commit 9598db054e50f10d1ff1612741966f679caf441d
author Charles-Francois Natali <cf.natali@gmail.com> Mon May 31 21:23:29 2021 +0800
committer Qian Zhang <zhq527725@gmail.com> Mon May 31 21:23:29 2021 +0800
tree 49177ac3dcc3808c1b5be7a9ab5c5a48cd6d0b45
parent 85981d7c728798783b2e1e7cbed4f27a1497ccb2

Fixed parsing of ld.so.cache on new glibc.

Since glibc 2.32, `ld.so.cache` now defaults to the "new" format, instead
of the "compat" format which was in use since glibc 2.2 (around 20 years
ago). It is now the default on e.g. Debian bullseye, and any recent Linux
distribution.

The code change adds support for the "new" format along with the existing
support for the "compat".

Before:
```
root@thinkpad:/home/cf/src/mesos/build# ldconfig -c new
root@thinkpad:/home/cf/src/mesos/build# ./bin/mesos-tests.sh --gtest_filter=*Ld*
[...]
[==========] Running 4 tests from 2 test cases.
[----------] Global test environment set-up.
[----------] 1 test from LdcacheTest
[ RUN      ] LdcacheTest.Parse
../../src/tests/ldcache_tests.cpp:43: Failure
cache: Invalid format
[  FAILED  ] LdcacheTest.Parse (0 ms)
[----------] 1 test from LdcacheTest (0 ms total)

[----------] 3 tests from Ldd
[ RUN      ] Ldd.BinSh
../../src/tests/ldd_tests.cpp:43: Failure
cache: Invalid format
[  FAILED  ] Ldd.BinSh (0 ms)
[ RUN      ] Ldd.EmptyCache
[       OK ] Ldd.EmptyCache (1 ms)
[ RUN      ] Ldd.MissingFile
../../src/tests/ldd_tests.cpp:77: Failure
cache: Invalid format
[  FAILED  ] Ldd.MissingFile (0 ms)
[----------] 3 tests from Ldd (1 ms total)

[----------] Global test environment tear-down
[==========] 4 tests from 2 test cases ran. (8 ms total)
[  PASSED  ] 1 test.
[  FAILED  ] 3 tests, listed below:
[  FAILED  ] LdcacheTest.Parse
[  FAILED  ] Ldd.BinSh
[  FAILED  ] Ldd.MissingFile

 3 FAILED TESTS
```

After:

```
root@thinkpad:/home/cf/src/mesos/build# ldconfig -c new
root@thinkpad:/home/cf/src/mesos/build# ./bin/mesos-tests.sh --gtest_filter=*Ld*
[...]
[==========] Running 4 tests from 2 test cases.
[----------] Global test environment set-up.
[----------] 1 test from LdcacheTest
[ RUN      ] LdcacheTest.Parse
[       OK ] LdcacheTest.Parse (529 ms)
[----------] 1 test from LdcacheTest (529 ms total)

[----------] 3 tests from Ldd
[ RUN      ] Ldd.BinSh
[       OK ] Ldd.BinSh (3 ms)
[ RUN      ] Ldd.EmptyCache
[       OK ] Ldd.EmptyCache (0 ms)
[ RUN      ] Ldd.MissingFile
[       OK ] Ldd.MissingFile (0 ms)
[----------] 3 tests from Ldd (3 ms total)

[----------] Global test environment tear-down
[==========] 4 tests from 2 test cases ran. (541 ms total)
[  PASSED  ] 4 tests.
```

This closes #384