namespace implementations of FileID

In trying to create a backend service that can process both ELF and
Mach-O binaries, I found that symbol collisions occur when trying to
link different implementations of FileID. This change puts the
different implementations into separate namespaces to avoid the
collision.

Change-Id: I15aabb222803f2ffbda15ed13e66793bae32ddce
Reviewed-on: https://chromium-review.googlesource.com/c/breakpad/breakpad/+/3421417
Reviewed-by: Mark Mentovai <mark@chromium.org>

src/common/linux/dump_symbols.cc

@@ -87,11 +87,11 @@ using google_breakpad::DwarfRangeListHandler;
 using google_breakpad::ElfClass;
 using google_breakpad::ElfClass32;
 using google_breakpad::ElfClass64;
-using google_breakpad::FileID;
+using google_breakpad::elf::FileID;
 using google_breakpad::FindElfSectionByName;
 using google_breakpad::GetOffset;
 using google_breakpad::IsValidElf;
-using google_breakpad::kDefaultBuildIdSize;
+using google_breakpad::elf::kDefaultBuildIdSize;
 using google_breakpad::Module;
 using google_breakpad::PageAllocator;
 #ifndef NO_STABS_SUPPORT

src/common/linux/file_id.cc

@@ -49,6 +49,7 @@
 #include "third_party/lss/linux_syscall_support.h"
 
 namespace google_breakpad {
+namespace elf {
 
 // Used in a few places for backwards-compatibility.
 const size_t kMDGUIDSize = sizeof(MDGUID);
@@ -198,4 +199,5 @@ string FileID::ConvertIdentifierToString(
   return bytes_to_hex_string(&identifier[0], identifier.size());
 }
 
+}  // elf
 }  // namespace google_breakpad

src/common/linux/file_id.h

@@ -41,6 +41,7 @@
 #include "common/using_std_string.h"
 
 namespace google_breakpad {
+namespace elf {
 
 // GNU binutils' ld defaults to 'sha1', which is 160 bits == 20 bytes,
 // so this is enough to fit that, which most binaries will use.
@@ -83,6 +84,7 @@ class FileID {
   string path_;
 };
 
+}  // namespace elf
 }  // namespace google_breakpad
 
 #endif  // COMMON_LINUX_FILE_ID_H__

src/common/linux/file_id_unittest.cc

@@ -50,6 +50,8 @@
 #include "breakpad_googletest_includes.h"
 
 using namespace google_breakpad;
+using google_breakpad::elf::FileID;
+using google_breakpad::elf::kDefaultBuildIdSize;
 using google_breakpad::synth_elf::ELF;
 using google_breakpad::synth_elf::Notes;
 using google_breakpad::test_assembler::kLittleEndian;