Resolve relative paths of import_module_from_file against the testbench directory

docs/user_guide.rst

@@ -459,11 +459,15 @@ import_module_from_file and to_py_list_str
 
 ``import_module_from_file`` imports any Python file as a module by path (also
 taking an optional :ref:`session <python_bridge:sessions>` parameter), and is
-what ``import_run_script`` uses internally:
+what ``import_run_script`` uses internally. Like the file name of
+``exec_file``, a relative path is relative to the directory of the testbench
+file, ``tb_path``, so ``test_runner_setup`` must have been called; this works
+from verification components without ``runner_cfg``. An absolute path is used
+as it is given:
 
 .. code-block:: vhdl
 
-    import_module_from_file(join(tb_path(runner_cfg), "reference_model.py"), "reference_model");
+    import_module_from_file("reference_model.py", "reference_model");
     exec("reference_model.configure(gain=4)");
 
 ``to_py_list_str`` converts an ``integer_vector``, ``integer_vector_ptr_t`` or

release_notes/0.2.0.md

@@ -0,0 +1,3 @@
+## Changes
+
+- `import_module_from_file` resolves a relative path against the directory of the testbench file, like `exec_file`, rather than against the working directory of the simulator. It must be called after `test_runner_setup`. Callers that relied on a path relative to the working directory must pass an absolute path instead. See #7.

src/vunit_python_bridge/hdl/src/python_pkg.vhd

@@ -28,6 +28,9 @@ use vunit_lib.logger_pkg.all;
 ------------------------------------------------------------------------------
 
 package python_pkg is
+  -- Import a Python file as a module. A relative path is relative to the
+  -- directory of the testbench file, tb_path, so test_runner_setup must have
+  -- been called. An absolute path is used as it is given.
   procedure import_module_from_file(
     module_path, as_module_name : string; session : python_session_t := default_session
   );
@@ -274,6 +277,8 @@ package python_pkg is
 end package;
 
 package body python_pkg is
+  impure function p_file_path(file_name : string) return string;
+
   -- @formatter:off
   procedure import_module_from_file(
     module_path, as_module_name : string; session : python_session_t := default_session
@@ -283,7 +288,7 @@ package body python_pkg is
     "from importlib.util import spec_from_file_location, module_from_spec" & LF &
     "from pathlib import Path" & LF &
     "import sys" & LF &
-    spec_name & " = spec_from_file_location('" & as_module_name & "', str(Path('" & module_path & "')))" & LF &
+    spec_name & " = spec_from_file_location('" & as_module_name & "', str(Path('" & p_file_path(module_path) & "')))" & LF &
     as_module_name & " = module_from_spec(" & spec_name & ")" & LF &
     "sys.modules['" & as_module_name & "'] = " & as_module_name & LF &
      spec_name & ".loader.exec_module(" & as_module_name & ")";
@@ -893,8 +898,9 @@ package body python_pkg is
     return false;
   end;
 
-  -- The file name of exec_file, a relative one taken from the directory of the
-  -- testbench file like the file names of the other VUnit subprograms
+  -- The file name of exec_file and import_module_from_file, a relative one taken
+  -- from the directory of the testbench file like the file names of the other
+  -- VUnit subprograms
   impure function p_file_path(file_name : string) return string is
   begin
     if p_is_absolute(file_name) then

src/vunit_python_bridge/hdl/tools/python_pkg.vhd.in

@@ -28,6 +28,9 @@ use vunit_lib.logger_pkg.all;
 ------------------------------------------------------------------------------
 
 package python_pkg is
+  -- Import a Python file as a module. A relative path is relative to the
+  -- directory of the testbench file, tb_path, so test_runner_setup must have
+  -- been called. An absolute path is used as it is given.
   procedure import_module_from_file(
     module_path, as_module_name : string; session : python_session_t := default_session
   );
@@ -176,6 +179,8 @@ $call_declarations
 end package;
 
 package body python_pkg is
+  impure function p_file_path(file_name : string) return string;
+
   -- @formatter:off
   procedure import_module_from_file(
     module_path, as_module_name : string; session : python_session_t := default_session
@@ -185,7 +190,7 @@ package body python_pkg is
     "from importlib.util import spec_from_file_location, module_from_spec" & LF &
     "from pathlib import Path" & LF &
     "import sys" & LF &
-    spec_name & " = spec_from_file_location('" & as_module_name & "', str(Path('" & module_path & "')))" & LF &
+    spec_name & " = spec_from_file_location('" & as_module_name & "', str(Path('" & p_file_path(module_path) & "')))" & LF &
     as_module_name & " = module_from_spec(" & spec_name & ")" & LF &
     "sys.modules['" & as_module_name & "'] = " & as_module_name & LF &
      spec_name & ".loader.exec_module(" & as_module_name & ")";
@@ -737,8 +742,9 @@ $arg_functions
     return false;
   end;
 
-  -- The file name of exec_file, a relative one taken from the directory of the
-  -- testbench file like the file names of the other VUnit subprograms
+  -- The file name of exec_file and import_module_from_file, a relative one taken
+  -- from the directory of the testbench file like the file names of the other
+  -- VUnit subprograms
   impure function p_file_path(file_name : string) return string is
   begin
     if p_is_absolute(file_name) then

tests/tb_python_pkg_bridge.vhd

@@ -143,6 +143,12 @@ begin
       check_equal(integer'(call("bump", data)), 5);
     end;
 
+    -- Imports the way a verification component would, without runner_cfg
+    procedure import_filters is
+    begin
+      import_module_from_file("models/filters.py", "filters_model");
+    end;
+
   begin
     test_runner_setup(runner, runner_cfg);
 
@@ -219,6 +225,16 @@ begin
         exec_file("models/counter.py");
         check_equal(integer'(call("get_call_count")), 2);
 
+      elsif run("Test importing a module with a relative file name") then
+        -- The simulator runs in the VUnit output path, not the testbench directory
+        check_false(eval_boolean("__import__('os').path.samefile('.', '" & tb_path(runner_cfg) & "')"));
+        import_filters;
+        check_equal(integer'(call("filters_model.fir", arg(2))), 3);
+
+      elsif run("Test importing a module with an absolute file name") then
+        import_module_from_file(join(tb_path(runner_cfg), "models/filters.py"), "filters_model");
+        check_equal(integer'(call("filters_model.fir", arg(2))), 3);
+
       elsif run("Test that exec_file with a missing file fails") then
         -- The error message shows the path in the native format of the OS
         exec("import os" + "def native_repr(path):" + "    return repr(os.path.normpath(path))");