upload android base code part6

android/system/core/libunwindstack/MapInfo.cpp

@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <memory>
+#include <string>
+
+#include <unwindstack/Elf.h>
+#include <unwindstack/MapInfo.h>
+#include <unwindstack/Maps.h>
+#include <unwindstack/Memory.h>
+
+namespace unwindstack {
+
+Memory* MapInfo::CreateMemory(pid_t pid) {
+  if (end <= start) {
+    return nullptr;
+  }
+
+  elf_offset = 0;
+
+  // First try and use the file associated with the info.
+  if (!name.empty()) {
+    // Fail on device maps.
+    if (flags & MAPS_FLAGS_DEVICE_MAP) {
+      return nullptr;
+    }
+
+    std::unique_ptr<MemoryFileAtOffset> file_memory(new MemoryFileAtOffset);
+    uint64_t map_size;
+    if (offset != 0) {
+      // Only map in a piece of the file.
+      map_size = end - start;
+    } else {
+      map_size = UINT64_MAX;
+    }
+    if (file_memory->Init(name, offset, map_size)) {
+      // It's possible that a non-zero offset might not be pointing to
+      // valid elf data. Check if this is a valid elf, and if not assume
+      // that this was meant to incorporate the entire file.
+      if (offset != 0 && !Elf::IsValidElf(file_memory.get())) {
+        // Don't bother checking the validity that will happen on the elf init.
+        if (file_memory->Init(name, 0)) {
+          elf_offset = offset;
+          return file_memory.release();
+        }
+        // Fall through if the init fails.
+      } else {
+        return file_memory.release();
+      }
+    }
+  }
+
+  Memory* memory = nullptr;
+  if (pid == getpid()) {
+    memory = new MemoryLocal();
+  } else {
+    memory = new MemoryRemote(pid);
+  }
+  return new MemoryRange(memory, start, end);
+}
+
+Elf* MapInfo::GetElf(pid_t pid, bool init_gnu_debugdata) {
+  if (elf) {
+    return elf;
+  }
+
+  elf = new Elf(CreateMemory(pid));
+  if (elf->Init() && init_gnu_debugdata) {
+    elf->InitGnuDebugdata();
+  }
+  // If the init fails, keep the elf around as an invalid object so we
+  // don't try to reinit the object.
+  return elf;
+}
+
+}  // namespace unwindstack