rather than having to do this in a two step process:
1. heap_page obj
2. dump_page $2 (or whatever lldb variable heap_page set)
we can now just
dump_page_rvalue obj
Update the lldb script so it can mostly recover a Ruby stack trace from
a core file. It's still missing line numbers and dealing with CFUNCs,
but you use it like this:
```
(lldb) rbbt ec
rb_control_frame_t TYPE
0x7f6fd6555fa0 EVAL ./bootstraptest/runner.rb error!!
0x7f6fd6555f68 METHOD ./bootstraptest/runner.rb main
0x7f6fd6555f30 METHOD ./bootstraptest/runner.rb in_temporary_working_directory
0x7f6fd6555ef8 METHOD /home/aaron/git/ruby/lib/tmpdir.rb mktmpdir
0x7f6fd6555ec0 BLOCK ./bootstraptest/runner.rb block in in_temporary_working_directory
0x7f6fd6555e88 CFUNC
0x7f6fd6555e50 BLOCK ./bootstraptest/runner.rb block (2 levels) in in_temporary_working_directory
0x7f6fd6555e18 BLOCK ./bootstraptest/runner.rb block in main
0x7f6fd6555de0 METHOD ./bootstraptest/runner.rb exec_test
0x7f6fd6555da8 CFUNC
0x7f6fd6555d70 BLOCK ./bootstraptest/runner.rb block in exec_test
0x7f6fd6555d38 CFUNC
0x7f6fd6555d00 TOP /home/aaron/git/ruby/bootstraptest/test_insns.rb error!!
0x7f6fd6555cc8 CFUNC
0x7f6fd6555c90 BLOCK /home/aaron/git/ruby/bootstraptest/test_insns.rb block in <top (required)>
0x7f6fd6555c58 METHOD ./bootstraptest/runner.rb assert_equal
0x7f6fd6555c20 METHOD ./bootstraptest/runner.rb assert_check
0x7f6fd6555be8 METHOD ./bootstraptest/runner.rb show_progress
0x7f6fd6555bb0 METHOD ./bootstraptest/runner.rb with_stderr
0x7f6fd6555b78 BLOCK ./bootstraptest/runner.rb block in show_progress
0x7f6fd6555b40 BLOCK ./bootstraptest/runner.rb block in assert_check
0x7f6fd6555b08 METHOD ./bootstraptest/runner.rb get_result_string
0x7f6fd6555ad0 METHOD ./bootstraptest/runner.rb make_srcfile
0x7f6fd6555a98 CFUNC
0x7f6fd6555a60 BLOCK ./bootstraptest/runner.rb block in make_srcfile
```
Getting the main execution context is difficult (it is stored in a
thread local) so for now you must supply an ec and this will make a
backtrace
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)
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 😆
Show the size of String.
To see the whole contents even after NUL char:
```
(lldb) rp str
(const char [5]) $1 = "x"
(lldb) memory read -s1 --format x --count `sizeof($1)` -- &$1 0x1010457a8: 0x78 0x00 0x61 0x61 0x61
```
This fixes the following in my environment:
misc/expand_tabs.rb:29:in `=~': invalid byte sequence in US-ASCII (ArgumentError)
This switches from =~ to start_with? as a regular expression is
not actually needed here.
This is implemented to close [Misc #16112] because all other options got
at least one objection, and nobody has objected to this solution.
This code is a little complicated for the purpose, but that's just
because it includes some historical code for auto-style.rb:
918a7c31b6/bin/auto-style.rb
Please feel free to improve this file as you like.
[Misc #16112]
Nobuyoshi Nakada
Hiroshi SHIBATA
Aaron Patterson
Peter Zhu
Matt Valentine-House
Alexander Popov
Martin Rey
Romain Tartière
Jeremy Evans
Takashi Kokubun
tenderlove