2 files changed, 35 insertions, 0 deletions

diff --git a/crates/nasm/README.md b/crates/nasm/README.md
index 2675bfb..750e795 100644
--- a/crates/nasm/README.md
+++ b/crates/nasm/README.md
@@ -246,6 +246,22 @@ fit in a byte. Hence, you could have a code like follows:
 If you compile the code with `-D PAL=1`, then the first branch will be taken
 instead of the second one.
 
+## The .nasm/ directory
+
+When you enable the `--write-info` flag, some files will be written into a
+hidden `.nasm/` directory. This directory will contain debug information that
+can be later used by other tools. That being said, some of these files can also
+be useful to programmers. They are as follows:
+
+- `segments.txt`: summary of the segments being used and how much they have been
+  filled. Note that you need to also pass `--stats` to get this file.
+- `memory.txt`: list of variables being used, expressed as ranges to account for
+  reservation via the `asan:reserve` special comment. Note that you need to also
+  pass `--asan` to get this file.
+- `addresses.txt`: list of addresses known by the assembler, expressed as ranges
+  to account for blocks of code like proc's. You don't need any other flag for
+  this file.
+
 ## Unused code
 
 This assembler will also issue a warning whenever it finds unreferenced
diff --git a/crates/nasm/src/main.rs b/crates/nasm/src/main.rs
index 55a8f21..010e7d5 100644
--- a/crates/nasm/src/main.rs
+++ b/crates/nasm/src/main.rs
@@ -270,6 +270,20 @@ fn print_memory_summary(mut output: Box<dyn Write>, memory: &MemoryResult, has_w
     }
 }
 
+// Save the 'addresses' list into the `<source>/.nasm/addresses.txt` file.
+fn save_addresses(source: &SourceInfo, mut addresses: Vec<xixanta::assembler::Range>) {
+    let Ok(mut file) = File::create(get_directory_from_source(source).join("addresses.txt")) else {
+        return die("could not write memory.txt file".to_string());
+    };
+
+    addresses.sort_by_key(|a| a.range.start);
+    for a in addresses {
+        if let Err(e) = writeln!(file, "{},{:04X},{:04X}", a.name, a.range.start, a.range.end) {
+            return die(format!("could not write addresses.txt file: {e}"));
+        }
+    }
+}
+
 // Print to the `output` stream the statistics that can be gathered from the
 // given `mappings`.
 fn print_segments_stats(mut output: Box<dyn Write>, mappings: &[Mapping]) {
@@ -463,4 +477,9 @@ fn main() {
             print_memory_summary(Box::new(io::stdout()), &memory, has_working_ram);
         }
     }
+
+    // Print addresses.
+    if args.info {
+        save_addresses(&source, res.addresses);
+    }
 }