Add function that modifies the default profiler/compiler arguments to allow reusing them in multiple magic command calls

nvcc4jupyter/parsers.py

@@ -3,6 +3,39 @@ Parsers for the CUDA magic commands.
 """
 
 import argparse
+from typing import Callable, Optional
+
+_default_profiler_args: str = ""
+_default_compiler_args: str = ""
+
+
+def set_defaults(
+    compiler_args: Optional[str] = None, profiler_args: Optional[str] = None
+) -> None:
+    """
+    Set the default values for various arguments of the magic commands. These
+    values will be used if the user does not explicitly provide those arguments
+    to override this behaviour on a cell by cell basis.
+
+    Args:
+        compiler_args: If not None, this value becomes the new default compiler
+            config. Defaults to "".
+        profiler_args: If not None, this value becomes the new default profiler
+            config. Defaults to "".
+    """
+
+    # pylint: disable=global-statement
+    global _default_compiler_args
+    global _default_profiler_args
+    if compiler_args is not None:
+        _default_compiler_args = compiler_args
+    if profiler_args is not None:
+        _default_profiler_args = profiler_args
+
+
+def str_to_lambda(arg: str) -> Callable[[], str]:
+    """Convert argparse string to lambda"""
+    return lambda: arg
 
 
 def get_parser_cuda() -> argparse.ArgumentParser:
@@ -18,8 +51,22 @@ def get_parser_cuda() -> argparse.ArgumentParser:
     )
     parser.add_argument("-t", "--timeit", action="store_true")
     parser.add_argument("-p", "--profile", action="store_true")
-    parser.add_argument("-a", "--profiler-args", type=str, default="")
-    parser.add_argument("-c", "--compiler-args", type=str, default="")
+
+    # --profiler-args and --compiler-args values are lambda functions to allow
+    # changing the default value at runtime
+    parser.add_argument(
+        "-a",
+        "--profiler-args",
+        type=str_to_lambda,
+        default=lambda: _default_profiler_args,
+    )
+    parser.add_argument(
+        "-c",
+        "--compiler-args",
+        type=str_to_lambda,
+        default=lambda: _default_compiler_args,
+    )
+
     return parser