liblldb.so link failure due to missing -ltinfo flag on systems with split ncurses/tinfo #25067
Description
| Bugzilla Link | 24693 |
| Version | 3.7 |
| OS | Linux |
| Attachments | patch to LLDBDependencies.cmake to pull in libtinfo if necessary., build log showing cmake invocation, and link command that fails along with error message |
| Reporter | LLVM Bugzilla Contributor |
| CC | @k15tfu |
Extended Description
Some systems come with ncurses split into two libraries, libncurses and libtinfo, with symbols divided between the two. This is achieved through the --with-termlib configure flag passed to the ncurses configure script. This is correctly handled in the main llvm cmake scripts (cmake/config-ix.cmake:119) but the lldb one links to only libncurses which results in link failure on such systems with undefined references to:
acs_map
stdscr
halfdelay
curs_set
keypad
These symbols are found in libtinfo.so:
$ nm -D libncurses.so.5.9 | grep -E 'acs_map|stdscr|halfdelay|curs_set|keypad'
U acs_map
U curs_set
000000000000c780 T is_keypad
U _nc_keypad
U stdscr
$ nm -D libtinfo.so.5.9 | grep -E 'acs_map|stdscr|halfdelay|curs_set|keypad'
0000000000234a80 B acs_map
0000000000011b60 T curs_set
00000000000119b0 T halfdelay
0000000000011ce0 T keypad
0000000000011c50 T _nc_keypad
0000000000234eb0 B stdscr
The correct way to handle this would be to use pkg-config within cmake which knows which libraries are needed
$ pkg-config ncurses --libs
-lncurses -ltinfo
but since llvm doesn't seem to rely on pkg-config, an alternative (for which I provide a patch) is to piggyback on what is done within llvm cmake already.