[Lldb-commits] [PATCH] D146765: [lldb/crashlog] Load inlined symbol into interactive crashlog

[Dave Lee via Phabricator via lldb-commits]

kastiglione added inline comments.


================
Comment at: lldb/examples/python/crashlog.py:669
+                             r'(0x[0-9a-fA-F]{4,}) +'               # addr (4 chars or more)
+                             r'((.*)(?:(?: +\+ +)([0-9]+))|[^\s]+)' # symbol + offset
                             )
----------------
mib wrote:
> kastiglione wrote:
> > mib wrote:
> > > @kastiglione may be you have a better idea how to handle `symbol + offset` where ` + offset` might be optional.
> > symbol is always present?
> Technically, in the past the `offs` (symbol + offset) was optional:
> ```
> r'(?: +(.*))?'
> ```
> So I guess `symbol` could be missing.
Breaking it down, there is:

1. a symbol (maybe)
2. the literal text " + " followed by a number (also maybe)

I'll start start with 2:

```
 \+ (\d+)
```

For the symbol, `.*`, it should instead have at least a length of 1. I'd use `+` instead of `*`. And, it shouldn't be _any_ character. At the very least it should be non-space, which is `\S`.

To combine these at a high level it looks like:

```
(?:(<symbol>)(?:<offset>)?)?
```

Filling in these two with symbol='\S+' and offset=' \+ (\d+)', it becomes:

```
(?:(\S+)(?: \+ (\d+))?)?
```

Here's some python real session that minimally exercises this code:

```
% python
>>> import re
>>> pat = re.compile(r"(?:(\S+)(?: \+ (\d+))?)?")
>>> pat.match("func + 123").groups()
('func', '123')
>>> pat.match("func").groups()
('func', None)
>>> pat.match("").groups()
(None, None)
>>> 
```


Repository:
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  https://reviews.llvm.org/D146765/new/

https://reviews.llvm.org/D146765