Reorganize how tb infrstructure selects toolchains

tests/lib/sim_testcase.py

@@ -1,24 +1,21 @@
 from typing import List
 import os
+
 import jinja2 as jj
+import pytest
 
 from .sv_line_anchor import SVLineAnchor
 
-from .simulators.questa import Questa
-from .simulators import StubSimulator
+from .simulators import get_simulator_cls
 
 from .base_testcase import BaseTestCase
 
-SIM_CLS = Questa
-if os.environ.get("STUB_SIMULATOR", False):
-    SIM_CLS = StubSimulator
-
 
 class SimTestCase(BaseTestCase):
     #: Abort test if it exceeds this number of clock cycles
     timeout_clk_cycles = 5000
 
-    simulator_cls = SIM_CLS
+    incompatible_sim_tools = set()
 
     tb_template_file = "tb_template.sv"
 
@@ -32,17 +29,14 @@ class SimTestCase(BaseTestCase):
     clocking_hwif_in = True
     clocking_hwif_out = True
 
-
-    @classmethod
-    def get_extra_tb_files(cls) -> List[str]:
+    def get_extra_tb_files(self) -> List[str]:
         paths = []
-        for path in cls.extra_tb_files:
-            path = os.path.join(cls.get_testcase_dir(), path)
+        for path in self.extra_tb_files:
+            path = os.path.join(self.get_testcase_dir(), path)
             paths.append(path)
         return paths
 
-    @classmethod
-    def _generate_tb(cls):
+    def _generate_tb(self):
         """
         Render the testbench template into actual tb.sv
         """
@@ -57,32 +51,38 @@ class SimTestCase(BaseTestCase):
         )
 
         context = {
-            "cls": cls,
-            "exporter": cls.exporter,
+            "testcase": self,
+            "exporter": self.exporter,
         }
 
         # template path needs to be relative to the Jinja loader root
-        template_path = os.path.join(cls.get_testcase_dir(), cls.tb_template_file)
+        template_path = os.path.join(self.get_testcase_dir(), self.tb_template_file)
         template_path = os.path.relpath(template_path, template_root_path)
         template = jj_env.get_template(template_path)
 
-        output_path = os.path.join(cls.get_run_dir(), "tb.sv")
+        output_path = os.path.join(self.get_run_dir(), "tb.sv")
         stream = template.stream(context)
         stream.dump(output_path)
 
 
-    @classmethod
-    def setUpClass(cls):
-        super().setUpClass()
+    def setUp(self):
+        name = self.request.config.getoption("--sim-tool")
+        if name in self.incompatible_sim_tools:
+            pytest.skip()
+        simulator_cls = get_simulator_cls(name)
+        if simulator_cls is None:
+            pytest.skip()
+
+        super().setUp()
 
         # Create testbench from template
-        cls._generate_tb()
+        self._generate_tb()
 
-        simulator = cls.simulator_cls(testcase_cls=cls)
+        simulator = simulator_cls(self)
 
         # cd into the build directory
         cwd = os.getcwd()
-        os.chdir(cls.get_run_dir())
+        os.chdir(self.get_run_dir())
         try:
             simulator.compile()
         finally:
@@ -91,5 +91,16 @@ class SimTestCase(BaseTestCase):
 
 
     def run_test(self, plusargs:List[str] = None) -> None:
-        simulator = self.simulator_cls(testcase_cls_inst=self)
-        simulator.run(plusargs)
+        name = self.request.config.getoption("--sim-tool")
+        simulator_cls = get_simulator_cls(name)
+        simulator = simulator_cls(self)
+
+        # cd into the build directory
+        cwd = os.getcwd()
+        os.chdir(self.get_run_dir())
+
+        try:
+            simulator.run(plusargs)
+        finally:
+            # cd back
+            os.chdir(cwd)