Feature/php strategy

[Sangoku]

Added a php tree sitter parser so we have support for php.

[johnhuang316]

Thanks for the PR - adding PHP support with a dedicated tree-sitter strategy is definitely the right direction.

I’m going to request changes before merging though.

Main concerns:

• there are no tests for the new PHP strategy yet
• call relationship tracking seems to miss forward references
• member call resolution looks a bit too broad and may resolve to the wrong method if multiple classes use the same method name
• this PR also mixes the shallow index path/hash fix with the PHP parser work, which makes it harder to review

Could you update this by:

• adding PHP strategy tests
• handling deferred/pending calls for forward references
• tightening member call resolution
• ideally splitting the index-path fix from the PHP feature

Happy to take another look after that.

[johnhuang316]

Code Review Summary

Thanks for adding PHP support — this is a useful direction for the project. However, I found several issues that should be addressed before this can be merged.

Blocking

1. Circular import introduced by ShallowIndexManager

   src/code_index_mcp/indexing/shallow_index_manager.py now imports ProjectSettings at module import time:

   from ..project_settings import ProjectSettings

   This creates a circular import through:

   project_settings.py
    -> search.ag
    -> search.base
    -> indexing.__init__
    -> shallow_index_manager
    -> project_settings
   

   Running the test suite currently fails during import:

   ImportError: cannot import name 'ProjectSettings' from partially initialized module 'code_index_mcp.project_settings'
   

   Please avoid importing ProjectSettings at module scope here. A lazy import inside the method may be enough as a minimal fix, but the cleaner approach would be to move shared index-root resolution into a small helper that does not import the indexing package back through project_settings.

2. uv.lock is not updated

   pyproject.toml adds:

   tree-sitter-php>=0.22.0

   but uv.lock is not included in the PR. Please run:

   uv lock

   and commit the updated lockfile.

3. PHP call relationship tracking is incomplete

   The PR description says this tracks function/method call relationships, but the current implementation only resolves calls to symbols that have already been encountered earlier in the same traversal.

   For common PHP code like this:

   <?php
   class A {
       function b() {
           helper();
           $this->validate();
       }
   
       function validate() {}
   }
   
   function helper() {}

   both helper() and $this->validate() are missed because those symbols are registered later in the file.

   Please consider a two-pass approach:

   • first pass: register all classes/functions/methods
   • second pass: analyze calls and fill called_by

   Alternatively, unresolved calls should be stored as pending calls, similar to the existing strategies that handle forward references.

Warnings / Suggestions

• self::method() / static::method() are parsed as scoped_call_expression, but the strategy currently only handles function_call_expression and member_call_expression.
• Grouped imports such as use Foo\{Baz, Qux as Alias}; are not extracted correctly because namespace_use_group is not traversed for individual clauses.
• Please add focused tests for the new PHP strategy, including:
  • extension routing to PhpParsingStrategy
  • namespace and use extraction
  • class / interface / trait / enum extraction
  • function and method extraction
  • $this->method() relationships
  • forward-reference function/method calls
  • self::method() / scoped calls
  • grouped use declarations

Additional note

GitHub currently reports this PR as conflicting with master, so it will also need to be rebased or updated after the above issues are fixed.

Thanks again for the contribution — once the import failure, lockfile, and PHP call-resolution behavior are addressed, this should be much safer to review again.