Handle source node ID + line number for sections (#13)

See gbdev/rgbds#1494

rgbobj.1

@@ -138,6 +138,8 @@ The section's address, or
 if it isn't fixed.
 .It Cm size
 The section's size.
+.It Cm src
+Where the section was defined.
 .It Cm type
 The section's type (ROM0, ROMX, etc.) and modifier (normal, union, fragment).
 .El

src/args.rs

@@ -233,7 +233,7 @@ pub mod features {
 
     features!(HeaderFeatures: +size, counts);
     features!(SymbolFeatures: +name, type, src, section, value, id);
-    features!(SectionFeatures: +name, size, type, org, bank, align, data);
+    features!(SectionFeatures: +name, size, type, org, bank, align, src, data);
     features!(PatchFeatures: +count, src, offset, pcsection, pcoffset, type, rpn, data);
     features!(AssertionFeatures: +src, +offset, section, pcoffset, type, rpn, -data, +message);
 }

src/main.rs

@@ -123,9 +123,9 @@ fn work(args: &Args) -> Result<(), MainError> {
         };
     }
 
-    macro_rules! print_source_nodes {
+    macro_rules! print_source_nodes_helper {
         ($source:expr) => {{
-            let (id, line_no) = ($source).source();
+            let (id, line_no) = $source;
             // TODO: wrap the node stack nicely
             object
                 .walk_nodes::<Infallible, _>(id, &mut |node: &Node| {
@@ -158,6 +158,21 @@ fn work(args: &Args) -> Result<(), MainError> {
         }};
     }
 
+    macro_rules! print_source_nodes {
+        ($source:expr) => {{
+            print_source_nodes_helper!(($source).source())
+        }};
+    }
+
+    macro_rules! opt_print_source_nodes {
+        ($source:expr) => {{
+            match ($source).source() {
+                Some(tup) => print_source_nodes_helper!(tup),
+                _ => Ok(()),
+            }
+        }};
+    }
+
     macro_rules! print_rpn_expr {
         ($indent:expr, $expr:expr) => {
             println!("{}{} expression:", $indent, args.rpn);
@@ -397,6 +412,15 @@ fn work(args: &Args) -> Result<(), MainError> {
 
             let indent = if first_line_empty { "" } else { "    " };
 
+            if args.section.get(SectionFeatures::SRC) {
+                print!("{indent}");
+                if let Err(err) = opt_print_source_nodes!(section) {
+                    error!("Invalid section file stack: {}", err);
+                }
+                println!();
+                printed_lines += 1;
+            }
+
             if args.section.get(SectionFeatures::SIZE) {
                 let len = section.size();
                 println!(