pkgs/build-essentials/buildsystem-tools/functions-files

   1 #!/bin/bash
   2
   3 # Check if a file is an ELF binary
   4 #
   5 function file_is_elf() {
   6         local file=${1}
   7
   8         file "${file}" | grep -q "ELF"
   9 }
  10
  11 # Check if a file is a script.
  12 #   If the first line starts with #! this is sufficient.
  13 #
  14 function file_is_script() {
  15         local file=${1}
  16
  17         local first_line=$(head -n1 ${file})
  18
  19         [ "${first_line:0:2}" = "#!" ]
  20 }
  21
  22 # Get the interpreter of a file.
  23 #
  24 function file_get_interpreter() {
  25         local file=${1}
  26
  27         if file_is_elf ${file}; then
  28                 _file_get_elf_interpreter ${file}
  29         elif file_is_script ${file}; then
  30                 _file_get_script_interpreter ${file}
  31         fi
  32 }
  33
  34 # Hidden function that gets the interpreter from an ELF file.
  35 #
  36 function _file_get_elf_interpreter() {
  37         local file=${1}
  38
  39         readelf -l ${file} | grep "program interpreter" | \
  40                 tr -d "]" | awk '{ print $NF }'
  41 }
  42
  43 # Hidden fucntion that gets the interpreter from a script file.
  44 #
  45 function _file_get_script_interpreter() {
  46         local file=${1}
  47
  48         # If the file is not executeable, no interpreter will be needed
  49         [ -x "${file}" ] || return
  50
  51         local first_line=$(head -n1 ${file})
  52
  53         first_line="${first_line:2:${#first_line}}"
  54
  55         # Choose the first argument and strip any parameters if available
  56         local interpreter
  57         for interpreter in ${first_line}; do
  58                 echo "${interpreter}"
  59                 return
  60         done
  61 }
  62
  63 # Check if a file is statically linked.
  64 #
  65 function file_is_static() {
  66         local file=${1}
  67
  68         file ${file} | grep -q "statically linked"
  69 }
  70
  71 # Get NEEDED from a file.
  72 #
  73 function file_get_needed() {
  74         local file=${1}
  75
  76         readelf -d ${file} | grep NEEDED | \
  77                 tr -d "[]" | awk '{ print $NF }'
  78 }
  79
  80 # Get RPATH from a file.
  81 #
  82 function file_get_rpath() {
  83         local file=${1}
  84
  85         readelf -d ${file} | grep RPATH | \
  86                 tr -d "[]" | awk '{ print $NF }'
  87 }
  88
  89 # Get SONAME from a file.
  90 #
  91 function file_get_soname() {
  92         local file=${1}
  93
  94         local file_basename=$(basename ${file})
  95         if [ "${file_basename:0:3}" = "ld-" ]; then
  96                 log DEBUG "Don't return a SONAME for linkers: ${file}"
  97                 return
  98         fi
  99
 100         readelf -d ${file} | grep SONAME | \
 101                 tr -d "[]" | awk '{ print $NF }'
 102 }
 103
 104 # Check if a file is a shared object.
 105 #
 106 function file_is_shared_object() {
 107         local file=${1}
 108
 109         file ${file} | grep -q "shared object"
 110 }
 111
 112 # Check if a file has the canary.
 113 #
 114 function file_has_canary() {
 115         local file=${1}
 116
 117         readelf -s ${file} | grep -q "__stack_chk_fail"
 118 }
 119
 120 # Check if a file has an executeable stack.
 121 #
 122 function file_has_execstack() {
 123         local file=${1}
 124
 125         readelf -h ${file} | grep -qE "Type:[[:space:]]*EXEC"
 126 }
 127
 128 # Check if a file has NX.
 129 #
 130 function file_has_nx() {
 131         local file=${1}
 132
 133         readelf -l ${file} | grep "GNU_STACK" | grep -q "RWE"
 134         [ $? != 0 ]
 135 }
 136
 137 # Check if a file is partly RELRO.
 138 #
 139 function file_is_relro_partly() {
 140         local file=${1}
 141
 142         readelf -l ${file} | grep -q "GNU_RELRO"
 143 }
 144
 145 # Check if a file is fully RELRO.
 146 #
 147 function file_is_relro_full() {
 148         local file=${1}
 149
 150         if file_is_relro_partly ${file}; then
 151                 readelf -d ${file} | grep -q "BIND_NOW"
 152                 return $?
 153         fi
 154         return 1
 155 }
 156
 157 # Find all ELF files.
 158 #
 159 function find_elf_files() {
 160         local dir
 161         local dirs
 162         local prefix
 163
 164         while [ $# -gt 0 ]; do
 165                 case "${1}" in
 166                         --prefix=*)
 167                                 prefix="${1#--prefix=}/"
 168                                 ;;
 169                         *)
 170                                 dirs="${dirs} ${1}"
 171                                 ;;
 172                 esac
 173                 shift
 174         done
 175
 176         local file
 177         local files
 178
 179         for dir in ${dirs}; do
 180                 dir="${prefix}${dir}"
 181                 for file in $(find ${dir} -type f 2>/dev/null); do
 182                         if file_is_elf ${file} && ! file_is_static ${file}; then
 183                                 files="${files} ${file}"
 184                         fi
 185                 done
 186         done
 187
 188         echo ${files}
 189 }
 190
 191 function filter_startfiles() {
 192         local file=${1}
 193
 194         grep -qE "crt[1in]\.o$" <<<${file}
 195 }