build/mac/copy_framework_unversioned.sh

   1 #!/bin/bash
   2
   3 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
   4 # Use of this source code is governed by a BSD-style license that can be
   5 # found in the LICENSE file.
   6
   7 # Copies a framework to its new home, "unversioning" it.
   8 #
   9 # Normally, frameworks are versioned bundles.  The contents of a framework are
  10 # stored in a versioned directory within the bundle, and symbolic links
  11 # provide access to the actual code and resources.  See
  12 # http://developer.apple.com/mac/library/documentation/MacOSX/Conceptual/BPFrameworks/Concepts/FrameworkAnatomy.html
  13 #
  14 # The symbolic links usually found in frameworks create problems.  Symbolic
  15 # links are excluded from code signatures.  That means that it's possible to
  16 # remove or retarget a symbolic link within a framework without affecting the
  17 # seal.  In Chrome's case, the outer .app bundle contains a framework where
  18 # all application code and resources live.  In order for the signature on the
  19 # .app to be meaningful, it encompasses the framework.  Because framework
  20 # resources are accessed through the framework's symbolic links, this
  21 # arrangement results in a case where the resources can be altered without
  22 # affecting the .app signature's validity.
  23 #
  24 # Indirection through symbolic links also carries a runtime performance
  25 # penalty on open() operations, although open() typically completes so quickly
  26 # that this is not considered a major performance problem.
  27 #
  28 # To resolve these problems, the frameworks that ship within Chrome's .app
  29 # bundle are unversioned.  Unversioning is simple: instead of using the
  30 # original outer .framework directory as the framework that ships within the
  31 # .app, the inner versioned directory is used.  Instead of accessing bundled
  32 # resources through symbolic links, they are accessed directly.  In normal
  33 # situations, the only hard-coded use of the versioned directory is by dyld,
  34 # when loading the framework's code, but this is handled through a normal
  35 # Mach-O load command, and it is easy to adjust the load command to point to
  36 # the unversioned framework code rather than the versioned counterpart.
  37 #
  38 # The resulting framework bundles aren't strictly conforming, but they work
  39 # as well as normal versioned framework bundles.
  40 #
  41 # An option to skip running install_name_tool is available. By passing -I as
  42 # the first argument to this script, install_name_tool will be skipped. This
  43 # is only suitable for copied frameworks that will not be linked against, or
  44 # when install_name_tool will be run on any linker output when something is
  45 # linked against the copied framework. This option exists to allow signed
  46 # frameworks to pass through without subjecting them to any modifications that
  47 # would break their signatures.
  48
  49 set -e
  50
  51 RUN_INSTALL_NAME_TOOL=1
  52 if [ $# -eq 3 ] && [ "${1}" = "-I" ] ; then
  53   shift
  54   RUN_INSTALL_NAME_TOOL=
  55 fi
  56
  57 if [ $# -ne 2 ] ; then
  58   echo "usage: ${0} [-I] FRAMEWORK DESTINATION_DIR" >& 2
  59   exit 1
  60 fi
  61
  62 # FRAMEWORK should be a path to a versioned framework bundle, ending in
  63 # .framework.  DESTINATION_DIR is the directory that the unversioned framework
  64 # bundle will be copied to.
  65
  66 FRAMEWORK="${1}"
  67 DESTINATION_DIR="${2}"
  68
  69 FRAMEWORK_NAME="$(basename "${FRAMEWORK}")"
  70 if [ "${FRAMEWORK_NAME: -10}" != ".framework" ] ; then
  71   echo "${0}: ${FRAMEWORK_NAME} does not end in .framework" >& 2
  72   exit 1
  73 fi
  74 FRAMEWORK_NAME_NOEXT="${FRAMEWORK_NAME:0:$((${#FRAMEWORK_NAME} - 10))}"
  75
  76 # Find the current version.
  77 VERSIONS="${FRAMEWORK}/Versions"
  78 CURRENT_VERSION_LINK="${VERSIONS}/Current"
  79 CURRENT_VERSION_ID="$(readlink "${VERSIONS}/Current")"
  80 CURRENT_VERSION="${VERSIONS}/${CURRENT_VERSION_ID}"
  81
  82 # Make sure that the framework's structure makes sense as a versioned bundle.
  83 if [ ! -e "${CURRENT_VERSION}/${FRAMEWORK_NAME_NOEXT}" ] ; then
  84   echo "${0}: ${FRAMEWORK_NAME} does not contain a dylib" >& 2
  85   exit 1
  86 fi
  87
  88 DESTINATION="${DESTINATION_DIR}/${FRAMEWORK_NAME}"
  89
  90 # Copy the versioned directory within the versioned framework to its
  91 # destination location.
  92 mkdir -p "${DESTINATION_DIR}"
  93 rsync -acC --delete --exclude Headers --exclude PrivateHeaders \
  94     --include '*.so' "${CURRENT_VERSION}/" "${DESTINATION}"
  95
  96 if [[ -n "${RUN_INSTALL_NAME_TOOL}" ]]; then
  97   # Adjust the Mach-O LC_ID_DYLIB load command in the framework.  This does not
  98   # change the LC_LOAD_DYLIB load commands in anything that may have already
  99   # linked against the framework.  Not all frameworks will actually need this
 100   # to be changed.  Some frameworks may already be built with the proper
 101   # LC_ID_DYLIB for use as an unversioned framework.  Xcode users can do this
 102   # by setting LD_DYLIB_INSTALL_NAME to
 103   # $(DYLIB_INSTALL_NAME_BASE:standardizepath)/$(WRAPPER_NAME)/$(PRODUCT_NAME)
 104   # If invoking ld via gcc or g++, pass the desired path to -Wl,-install_name
 105   # at link time.
 106   FRAMEWORK_DYLIB="${DESTINATION}/${FRAMEWORK_NAME_NOEXT}"
 107   LC_ID_DYLIB_OLD="$(otool -l "${FRAMEWORK_DYLIB}" |
 108                          grep -A10 "^ *cmd LC_ID_DYLIB$" |
 109                          grep -m1 "^ *name" |
 110                          sed -Ee 's/^ *name (.*) \(offset [0-9]+\)$/\1/')"
 111   VERSION_PATH="/Versions/${CURRENT_VERSION_ID}/${FRAMEWORK_NAME_NOEXT}"
 112   LC_ID_DYLIB_NEW="$(echo "${LC_ID_DYLIB_OLD}" |
 113                      sed -Ee "s%${VERSION_PATH}$%/${FRAMEWORK_NAME_NOEXT}%")"
 114
 115   if [ "${LC_ID_DYLIB_NEW}" != "${LC_ID_DYLIB_OLD}" ] ; then
 116     install_name_tool -id "${LC_ID_DYLIB_NEW}" "${FRAMEWORK_DYLIB}"
 117   fi
 118 fi