1 files changed, 93 insertions, 0 deletions
diff --git a/contrib/llvm-project/llvm/lib/Object/BuildID.cpp b/contrib/llvm-project/llvm/lib/Object/BuildID.cpp
new file mode 100644
index 000000000000..795c22e769aa
--- /dev/null
+++ b/contrib/llvm-project/llvm/lib/Object/BuildID.cpp
@@ -0,0 +1,93 @@
+//===- llvm/Object/BuildID.cpp - Build ID ---------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file defines a library for handling Build IDs and using them to find
+/// debug info.
+///
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Object/BuildID.h"
+
+#include "llvm/Object/ELFObjectFile.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Path.h"
+
+namespace llvm {
+namespace object {
+
+namespace {
+
+template <typename ELFT>
+std::optional<BuildIDRef> getBuildID(const ELFFile<ELFT> &Obj) {
+  auto PhdrsOrErr = Obj.program_headers();
+  if (!PhdrsOrErr) {
+    consumeError(PhdrsOrErr.takeError());
+    return {};
+  }
+  for (const auto &P : *PhdrsOrErr) {
+    if (P.p_type != ELF::PT_NOTE)
+      continue;
+    Error Err = Error::success();
+    for (auto N : Obj.notes(P, Err))
+      if (N.getType() == ELF::NT_GNU_BUILD_ID &&
+          N.getName() == ELF::ELF_NOTE_GNU)
+        return N.getDesc();
+    consumeError(std::move(Err));
+  }
+  return {};
+}
+
+} // namespace
+
+std::optional<BuildIDRef> getBuildID(const ObjectFile *Obj) {
+  if (auto *O = dyn_cast<ELFObjectFile<ELF32LE>>(Obj))
+    return getBuildID(O->getELFFile());
+  if (auto *O = dyn_cast<ELFObjectFile<ELF32BE>>(Obj))
+    return getBuildID(O->getELFFile());
+  if (auto *O = dyn_cast<ELFObjectFile<ELF64LE>>(Obj))
+    return getBuildID(O->getELFFile());
+  if (auto *O = dyn_cast<ELFObjectFile<ELF64BE>>(Obj))
+    return getBuildID(O->getELFFile());
+  return std::nullopt;
+}
+
+std::optional<std::string> BuildIDFetcher::fetch(BuildIDRef BuildID) const {
+  auto GetDebugPath = [&](StringRef Directory) {
+    SmallString<128> Path{Directory};
+    sys::path::append(Path, ".build-id",
+                      llvm::toHex(BuildID[0], /*LowerCase=*/true),
+                      llvm::toHex(BuildID.slice(1), /*LowerCase=*/true));
+    Path += ".debug";
+    return Path;
+  };
+  if (DebugFileDirectories.empty()) {
+    SmallString<128> Path = GetDebugPath(
+#if defined(__NetBSD__)
+        // Try /usr/libdata/debug/.build-id/../...
+        "/usr/libdata/debug"
+#else
+        // Try /usr/lib/debug/.build-id/../...
+        "/usr/lib/debug"
+#endif
+    );
+    if (llvm::sys::fs::exists(Path))
+      return std::string(Path);
+  } else {
+    for (const auto &Directory : DebugFileDirectories) {
+      // Try <debug-file-directory>/.build-id/../...
+      SmallString<128> Path = GetDebugPath(Directory);
+      if (llvm::sys::fs::exists(Path))
+        return std::string(Path);
+    }
+  }
+  return std::nullopt;
+}
+
+} // namespace object
+} // namespace llvm