Reapply "Add call to python compiler (#1715)" (#1760) (#1761)

This reverts commit a2e4742.

Author: erick-xanadu

.dep-versions

@@ -8,7 +8,7 @@ enzyme=v0.0.149
 
 # For a custom PL version, update the package version here and at
 # 'doc/requirements.txt
-pennylane=0.42.0-dev29
+pennylane=0.42.0-dev33
 
 # For a custom LQ/LK version, update the package version here and at
 # 'doc/requirements.txt'

doc/releases/changelog-dev.md

@@ -2,6 +2,10 @@
 
 <h3>New features since last release</h3>
 
+* Added integration with PennyLane's experimental python compiler based on xDSL.
+  This allows developers and users to write xDSL transformations that can be used with Catalyst.
+  [(#1715)](https://github.com/PennyLaneAI/catalyst/pull/1715)
+
 * A new compilation pass called :func:`~.passes.ppr_to_ppm` has been added to Catalyst
   to decompose Pauli product rotations (PPRs), :math:`\exp(-iP_{\{x, y, z\}} \theta)`, into
   Pauli product measurements (PPMs). Non-Clifford PPR (:math:`\theta = \tfrac{\pi}{8}`) requires

doc/requirements.txt

@@ -33,4 +33,4 @@ lxml_html_clean
 --extra-index-url https://test.pypi.org/simple/
 pennylane-lightning-kokkos==0.42.0-dev16
 pennylane-lightning==0.42.0-dev16
-pennylane==0.42.0-dev29
+pennylane==0.42.0-dev33

frontend/catalyst/compiler.py

@@ -506,7 +506,14 @@ def run(self, mlir_module, *args, **kwargs):
             (str): filename of shared object
         """
 
-        self.is_using_python_compiler()
+        if self.is_using_python_compiler():
+            # We keep this module here to keep xDSL requirement optional
+            # Only move this is it has been decided that xDSL is no longer optional.
+            # pylint: disable-next=import-outside-toplevel
+            from pennylane.compiler.python_compiler.impl import Compiler as PythonCompiler
+
+            compiler = PythonCompiler()
+            mlir_module = compiler.run(mlir_module)
 
         return self.run_from_ir(
             mlir_module.operation.get_asm(