1 files changed, 75 insertions, 0 deletions
diff --git a/tools/profiler/core/ProfilerCodeAddressService.cpp b/tools/profiler/core/ProfilerCodeAddressService.cpp
new file mode 100644
index 0000000000..5a65e06379
--- /dev/null
+++ b/tools/profiler/core/ProfilerCodeAddressService.cpp
@@ -0,0 +1,75 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ProfilerCodeAddressService.h"
+
+#include "platform.h"
+#include "mozilla/StackWalk.h"
+
+using namespace mozilla;
+
+#if defined(XP_LINUX) || defined(XP_FREEBSD)
+static char* SearchSymbolTable(SymbolTable& aTable, uint32_t aOffset) {
+  size_t index;
+  bool exact =
+      BinarySearch(aTable.mAddrs, 0, aTable.mAddrs.Length(), aOffset, &index);
+
+  if (index == 0 && !exact) {
+    // Our offset is before the first symbol in the table; no result.
+    return nullptr;
+  }
+
+  // Extract the (mangled) symbol name out of the string table.
+  auto strings = reinterpret_cast<char*>(aTable.mBuffer.Elements());
+  nsCString symbol;
+  symbol.Append(strings + aTable.mIndex[index - 1],
+                aTable.mIndex[index] - aTable.mIndex[index - 1]);
+
+  // First try demangling as a Rust identifier.
+  char demangled[1024];
+  if (!profiler_demangle_rust(symbol.get(), demangled,
+                              ArrayLength(demangled))) {
+    // Then as a C++ identifier.
+    DemangleSymbol(symbol.get(), demangled, ArrayLength(demangled));
+  }
+  demangled[ArrayLength(demangled) - 1] = '\0';
+
+  // Use the mangled name if we didn't successfully demangle.
+  return strdup(demangled[0] != '\0' ? demangled : symbol.get());
+}
+#endif
+
+bool ProfilerCodeAddressService::GetFunction(const void* aPc,
+                                             nsACString& aResult) {
+  Entry& entry = GetEntry(aPc);
+
+#if defined(XP_LINUX) || defined(XP_FREEBSD)
+  // On Linux, most symbols will not be found by the MozDescribeCodeAddress call
+  // that GetEntry does.  So we read the symbol table directly from the ELF
+  // image.
+
+  // SymbolTable currently assumes library offsets will not be larger than
+  // 4 GiB.
+  if (entry.mLOffset <= 0xFFFFFFFF && !entry.mFunction) {
+    auto p = mSymbolTables.lookupForAdd(entry.mLibrary);
+    if (!p) {
+      if (!mSymbolTables.add(p, entry.mLibrary, SymbolTable())) {
+        MOZ_CRASH("ProfilerCodeAddressService OOM");
+      }
+      profiler_get_symbol_table(entry.mLibrary, nullptr, &p->value());
+    }
+    entry.mFunction =
+        SearchSymbolTable(p->value(), static_cast<uint32_t>(entry.mLOffset));
+  }
+#endif
+
+  if (!entry.mFunction || entry.mFunction[0] == '\0') {
+    return false;
+  }
+
+  aResult = nsDependentCString(entry.mFunction);
+  return true;
+}