Dynamically determine value of use_tmpcpy based on library (DLL) ve…

…rsion (#223)

CONTRIBUTORS.md

@@ -24,3 +24,4 @@ In the order of appearance in the commit history:
 | Dominic Shelton           | @frogamic          |
 | Fletcher D                | @FletcherD         |
 | G Towers                  | @gtowers-dukosi    |
+| Ben Brown                 | @bbrown1867        |

pylink/jlink.py

@@ -247,7 +247,7 @@ def wrapper(self, *args, **kwargs):
         return _interface_required
 
     def __init__(self, lib=None, log=None, detailed_log=None, error=None, warn=None, unsecure_hook=None,
-                 serial_no=None, ip_addr=None, open_tunnel=False, use_tmpcpy=True):
+                 serial_no=None, ip_addr=None, open_tunnel=False, use_tmpcpy=None):
         """Initializes the J-Link interface object.
 
         Note:
@@ -279,7 +279,8 @@ def __init__(self, lib=None, log=None, detailed_log=None, error=None, warn=None,
             of ``open`` method.
             If ``None``, the driver will not be opened automatically
             (however, it is still closed when exiting the context manager).
-          use_tmpcpy (bool): True to load a temporary copy of J-Link DLL
+          use_tmpcpy (Optional[bool]): ``True`` to load a temporary copy of
+            J-Link DLL, ``None`` to dynamically decide based on DLL version.
 
         Returns:
           ``None``

pylink/library.py

@@ -18,6 +18,7 @@
 import ctypes.util as ctypes_util
 import os
 import platform
+import re
 import sys
 import tempfile
 
@@ -279,7 +280,7 @@ def find_library_darwin(cls):
                     if f.startswith(dll):
                         yield os.path.join(dir_path, f)
 
-    def __init__(self, dllpath=None, use_tmpcpy=True):
+    def __init__(self, dllpath=None, use_tmpcpy=None):
         """Initializes an instance of a ``Library``.
 
         Loads the default J-Link DLL if ``dllpath`` is ``None``, otherwise
@@ -288,7 +289,8 @@ def __init__(self, dllpath=None, use_tmpcpy=True):
         Args:
           self (Library): the ``Library`` instance
           dllpath (str): the DLL to load into the library
-          use_tmpcpy (bool): True to load a temporary copy of J-Link DLL
+          use_tmpcpy (Optional[bool]): ``True`` to load a temporary copy of
+            J-Link DLL, ``None`` to dynamically decide based on DLL version.
 
         Returns:
           ``None``
@@ -410,6 +412,11 @@ def load(self, path=None):
 
         lib_path = self._path
 
+        if self._use_tmpcpy is None:
+            # Fall back to ``True`` if version lookup failed (old pylink default)
+            maybe_version = self.dll_version()
+            self._use_tmpcpy = (maybe_version <= 6.10) if maybe_version else True
+
         if self._use_tmpcpy:
             # Copy the J-Link DLL to a temporary file.  This will be cleaned up the
             # next time we load a DLL using this library or if this library is
@@ -500,6 +507,22 @@ def dll(self):
         """
         return self._lib
 
+    def dll_version(self):
+        """Returns the DLL version number.
+
+        Args:
+          self (Library): the ``Library`` instance
+
+        Returns:
+            DLL version number (e.g. 7.96) or ``None`` if parsing fails.
+        """
+        if self._path is not None:
+            match = re.search(r"JLink(?:_Linux)?_V(\d+)", self._path)
+            if match:
+                num_part = match.group(1)
+                return float(f"{num_part[0]}.{num_part[1:]}")
+        return None
+
 
 class JLinkarmDlInfo:
     """Helper to retrieve the absolute path of the JLink library (aka DLL)

tests/unit/test_library.py

@@ -1124,6 +1124,18 @@ def test_linux_dl_oserror(self, mock_load_library, mock_find_library, mock_libc_
         self.assertEqual(2, mock_find_library.call_count)
         self.assertEqual(2, mock_load_library.call_count)
 
+    @mock.patch('ctypes.cdll.LoadLibrary')
+    def test_dll_version_linux(self, _mock_load_library):
+        path = "/opt/SEGGER/JLink_Linux_V684b_x86_64/libjlinkarm.so"
+        lib = library.Library(path)
+        self.assertEqual(lib.dll_version(), 6.84)
+
+    @mock.patch('ctypes.cdll.LoadLibrary')
+    def test_dll_version_mac(self, _mock_load_library):
+        path = "/Applications/SEGGER/JLink_V796n/libjlinkarm.dylib"
+        lib = library.Library(path)
+        self.assertEqual(lib.dll_version(), 7.96)
+
 
 if __name__ == '__main__':
     unittest.main()