Add --waves argument to generate waveforms for GHDL and NVC

docs/news.d/1101.feature.rst

@@ -0,0 +1,5 @@
+[GHDL/NVC] It is now possible to pass ``--waves`` to generate waveform files without
+opening the GUI. The earlier GHDL-only approach of passing ``--viewer-fmt``
+(or ``--gtkwave-fmt``) is deprecated and will be removed in a later version.
+There is also a new alias for providing the waveform format, ``--waves-fmt``,
+to make it consistent with the new flag.

vunit/sim_if/ghdl.py

@@ -58,13 +58,15 @@ def add_arguments(parser):
         group = parser.add_argument_group("ghdl/nvc", description="GHDL/NVC specific flags")
         group.add_argument(
             "--viewer-fmt",
+            "--waves-fmt",
             "--gtkwave-fmt",
             choices=["vcd", "fst", "ghw"],
             default=None,
             help="Save .vcd, .fst, or .ghw to open in waveform viewer. NVC does not support ghw.",
         )
         group.add_argument("--viewer-args", "--gtkwave-args", default="", help="Arguments to pass to waveform viewer")
         group.add_argument("--viewer", default=None, help="Waveform viewer to use")
+        group.add_argument("--waves", action='store_true', help="Generate waveform file")
 
     @classmethod
     def from_args(cls, args, output_path, **kwargs):
@@ -79,6 +81,7 @@ def from_args(cls, args, output_path, **kwargs):
             viewer_fmt=args.viewer_fmt,
             viewer_args=args.viewer_args,
             viewer=args.viewer,
+            waves=args.waves,
             backend=cls.determine_backend(prefix),
         )
 
@@ -98,6 +101,7 @@ def __init__(  # pylint: disable=too-many-arguments
         viewer_fmt=None,
         viewer_args="",
         viewer=None,
+        waves=False,
         backend="llvm",
     ):
         SimulatorInterface.__init__(self, output_path, gui)
@@ -111,6 +115,7 @@ def __init__(  # pylint: disable=too-many-arguments
 
         self._prefix = prefix
         self._project = None
+        self._waves = waves
 
         self._backend = backend
         self._vhdl_standard = None
@@ -366,6 +371,10 @@ def simulate(self, output_path, test_suite_name, config, elaborate_only):  # pyl
         ghdl_e = elaborate_only and config.sim_options.get("ghdl.elab_e", False)
 
         if self._viewer_fmt is not None:
+            if not self._waves and not self._gui:
+                LOGGER.warning("Passing --viewer-fmt, or any alias of that, without either "
+                               "--gui or --waves is deprecated and will be removed in a future version.")
+
             data_file_name = str(Path(script_path) / f"wave.{self._viewer_fmt!s}")
             if Path(data_file_name).exists():
                 remove(data_file_name)

vunit/sim_if/nvc.py

@@ -64,6 +64,7 @@ def from_args(cls, args, output_path, **kwargs):
             viewer_fmt=args.viewer_fmt,
             viewer_args=args.viewer_args,
             viewer=args.viewer,
+            waves=args.waves,
         )
 
     @classmethod
@@ -74,7 +75,7 @@ def find_prefix_from_path(cls):
         return cls.find_toolchain([cls.executable])
 
     def __init__(  # pylint: disable=too-many-arguments
-        self, output_path, prefix, *, num_threads, gui=False, viewer_fmt=None, viewer_args="", viewer=None
+        self, output_path, prefix, *, num_threads, gui=False, viewer_fmt=None, viewer_args="", viewer=None, waves=False
     ):
         SimulatorInterface.__init__(self, output_path, gui)
         if viewer_fmt == "ghw":
@@ -84,6 +85,7 @@ def __init__(  # pylint: disable=too-many-arguments
 
         self._prefix = prefix
         self._project = None
+        self._waves = waves
 
         self._vhdl_standard = None
         self._coverage_test_dirs = set()
@@ -257,7 +259,7 @@ def simulate(
         libdir = self._project.get_library(config.library_name).directory
         cmd = self._get_command(self._vhdl_standard, config.library_name, libdir)
 
-        if self._gui:
+        if self._gui or self._waves:
             wave_file = script_path / (f"{config.entity_name}.{self._viewer_fmt or 'fst'}")
             if wave_file.exists():
                 remove(wave_file)