Issue 33001: Add missing includes and update comments to DWARF code

http://breakpad.appspot.com/33001

A=jim.blandy
R=nealsid


git-svn-id: http://google-breakpad.googlecode.com/svn/branches/linux-dwarf@412 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/common/dwarf/bytereader-inl.h

@@ -29,6 +29,8 @@
 #ifndef UTIL_DEBUGINFO_BYTEREADER_INL_H__
 #define UTIL_DEBUGINFO_BYTEREADER_INL_H__
 
+#include <cassert>
+
 #include "common/dwarf/bytereader.h"
 
 namespace dwarf2reader {

src/common/dwarf/dwarf2reader.cc

@@ -28,6 +28,8 @@
 
 #include <stack>
 #include <utility>
+#include <memory>
+#include <cstring>
 
 #include "common/dwarf/bytereader-inl.h"
 #include "common/dwarf/dwarf2reader.h"
@@ -75,8 +77,12 @@ void CompilationUnit::ReadAbbrevs() {
   if (abbrevs_)
     return;
 
-  // First get the debug_abbrev section
-  SectionMap::const_iterator iter = sections_.find("__debug_abbrev");
+  // First get the debug_abbrev section.  ".debug_abbrev" is the name
+  // recommended in the DWARF spec, and used on Linux;
+  // "__debug_abbrev" is the name used in Mac OS X Mach-O files.
+  SectionMap::const_iterator iter = sections_.find(".debug_abbrev");
+  if (iter == sections_.end())
+    iter = sections_.find("__debug_abbrev");
   assert(iter != sections_.end());
 
   abbrevs_ = new vector<Abbrev>;
@@ -88,7 +94,9 @@ void CompilationUnit::ReadAbbrevs() {
   const char* abbrev_start = iter->second.first +
                                       header_.abbrev_offset;
   const char* abbrevptr = abbrev_start;
+#ifndef NDEBUG
   const uint64 abbrev_length = iter->second.second - header_.abbrev_offset;
+#endif
 
   while (1) {
     CompilationUnit::Abbrev abbrev;
@@ -261,8 +269,12 @@ void CompilationUnit::ReadHeader() {
 }
 
 uint64 CompilationUnit::Start() {
-  // First get the debug_info section
-  SectionMap::const_iterator iter = sections_.find("__debug_info");
+  // First get the debug_info section.  ".debug_info" is the name
+  // recommended in the DWARF spec, and used on Linux; "__debug_info"
+  // is the name used in Mac OS X Mach-O files.
+  SectionMap::const_iterator iter = sections_.find(".debug_info");
+  if (iter == sections_.end())
+    iter = sections_.find("__debug_info");
   assert(iter != sections_.end());
 
   // Set up our buffer
@@ -292,8 +304,12 @@ uint64 CompilationUnit::Start() {
   // Otherwise, continue by reading our abbreviation entries.
   ReadAbbrevs();
 
-  // Set the string section if we have one.
-  iter = sections_.find("__debug_str");
+  // Set the string section if we have one.  ".debug_str" is the name
+  // recommended in the DWARF spec, and used on Linux; "__debug_str"
+  // is the name used in Mac OS X Mach-O files.
+  iter = sections_.find(".debug_str");
+  if (iter == sections_.end())
+    iter = sections_.find("__debug_str");
   if (iter != sections_.end()) {
     string_buffer_ = iter->second.first;
     string_buffer_length_ = iter->second.second;
@@ -464,7 +480,7 @@ void CompilationUnit::ProcessDIEs() {
   // we need semantics of boost scoped_ptr here - no intention of trasnferring
   // ownership of the stack.  use const, but then we limit ourselves to not
   // ever being able to call .reset() on the smart pointer.
-  auto_ptr<stack<uint64> > const die_stack(new stack<uint64>);
+  std::auto_ptr<stack<uint64> > const die_stack(new stack<uint64>);
 
   while (dieptr < (lengthstart + header_.length)) {
     // We give the user the absolute offset from the beginning of

src/common/dwarf/dwarf2reader.h

@@ -224,8 +224,11 @@ class CompilationUnit {
 
   // Begin reading a Dwarf2 compilation unit, and calling the
   // callbacks in the Dwarf2Handler
-  // Return the offset of the end of the compilation unit - the passed
-  // in offset.
+
+  // Return the full length of the compilation unit, including
+  // headers.  This plus the starting offset passed to the constructor
+  // is the offset of the end of the compilation unit --- the start of
+  // the next compilation unit, if there is one.
   uint64 Start();
 
  private: