_t strDWOOffset = 0;
+      while (const char *s = strDWOData.getCStr(&offset)) {
+	OS << format("0x%8.8x: \"%s\"\n", strDWOOffset, s);
+	strDWOOffset = offset;
+      }
     }
-  }
 
-  if (DumpType == DIDT_All || DumpType == DIDT_StrOffsetsDwo) {
-    OS << "\n.debug_str_offsets.dwo contents:\n";
-    DataExtractor strOffsetExt(getStringOffsetDWOSection(), isLittleEndian(), 0);
-    offset = 0;
-    while (offset < getStringOffsetDWOSection().size()) {
-      OS << format("0x%8.8x: ", offset);
-      OS << format("%8.8x\n", strOffsetExt.getU32(&offset));
+  if (DumpType == DIDT_All || DumpType == DIDT_StrOffsetsDwo)
+    if (!getStringOffsetDWOSection().empty()) {
+      OS << "\n.debug_str_offsets.dwo contents:\n";
+      DataExtractor strOffsetExt(getStringOffsetDWOSection(), isLittleEndian(), 0);
+      offset = 0;
+      while (offset < getStringOffsetDWOSection().size()) {
+	OS << format("0x%8.8x: ", offset);
+	OS << format("%8.8x\n", strOffsetExt.getU32(&offset));
+      }
     }
-  }
 }
 
 const DWARFDebugAbbrev *DWARFContext::getDebugAbbrev() {
-- 
2.34.1