1701978 - symbolication returns "line: 0" for symbols in SYM files with no line information

Status: RESOLVED FIXED

(Eliot :: General, defect, P2)

Description

[Will Kahn-Greene [:willkg] ET needinfo? me]

If we have a SYM file that has symbols and no LINE information, then doing lookups with symbolic will return "line: 0" as part of the LineInfo.

For example, minidump-stackwalk will return something like this:

{
    "frame": 0,
    "function": "KiFastSystemCallRet",
    "function_offset": "0x0",
    "module": "ntdll.dll",
    "module_offset": "0x470b4",
    "offset": "0x771b70b4",
    "trust": "context"
},

And the new symbolication API that uses symbolic will return something like this:

{
    "frame": 0,
    "function": "KiFastSystemCallRet",
    "function_offset": "0x0",
    "line": 0,
    "module": "ntdll.dll",
    "module_offset": "0x470b4",
    "offset": "0x771b70b4",
    "trust": "context"
},

As near as I can tell, this only occurs with SYM files from system libraries and other situations where we don't have the source code. If we don't have the source code, there isn't anything to look at for line 0, so maybe this isn't wildly important. I'm making it a P3 for now.

However, it is weird that "line: 0" indicates it's an invalid value for the line.

Comment 1

[Markus Stange [:mstange]]

As for the profiler, this doesn't cause any trouble because these results don't have a "file" property. The profiler only looks at the "line" property of results that also have a "file" property.

Comment 2

[Will Kahn-Greene [:willkg] ET needinfo? me]

That's incredibly helpful to know!

I'll fix the code to check for the file and if there's no file, then drop the line from the outgoing data because it doesn't make any sense.

Comment 3

[Will Kahn-Greene [:willkg] ET needinfo? me]

Attachment: pr 2411: bug 1701978: don't include line if there's no file

Comment 4

[Will Kahn-Greene [:willkg] ET needinfo? me]

willkg merged PR #2411: "bug 1701978: don't include line if there's no file" in 028fbe1.

Comment 5

[Will Kahn-Greene [:willkg] ET needinfo? me]

I merged this to main and deployed it to stage. We should be good here.