Supersize: Create aliases for inline symbols

If a symbol was found in multiple object files, we would previously have
changed its object path to be the common ancestor of all paths it
appeared in. This is a problem because it would cause queries based on
path to not find these symbols.

On the flip side, we were creating string literal aliases for every
path a string literal appeared in. For small strings such as "", or
"\n", this would lead to an unreasonable number of aliases.

This changes supersize to first create symbols for all paths, and then
collapse groups with a large number of aliases into a single symbol with
ancestor paths.

Before this change:
.text: 48998 symbols have shared ownership (1553806 bytes)
.rodata: 541 symbols have shared ownership (285728 bytes)

After:
.text: 1586 symbols have shared ownership (48252 bytes)
.rodata: 141 symbols have shared ownership (2828 bytes)

This increases the symbol count 702115->912322 and the file size
9.67mb->10.39mb.

This increases the runtime on my machine from ~40s -> ~42s.

Bug: 776032
Change-Id: I457361762b1f241f114b52464812e6035e881538
Reviewed-on: https://chromium-review.googlesource.com/726460
Commit-Queue: agrieve <agrieve@chromium.org>
Reviewed-by: Samuel Huang <huangs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#510205}

tools/binary_size/README.md

@@ -72,13 +72,12 @@ between milestones.
 1. A list of symbols, including name, address, size,
   padding (caused by alignment), and associated `.o` / `.cc` files.
 
-
 #### How are Symbols Collected?
 
 1. Symbol list is Extracted from linker `.map` file.
-   * Map files contain some unique pieces of information, such as
-     `** merge strings` entries, and the odd unnamed symbol (which map at least
-     lists a `.o` path).
+   * Map files contain some unique pieces of information compared to `nm` output,
+      such as `** merge strings` entries, and some unnamed symbols (which
+      although unnamed, contain the `.o` path).
 1. `.o` files are mapped to `.cc` files by parsing `.ninja` files.
    * This means that `.h` files are never listed as sources. No information about
      inlined symbols is gathered.
@@ -87,8 +86,15 @@ between milestones.
    * Aliases are created by identical code folding (linker optimization).
    * Aliases have the same address and size, but report their `.pss` as
       `.size / .num_aliases`.
-1. Paths for shared symbols (those found in multiple `.o` files) are collected
-   by running `nm` on every `.o` file.
+1. `** merge strings` symbols are further broken down into individual string
+  literal symbols. This is done by reading string literals from `.o` files, and
+  then searching for them within the `** merge strings` sections.
+1. "Shared symbols" are those that are owned by multiple `.o` files. These include
+  inline functions defined in `.h` files, and string literals that are de-duped
+  at link-time. Shared symbols are normally represented using one symbol alias
+  per path, but are sometimes collapsed into a single symbol where the path is
+  set to `{shared}/$SYMBOL_COUNT`. This collapsing is done only for symbols owned
+  by a large number of paths.
 
 #### What Other Processing Happens?
 

tools/binary_size/libsupersize/file_format.py

@@ -6,7 +6,6 @@
 
 import cStringIO
 import calendar
-import collections
 import datetime
 import gzip
 import json
@@ -43,13 +42,13 @@ def _SaveSizeInfoToFile(size_info, file_obj):
   _LogSize(file_obj, 'header')  # For libchrome: 570 bytes.
 
   # Store a single copy of all paths and have them referenced by index.
-  # Using an OrderedDict makes the indices more repetitive (better compression).
-  path_tuples = collections.OrderedDict.fromkeys(
-      (s.object_path, s.source_path) for s in size_info.raw_symbols)
-  for i, key in enumerate(path_tuples):
-    path_tuples[key] = i
-  file_obj.write('%d\n' % len(path_tuples))
-  file_obj.writelines('%s\t%s\n' % pair for pair in path_tuples)
+  unique_path_tuples = sorted(set(
+      (s.object_path, s.source_path) for s in size_info.raw_symbols))
+  path_tuples = dict.fromkeys(unique_path_tuples)
+  for i, tup in enumerate(unique_path_tuples):
+    path_tuples[tup] = i
+  file_obj.write('%d\n' % len(unique_path_tuples))
+  file_obj.writelines('%s\t%s\n' % pair for pair in unique_path_tuples)
   _LogSize(file_obj, 'paths')  # For libchrome, adds 200kb.
 
   # Symbol counts by section.

tools/binary_size/libsupersize/integration_test.py

@@ -218,8 +218,8 @@ class IntegrationTest(unittest.TestCase):
     size_info2 = self._CloneSizeInfo()
 
     # Removing 1 alias should not change the size.
-    a1, _, _ = (
-        size_info2.raw_symbols.Filter(lambda s: s.num_aliases == 3)[0].aliases)
+    a1, _, _, _ = (
+        size_info2.raw_symbols.Filter(lambda s: s.num_aliases == 4)[0].aliases)
     size_info2.raw_symbols -= [a1]
     a1.aliases.remove(a1)
     d = diff.Diff(size_info1, size_info2)
@@ -239,8 +239,8 @@ class IntegrationTest(unittest.TestCase):
     size_info2 = self._CloneSizeInfo()
 
     # Removing 2 aliases should not change the size.
-    a1, a2, _ = (
-        size_info2.raw_symbols.Filter(lambda s: s.num_aliases == 3)[0].aliases)
+    a1, _, a2, _ = (
+        size_info2.raw_symbols.Filter(lambda s: s.num_aliases == 4)[0].aliases)
     size_info2.raw_symbols -= [a1, a2]
     a1.aliases.remove(a1)
     a1.aliases.remove(a2)
@@ -255,22 +255,22 @@ class IntegrationTest(unittest.TestCase):
     self.assertEquals((0, 2, 0), _DiffCounts(d.raw_symbols))
     self.assertEquals((1, 1, 0), _DiffCounts(d.symbols.GroupedByFullName()))
 
-  def test_Diff_Aliases3(self):
+  def test_Diff_Aliases4(self):
     size_info1 = self._CloneSizeInfo()
     size_info2 = self._CloneSizeInfo()
 
-    # Removing all 3 aliases should change the size.
-    a1, a2, a3 = (
-        size_info2.raw_symbols.Filter(lambda s: s.num_aliases == 3)[0].aliases)
-    size_info2.raw_symbols -= [a1, a2, a3]
+    # Removing all 4 aliases should change the size.
+    a1, a2, a3, a4 = (
+        size_info2.raw_symbols.Filter(lambda s: s.num_aliases == 4)[0].aliases)
+    size_info2.raw_symbols -= [a1, a2, a3, a4]
     d = diff.Diff(size_info1, size_info2)
-    self.assertEquals((0, 0, 3), _DiffCounts(d.raw_symbols))
+    self.assertEquals((0, 0, 4), _DiffCounts(d.raw_symbols))
     self.assertEquals((1, 0, 2), _DiffCounts(d.symbols.GroupedByFullName()))
 
-    # Adding all 3 aliases should change size.
+    # Adding all 4 aliases should change size.
     d = diff.Diff(size_info2, size_info1)
     self.assertEquals(d.raw_symbols.pss, a1.size)
-    self.assertEquals((0, 3, 0), _DiffCounts(d.raw_symbols))
+    self.assertEquals((0, 4, 0), _DiffCounts(d.raw_symbols))
     self.assertEquals((1, 2, 0), _DiffCounts(d.symbols.GroupedByFullName()))
 
   def test_Diff_Clustering(self):

tools/binary_size/libsupersize/nm.py

@@ -31,6 +31,7 @@ BulkObjectFileAnalyzer:
   alias for _BulkObjectFileAnalyzerWorker.
   * AnalyzePaths: Run "nm" on all .o files to collect symbol names that exist
     within each.
+  * SortPaths: Sort results of AnalyzePaths().
   * AnalyzeStringLiterals: Must be run after AnalyzePaths() has completed.
     Extracts string literals from .o files, and then locates them within the
     "** merge strings" sections within an ELF's .rodata section.
@@ -58,9 +59,10 @@ import threading
 import concurrent
 
 _MSG_ANALYZE_PATHS = 1
-_MSG_ANALYZE_STRINGS = 2
-_MSG_GET_SYMBOL_NAMES = 3
-_MSG_GET_STRINGS = 4
+_MSG_SORT_PATHS = 2
+_MSG_ANALYZE_STRINGS = 3
+_MSG_GET_SYMBOL_NAMES = 4
+_MSG_GET_STRINGS = 5
 
 _active_pids = None
 
@@ -128,7 +130,8 @@ def _IsRelevantObjectFileName(name):
 
 def CollectAliasesByAddress(elf_path, tool_prefix):
   """Runs nm on |elf_path| and returns a dict of address->[names]"""
-  names_by_address = collections.defaultdict(list)
+  # Constructors often show up twice, so use sets to ensure no duplicates.
+  names_by_address = collections.defaultdict(set)
 
   # About 60mb of output, but piping takes ~30s, and loading it into RAM
   # directly takes 3s.
@@ -151,17 +154,12 @@ def CollectAliasesByAddress(elf_path, tool_prefix):
     address = int(address_str, 16)
     if not address:
       continue
-    # Constructors often show up twice.
-    name_list = names_by_address[address]
-    if name not in name_list:
-      name_list.append(name)
+    names_by_address[address].add(name)
 
   # Since this is run in a separate process, minimize data passing by returning
   # only aliased symbols.
-  names_by_address = {k: v for k, v in names_by_address.iteritems()
-                      if len(v) > 1}
-
-  return names_by_address
+  # Also: Sort to ensure stable ordering.
+  return {k: sorted(v) for k, v in names_by_address.iteritems() if len(v) > 1}
 
 
 def _CollectAliasesByAddressAsyncHelper(elf_path, tool_prefix):
@@ -350,9 +348,17 @@ def _ExtractArchivePath(path):
   return None
 
 
-def _IterStringLiterals(path, addresses, string_sections_by_path):
+def _IterStringLiterals(path, addresses, obj_sections):
+  """Yields all string literals (including \0) for the given object path.
+
+  Args:
+    path: Object file path.
+    addresses: List of string offsets encoded as hex strings.
+    obj_sections: List of contents of .rodata.str sections read from the given
+        object file.
+  """
+
   next_offsets = sorted(int(a, 16) for a in addresses)
-  obj_sections = string_sections_by_path.get(path)
   if not obj_sections:
     # Happens when there is an address for a symbol which is not actually a
     # string literal, or when string_sections_by_path is missing an entry.
@@ -410,7 +416,7 @@ def _ResolveStringPieces(encoded_string_addresses_by_path, string_data,
   #     least for ascii strings).
   for path, object_addresses in string_addresses_by_path.iteritems():
     for value in _IterStringLiterals(
-        path, object_addresses, string_sections_by_path):
+        path, object_addresses, string_sections_by_path.get(path)):
       first_match = -1
       first_match_dict = None
       for target_dict, data in itertools.izip(ret, string_data):
@@ -530,6 +536,10 @@ class _BulkObjectFileAnalyzerWorker(object):
         self._encoded_string_addresses_by_path_chunks.append(encoded_strs)
     logging.debug('worker: AnalyzePaths() completed.')
 
+  def SortPaths(self):
+    for paths in self._paths_by_name.itervalues():
+      paths.sort()
+
   def AnalyzeStringLiterals(self, elf_path, elf_string_positions):
     logging.debug('worker: AnalyzeStringLiterals() started.')
     # Read string_data from elf_path, to be shared by forked processes.
@@ -612,6 +622,9 @@ class _BulkObjectFileAnalyzerMaster(object):
     payload = '\x01'.join(paths)
     self._pipe.send((_MSG_ANALYZE_PATHS, payload))
 
+  def SortPaths(self):
+    self._pipe.send((_MSG_SORT_PATHS,))
+
   def AnalyzeStringLiterals(self, elf_path, string_positions):
     self._pipe.send((_MSG_ANALYZE_STRINGS, elf_path, string_positions))
 
@@ -669,6 +682,10 @@ class _BulkObjectFileAnalyzerSlave(object):
               'Cannot call AnalyzePaths() after AnalyzeStringLiterals()s.')
           paths = message[1].split('\x01')
           self._job_queue.put(lambda: self._worker_analyzer.AnalyzePaths(paths))
+        elif message[0] == _MSG_SORT_PATHS:
+          assert self._allow_analyze_paths, (
+              'Cannot call SortPaths() after AnalyzeStringLiterals()s.')
+          self._job_queue.put(self._worker_analyzer.SortPaths)
         elif message[0] == _MSG_ANALYZE_STRINGS:
           self._WaitForAnalyzePathJobs()
           elf_path, string_positions = message[1:]
@@ -726,6 +743,7 @@ def main():
   # Pass individually to test multiple calls.
   for path in args.objects:
     bulk_analyzer.AnalyzePaths([path])
+  bulk_analyzer.SortPaths()
 
   names_to_paths = bulk_analyzer.GetSymbolNames()
   print('Found {} names'.format(len(names_to_paths)))

tools/binary_size/libsupersize/testdata/Archive_Elf.golden

@@ -6,11 +6,11 @@ git_revision=abc123
 gn_args=var1=true var2="foo"
 map_file_name=../test.map
 tool_prefix=tools/binary_size/libsupersize/testdata/mock_toolchain/
-Section .text: has 100.0% of 35900712 bytes accounted for from 18 symbols. 0 bytes are unaccounted for.
+Section .text: has 100.0% of 35900712 bytes accounted for from 19 symbols. 0 bytes are unaccounted for.
 * Padding accounts for 48 bytes (0.0%)
 * 3 placeholders (symbols that start with **) account for 35830760 bytes (99.8%)
-* Contains 5 aliases, mapped to 2 unique addresses (60 bytes)
-* 1 symbols have shared ownership (12 bytes)
+* Contains 6 aliases, mapped to 2 unique addresses (60 bytes)
+* 0 symbols have shared ownership
 Section .rodata: has 100.0% of 5927652 bytes accounted for from 12 symbols. 0 bytes are unaccounted for.
 * Padding accounts for 675996 bytes (11.4%)
 * 4 placeholders (symbols that start with **) account for 5251503 bytes (88.6%)
@@ -42,9 +42,10 @@ Section .bss: has 40.3% of 524520 bytes accounted for from 6 symbols. 775936 byt
 .text@28f1e0(size_without_padding=69120,padding=4,full_name=foo_bar,object_path=third_party/icu/icuuc/ucnv_ext.o,source_path=third_party/icu/ucnv_ext.c,flags={unlikely,gen},num_aliases=1)
 .text@2a0000(size_without_padding=16,padding=32,full_name=blink::ContiguousContainerBase::shrinkToFit(),object_path=,source_path=,flags={},num_aliases=2)
 .text@2a0000(size_without_padding=16,padding=32,full_name=BazAlias(bool),object_path=third_party/icu/icuuc/ucnv_ext.o,source_path=third_party/icu/ucnv_ext.c,flags={gen},num_aliases=2)
-.text@2a0010(size_without_padding=12,padding=0,full_name=blink::ContiguousContainerBase::shrinkToFit(),object_path=third_party/{shared}/2,source_path=third_party/{shared}/2,flags={clone},num_aliases=3)
-.text@2a0010(size_without_padding=12,padding=0,full_name=FooAlias(),object_path=third_party/ffmpeg/libffmpeg_internal.a/fft_float.o,source_path=third_party/fft_float.cc,flags={},num_aliases=3)
-.text@2a0010(size_without_padding=12,padding=0,full_name=BarAlias(),object_path=third_party/ffmpeg/libffmpeg_internal.a/fft_float.o,source_path=third_party/fft_float.cc,flags={},num_aliases=3)
+.text@2a0010(size_without_padding=12,padding=0,full_name=blink::ContiguousContainerBase::shrinkToFit(),object_path=third_party/WebKit.a/PaintChunker.o,source_path=third_party/paint.cc,flags={clone},num_aliases=4)
+.text@2a0010(size_without_padding=12,padding=0,full_name=blink::ContiguousContainerBase::shrinkToFit(),object_path=third_party/icu/icuuc/ucnv_ext.o,source_path=third_party/icu/ucnv_ext.c,flags={gen,clone},num_aliases=4)
+.text@2a0010(size_without_padding=12,padding=0,full_name=FooAlias(),object_path=third_party/ffmpeg/libffmpeg_internal.a/fft_float.o,source_path=third_party/fft_float.cc,flags={},num_aliases=4)
+.text@2a0010(size_without_padding=12,padding=0,full_name=BarAlias(),object_path=third_party/ffmpeg/libffmpeg_internal.a/fft_float.o,source_path=third_party/fft_float.cc,flags={},num_aliases=4)
 .text@2a0020(size_without_padding=24,padding=4,full_name=blink::ContiguousContainerBase::ContiguousContainerBase(blink::ContiguousContainerBase&&),object_path=third_party/WebKit.a/ContiguousContainer.o,source_path=third_party/container.c,flags={},num_aliases=1)
 .text@2a1000(size_without_padding=0,padding=4040,full_name=** symbol gap 1,object_path=,source_path=,flags={},num_aliases=1)
 .text@2a1000(size_without_padding=94,padding=0,full_name=blink::PaintChunker::releasePaintChunks(),object_path=third_party/WebKit.a/ContiguousContainer.o,source_path=third_party/container.c,flags={anon,clone},num_aliases=1)

tools/binary_size/libsupersize/testdata/Console.golden

@@ -79,10 +79,10 @@ Section Sizes (Total=95.6mb (100233874 bytes)):
     .symtab: 16.4mb (17166112 bytes) (17.1%)
     .text: 34.2mb (35900712 bytes) (35.8%)
 
-Showing 47 symbols (44 unique) with total pss: 43785380 bytes
+Showing 48 symbols (44 unique) with total pss: 43785380 bytes
 Histogram of symbols based on PSS:
-     [2,4): 1    [16,32): 10        [128,256): 2    [131072,262144): 2     [1048576,2097152): 2
-     [4,8): 9    [32,64): 9         [256,512): 1    [262144,524288): 1     [2097152,4194304): 1
+     [2,4): 5    [16,32): 10        [128,256): 2    [131072,262144): 2     [1048576,2097152): 2
+     [4,8): 6    [32,64): 9         [256,512): 1    [262144,524288): 1     [2097152,4194304): 1
     [8,16): 3   [64,128): 1    [65536,131072): 2   [524288,1048576): 2   [33554432,67108864): 1
 .text=34.2mb     .rodata=5.65mb     .data.rel.ro=1.02mb     .data=99.4kb     .bss=512kb      total=41.8mb
 Number of unique paths: 9
@@ -112,74 +112,76 @@ Index | Running Total | Section@Address | PSS | Path
              blink::ContiguousContainerBase::shrinkToFit (num_aliases=2)
 10)  35900578 (82.0%) t@0x2a0000   24 (size=48)   third_party/icu/ucnv_ext.c
              BazAlias (num_aliases=2)
-11)  35900582 (82.0%) t@0x2a0010   4 (size=12)    third_party/{shared}/2
-             blink::ContiguousContainerBase::shrinkToFit (num_aliases=3)
-12)  35900586 (82.0%) t@0x2a0010   4 (size=12)    third_party/fft_float.cc
-             FooAlias (num_aliases=3)
-13)  35900590 (82.0%) t@0x2a0010   4 (size=12)    third_party/fft_float.cc
-             BarAlias (num_aliases=3)
-14)  35900618 (82.0%) t@0x2a0020   28             third_party/container.c
+11)  35900581 (82.0%) t@0x2a0010   3 (size=12)    third_party/paint.cc
+             blink::ContiguousContainerBase::shrinkToFit (num_aliases=4)
+12)  35900584 (82.0%) t@0x2a0010   3 (size=12)    third_party/icu/ucnv_ext.c
+             blink::ContiguousContainerBase::shrinkToFit (num_aliases=4)
+13)  35900587 (82.0%) t@0x2a0010   3 (size=12)    third_party/fft_float.cc
+             FooAlias (num_aliases=4)
+14)  35900590 (82.0%) t@0x2a0010   3 (size=12)    third_party/fft_float.cc
+             BarAlias (num_aliases=4)
+15)  35900618 (82.0%) t@0x2a0020   28             third_party/container.c
              blink::ContiguousContainerBase::ContiguousContainerBase
-15)  35900712 (82.0%) t@0x2a1000   94             third_party/container.c
+16)  35900712 (82.0%) t@0x2a1000   94             third_party/container.c
              blink::PaintChunker::releasePaintChunks
-16)  35900714 (82.0%) r@0x266e600  2.5 (size=5)   base/page_allocator.cc
+17)  35900714 (82.0%) r@0x266e600  2.5 (size=5)   base/page_allocator.cc
              string literal 0 (num_aliases=2)
-17)  35900733 (82.0%) r@Group      18             third_party/icu/ucnv_ext.c
+18)  35900733 (82.0%) r@Group      18             third_party/icu/ucnv_ext.c
              string literal 0 (count=2)
-18)  35900776 (82.0%) r@0x266e630  43             {no path}
+19)  35900776 (82.0%) r@0x266e630  43             {no path}
              ** merge strings
-19)  37866121 (86.5%) r@0x284d600  1965345        {no path}
+20)  37866121 (86.5%) r@0x284d600  1965345        {no path}
              ** merge constants
-20)  41152236 (94.0%) r@Group      3286115        {no path}
+21)  41152236 (94.0%) r@Group      3286115        {no path}
              ** symbol gaps (count=2)
-21)  41152244 (94.0%) r@0x284e364  8              base/page_allocator.cc
-22)  41152288 (94.0%) r@0x284e370  44             base/page_allocator.cc
+22)  41152244 (94.0%) r@0x284e364  8              base/page_allocator.cc
+23)  41152288 (94.0%) r@0x284e370  44             base/page_allocator.cc
              Name
-23)  41152320 (94.0%) r@0x284e398  32             third_party/container.c
+24)  41152320 (94.0%) r@0x284e398  32             third_party/container.c
              chrome::mojom::FilePatcher::Name_
-24)  41828360 (95.5%) r@0x28f3450  676040         third_party/paint.cc
+25)  41828360 (95.5%) r@0x28f3450  676040         third_party/paint.cc
              kAnimationFrameTimeHistogramClassPath
-25)  41828364 (95.5%) r@0x28f3480  4              third_party/paint.cc
+26)  41828364 (95.5%) r@0x28f3480  4              third_party/paint.cc
              blink::CSSValueKeywordsHash::findValueImpl::value_word_list
-26)  41828420 (95.5%) R@0x2c176f0  56             third_party/icu/ucnv_ext.c
+27)  41828420 (95.5%) R@0x2c176f0  56             third_party/icu/ucnv_ext.c
              ChromeMainDelegate [vtable]
-27)  41828444 (95.5%) R@0x2c17728  24             third_party/icu/ucnv_ext.c
+28)  41828444 (95.5%) R@0x2c17728  24             third_party/icu/ucnv_ext.c
              chrome::mojom::FieldTrialRecorder [vtable]
-28)  42618348 (97.3%) R@0x2c17740  789904         third_party/container.c
+29)  42618348 (97.3%) R@0x2c17740  789904         third_party/container.c
              chrome::mojom::FieldTrialRecorderProxy [vtable]
-29)  42618380 (97.3%) R@0x2cd84e0  32             third_party/gvr-android-sdk/libgvr_shim_static_arm.a/libcontroller_api_impl.a_controller_api_impl.o
+30)  42618380 (97.3%) R@0x2cd84e0  32             third_party/gvr-android-sdk/libgvr_shim_static_arm.a/libcontroller_api_impl.a_controller_api_impl.o
              .Lswitch.table.45
-30)  42618388 (97.3%) R@0x2cd84f0  8              third_party/gvr-android-sdk/libgvr_shim_static_arm.a/libport_android_jni.a_jni_utils.o
+31)  42618388 (97.3%) R@0x2cd84f0  8              third_party/gvr-android-sdk/libgvr_shim_static_arm.a/libport_android_jni.a_jni_utils.o
              kSystemClassPrefixes
-31)  42618444 (97.3%) R@0x2cd8500  56             third_party/paint.cc
+32)  42618444 (97.3%) R@0x2cd8500  56             third_party/paint.cc
              ChromeMainDelegateAndroid [vtable]
-32)  42618468 (97.3%) R@0x2cd8538  24             base/page_allocator.cc
+33)  42618468 (97.3%) R@0x2cd8538  24             base/page_allocator.cc
              mojo::MessageReceiver [vtable]
-33)  42618480 (97.3%) R@0x2cd8550  12             base/page_allocator.cc
+34)  42618480 (97.3%) R@0x2cd8550  12             base/page_allocator.cc
              kMethodsAnimationFrameTimeHistogram
-34)  43683612 (99.8%) R@0x2ddc608  1065132        {no path}
+35)  43683612 (99.8%) R@0x2ddc608  1065132        {no path}
              ** symbol gap 0 (end of section)
-35)  43683616 (99.8%) d@0x2de7000  4              base/page_allocator.cc
+36)  43683616 (99.8%) d@0x2de7000  4              base/page_allocator.cc
              google::protobuf::internal::pLinuxKernelCmpxchg
-36)  43683620 (99.8%) d@0x2de7004  4              third_party/container.c
+37)  43683620 (99.8%) d@0x2de7004  4              third_party/container.c
              google::protobuf::internal::pLinuxKernelMemoryBarrier
-37)  43683772 (99.8%) d@0x2de7008  152            third_party/container.c
+38)  43683772 (99.8%) d@0x2de7008  152            third_party/container.c
              base::android::kBaseRegisteredMethods
-38)  43683776 (99.8%) d@0x2de70a0  4              third_party/container.c
+39)  43683776 (99.8%) d@0x2de70a0  4              third_party/container.c
              base::android::g_renderer_histogram_code
-39)  43683780 (99.8%) d@0x2de70a4  4              third_party/container.c
+40)  43683780 (99.8%) d@0x2de70a4  4              third_party/container.c
              base::android::g_library_version_number
-40)  43785380 (100.0%) d@0x2dffd88  101600         {no path}
+41)  43785380 (100.0%) d@0x2dffd88  101600         {no path}
              ** symbol gap 0 (end of section)
-41)  43785380 (100.0%) b@0x0        262144         third_party/fft_float.cc
+42)  43785380 (100.0%) b@0x0        262144         third_party/fft_float.cc
              ff_cos_131072
-42)  43785380 (100.0%) b@0x0        131072         third_party/fft_fixed.cc
+43)  43785380 (100.0%) b@0x0        131072         third_party/fft_fixed.cc
              ff_cos_131072_fixed
-43)  43785380 (100.0%) b@0x0        131072         third_party/fft_float.cc
+44)  43785380 (100.0%) b@0x0        131072         third_party/fft_float.cc
              ff_cos_65536
-44)  43785380 (100.0%) b@0x2dffda0  28             third_party/icu/ucnv_ext.c
+45)  43785380 (100.0%) b@0x2dffda0  28             third_party/icu/ucnv_ext.c
              g_chrome_content_browser_client
-45)  43785380 (100.0%) b@0x2dffe80  200            third_party/icu/ucnv_ext.c
+46)  43785380 (100.0%) b@0x2dffe80  200            third_party/icu/ucnv_ext.c
              SaveHistogram::atomic_histogram_pointer
-46)  43785380 (100.0%) b@0x2dffe84  4              third_party/icu/ucnv_ext.c
+47)  43785380 (100.0%) b@0x2dffe84  4              third_party/icu/ucnv_ext.c
              g_AnimationFrameTimeHistogram_clazz

tools/binary_size/libsupersize/testdata/Csv.golden

@@ -21,9 +21,10 @@ GroupCount,Address,SizeWithoutPadding,Padding,NumAliases,PSS,Section,Name
 ,0x28f1e0,69120,4,1,69124.0,t,foo_bar
 ,0x2a0000,16,32,2,24.0,t,blink::ContiguousContainerBase::shrinkToFit
 ,0x2a0000,16,32,2,24.0,t,BazAlias
-,0x2a0010,12,0,3,4.0,t,blink::ContiguousContainerBase::shrinkToFit
-,0x2a0010,12,0,3,4.0,t,FooAlias
-,0x2a0010,12,0,3,4.0,t,BarAlias
+,0x2a0010,12,0,4,3.0,t,blink::ContiguousContainerBase::shrinkToFit
+,0x2a0010,12,0,4,3.0,t,blink::ContiguousContainerBase::shrinkToFit
+,0x2a0010,12,0,4,3.0,t,FooAlias
+,0x2a0010,12,0,4,3.0,t,BarAlias
 ,0x2a0020,24,4,1,28.0,t,blink::ContiguousContainerBase::ContiguousContainerBase
 ,0x2a1000,94,0,1,94.0,t,blink::PaintChunker::releasePaintChunks
 ,0x266e600,5,0,2,2.5,r,string literal 0

tools/binary_size/libsupersize/testdata/Diff_NullDiff.golden

@@ -18,14 +18,14 @@ Section Sizes (Total=0 bytes (0 bytes)):
     .rodata: 0 bytes (0 bytes) (0.0%)
     .text: 0 bytes (0 bytes) (0.0%)
 
-0 symbols added (+), 0 changed (~), 0 removed (-), 47 unchanged (not shown)
+0 symbols added (+), 0 changed (~), 0 removed (-), 48 unchanged (not shown)
 Of changed symbols, 0 grew, 0 shrank
 Number of unique symbols 47 -> 47 (+0)
 0 paths added, 0 removed, 0 changed
 
 Showing 0 symbols (aliases not grouped for diffs) with total pss: 0 bytes
 Histogram of symbols based on PSS:
-    {0}: 47
+    {0}: 48
 .text=0 bytes    .rodata=0 bytes    .data.rel.ro=0 bytes    .data=0 bytes    .bss=0 bytes    total=0 bytes
 Number of unique paths: 0
 

tools/binary_size/libsupersize/testdata/SymbolGroupMethods.golden

 GroupedByName()
 Showing 42 symbols (42 unique) with total pss: 43785380 bytes
 Histogram of symbols based on PSS:
-      {0}: 6    [8,16): 3    [32,64): 7   [128,256): 1     [65536,131072): 1     [1048576,2097152): 2
-    [4,8): 7   [16,32): 9   [64,128): 2   [256,512): 1   [524288,1048576): 2   [33554432,67108864): 1
+      {0}: 6    [8,16): 3    [64,128): 2      [65536,131072): 1   [33554432,67108864): 1
+    [2,4): 2   [16,32): 9   [128,256): 1    [524288,1048576): 2
+    [4,8): 5   [32,64): 7   [256,512): 1   [1048576,2097152): 2
 .text=34.2mb     .rodata=5.65mb     .data.rel.ro=1.02mb     .data=99.4kb     .bss=512kb      total=41.8mb
 Number of unique paths: 9
 
@@ -17,10 +18,10 @@ Index | Running Total | Section@Address | PSS | Path
 5)   39117493 (89.3%) *@Group      448             ucnv_extMatchFromU (count=1)
 6)   39117521 (89.3%) *@Group      28              _GLOBAL__sub_I_SkDeviceProfile.cpp (count=1)
 7)   39186645 (89.5%) *@Group      69124           foo_bar (count=1)
-8)   39186673 (89.5%) *@Group      28              blink::ContiguousContainerBase::shrinkToFit (count=2)
-9)   39186697 (89.5%) *@Group      24              BazAlias (count=1)
-10)  39186701 (89.5%) *@Group      4               FooAlias (count=1)
-11)  39186705 (89.5%) *@Group      4               BarAlias (count=1)
+8)   39186675 (89.5%) *@Group      30              blink::ContiguousContainerBase::shrinkToFit (count=3)
+9)   39186699 (89.5%) *@Group      24              BazAlias (count=1)
+10)  39186702 (89.5%) *@Group      3               FooAlias (count=1)
+11)  39186705 (89.5%) *@Group      3               BarAlias (count=1)
 12)  39186733 (89.5%) *@Group      28              blink::ContiguousContainerBase::ContiguousContainerBase (count=1)
 13)  39186827 (89.5%) *@Group      94              blink::PaintChunker::releasePaintChunks (count=1)
 14)  39186848 (89.5%) *@Group      21              string literal 0 (count=2)
@@ -55,7 +56,7 @@ GroupedByName(depth=1)
 Showing 34 symbols (34 unique) with total pss: 43785380 bytes
 Histogram of symbols based on PSS:
       {0}: 6    [8,16): 4    [32,64): 6   [128,256): 2     [65536,131072): 1     [1048576,2097152): 2
-    [4,8): 2   [16,32): 6   [64,128): 1   [256,512): 1   [524288,1048576): 2   [33554432,67108864): 1
+    [2,4): 2   [16,32): 6   [64,128): 1   [256,512): 1   [524288,1048576): 2   [33554432,67108864): 1
 .text=34.2mb     .rodata=5.65mb     .data.rel.ro=1.02mb     .data=99.4kb     .bss=512kb      total=41.8mb
 Number of unique paths: 9
 
@@ -70,10 +71,10 @@ Index | Running Total | Section@Address | PSS | Path
 5)   39117493 (89.3%) *@Group      448             ucnv_extMatchFromU (count=1)
 6)   39117521 (89.3%) *@Group      28              _GLOBAL__sub_I_SkDeviceProfile.cpp (count=1)
 7)   39186645 (89.5%) *@Group      69124           foo_bar (count=1)
-8)   39186799 (89.5%) *@Group      154             blink (count=5)
-9)   39186823 (89.5%) *@Group      24              BazAlias (count=1)
-10)  39186827 (89.5%) *@Group      4               FooAlias (count=1)
-11)  39186831 (89.5%) *@Group      4               BarAlias (count=1)
+8)   39186801 (89.5%) *@Group      156             blink (count=6)
+9)   39186825 (89.5%) *@Group      24              BazAlias (count=1)
+10)  39186828 (89.5%) *@Group      3               FooAlias (count=1)
+11)  39186831 (89.5%) *@Group      3               BarAlias (count=1)
 12)  39186852 (89.5%) *@Group      21              string literal 0 (count=2)
 13)  39186895 (89.5%) *@Group      43              ** merge strings (count=1)
 14)  41152240 (94.0%) *@Group      1965345         ** merge constants (count=1)
@@ -99,8 +100,9 @@ Index | Running Total | Section@Address | PSS | Path
 GroupedByName(depth=-1)
 Showing 37 symbols (37 unique) with total pss: 43785380 bytes
 Histogram of symbols based on PSS:
-      {0}: 6    [8,16): 4    [32,64): 8   [128,256): 1     [65536,131072): 1     [1048576,2097152): 2
-    [4,8): 3   [16,32): 6   [64,128): 2   [256,512): 1   [524288,1048576): 2   [33554432,67108864): 1
+      {0}: 6    [8,16): 4    [64,128): 2      [65536,131072): 1   [33554432,67108864): 1
+    [2,4): 2   [16,32): 6   [128,256): 1    [524288,1048576): 2
+    [4,8): 1   [32,64): 8   [256,512): 1   [1048576,2097152): 2
 .text=34.2mb     .rodata=5.65mb     .data.rel.ro=1.02mb     .data=99.4kb     .bss=512kb      total=41.8mb
 Number of unique paths: 9
 
@@ -115,10 +117,10 @@ Index | Running Total | Section@Address | PSS | Path
 5)   39117493 (89.3%) *@Group      448             ucnv_extMatchFromU (count=1)
 6)   39117521 (89.3%) *@Group      28              _GLOBAL__sub_I_SkDeviceProfile.cpp (count=1)
 7)   39186645 (89.5%) *@Group      69124           foo_bar (count=1)
-8)   39186701 (89.5%) *@Group      56              blink::ContiguousContainerBase (count=3)
-9)   39186725 (89.5%) *@Group      24              BazAlias (count=1)
-10)  39186729 (89.5%) *@Group      4               FooAlias (count=1)
-11)  39186733 (89.5%) *@Group      4               BarAlias (count=1)
+8)   39186703 (89.5%) *@Group      58              blink::ContiguousContainerBase (count=4)
+9)   39186727 (89.5%) *@Group      24              BazAlias (count=1)
+10)  39186730 (89.5%) *@Group      3               FooAlias (count=1)
+11)  39186733 (89.5%) *@Group      3               BarAlias (count=1)
 12)  39186827 (89.5%) *@Group      94              blink::PaintChunker (count=1)
 13)  39186848 (89.5%) *@Group      21              string literal 0 (count=2)
 14)  39186891 (89.5%) *@Group      43              ** merge strings (count=1)
@@ -147,9 +149,9 @@ Index | Running Total | Section@Address | PSS | Path
 GroupedByName(depth=1, min_count=2)
 Showing 34 symbols (33 unique) with total pss: 43785380 bytes
 Histogram of symbols based on PSS:
-      [4,8): 3     [32,64): 6         [256,512): 1     [262144,524288): 1   [33554432,67108864): 1
-     [8,16): 4    [64,128): 1    [65536,131072): 1    [524288,1048576): 2
-    [16,32): 7   [128,256): 3   [131072,262144): 2   [1048576,2097152): 2
+     [2,4): 2    [16,32): 7        [128,256): 3    [131072,262144): 2     [1048576,2097152): 2
+     [4,8): 1    [32,64): 6        [256,512): 1    [262144,524288): 1   [33554432,67108864): 1
+    [8,16): 4   [64,128): 1   [65536,131072): 1   [524288,1048576): 2
 .text=34.2mb     .rodata=5.65mb     .data.rel.ro=1.02mb     .data=99.4kb     .bss=512kb      total=41.8mb
 Number of unique paths: 9
 
@@ -172,14 +174,14 @@ Index | Running Total | Section@Address | PSS | Path
              _GLOBAL__sub_I_SkDeviceProfile.cpp
 7)   39186645 (89.5%) t@0x28f1e0   69124          third_party/icu/ucnv_ext.c
              foo_bar
-8)   39186799 (89.5%) *@Group      154            {no path}
-             blink (count=5)
-9)   39186823 (89.5%) t@0x2a0000   24 (size=48)   third_party/icu/ucnv_ext.c
+8)   39186801 (89.5%) *@Group      156            {no path}
+             blink (count=6)
+9)   39186825 (89.5%) t@0x2a0000   24 (size=48)   third_party/icu/ucnv_ext.c
              BazAlias (num_aliases=2)
-10)  39186827 (89.5%) t@0x2a0010   4 (size=12)    third_party/fft_float.cc
-             FooAlias (num_aliases=3)
-11)  39186831 (89.5%) t@0x2a0010   4 (size=12)    third_party/fft_float.cc
-             BarAlias (num_aliases=3)
+10)  39186828 (89.5%) t@0x2a0010   3 (size=12)    third_party/fft_float.cc
+             FooAlias (num_aliases=4)
+11)  39186831 (89.5%) t@0x2a0010   3 (size=12)    third_party/fft_float.cc
+             BarAlias (num_aliases=4)
 12)  39186852 (89.5%) *@Group      21             {no path}
              string literal 0 (count=2)
 13)  39186895 (89.5%) r@0x266e630  43             {no path}

tools/binary_size/libsupersize/testdata/mock_toolchain/mock_nm.py

@@ -64,7 +64,6 @@ _OBJECT_OUTPUTS = {
         '01010101 t _GLOBAL__sub_I_page_allocator.cc',
         '01010101 t _GLOBAL__sub_I_bbr_sender.cc',
         '01010101 t _GLOBAL__sub_I_pacing_sender.cc',
-        '01010101 t _GLOBAL__sub_I_bbr_sender.cc',
         '00000000 r .L.str',
         '01010101 t extFromUUseMapping(aj, int)',
         '01010101 t extFromUUseMapping(signed char, unsigned int, int)',