[lldb-dev] "image search-paths add" removes all breakpoints from remote server

[Jim Ingham via lldb-dev]

> On Nov 16, 2016, at 12:03 PM, Ted Woodward via lldb-dev <lldb-dev at lists.llvm.org> wrote:
> 
> Is “image search-paths add” supposed to remove all breakpoints from the remote server? I don’t think it should be doing this.
>  
> PathMappingList::Append calls Target::ImageSearchPathsChanged, which calls Target::SetExecutableModule, which calls Target::ClearModules, which removes the breakpoints. But SetExecutableModule doesn’t restore the breakpoints.
>  
>  
>  
> This test I use top-of-tree lldb, built on Ubuntu 12 with a native target. Packet log edited to remove chaff.
>  
> (lldb) log enable gdb-remote packets
> (lldb) process launch –s
> Process 18766 launched: '/usr2/tedwood/lldb_test/factlin' (x86_64)
> (lldb) process status
> Process 18766 stopped
> * thread #1, name = 'factlin', stop reason = signal SIGSTOP
>     frame #0: 0x00007ffff7ddb6b0
> ->  0x7ffff7ddb6b0: movq   %rsp, %rdi
>     0x7ffff7ddb6b3: callq  0x7ffff7ddf010
>     0x7ffff7ddb6b8: movq   %rax, %r12
>     0x7ffff7ddb6bb: movl   0x2215ff(%rip), %eax
> (lldb) b main
> <  15> send packet: $Z0,400586,1#4a
> <   6> read packet: $OK#9a
> Breakpoint 1: where = factlin`main + 22 at factorial.c:32, address = 0x0000000000400586
> (lldb) br l
> Current breakpoints:
> 1: name = 'main', locations = 1, resolved = 1, hit count = 0
>   1.1: where = factlin`main + 22 at factorial.c:32, address = 0x0000000000400586, resolved, hit count = 0 
> (lldb) image search-paths add /local /tmp
> <  15> send packet: $z0,400586,1#6a
> <   6> read packet: $OK#9a
> <  15> send packet: $z0,400410,1#5c
> <   6> read packet: $OK#9a
> (lldb) br l
> Current breakpoints:
> 1: name = 'main', locations = 1
>   1.1: where = factlin`main + 22 at factorial.c:32, address = factlin[0x0000000000400586], unresolved, hit count = 0 
> (lldb) c
> <   5> send packet: $c#63
> Process 18766 resuming
> Factorial of 10 is 3628800
> <   7> read packet: $W00#b7
> Process 18766 exited with status = 0 (0x00000000)

This is a distinction without much difference, but the break list output is actually telling you somebody forgot to re-install the breakpoints.  Note the state went from resolved (i.e. there is a site in the targeted process for this breakpoint location) to unresolved.  Still a bug, but the breakpoints aren't lying to you...

When you added search paths, all the breakpoints needed to be re-set, since the symbol world might have changed.  But apparently only the removal part is getting done.

Jim


>  
> As you can see, the breakpoint at main was removed on lldb-server, but shows as active in the breakpoint list. When I continue, the breakpoint isn’t hit, and the target runs to completion.
>  
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>  
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