Drop support for Python 3.7.

.github/workflows/main.yaml

@@ -6,12 +6,10 @@ jobs:
     strategy:
       matrix:
         python-version:
-        - '3.7'
         - '3.8'
         - '3.9'
         - '3.10'
         - '3.11'
-        - 'pypy-3.7'
         - 'pypy-3.8'
         - 'pypy-3.9'
         allow-failure:
@@ -37,7 +35,7 @@ jobs:
         sudo apt-get update
         sudo apt-get install yices2
         pip install coverage codecov
-        pip install yowasp-yosys==0.20.* # last version compatible with Python 3.7
+        pip install yowasp-yosys
         pip install -e .[builtin-yosys]
         pip install -r docs/requirements.txt
     - name: Preserve Wasm cache

amaranth/__init__.py

@@ -1,9 +1,7 @@
 try:
-    try:
+    from importlib import metadata as importlib_metadata
-        from importlib import metadata as importlib_metadata # py3.8+ stdlib
-    except ImportError:
-        import importlib_metadata # py3.7- shim
     __version__ = importlib_metadata.version(__package__)
+    del importlib_metadata
 except ImportError:
     # No importlib_metadata. This shouldn't normally happen, but some people prefer not installing
     # packages via pip at all, instead using PYTHONPATH directly or copying the package files into

amaranth/_toolchain/yosys.py

@@ -4,13 +4,7 @@ import re
 import subprocess
 import warnings
 import pathlib
-try:
+from importlib import metadata as importlib_metadata
-    from importlib import metadata as importlib_metadata # py3.8+ stdlib
-except ImportError:
-    try:
-        import importlib_metadata # py3.7- shim
-    except ImportError:
-        importlib_metadata = None # not installed
 try:
     from importlib import resources as importlib_resources
     try:

docs/changes.rst

@@ -13,7 +13,7 @@ The language includes several new extension points for integration with :class:`
 
 Several issues with shape inference have been resolved. Notably, ``a - b`` where both ``a`` and ``b`` are unsigned now returns a signed value.
 
-Support for Python 3.6 has been removed, and support for Python 3.11 and 3.12 has been added.
+Support for Python 3.6 and 3.7 has been removed, and support for Python 3.11 and 3.12 has been added.
 
 Features deprecated in version 0.3 have been removed. In particular, the ``nmigen.*`` namespace is not provided, ``# nmigen:`` annotations are not recognized, and ``NMIGEN_*`` envronment variables are not used.
 

docs/install.rst

@@ -6,7 +6,7 @@ System requirements
 
 .. |yosys-version| replace:: 0.10 (or newer)
 
-Amaranth HDL requires Python 3.7; it works on CPython_ 3.7 (or newer), and works faster on PyPy3.7_ 7.3.3 (or newer). Installation requires pip_ 23.0 (or newer).
+Amaranth HDL requires Python 3.8; it works on CPython_ 3.8 (or newer), and works faster on PyPy3.8_ 7.3.7 (or newer). Installation requires pip_ 23.0 (or newer).
 
 For most workflows, Amaranth requires Yosys_ |yosys-version|. A compatible version of Yosys is distributed via PyPI_ for most popular platforms.
 
@@ -17,7 +17,7 @@ Synthesizing, placing and routing an Amaranth design for an FPGA requires the FP
 .. TODO: Link to FPGA family docs here
 
 .. _CPython: https://www.python.org/
-.. _PyPy3.7: https://www.pypy.org/
+.. _PyPy3.8: https://www.pypy.org/
 .. _pip: https://pip.pypa.io/
 .. _Yosys: https://yosyshq.net/yosys/
 .. _PyPI: https://pypi.org/

pyproject.toml

@@ -10,9 +10,8 @@ description = "Amaranth hardware definition language"
 authors = [{name = "Amaranth HDL contributors"}]
 license = {file = "LICENSE.txt"}
 
-requires-python = "~=3.7"
+requires-python = "~=3.8"
 dependencies = [
-  "importlib_metadata;  python_version<'3.8'", # for __version__ and amaranth._toolchain.yosys
   "importlib_resources; python_version<'3.9'", # for amaranth._toolchain.yosys
   "pyvcd>=0.2.2,<0.5", # for amaranth.sim.pysim
   "Jinja2~=3.0", # for amaranth.build

tests/utils.py

@@ -56,6 +56,7 @@ class FHDLTestCase(unittest.TestCase):
         mode {mode}
         depth {depth}
         wait on
+        multiclock on
 
         [engines]
         smtbmc