Rework -f argfile mechanism to avoid argparse required checks. #11

src/peakrdl/main.py

@@ -1,6 +1,8 @@
 import argparse
 import sys
-from typing import TYPE_CHECKING, List, Dict
+import os
+import shlex
+from typing import TYPE_CHECKING, List, Dict, Optional, Set
 
 from systemrdl import RDLCompileError
 
@@ -48,6 +50,42 @@ def __call__ (self, parser, namespace, values, option_string = None): # type: ig
         sys.exit(0)
 
 
+def get_file_args(path: str) -> List[str]:
+    if not os.path.exists(path):
+        print(f"error: file not found: {path}", file=sys.stderr)
+        sys.exit(1)
+
+    with open(path, "r", encoding='utf-8') as f:
+        return shlex.split(f.read(), comments=True)
+
+
+def expand_file_args(argv: List[str], _pathlist: Optional[Set[str]] = None) -> List[str]:
+    if _pathlist is None:
+        _pathlist = set()
+
+    new_argv = []
+    argv_iter = iter(argv)
+    for arg in argv_iter:
+        if arg == "-f":
+            try:
+                path = next(argv_iter)
+            except StopIteration:
+                print("error: argument -f: expected FILE", file=sys.stderr)
+                sys.exit(1)
+
+            if path in _pathlist:
+                print(f"error: circular reference in -f files: '{path}' was already opened", file=sys.stderr)
+                sys.exit(1)
+            _pathlist.add(path)
+            file_args = get_file_args(path)
+            file_args = expand_file_args(file_args, _pathlist)
+            _pathlist.remove(path)
+            new_argv.extend(file_args)
+        else:
+            new_argv.append(arg)
+    return new_argv
+
+
 def main() -> None:
     # Collect all subcommands
     subcommands = [
@@ -83,7 +121,8 @@ def main() -> None:
         subcommand._init_subparser(subgroup)
 
     # Execute!
-    options = parser.parse_args()
+    argv = expand_file_args(sys.argv[1:])
+    options = parser.parse_args(argv)
     if not hasattr(options, 'subcommand'):
         parser.print_usage()
         print(f"{parser.prog}: error the following arguments are required: <subcommand>")

src/peakrdl/subcommand.py

@@ -14,22 +14,6 @@
     from systemrdl.node import AddrmapNode
     from systemrdl.udp import UDPDefinition
 
-
-class LoadArgsFromFile(argparse.Action):
-    def __call__ (self, parser, namespace, values, option_string = None): # type: ignore
-        argfile = values
-
-        if not os.path.exists(argfile):
-            print(f"file not found: {argfile}", file=sys.stderr)
-            sys.exit(1)
-
-        with open(argfile, "r", encoding='utf-8') as f:
-            parser.parse_args(
-                shlex.split(f.read(), comments=True),
-                namespace
-            )
-
-
 class Subcommand:
     """
     Base command line interface subcommand class
@@ -57,10 +41,11 @@ def _init_subparser(self, subgroup: 'argparse._SubParsersAction') -> None:
         self.add_arguments(subparser)
         subparser.set_defaults(subcommand=self)
 
+        # Add
         subparser.add_argument(
             '-f',
-            metavar="FILENAME",
-            action=LoadArgsFromFile,
+            metavar="FILE",
+            dest="argfile",
             help="Specify a file containing more command line arguments"
         )