[Lldb-commits] [lldb] r193242 - Initial DWARF64 support for .debug_line
Greg Clayton
gclayton at apple.com
Wed Oct 23 10:37:20 PDT 2013
In order to do DWARF 64 right, we should make a DWARFDataExtractor which inherits from DataExtractor so we can add DWARF kind of things. The first thing we add to it is:
class DWARFDataExtractor : public DataExtractor {
uint64_t
GetDWARFLength() const;
dw_offset_t
GetDWARFOffset() const;
protected:
bool m_is_dwarf64;
}
then your patches become much simpler. We then must switch all use of DataExtractor over to DWARFDataExtractor. This will allow us to store the DWARF 64 bit state in the data extractor and keep the parsing code clean.
This applies to both of your 64 bit DWARF patches.
Greg
On Oct 23, 2013, at 7:18 AM, Ed Maste <emaste at freebsd.org> wrote:
> Author: emaste
> Date: Wed Oct 23 09:18:41 2013
> New Revision: 193242
>
> URL: http://llvm.org/viewvc/llvm-project?rev=193242&view=rev
> Log:
> Initial DWARF64 support for .debug_line
>
> Some versions of the GNU MIPS toolchain generate 64-Bit DWARF (even though
> it isn't really necessary). This change adds support for the 64-Bit DWARF
> format, but is not actually tested with >4GB of debug data.
>
> Similar changes are in progress for llvm's version of DWARFDebugLine, in
> review D1988.
>
> Modified:
> lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugLine.cpp
> lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugLine.h
>
> Modified: lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugLine.cpp
> URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugLine.cpp?rev=193242&r1=193241&r2=193242&view=diff
> ==============================================================================
> --- lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugLine.cpp (original)
> +++ lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugLine.cpp Wed Oct 23 09:18:41 2013
> @@ -411,11 +411,22 @@ DWARFDebugLine::ParsePrologue(const Data
> uint32_t i;
> const char * s;
> prologue->total_length = debug_line_data.GetU32(offset_ptr);
> + // 7.4 32-Bit and 64-Bit DWARF Formats
> + if (prologue->total_length == 0xffffffff)
> + {
> + prologue->is_64_bit = true;
> + prologue->total_length = debug_line_data.GetU64(offset_ptr);
> + }
> + else if (prologue->total_length >= 0xffffff00)
> + {
> + // Reserved.
> + return false;
> + }
> prologue->version = debug_line_data.GetU16(offset_ptr);
> if (prologue->version != 2)
> return false;
>
> - prologue->prologue_length = debug_line_data.GetU32(offset_ptr);
> + prologue->prologue_length = debug_line_data.GetMaxU64(offset_ptr, prologue->SizeofPrologueLength());
> const lldb::offset_t end_prologue_offset = prologue->prologue_length + *offset_ptr;
> prologue->min_inst_length = debug_line_data.GetU8(offset_ptr);
> prologue->default_is_stmt = debug_line_data.GetU8(offset_ptr);
> @@ -456,6 +467,7 @@ DWARFDebugLine::ParsePrologue(const Data
> break;
> }
>
> + // XXX GNU as is broken for 64-Bit DWARF
> if (*offset_ptr != end_prologue_offset)
> {
> Host::SystemLog (Host::eSystemLogWarning,
> @@ -474,13 +486,20 @@ DWARFDebugLine::ParseSupportFiles (const
> dw_offset_t stmt_list,
> FileSpecList &support_files)
> {
> - lldb::offset_t offset = stmt_list + 4; // Skip the total length
> + lldb::offset_t offset = stmt_list;
> + // Skip the total length
> + size_t dwarf_offset_size = 4;
> + if (debug_line_data.GetU32(&offset) == 0xffffffff)
> + {
> + dwarf_offset_size = 8;
> + (void)debug_line_data.GetU64(&offset);
> + }
> const char * s;
> uint32_t version = debug_line_data.GetU16(&offset);
> if (version != 2)
> return false;
>
> - const dw_offset_t end_prologue_offset = debug_line_data.GetU32(&offset) + offset;
> + const dw_offset_t end_prologue_offset = debug_line_data.GetMaxU64(&offset, dwarf_offset_size) + offset;
> // Skip instruction length, default is stmt, line base, line range and
> // opcode base, and all opcode lengths
> offset += 4;
> @@ -600,7 +619,7 @@ DWARFDebugLine::ParseStatementTable
> if (log)
> prologue->Dump (log);
>
> - const dw_offset_t end_offset = debug_line_offset + prologue->total_length + sizeof(prologue->total_length);
> + const dw_offset_t end_offset = debug_line_offset + prologue->total_length + (prologue->SizeofTotalLength());
>
> State state(prologue, log, callback, userData);
>
>
> Modified: lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugLine.h
> URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugLine.h?rev=193242&r1=193241&r2=193242&view=diff
> ==============================================================================
> --- lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugLine.h (original)
> +++ lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugLine.h Wed Oct 23 09:18:41 2013
> @@ -64,7 +64,8 @@ public:
> opcode_base(0),
> standard_opcode_lengths(),
> include_directories(),
> - file_names()
> + file_names(),
> + is_64_bit(false)
> {
> }
>
> @@ -82,10 +83,13 @@ public:
> std::vector<std::string> include_directories;
> std::vector<FileNameEntry> file_names;
>
> + bool is_64_bit; // 64-bit dwarf
> + uint32_t SizeofTotalLength() const { return is_64_bit ? 12 : 4; }
> + uint32_t SizeofPrologueLength() const { return is_64_bit ? 8 : 4; }
> // Length of the prologue in bytes
> - uint32_t Length() const { return prologue_length + sizeof(total_length) + sizeof(version) + sizeof(prologue_length); }
> + uint32_t Length() const { return prologue_length + SizeofTotalLength() + sizeof(version) + SizeofPrologueLength(); }
> // Length of the line table data in bytes (not including the prologue)
> - uint32_t StatementTableLength() const { return total_length + sizeof(total_length) - Length(); }
> + uint32_t StatementTableLength() const { return total_length + SizeofPrologueLength() - Length(); }
> int32_t MaxLineIncrementForSpecialOpcode() const { return line_base + (int8_t)line_range - 1; }
> bool IsValid() const;
> // void Append(BinaryStreamBuf& buff) const;
> @@ -97,6 +101,7 @@ public:
> standard_opcode_lengths.clear();
> include_directories.clear();
> file_names.clear();
> + is_64_bit = false;
> }
> bool GetFile(uint32_t file_idx, std::string& file, std::string& dir) const;
>
>
>
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