Improve Elf object file UUID calculation performance.

This change makes significant improvements in the performance of
calculating a UUID within ObjectFileELF, and handles both running
processes and core files correctly. This does lazy evaluation of
UUID generation and caches the result when calculated.

Change by Piotr Rak.

llvm-svn: 204749

1 files changed, 12 insertions, 0 deletions

diff --git a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.h b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.h
index 44b40a4f123..ac7d38c0468 100644
--- a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.h
+++ b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.h
@@ -214,6 +214,7 @@ private:
 
     /// Version of this reader common to all plugins based on this class.
     static const uint32_t m_plugin_version = 1;
+    static const uint32_t g_core_uuid_magic;
 
     /// ELF file header.
     elf::ELFHeader m_header;
@@ -249,6 +250,17 @@ private:
     size_t
     SectionIndex(const SectionHeaderCollConstIter &I) const;
 
+    // Parses the ELF program headers.
+    static size_t
+    GetProgramHeaderInfo(ProgramHeaderColl &program_headers,
+                         lldb_private::DataExtractor &data,
+                         const elf::ELFHeader &header);
+
+    // Finds PT_NOTE segments and calculates their crc sum.
+    static uint32_t
+    CalculateELFNotesSegmentsCRC32(const ProgramHeaderColl& program_headers,
+                                   lldb_private::DataExtractor &data);
+
     /// Parses all section headers present in this object file and populates
     /// m_program_headers.  This method will compute the header list only once.
     /// Returns the number of headers parsed.