syntax = "proto3";

package objdiff.diff;

// Top-level diff result containing left and right object diffs
message DiffResult {
  optional DiffObject left = 1;
  optional DiffObject right = 2;
}

// Diff information for a single object file
message DiffObject {
  repeated DiffSection sections = 1;
  repeated DiffSymbol symbols = 2;
}

// Diff information for a section
message DiffSection {
  string name = 1;
  DiffSectionKind kind = 2;
  uint64 size = 3;
  uint64 address = 4;
  optional float match_percent = 5;
  repeated DiffDataSegment data_diff = 6;
  repeated DiffDataRelocation reloc_diff = 7;
}

enum DiffSectionKind {
  SECTION_UNKNOWN = 0;
  SECTION_CODE = 1;
  SECTION_DATA = 2;
  SECTION_BSS = 3;
  SECTION_COMMON = 4;
}

// Symbol with diff information
message DiffSymbol {
  string name = 1;
  optional string demangled_name = 2;
  uint64 address = 3;
  uint64 size = 4;
  uint32 flags = 5;
  // The symbol index in the _other_ object that this symbol was diffed against
  optional uint32 target_symbol = 6;
  optional float match_percent = 7;
  // Instruction diff rows (for code symbols)
  repeated DiffInstructionRow instructions = 8;
  // Data diff (for data symbols)
  repeated DiffDataSegment data_diff = 9;
}

// Symbol visibility flags (bitmask)
enum DiffSymbolFlag {
  SYMBOL_NONE = 0;
  SYMBOL_GLOBAL = 1;
  SYMBOL_LOCAL = 2;
  SYMBOL_WEAK = 4;
  SYMBOL_COMMON = 8;
  SYMBOL_HIDDEN = 16;
}

// A single instruction diff row
message DiffInstructionRow {
  DiffKind diff_kind = 1;
  optional DiffInstruction instruction = 2;
  repeated DiffInstructionArgDiff arg_diff = 3;
}

// Parsed instruction information
message DiffInstruction {
  uint64 address = 1;
  uint32 size = 2;
  // Formatted instruction string
  string formatted = 3;
  // Formatted instruction parts
  repeated DiffInstructionPart parts = 4;
  // Relocation information (if present)
  optional DiffRelocation relocation = 5;
  // Branch destination address
  optional uint64 branch_dest = 6;
  // Source line number (if present)
  optional uint32 line_number = 7;
}

// An instruction part
message DiffInstructionPart {
  oneof part {
    // Basic text (whitespace, punctuation, etc.)
    string basic = 1;
    // Opcode/mnemonic
    DiffOpcode opcode = 2;
    // Argument
    DiffInstructionArg arg = 3;
    // Separator between arguments (comma)
    bool separator = 4;
  }
}

message DiffOpcode {
  // Mnemonic string
  string mnemonic = 1;
  // Base opcode ID
  uint32 opcode = 2;
}

// An instruction argument
message DiffInstructionArg {
  oneof arg {
    // Signed immediate value
    sint64 signed = 1;
    // Unsigned immediate value
    uint64 unsigned = 2;
    // Opaque string value (register names, etc.)
    string opaque = 3;
    // Relocation
    bool reloc = 4;
    // Branch destination address
    uint64 branch_dest = 5;
  }
}

// Relocation information
message DiffRelocation {
  uint32 type = 1;
  string type_name = 2;
  uint32 target_symbol = 3;
  int64 addend = 4;
}

// Argument diff information
message DiffInstructionArgDiff {
  // If set, this argument differs from the other side.
  // The value is a rotating index for coloring.
  optional uint32 diff_index = 1;
}

// Diff kind for instructions and data
enum DiffKind {
  DIFF_NONE = 0;
  DIFF_REPLACE = 1;
  DIFF_DELETE = 2;
  DIFF_INSERT = 3;
  DIFF_OP_MISMATCH = 4;
  DIFF_ARG_MISMATCH = 5;
}

// Data diff segment
message DiffDataSegment {
  DiffKind kind = 1;
  bytes data = 2;
  // Size may be larger than data length for BSS
  uint64 size = 3;
}

// Data relocation diff
message DiffDataRelocation {
  DiffRelocation relocation = 1;
  DiffKind kind = 2;
  // Address range this relocation covers
  uint64 start = 3;
  uint64 end = 4;
}