[vlc-devel] Mac: Cannot get LLDB Symbols for libvlccore.dylib

Sridhar Sarnobat ss401533 at gmail.com
Wed Jan 15 03:38:00 CET 2020


Cannot get lldb to print local variables for method
src/playlist/control.c::playlist_vaControl() .

*Reproduction steps*

cd vlc

git checkout 8d432b0   # tag: 3.0.0-git

# follow steps at MacOSCompile wiki page

cd build/ \

&& PATH=/bin/:${PATH} make -j1

lldb build/bin/vlc-osx-static

(lldb) b playlist_vaControl
Breakpoint 1: where = libvlccore.dylib`playlist_vaControl, address =

(lldb) run ~/trash/videos/201611070302_51.mp4 vlc://quit

Process 82073 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
    frame #0: 0x0000000100109130 libvlccore.dylib`playlist_vaControl
->  0x100109130 <+0>:  pushq  %rbp
    0x100109131 <+1>:  movq   %rsp, %rbp
    0x100109134 <+4>:  subq   $0xa0, %rsp
    0x10010913b <+11>: movb   %dl, %al
Target 0: (vlc-osx-static) stopped.

(lldb) p i_query
error: use of undeclared identifier 'i_query'

*Version info & other info*

(-) git tag: 3.0.0-git

(-) Source file:

(-) Mac OS X Mojave (10.14.6 (18G2022)) - but also my home laptop whose
version I don't have in front of me

(-) Library compile info

(lldb) image lookup -vn  playlist_vaControl

1 match found in /Users/myusername/vlc/build/src/.libs/libvlccore.dylib:

        Address: libvlccore.dylib[0x0000000000039130]
(libvlccore.dylib.__TEXT.__text + 222784)

        Summary: libvlccore.dylib`playlist_vaControl

         Module: file =
"/Users/myusername/vlc/build/src/.libs/libvlccore.dylib", arch = "x86_64"

         Symbol: id = {0x000001ef}, range =
[0x0000000100109130-0x00000001001096f0), name="playlist_vaControl"

(-) I have created vlc/build/bin/vlc-osx-static.dSYM but that doesn't seem
to be useful

*End Goal*

Create a simple VLC plugin using C (not Lua) which writes the "now playing"
media file out to /tmp/now_playing.txt


(-) I wish to use lldb for my code comprehension needs. Then I can figure
out how to write the code to fulfill my goal

(-) I have never contributed to open source before, so please forgive me if
I am not following any etiquette.

(-) I'm mainly a java developer, but have done a bit of GCC development
early in my career. Never CLang, and I'm not familiar with XCode and would
prefer command line (but am willing to use XCode if that's the only
realistic option). I do have access to Ubuntu but would strongly prefer Mac
OS X initially (my Ubuntu machines are headless so would be headless, and
slower over ssh)

(-) I do not wish to use Lua, mainly because I want to (re)aquaint myself
with C programming, but also I vaguely recall a limitation of Lua
extensions that native modules do not have (but I could be wrong about).

(-) Thank you to all the people who created and maintain this, I've
depended on it a lot so far and am pleasantly surprised it all works :)

Sridhar Sarnobat
San Jose, CA 95128 | USA
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