|  support |  documentation |  report a bug |  advanced search |  search howto |  statistics |  random bug |  login
Request #70024 Add column information to AST
Submitted: 2015-07-08 14:47 UTC Modified: 2019-03-15 15:42 UTC
Avg. Score:3.0 ± 0.0
Reproduced:0 of 0 (0.0%)
From: krblock at computer dot org Assigned: nikic (profile)
Status: Assigned Package: *Compile Issues
PHP Version: 7.0.0alpha2 OS:
Private report: No CVE-ID: None
View Add Comment Developer Edit
Welcome! If you don't have a Git account, you can't do anything here.
You can add a comment by following this link or if you reported this bug, you can edit this bug over here.
Block user comment
Status: Assign to:
Bug Type:
From: krblock at computer dot org
New email:
PHP Version: OS:


 [2015-07-08 14:47 UTC] krblock at computer dot org
I am evaluating PHP Parsers to use in a Static Analysis tool. When defects are reported, we like to pin point the location of the issue as precisely as possible. We also like to provide cross reference information. It would be useful to have column location stored in the AST in addition to line location. 

Test script:
I used the AST dumper provided here:

RFC for AST is here:

Both omit column information.


Add a Patch

Pull Requests

Add a Pull Request


AllCommentsChangesGit/SVN commitsRelated reports
 [2015-07-09 07:41 UTC]
-Status: Open +Status: Assigned -Assigned To: +Assigned To: nikic
 [2015-07-09 07:41 UTC]
I don't think we uses columns anywhere in the code to help identify errors, so we would have to add it just for this feature, Nikita do you have any input on this? (Just unassign after if desired)
 [2015-07-09 09:42 UTC]
Yeah, we currently only store the line number. Adding accurate position information would require an additional 16 bytes per AST node. I'm not sure if this is worthwhile if we don't need this info ourselves.
 [2015-07-09 13:18 UTC] krblock at computer dot org
Static Analysis is not run on every invocation of a compiler, so it is much more tolerant of performance degradation. The column information could be stored in a data structure on the side that could be generated on demand and could be correlated back to the AST. For example, when doing Java Static Analysis, we run the compiler in debug mode to get debug symbol information.

To build tools like PHPDOC and PHPXREF, this information will probably be needed as well, and the tools will also probably be tolerant of some performance degradation.
 [2015-07-10 00:37 UTC]
Performance-wise it doesn't make sense to add this to the regular build, but it might be possible to add when PHP is compiled in debug mode. That means you would need a separate PHP build, of course.
 [2015-07-18 13:09 UTC]
I don't think there's much value in making this available only in debug builds. I mean, both things are pretty independent, there's no reason why you'd want to run a static analyzer using a slow debug build.

Having this in a separate on-demand structure sounds more useful, though not quite clear yet how it would like look.

In any case the first step towards this would be to start using bison location tracking instead of our current lineno tracking. Documentation for access in semantic actions is in and the reentrant yylex API is documented in
 [2019-03-15 15:42 UTC]
Finally got around to implementing the bison location tracking in

This would allow us to implement this FR from a technical perspective. As before, I'm not sure we actually want to do so though.
PHP Copyright © 2001-2024 The PHP Group
All rights reserved.
Last updated: Thu Apr 18 23:01:27 2024 UTC