Add option for generating -include directives in dependency file

CHANGELOG.md

@@ -1,5 +1,9 @@
 # splat Release Notes
 
+### 0.39.2
+
+* New `ld_dependencies_include` option for generating additional dependency include directives.
+
 ### 0.39.1
 
 * Fix data-only splits missing the initial `macro.inc` include.

docs/Configuration.md

@@ -562,6 +562,10 @@ Folder where the built partially linked segments will be placed by the build sys
 
 Generate a dependency file for every linker script generated. Dependency files will have the same path and name as the corresponding linker script, but changing the extension to `.d`. Requires `elf_path` to be set.
 
+### ld_dependencies_include
+
+Emit an `-include` directive in the generated dependency file that includes .o file dependencies if they exist.
+
 ### ld_legacy_generation
 
 Currently splat imposes the given `section_order` when generating the linker script. But in some cases it may not be desirable to impose the section ordering because the ROM itself may not follow a logical section ordering.

src/splat/segtypes/linker_entry.py

@@ -529,18 +529,25 @@ def save_symbol_header(self):
             )
 
     def save_dependencies_file(self, output_path: Path, target_elf_path: Path):
+        seen = dict.fromkeys(
+            entry.object_path
+            for entry in self.dependencies_entries
+            if entry.object_path is not None
+        )
         output = f"{clean_up_path(target_elf_path).as_posix()}:"
-
-        for entry in self.dependencies_entries:
-            if entry.object_path is None:
-                continue
-            output += f" \\\n    {entry.object_path.as_posix()}"
-
+        for path in seen:
+            output += f" \\\n    {path.as_posix()}"
         output += "\n"
-        for entry in self.dependencies_entries:
-            if entry.object_path is None:
-                continue
-            output += f"{entry.object_path.as_posix()}:\n"
+        for path in seen:
+            output += f"{path.as_posix()}:\n"
+        if options.opts.ld_dependencies_include:
+            deps = [
+                path.with_suffix(".d").as_posix()
+                for path in seen
+                if path.suffix == ".o"
+            ]
+            if deps:
+                output += f"-include {' '.join(deps)}\n"
         write_file_if_different(output_path, output)
 
     def _writeln(self, line: str):

src/splat/util/options.py

@@ -139,6 +139,8 @@ class SplatOpts:
     ld_partial_build_segments_path: Optional[Path]
     # Generate a dependency file for every linker script generated. Dependency files will have the same path and name as the corresponding linker script, but changing the extension to `.d`. Requires `elf_path` to be set.
     ld_dependencies: bool
+    # Emit an `-include` directive for each object file in the dependency file.
+    ld_dependencies_include: bool
     # Legacy linker script generation does not impose the section_order specified in the yaml options or per-segment options.
     ld_legacy_generation: bool
     # If enabled, the end symbol for each segment will be placed before the alignment directive for the segment
@@ -531,6 +533,7 @@ def parse_include_asm_macro_style() -> Literal["default", "maspsx_hack"]:
             base_path, "ld_partial_build_segments_path"
         ),
         ld_dependencies=p.parse_opt("ld_dependencies", bool, False),
+        ld_dependencies_include=p.parse_opt("ld_dependencies_include", bool, False),
         ld_legacy_generation=p.parse_opt("ld_legacy_generation", bool, False),
         segment_end_before_align=p.parse_opt("segment_end_before_align", bool, False),
         segment_symbols_style=p.parse_opt_within(

test/basic_app/expected/basic_app.d

@@ -4,18 +4,10 @@ build/basic_app_target.elf: \
     build/src/main.o \
     build/asm/handwritten.o \
     build/asm/data/main.data.o \
-    build/asm/handwritten.o \
-    build/src/main.o \
-    build/asm/handwritten.o \
-    build/asm/data/main.bss.o \
-    build/asm/handwritten.o
+    build/asm/data/main.bss.o
 build/asm/header.o:
 build/assets/dummy_ipl3.o:
 build/src/main.o:
 build/asm/handwritten.o:
 build/asm/data/main.data.o:
-build/asm/handwritten.o:
-build/src/main.o:
-build/asm/handwritten.o:
 build/asm/data/main.bss.o:
-build/asm/handwritten.o: