Adding upstream version 115.7.0esr.upstream/115.7.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 290 insertions, 0 deletions

diff --git a/third_party/libwebrtc/build/toolchain/win/ml.py b/third_party/libwebrtc/build/toolchain/win/ml.py
new file mode 100755
index 0000000000..6a1b6e577e
--- /dev/null
+++ b/third_party/libwebrtc/build/toolchain/win/ml.py
@@ -0,0 +1,290 @@
+#!/usr/bin/env python
+# Copyright 2018 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.
+
+"""Wraps ml.exe or ml64.exe and postprocesses the output to be deterministic.
+Sets timestamp in .obj file to 0, hence incompatible with link.exe /incremental.
+
+Use by prefixing the ml(64).exe invocation with this script:
+    python ml.py ml.exe [args...]"""
+
+import array
+import collections
+import struct
+import subprocess
+import sys
+
+
+class Struct(object):
+  """A thin wrapper around the struct module that returns a namedtuple"""
+  def __init__(self, name, *args):
+    """Pass the name of the return type, and then an interleaved list of
+    format strings as used by the struct module and of field names."""
+    self.fmt = '<' + ''.join(args[0::2])
+    self.type = collections.namedtuple(name, args[1::2])
+
+  def pack_into(self, buffer, offset, data):
+    return struct.pack_into(self.fmt, buffer, offset, *data)
+
+  def unpack_from(self, buffer, offset=0):
+    return self.type(*struct.unpack_from(self.fmt, buffer, offset))
+
+  def size(self):
+    return struct.calcsize(self.fmt)
+
+
+def Subtract(nt, **kwargs):
+  """Subtract(nt, f=2) returns a new namedtuple with 2 subtracted from nt.f"""
+  return nt._replace(**{k: getattr(nt, k) - v for k, v in kwargs.items()})
+
+
+def MakeDeterministic(objdata):
+  # Takes data produced by ml(64).exe (without any special flags) and
+  # 1. Sets the timestamp to 0
+  # 2. Strips the .debug$S section (which contains an unwanted absolute path)
+
+  # This makes several assumptions about ml's output:
+  # - Section data is in the same order as the corresponding section headers:
+  #   section headers preceding the .debug$S section header have their data
+  #   preceding the .debug$S section data; likewise for section headers
+  #   following the .debug$S section.
+  # - The .debug$S section contains only the absolute path to the obj file and
+  #   nothing else, in particular there's only a single entry in the symbol
+  #   table referring to the .debug$S section.
+  # - There are no COFF line number entries.
+  # - There's no IMAGE_SYM_CLASS_CLR_TOKEN symbol.
+  # These seem to hold in practice; if they stop holding this script needs to
+  # become smarter.
+
+  objdata = array.array('b', objdata)  # Writable, e.g. via struct.pack_into.
+
+  # Read coff header.
+  COFFHEADER = Struct('COFFHEADER',
+                      'H', 'Machine',
+                      'H', 'NumberOfSections',
+                      'I', 'TimeDateStamp',
+                      'I', 'PointerToSymbolTable',
+                      'I', 'NumberOfSymbols',
+
+                      'H', 'SizeOfOptionalHeader',
+                      'H', 'Characteristics')
+  coff_header = COFFHEADER.unpack_from(objdata)
+  assert coff_header.SizeOfOptionalHeader == 0  # Only set for binaries.
+
+  # Read section headers following coff header.
+  SECTIONHEADER = Struct('SECTIONHEADER',
+                         '8s', 'Name',
+                         'I', 'VirtualSize',
+                         'I', 'VirtualAddress',
+
+                         'I', 'SizeOfRawData',
+                         'I', 'PointerToRawData',
+                         'I', 'PointerToRelocations',
+                         'I', 'PointerToLineNumbers',
+
+                         'H', 'NumberOfRelocations',
+                         'H', 'NumberOfLineNumbers',
+                         'I', 'Characteristics')
+  section_headers = []
+  debug_section_index = -1
+  for i in range(0, coff_header.NumberOfSections):
+    section_header = SECTIONHEADER.unpack_from(
+        objdata, offset=COFFHEADER.size() + i * SECTIONHEADER.size())
+    assert not section_header[0].startswith(b'/')  # Support short names only.
+    section_headers.append(section_header)
+
+    if section_header.Name == b'.debug$S':
+      assert debug_section_index == -1
+      debug_section_index = i
+  assert debug_section_index != -1
+
+  data_start = COFFHEADER.size() + len(section_headers) * SECTIONHEADER.size()
+
+  # Verify the .debug$S section looks like we expect.
+  assert section_headers[debug_section_index].Name == b'.debug$S'
+  assert section_headers[debug_section_index].VirtualSize == 0
+  assert section_headers[debug_section_index].VirtualAddress == 0
+  debug_size = section_headers[debug_section_index].SizeOfRawData
+  debug_offset = section_headers[debug_section_index].PointerToRawData
+  assert section_headers[debug_section_index].PointerToRelocations == 0
+  assert section_headers[debug_section_index].PointerToLineNumbers == 0
+  assert section_headers[debug_section_index].NumberOfRelocations == 0
+  assert section_headers[debug_section_index].NumberOfLineNumbers == 0
+
+  # Make sure sections in front of .debug$S have their data preceding it.
+  for header in section_headers[:debug_section_index]:
+    assert header.PointerToRawData < debug_offset
+    assert header.PointerToRelocations < debug_offset
+    assert header.PointerToLineNumbers < debug_offset
+
+  # Make sure sections after of .debug$S have their data following it.
+  for header in section_headers[debug_section_index + 1:]:
+    # Make sure the .debug$S data is at the very end of section data:
+    assert header.PointerToRawData > debug_offset
+    assert header.PointerToRelocations == 0
+    assert header.PointerToLineNumbers == 0
+
+  # Make sure the first non-empty section's data starts right after the section
+  # headers.
+  for section_header in section_headers:
+    if section_header.PointerToRawData == 0:
+      assert section_header.PointerToRelocations == 0
+      assert section_header.PointerToLineNumbers == 0
+      continue
+    assert section_header.PointerToRawData == data_start
+    break
+
+  # Make sure the symbol table (and hence, string table) appear after the last
+  # section:
+  assert (coff_header.PointerToSymbolTable >=
+      section_headers[-1].PointerToRawData + section_headers[-1].SizeOfRawData)
+
+  # The symbol table contains a symbol for the no-longer-present .debug$S
+  # section. If we leave it there, lld-link will complain:
+  #
+  #    lld-link: error: .debug$S should not refer to non-existent section 5
+  #
+  # so we need to remove that symbol table entry as well. This shifts symbol
+  # entries around and we need to update symbol table indices in:
+  # - relocations
+  # - line number records (never present)
+  # - one aux symbol entry (IMAGE_SYM_CLASS_CLR_TOKEN; not present in ml output)
+  SYM = Struct('SYM',
+               '8s', 'Name',
+               'I', 'Value',
+               'h', 'SectionNumber',  # Note: Signed!
+               'H', 'Type',
+
+               'B', 'StorageClass',
+               'B', 'NumberOfAuxSymbols')
+  i = 0
+  debug_sym = -1
+  while i < coff_header.NumberOfSymbols:
+    sym_offset = coff_header.PointerToSymbolTable + i * SYM.size()
+    sym = SYM.unpack_from(objdata, sym_offset)
+
+    # 107 is IMAGE_SYM_CLASS_CLR_TOKEN, which has aux entry "CLR Token
+    # Definition", which contains a symbol index. Check it's never present.
+    assert sym.StorageClass != 107
+
+    # Note: sym.SectionNumber is 1-based, debug_section_index is 0-based.
+    if sym.SectionNumber - 1 == debug_section_index:
+      assert debug_sym == -1, 'more than one .debug$S symbol found'
+      debug_sym = i
+      # Make sure the .debug$S symbol looks like we expect.
+      # In particular, it should have exactly one aux symbol.
+      assert sym.Name == b'.debug$S'
+      assert sym.Value == 0
+      assert sym.Type == 0
+      assert sym.StorageClass == 3
+      assert sym.NumberOfAuxSymbols == 1
+    elif sym.SectionNumber > debug_section_index:
+      sym = Subtract(sym, SectionNumber=1)
+      SYM.pack_into(objdata, sym_offset, sym)
+    i += 1 + sym.NumberOfAuxSymbols
+  assert debug_sym != -1, '.debug$S symbol not found'
+
+  # Note: Usually the .debug$S section is the last, but for files saying
+  # `includelib foo.lib`, like safe_terminate_process.asm in 32-bit builds,
+  # this isn't true: .drectve is after .debug$S.
+
+  # Update symbol table indices in relocations.
+  # There are a few processor types that have one or two relocation types
+  # where SymbolTableIndex has a different meaning, but not for x86.
+  REL = Struct('REL',
+               'I', 'VirtualAddress',
+               'I', 'SymbolTableIndex',
+               'H', 'Type')
+  for header in section_headers[0:debug_section_index]:
+    for j in range(0, header.NumberOfRelocations):
+      rel_offset = header.PointerToRelocations + j * REL.size()
+      rel = REL.unpack_from(objdata, rel_offset)
+      assert rel.SymbolTableIndex != debug_sym
+      if rel.SymbolTableIndex > debug_sym:
+        rel = Subtract(rel, SymbolTableIndex=2)
+        REL.pack_into(objdata, rel_offset, rel)
+
+  # Update symbol table indices in line numbers -- just check they don't exist.
+  for header in section_headers:
+    assert header.NumberOfLineNumbers == 0
+
+  # Now that all indices are updated, remove the symbol table entry referring to
+  # .debug$S and its aux entry.
+  del objdata[coff_header.PointerToSymbolTable + debug_sym * SYM.size():
+              coff_header.PointerToSymbolTable + (debug_sym + 2) * SYM.size()]
+
+  # Now we know that it's safe to write out the input data, with just the
+  # timestamp overwritten to 0, the last section header cut out (and the
+  # offsets of all other section headers decremented by the size of that
+  # one section header), and the last section's data cut out. The symbol
+  # table offset needs to be reduced by one section header and the size of
+  # the missing section.
+  # (The COFF spec only requires on-disk sections to be aligned in image files,
+  # for obj files it's not required. If that wasn't the case, deleting slices
+  # if data would not generally be safe.)
+
+  # Update section offsets and remove .debug$S section data.
+  for i in range(0, debug_section_index):
+    header = section_headers[i]
+    if header.SizeOfRawData:
+      header = Subtract(header, PointerToRawData=SECTIONHEADER.size())
+    if header.NumberOfRelocations:
+      header = Subtract(header, PointerToRelocations=SECTIONHEADER.size())
+    if header.NumberOfLineNumbers:
+      header = Subtract(header, PointerToLineNumbers=SECTIONHEADER.size())
+    SECTIONHEADER.pack_into(
+        objdata, COFFHEADER.size() + i * SECTIONHEADER.size(), header)
+  for i in range(debug_section_index + 1, len(section_headers)):
+    header = section_headers[i]
+    shift = SECTIONHEADER.size() + debug_size
+    if header.SizeOfRawData:
+      header = Subtract(header, PointerToRawData=shift)
+    if header.NumberOfRelocations:
+      header = Subtract(header, PointerToRelocations=shift)
+    if header.NumberOfLineNumbers:
+      header = Subtract(header, PointerToLineNumbers=shift)
+    SECTIONHEADER.pack_into(
+        objdata, COFFHEADER.size() + i * SECTIONHEADER.size(), header)
+
+  del objdata[debug_offset:debug_offset + debug_size]
+
+  # Finally, remove .debug$S section header and update coff header.
+  coff_header = coff_header._replace(TimeDateStamp=0)
+  coff_header = Subtract(coff_header,
+                         NumberOfSections=1,
+                         PointerToSymbolTable=SECTIONHEADER.size() + debug_size,
+                         NumberOfSymbols=2)
+  COFFHEADER.pack_into(objdata, 0, coff_header)
+
+  del objdata[
+      COFFHEADER.size() + debug_section_index * SECTIONHEADER.size():
+      COFFHEADER.size() + (debug_section_index + 1) * SECTIONHEADER.size()]
+
+  # All done!
+  if sys.version_info.major == 2:
+    return objdata.tostring()
+  else:
+    return objdata.tobytes()
+
+
+def main():
+  ml_result = subprocess.call(sys.argv[1:])
+  if ml_result != 0:
+    return ml_result
+
+  objfile = None
+  for i in range(1, len(sys.argv)):
+    if sys.argv[i].startswith('/Fo'):
+      objfile = sys.argv[i][len('/Fo'):]
+  assert objfile, 'failed to find ml output'
+
+  with open(objfile, 'rb') as f:
+    objdata = f.read()
+  objdata = MakeDeterministic(objdata)
+  with open(objfile, 'wb') as f:
+    f.write(objdata)
+
+
+if __name__ == '__main__':
+  sys.exit(main())