ruby.git/misc/lldb_disasm.py, branch v4.0.2

Get the insns_address_table from the vm_exec_core module table...

2022-07-14T15:25:37+00:00

Update lldb helper for iseq disassembly to use correct var name

2022-05-04T19:48:49+00:00

Fix up global name references in misc/lldb_disasm.py

2022-04-01T18:48:22+00:00

Some of the symbols had changed names and the script was no longer
finding them.

Treat TS_ICVARC cache as separate from TS_IVC cache

2022-02-02T17:20:34+00:00

Fix typos

2021-11-02T10:17:37+00:00

Fix lldb disassembler so it works with core files

2020-10-08T23:43:11+00:00

This fixes the lldb disassembler script so that it doesn't need a live
process when disassembling rb_iseq_t.  I also added the PC to the output
so you can tell what the VM is executing when it crashed.

For example:

```
(lldb) rbdisasm ec->cfp->iseq
PC             IDX  insn_name(operands)
0x56039f0a1720 0000 nop
0x56039f0a1728 0001 getlocal_WC_1( 5 )
0x56039f0a1738 0003 branchunless( 7 )
0x56039f0a1748 0005 getlocal_WC_0( 3 )
0x56039f0a1758 0007 putstring( (VALUE)0x56039f0c7eb8 )
0x56039f0a1768 0009 opt_send_without_block( (struct rb_call_data *)0x56039f09f140 )
0x56039f0a1778 0011 pop
0x56039f0a1780 0012 getglobal( ID: 0x7fd7 )
0x56039f0a1790 0014 branchunless( 7 )
0x56039f0a17a0 0016 getlocal_WC_0( 3 )
0x56039f0a17b0 0018 putstring( (VALUE)0x56039f0c7e90 )
0x56039f0a17c0 0020 opt_send_without_block( (struct rb_call_data *)0x56039f09f150 )
0x56039f0a17d0 0022 pop
0x56039f0a17d8 0023 getlocal_WC_0( 3 )
0x56039f0a17e8 0025 putobject( (VALUE)0x56039f0c7e68 )
0x56039f0a17f8 0027 getlocal_WC_1( 6 )
0x56039f0a1808 0029 dup
0x56039f0a1810 0030 checktype( 5 )
0x56039f0a1820 0032 branchif( 4 )
0x56039f0a1830 0034 dup
0x56039f0a1838 0035 opt_send_without_block( (struct rb_call_data *)0x56039f09f160 )
0x56039f0a1848 0037 tostring
0x56039f0a1850 0038 putobject( (VALUE)0x56039f0c7e40 )
0x56039f0a1860 0040 concatstrings( 3 )
0x56039f0a1870 0042 opt_send_without_block( (struct rb_call_data *)0x56039f09f170 )
0x56039f0a1880 0044 nop
0x56039f0a1888 0045 leave
(lldb) p ec->cfp->pc
(const VALUE *) $146 = 0x000056039f0a1848
```

Here we can see the VM is currently executing `opt_send_without_block`
(because the PC is one ahead of the current instruction)

Rudimentary support for disassembling rb_iseq_t

2020-09-22T20:40:57+00:00

I need to disassemble instruction sequences while debugging, so I wrote
this.

Usage is like this:

```
(lldb) p iseq
(rb_iseq_t *) $147 = 0x0000000101068400
(lldb) rbdisasm iseq
0000 putspecialobject( 3 )
0002 putnil
0003 defineclass( ID: 0x560b, (rb_iseq_t *)0x1010681d0, 2 )
0007 pop
0008 putspecialobject( 3 )
0010 putnil
0011 defineclass( ID: 0x56eb, (rb_iseq_t *)0x101063b58, 2 )
0015 leave
```

Also thanks a ton to @kivikakk helping me figure out how to navigate LLDB's Python 😆