Dwarf argspec is not loaded for shared libraries

[honggyukim]

It seems that dwarf argspec is not loaded for shared libraries.
1. build

$ cd uftrace/tests
$ gcc -pg -g -o libabc_test_lib.so -shared -fPIC s-lib.c
$ gcc -pg -g -o t-lib.pg s-libmain.c -L. -labc_test_lib
$ gcc     -g -o t-lib    s-libmain.c -L. -labc_test_lib

2. tracing -pg compiled t-lib.pg
In this case, all the functions are normally traced with their arguments and return values.

$ LD_LIBRARY_PATH=. uftrace --no-pager -la t-lib.pg
# DURATION     TID     FUNCTION
            [145706] | main(1, 0x7ffc05116da8) {
            [145706] |   foo() {
            [145706] |     lib_a() {
            [145706] |       lib_a(4095) {
            [145706] |         lib_b(4096) {
            [145706] |           lib_c(4095) {
   1.226 us [145706] |             getpid() = 145706;
   7.047 us [145706] |           } = 2381; /* lib_c */
  11.637 us [145706] |         } = 2382; /* lib_b */
  12.667 us [145706] |       } = 2381; /* lib_a */
  14.890 us [145706] |     } /* lib_a */
  16.233 us [145706] |   } = 2381; /* foo */
  18.994 us [145706] | } = 0; /* main */

3. tracing t-lib
But t-lib is not compiled with -pg so it can only be traced with --force option. In this case, argspec in libabc_test_lib.so is not used during tracing.

$ LD_LIBRARY_PATH=. uftrace --no-pager -la --force t-lib
# DURATION     TID     FUNCTION
            [145694] | lib_a() {
            [145694] |   lib_a() {
            [145694] |     lib_b() {
            [145694] |       lib_c() {
   0.985 us [145694] |         getpid() = 145694;
   8.358 us [145694] |       } /* lib_c */
   9.001 us [145694] |     } /* lib_b */
   9.481 us [145694] |   } /* lib_a */
  11.503 us [145694] | } /* lib_a */

I'm just wondering if this is expected result or not.