stubgen: add DLL_PATH option to locate dependent DLLs on Windows

Author: Doekin

cmake/nanobind-config.cmake

@@ -562,7 +562,7 @@ endfunction()
 # ---------------------------------------------------------------------------
 
 function (nanobind_add_stub name)
-  cmake_parse_arguments(PARSE_ARGV 1 ARG "VERBOSE;INCLUDE_PRIVATE;EXCLUDE_DOCSTRINGS;INSTALL_TIME;EXCLUDE_FROM_ALL" "MODULE;OUTPUT;MARKER_FILE;COMPONENT;PATTERN_FILE" "PYTHON_PATH;DEPENDS")
+  cmake_parse_arguments(PARSE_ARGV 1 ARG "VERBOSE;INCLUDE_PRIVATE;EXCLUDE_DOCSTRINGS;INSTALL_TIME;EXCLUDE_FROM_ALL" "MODULE;OUTPUT;MARKER_FILE;COMPONENT;PATTERN_FILE" "PYTHON_PATH;DLL_PATH;DEPENDS")
 
   if (EXISTS ${NB_DIR}/src/stubgen.py)
     set(NB_STUBGEN "${NB_DIR}/src/stubgen.py")
@@ -590,6 +590,10 @@ function (nanobind_add_stub name)
     list(APPEND NB_STUBGEN_ARGS -i "${TMP}")
   endforeach()
 
+  foreach (TMP IN LISTS ARG_DLL_PATH)
+    list(APPEND NB_STUBGEN_ARGS -L "${TMP}")
+  endforeach()
+
   if (ARG_PATTERN_FILE)
     list(APPEND NB_STUBGEN_ARGS -p "${ARG_PATTERN_FILE}")
   endif()

src/stubgen.py

@@ -1210,6 +1210,16 @@ def parse_options(args: List[str]) -> argparse.Namespace:
         help="add the directory to the Python import path (can specify multiple times)",
     )
 
+    parser.add_argument(
+        "-L",
+        "--dll-path",
+        action="append",
+        metavar="PATH",
+        dest="dll_paths",
+        default=[],
+        help="add directory to DLL search path (ignored on non-Windows, can specify multiple times)",
+    )
+
     parser.add_argument(
         "-m",
         "--module",
@@ -1342,6 +1352,7 @@ def add_pattern(query: str, lines: List[str]):
 
 def main(args: Optional[List[str]] = None) -> None:
     import sys
+    import os
 
     # Ensure that the current directory is on the path
     if "" not in sys.path and "." not in sys.path:
@@ -1362,6 +1373,10 @@ def main(args: Optional[List[str]] = None) -> None:
     for i in opt.imports:
         sys.path.insert(0, i)
 
+    if os.name == 'nt':
+        for dll_path in opt.dll_paths:
+            os.add_dll_directory(dll_path)
+
     for i, mod in enumerate(opt.modules):
         if not opt.quiet:
             if i > 0: