Linux compile link - WinChua/blog GitHub Wiki

rpath

• 相关文档查看: man ld.so; man ld
• 操作: patchelf
• 相关变量:
  • ORIGIN: gcc -Wl,-rpath, '$ORIGIN/../lib' main.c

    ORIGIN的作用是将rpath的搜索路径设置为可执行文件
    运行时相对路径, 类似于bash的
    cur_dir=`dirname $0`
    cd ${cur_dir}
  

  eg

  % gcc main.c && patchelf --print-needed a.out
  libc.so.6
  % patchelf --add-needed libhello.so a.out
  % patchelf --print-needed a.out
  libhello.so
  libc.so.6
  % ldd -r a.out
      linux-vdso.so.1 =>  (0x00007ffdd8372000)
    /$LIB/libonion.so => /lib64/libonion.so (0x00007f15dd624000)
      libhello.so => not found
      libc.so.6 => /lib64/libc.so.6 (0x00007f15dd147000)
      libdl.so.2 => /lib64/libdl.so.2 (0x00007f15dcf43000)
      /lib64/ld-linux-x86-64.so.2 (0x00007f15dd50b000)
  % mkdir lib
  % touch lib/libhello.so
  % ldd -r a.out
      linux-vdso.so.1 =>  (0x00007ffd95da5000)
      /$LIB/libonion.so => /lib64/libonion.so (0x00007f37f2681000)
      libhello.so => not found
      libc.so.6 => /lib64/libc.so.6 (0x00007f37f21a4000)
      libdl.so.2 => /lib64/libdl.so.2 (0x00007f37f1fa0000)
      /lib64/ld-linux-x86-64.so.2 (0x00007f37f2568000)
  % patchelf --set-rpath '$ORIGIN/lib' a.out
  % patchelf --print-rpath a.out
  $ORIGIN/lib
  % ldd -r a.out
  ./a.out: error while loading shared libraries: /home/winchua/benchmark/tool/testrpath/./lib/libhello.so: file too short
  % echo 'void hello(){}' > lib/hello.c && gcc -shared lib/hello.c -o lib/libhello.so
  % ldd -r a.out
      linux-vdso.so.1 =>  (0x00007ffc326d6000)
      /$LIB/libonion.so => /lib64/libonion.so (0x00007f9526b4e000)
      libhello.so => /home/winchua/benchmark/tool/testrpath/./lib/libhello.so (0x00007f9526833000)
      libc.so.6 => /lib64/libc.so.6 (0x00007f952646f000)
      libdl.so.2 => /lib64/libdl.so.2 (0x00007f952626b000)
      /lib64/ld-linux-x86-64.so.2 (0x00007f9526a35000)
  

  gcc -Wl,-rpath,'$ORIGIN/lib' main.c