[lldb-dev] [Bug 36547] New: Namespace clash displaying 'this'

[via lldb-dev]

https://bugs.llvm.org/show_bug.cgi?id=36547

            Bug ID: 36547
           Summary: Namespace clash displaying 'this'
           Product: lldb
           Version: 6.0
          Hardware: PC
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P
         Component: All Bugs
          Assignee: lldb-dev at lists.llvm.org
          Reporter: dantipov at nvidia.com
                CC: llvm-bugs at lists.llvm.org

Created attachment 19970
  --> https://bugs.llvm.org/attachment.cgi?id=19970&action=edit
Sample program

$ /home/dantipov/.local/llvm-6.0.0/bin/lldb t-class2
(lldb) target create "t-class2"
Current executable set to 't-class2' (x86_64).
(lldb) breakpoint set -n S::B::f
Breakpoint 1: where = t-class2`S::B::f(int) at t-class2.cc:25, address =
0x000000000040076a
(lldb) breakpoint set -n S::B::g
Breakpoint 2: where = t-class2`S::B::g(int) + 11 at t-class2.cc:26, address =
0x0000000000400789
(lldb) run
Process 5180 launched: '/home/dantipov/tmp/t-class2' (x86_64)
Process 5180 stopped
* thread #1, name = 't-class2', stop reason = breakpoint 1.1
    frame #0: 0x000000000040076a t-class2`S::B::f(this=0x00007fffffffdb50, x=1)
at t-class2.cc:25
   22     struct B: AS {
   23       int id1;
   24       B () { id1 = 444; }
-> 25       virtual int f (int x) { return x + 4; }
   26       int g (int x) { return x + 14; }
   27     };
   28   }
(lldb) bt
* thread #1, name = 't-class2', stop reason = breakpoint 1.1
  * frame #0: 0x000000000040076a t-class2`S::B::f(this=0x00007fffffffdb50, x=1)
at t-class2.cc:25
    frame #1: 0x0000000000400643 t-class2`main(argc=1, argv=0x00007fffffffdc58)
at t-class2.cc:36
    frame #2: 0x00007ffff712000a
libc.so.6`__libc_start_main(main=(t-class2`main at t-class2.cc:31), argc=1,
argv=0x00007fffffffdc58, init=<unavailable>, fini=<unavailable>,
rtld_fini=<unavailable>, stack_end=0x00007fffffffdc48) at libc-start.c:308
    frame #3: 0x000000000040054a t-class2`_start + 42
(lldb) p this
(S::B *) $0 = 0x00007fffffffdb50
(lldb) p *this
(S::B) $1 = {
  S::AS = (id0 = 111)
  id1 = 222
}
(lldb) c
Process 5180 resuming
Process 5180 stopped
* thread #1, name = 't-class2', stop reason = breakpoint 2.1
    frame #0: 0x0000000000400789 t-class2`S::B::g(this=0x00007fffffffdb40, x=1)
at t-class2.cc:26
   23       int id1;
   24       B () { id1 = 444; }
   25       virtual int f (int x) { return x + 4; }
-> 26       int g (int x) { return x + 14; }
   27     };
   28   }
   29   
(lldb) bt
* thread #1, name = 't-class2', stop reason = breakpoint 2.1
  * frame #0: 0x0000000000400789 t-class2`S::B::g(this=0x00007fffffffdb40, x=1)
at t-class2.cc:26
    frame #1: 0x0000000000400669 t-class2`main(argc=1, argv=0x00007fffffffdc58)
at t-class2.cc:38
    frame #2: 0x00007ffff712000a
libc.so.6`__libc_start_main(main=(t-class2`main at t-class2.cc:31), argc=1,
argv=0x00007fffffffdc58, init=<unavailable>, fini=<unavailable>,
rtld_fini=<unavailable>, stack_end=0x00007fffffffdc48) at libc-start.c:308
    frame #3: 0x000000000040054a t-class2`_start + 42
(lldb) p this
(S::B *) $2 = 0x00007fffffffdb40
(lldb) p *this
(S::B) $3 = {
  S::AS = (id0 = 333)
  id1 = 444
}

Here 'this' is different between calls to obj2.f () and obj2.g ()
(0x00007fffffffdb50 vs.
0x00007fffffffdb40), and objects are shown as different as well - {111, 222}
vs. {333, 444}.

OTOH in gdb it is:

$ gdb -q t-class2
Reading symbols from t-class2...done.
(gdb) b S::B::f
Breakpoint 1 at 0x400775: file t-class2.cc, line 25.
(gdb) b S::B::g
Breakpoint 2 at 0x400789: file t-class2.cc, line 26.
(gdb) r
Starting program: /home/dantipov/tmp/t-class2 

Breakpoint 1, S::B::f (this=0x7fffffffdb50, x=1) at t-class2.cc:25
25          virtual int f (int x) { return x + 4; }
(gdb) bt
#0  S::B::f (this=0x7fffffffdb50, x=1) at t-class2.cc:25
#1  0x0000000000400643 in main (argc=1, argv=0x7fffffffdc68) at t-class2.cc:36
(gdb) p this
$1 = (S::B * const) 0x7fffffffdb50
(gdb) p *this
$2 = {<S::AS> = {_vptr.AS = 0x400840 <vtable for S::B+16>, id0 = 333}, id1 =
444}
(gdb) c
Continuing.

Breakpoint 2, S::B::g (this=0x7fffffffdb50, x=1) at t-class2.cc:26
26          int g (int x) { return x + 14; }
(gdb) bt
#0  S::B::g (this=0x7fffffffdb50, x=1) at t-class2.cc:26
#1  0x0000000000400669 in main (argc=1, argv=0x7fffffffdc68) at t-class2.cc:38
(gdb) p this
$3 = (S::B * const) 0x7fffffffdb50
(gdb) p *this
$4 = {<S::AS> = {_vptr.AS = 0x400840 <vtable for S::B+16>, id0 = 333}, id1 =
444}

E.g. in calls to obj2.f () and obj2.g (), 'this' is 0x7fffffffdb50, and the
object
itself is {333, 444}.

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