Implement /proc/self/maps/ parsing code.

base/debug/proc_maps.h

Index: base/debug/proc_maps.h
diff --git a/base/debug/proc_maps.h b/base/debug/proc_maps.h
new file mode 100644
index 0000000000000000000000000000000000000000..0dadbc13d3915c6d6d938378bce5a241f4cf5ab7
--- /dev/null
+++ b/base/debug/proc_maps.h
@@ -0,0 +1,61 @@
+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef BASE_DEBUG_PROC_MAPS_H_
+#define BASE_DEBUG_PROC_MAPS_H_
+
+#include <string>
+#include <vector>
+
+#include "base/base_export.h"
+#include "base/basictypes.h"
+#include "base/files/file_path.h"
+
+namespace base {
+namespace debug {

[Mark Mentovai, 2013/07/02 19:36:57]

Aren’t we not doing second-level nested namespaces for new code now?

[scherkus (not reviewing), 2013/07/02 21:43:01]

here's the most relevant discussion I could find:
https://groups.google.com/a/chromium.org/forum/#!msg/chromium-dev/RVps606IB_g...

they're not outright banned ... but rather discouraged for cases where they're
not providing much value (e.g., net::url_request)

personally I find this is an acceptable use of nested namespaces since it groups
together a variety of debugging-related code that isn't typically used in
production code

for now I'd rather keep base/debug/ consistent + should we make the change
tackle that in a future CL

+
+#if defined(OS_LINUX) || defined(OS_ANDROID)

[Mark Mentovai, 2013/07/02 19:36:57]

Get rid of this. Just rename the file with _linux or something that works for
both Linux or Android, or if there’s nothing appropriate, you’ll have to write
an exclude in the gyp file. You shouldn’t be #including this file on platforms
where it doesn’t make sense.

[scherkus (not reviewing), 2013/07/02 21:43:01]

Done.

+
+// Describes a region of mapped memory and the path of the file mapped.
+struct MappedMemoryRegion {
+  enum Permissions {

[Mark Mentovai, 2013/07/02 19:36:57]

The members of this enum are single permissions, so I think it’d be usual to
name this enum “Permission” in the singular.

  Permission p = MappedMemoryRegion::READ

makes more sense, right?

[scherkus (not reviewing), 2013/07/02 21:43:01]

Done.

+    READ = 1 << 0,
+    WRITE = 1 << 1,
+    EXECUTE = 1 << 2,
+    PRIVATE = 1 << 3,  // If set, region is private otherwise it is shared.

[Mark Mentovai, 2013/07/02 19:36:57]

Missing comma?

[scherkus (not reviewing), 2013/07/02 21:43:01]

Hrm. Not sure which comma is missing. I assume you mean between "private" and
"otherwise"

[Mark Mentovai, 2013/07/02 22:21:35]

scherkus wrote:
Yeah, that’s the one I meant.

+  };
+
+  // The address range [start,end) of mapped memory.
+  uintptr_t start;
+  uintptr_t end;
+
+  // Byte offset into |path| of the range mapped into memory.
+  size_t offset;
+
+  // Bitmask of read/write/execute/private/shared permissions.
+  uint8 permissions;
+
+  // Path of the file mapped into memory.
+  FilePath path;
+};
+
+// Reads the data from /proc/self/maps. Returns an empty string if unable to
+// do so.

[Mark Mentovai, 2013/07/02 19:36:57]

What’s it return otherwise? Just the contents of /proc/self/maps? Say so.

[scherkus (not reviewing), 2013/07/02 21:43:01]

Done.

+BASE_EXPORT std::string ReadProcMaps();
+
+// Parses /proc/<pid>/maps input data and stores in |regions|. Returns true
+// and updates |regions| if and only if all of |input| was successfully parsed.
+//
+// NOTE: Parsed path names aren't guaranteed to point at valid files. For
+// example, "[heap]" and "[stack]" are used to represent the location of the
+// process' heap and stack, respectively.
+BASE_EXPORT bool ParseProcMaps(const std::string& input,
+                               std::vector<MappedMemoryRegion>* regions);
+
+#endif
+
+}  // namespace debug
+}  // namespace base
+
+#endif  // BASE_DEBUG_PROC_MAPS_H_