Improvements to REL & map support

- Fix symbols.txt align attribute
- Fully support nested RARC files & transparent Yaz0 decompression
- Guess symbol visibility for maps without link map
- Add module name config
- Add manual force_active config
- Quiet option for shasum
- `symbols_known` and `fill_gaps` config
- Allow disabling .comment generation per-unit (`comment:0`)
- Various minor fixes
- Add `rarc` and `yaz0` commands

src/obj/sections.rs

@@ -172,6 +172,9 @@ impl ObjSection {
 
     #[inline]
     pub fn symbol_data(&self, symbol: &ObjSymbol) -> Result<&[u8]> {
+        if symbol.size == 0 {
+            return Ok(&[]);
+        }
         self.data_range(symbol.address as u32, symbol.address as u32 + symbol.size as u32)
     }
 

src/obj/symbols.rs

@@ -329,7 +329,13 @@ impl ObjSymbols {
         self.at_section_address(section_idx, addr)
             .filter(|(_, sym)| sym.kind == kind)
             .at_most_one()
-            .map_err(|_| anyhow!("Multiple symbols of kind {:?} at address {:#010X}", kind, addr))
+            .map_err(|e| {
+                let symbols = e.map(|(_, s)| s).collect_vec();
+                for symbol in symbols {
+                    log::error!("{:?}", symbol);
+                }
+                anyhow!("Multiple symbols of kind {:?} at address {:#010X}", kind, addr)
+            })
     }
 
     // Iterate over all in address ascending order, excluding ABS symbols