appio: Mark intercepting functions as public such that they are properly linked when using the PAPI shared library

[Treece-Burgess]

Pull Request Description

In the appio component, if you compile the tests appio_test_seek.c, appio_test_fread_fwrite.c, appio_test_read_write.c, appio_test_values_by_code.c, appio_test_values_by_name.c , and appio_test_pthreads.c with the PAPI shared library, the counter values will be zero:

[ICL:methane tests]$ gcc -I. -I../../.. -I../../../testlib -I../../../validation_tests appio_test_read_write.c -o appio_test_read_write ../../../testlib/libtestlib.a ../../../libpapi.so
[ICL:methane tests]$ ./appio_test_read_write
This program will read /etc/group and write it to /dev/null
----
OPEN_CALLS: 0
OPEN_FDS: 0
READ_CALLS: 0
READ_BYTES: 0
READ_USEC: 0
READ_ERR: 0
READ_INTERRUPTED: 0
READ_WOULD_BLOCK: 0
WRITE_CALLS: 0
WRITE_BYTES: 0
WRITE_USEC: 0
WRITE_WOULD_BLOCK: 0
PASSED

With the PAPI static library this does not occur.

Further, if we use LD_DEBUG=all on the executable for test_appio_read_write.c you will see that for open we bind with libc.so.6versions rather than our own implementation:

3890941: symbol=open;  lookup in file=/home/tburgess/papi_fork/papi/src/test-install/lib/libpapi.so.7.2 [0]
3890941: symbol=open;  lookup in file=/lib64/libc.so.6 [0]
3890941: binding file ./appio_test_read_write [0] to /lib64/libc.so.6 [0]: normal symbol `open' [GLIBC_2.2.5]

This PR resolves this behavior by explicitly setting our intercepting functions as public.

Testing

Testing was done on Methane at ICL with the setup of:

• CPU: Intel Xeon Gold 6140
• OS: Rocky Linux 9.6
• GCC: 11.5

The aforementioned tests that returned 0 values when linking with the PAPI shared library now do not show zero values. Further, these values are comparable to the case of linking with the static library:

[ICL:methane tests]$ gcc -I. -I../../.. -I../../../testlib -I../../../validation_tests appio_test_read_write.c -o appio_test_read_write ../../../testlib/libtestlib.a ../../../libpapi.so
[ICL:methane tests]$ ./appio_test_read_write 
This program will read /etc/group and write it to /dev/null
----
OPEN_CALLS: 2
OPEN_FDS: 0
READ_CALLS: 2
READ_BYTES: 766
READ_USEC: 3
READ_ERR: 0
READ_INTERRUPTED: 0
READ_WOULD_BLOCK: 0
WRITE_CALLS: 1
WRITE_BYTES: 766
WRITE_USEC: 1
WRITE_WOULD_BLOCK: 0
PASSED

If we again look at the output when using LD_DEBUG=all on the executable for test_appio_read_write.c, you will now see we bind with our internal implementation of open:

symbol=open;  lookup in file=./appio_test_read_write [0]
symbol=open;  lookup in file=/home/tburgess/papi_fork/papi/src/test-install/lib/libpapi.so.7.2 [0]
binding file ./appio_test_read_write [0] to /home/tburgess/papi_fork/papi/src/test-install/lib/libpapi.so.7.2 [0]: normal symbol `open'

NOTE: The tests appio_test_blocking.c, appio_test_recv, appio_test_select, and appio_test_socket were not tested as they currently hang in the master branch and need to be addressed in a separate PR.

Author Checklist

• Description
  Why this PR exists. Reference all relevant information, including background, issues, test failures, etc
• Commits
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• Tests
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[dbarry9]

I am reviewing this PR.

[dbarry9]

I have tested this pull request on the Frontier supercomputer (AMD Zen3 architecture, GCC 12.2.0). All PAPI utilities function properly. With the changes in this PR, I observe that the following appio component tests (built by dynamically linking PAPI) now return non-zero event counts, consistent with builds which statically link PAPI:

• appio_test_fread_fwrite
• appio_test_pthreads
• appio_test_read_write
• appio_test_seek
• appio_values_by_name
• appio_values_by_code

@Treece-Burgess In order to test that these changes had the intended effect on the component tests, I had to manually edit 'components/appio/tests/Makefile' to dynamically link PAPI to the targets. Should we make a variable in this Makefile that is commented-out by default, but can be toggled? This might be overkill, but it could be helpful for future testing.