Reimplement impl with fpp-to-cpp

src/fprime/fbuild/builder.py

@@ -247,6 +247,15 @@ def is_project_root(self, context: Path) -> bool:
         except CMakeException:
             return False
 
+    def is_submodule_build_structure(self) -> bool:
+        """Returns whether the F´ source code is a parent of the build.
+
+        Returns:
+            bool: True if the F´ code is a externally linked directory (e.g. a submodule)
+                  False if the build is self-contained within the F´ code (e.g. the Ref app)
+        """
+        return self.get_settings("framework_path", "") not in self.cmake_root.parents
+
     def find_toolchain(self):
         """Locates a toolchain file in know locations
 

src/fprime/fpp/common.py

@@ -142,7 +142,8 @@ def execute(
             ]
         else:
             input_args.extend(["-i", ",".join(map(str, imports))] if imports else [])
-            input_args.extend(sources)
+            input_args.extend([str(source) for source in sources])
+            input_args.append(str(locations))
 
         user_args = args[1]
         app_args = [self.utility] + user_args + input_args

src/fprime/fpp/impl.py

@@ -25,7 +25,7 @@ def fpp_generate_implementation(
     output_dir: Path,
     context: Path,
     apply_formatting: bool,
-    ut: bool,
+    generate_ut: bool,
     auto_test_helpers: bool = False,
 ) -> int:
     """
@@ -42,18 +42,16 @@ def fpp_generate_implementation(
     prefixes = [
         build.get_settings("framework_path", ""),
         *build.get_settings("library_locations", []),
-        build.cmake_root,
         build.build_dir / "F-Prime",
         build.build_dir,
     ]
+    if build.is_submodule_build_structure():
+        prefixes.append(build.cmake_root)
 
     # Holds the list of generated files to be passed to clang-format
     gen_files = tempfile.NamedTemporaryFile(prefix="fprime-impl-")
 
-    output_path = Path(output_dir)
-    if ut:
-        output_path = output_path / "test/ut"
-    output_path.mkdir(parents=True, exist_ok=True)
+    output_dir.mkdir(parents=True, exist_ok=True)
 
     # Run fpp-to-cpp --template
     FppUtility("fpp-to-cpp", imports_as_sources=False).execute(
@@ -63,12 +61,12 @@ def fpp_generate_implementation(
             {},
             [
                 "--template",
-                *(["--unit-test"] if ut else []),
+                *(["--unit-test"] if generate_ut else []),
                 *(["--auto-test-helpers"] if auto_test_helpers else []),
                 "--names",
                 gen_files.name,
                 "--directory",
-                output_path,
+                output_dir,
                 "--path-prefixes",
                 ",".join(map(str, prefixes)),
             ],
@@ -88,7 +86,7 @@ def fpp_generate_implementation(
         for line in gen_files.readlines():
             # FPP --names outputs a list of file names. output_dir is added to get relative path
             filename = Path(line.decode("utf-8").strip())
-            clang_formatter.stage_file(output_path / filename)
+            clang_formatter.stage_file(output_dir / filename)
         clang_formatter.execute(None, None, ({}, []))
 
     return 0
@@ -113,8 +111,8 @@ def run_fpp_impl(
 
     return fpp_generate_implementation(
         build,
-        parsed.output_dir,
-        parsed.path,
+        Path(parsed.output_dir),
+        Path(parsed.path),
         not parsed.no_format,
         parsed.ut,
         parsed.auto_test_helpers,