2 files changed, 112 insertions, 0 deletions
diff --git a/llvm/lib/DebugInfo/GSYM/CMakeLists.txt b/llvm/lib/DebugInfo/GSYM/CMakeLists.txt
index af9910fb491..e05b2c112ce 100644
--- a/llvm/lib/DebugInfo/GSYM/CMakeLists.txt
+++ b/llvm/lib/DebugInfo/GSYM/CMakeLists.txt
@@ -1,4 +1,5 @@
 add_llvm_library(LLVMDebugInfoGSYM
+  Header.cpp
   FileWriter.cpp
   FunctionInfo.cpp
   InlineInfo.cpp
diff --git a/llvm/lib/DebugInfo/GSYM/Header.cpp b/llvm/lib/DebugInfo/GSYM/Header.cpp
new file mode 100644
index 00000000000..fbf991682e7
--- /dev/null
+++ b/llvm/lib/DebugInfo/GSYM/Header.cpp
@@ -0,0 +1,111 @@
+//===- Header.cpp -----------------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DebugInfo/GSYM/Header.h"
+#include "llvm/DebugInfo/GSYM/FileWriter.h"
+#include "llvm/Support/DataExtractor.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/raw_ostream.h"
+
+#define HEX8(v) llvm::format_hex(v, 4)
+#define HEX16(v) llvm::format_hex(v, 6)
+#define HEX32(v) llvm::format_hex(v, 10)
+#define HEX64(v) llvm::format_hex(v, 18)
+
+using namespace llvm;
+using namespace gsym;
+
+raw_ostream &llvm::gsym::operator<<(raw_ostream &OS, const Header &H) {
+  OS << "Header:\n";
+  OS << "  Magic        = " << HEX32(H.Magic) << "\n";
+  OS << "  Version      = " << HEX16(H.Version) << '\n';
+  OS << "  AddrOffSize  = " << HEX8(H.AddrOffSize) << '\n';
+  OS << "  UUIDSize     = " << HEX8(H.UUIDSize) << '\n';
+  OS << "  BaseAddress  = " << HEX64(H.BaseAddress) << '\n';
+  OS << "  NumAddresses = " << HEX32(H.NumAddresses) << '\n';
+  OS << "  StrtabOffset = " << HEX32(H.StrtabOffset) << '\n';
+  OS << "  StrtabSize   = " << HEX32(H.StrtabSize) << '\n';
+  OS << "  UUID         = ";
+  for (uint8_t I = 0; I < H.UUIDSize; ++I)
+    OS << format_hex_no_prefix(H.UUID[I], 2);
+  OS << '\n';
+  return OS;
+}
+
+/// Check the header and detect any errors.
+static llvm::Error getHeaderError(const Header &H) {
+  if (H.Magic != GSYM_MAGIC)
+    return createStringError(std::errc::invalid_argument,
+                             "invalid GSYM magic 0x%8.8x", H.Magic);
+  if (H.Version != GSYM_VERSION)
+    return createStringError(std::errc::invalid_argument,
+                             "unsupported GSYM version %u", H.Version);
+  switch (H.AddrOffSize) {
+    case 1: break;
+    case 2: break;
+    case 4: break;
+    case 8: break;
+    default:
+        return createStringError(std::errc::invalid_argument,
+                                 "invalid address offset size %u",
+                                 H.AddrOffSize);
+  }
+  if (H.UUIDSize > GSYM_MAX_UUID_SIZE)
+    return createStringError(std::errc::invalid_argument,
+                             "invalid UUID size %u", H.UUIDSize);
+  return Error::success();
+}
+
+llvm::Expected<Header> Header::decode(DataExtractor &Data) {
+  uint64_t Offset = 0;
+  // The header is stored as a single blob of data that has a fixed byte size.
+  if (!Data.isValidOffsetForDataOfSize(Offset, sizeof(Header)))
+    return createStringError(std::errc::invalid_argument,
+                             "not enough data for a gsym::Header");
+  Header H;
+  H.Magic = Data.getU32(&Offset);
+  H.Version = Data.getU16(&Offset);
+  H.AddrOffSize = Data.getU8(&Offset);
+  H.UUIDSize = Data.getU8(&Offset);
+  H.BaseAddress = Data.getU64(&Offset);
+  H.NumAddresses = Data.getU32(&Offset);
+  H.StrtabOffset = Data.getU32(&Offset);
+  H.StrtabSize = Data.getU32(&Offset);
+  Data.getU8(&Offset, H.UUID, GSYM_MAX_UUID_SIZE);
+  llvm::Error Err = getHeaderError(H);
+  if (Err)
+    return std::move(Err);
+  return H;
+}
+
+llvm::Error Header::encode(FileWriter &O) const {
+  // Users must verify the Header is valid prior to calling this funtion.
+  llvm::Error Err = getHeaderError(*this);
+  if (Err)
+    return Err;
+  O.writeU32(Magic);
+  O.writeU16(Version);
+  O.writeU8(AddrOffSize);
+  O.writeU8(UUIDSize);
+  O.writeU64(BaseAddress);
+  O.writeU32(NumAddresses);
+  O.writeU32(StrtabOffset);
+  O.writeU32(StrtabSize);
+  O.writeData(llvm::ArrayRef<uint8_t>(UUID));
+  return Error::success();
+}
+
+bool llvm::gsym::operator==(const Header &LHS, const Header &RHS) {
+  return LHS.Magic == RHS.Magic && LHS.Version == RHS.Version &&
+      LHS.AddrOffSize == RHS.AddrOffSize && LHS.UUIDSize == RHS.UUIDSize &&
+      LHS.BaseAddress == RHS.BaseAddress &&
+      LHS.NumAddresses == RHS.NumAddresses &&
+      LHS.StrtabOffset == RHS.StrtabOffset &&
+      LHS.StrtabSize == RHS.StrtabSize &&
+      memcmp(LHS.UUID, RHS.UUID, LHS.UUIDSize) == 0;
+}