1 files changed, 78 insertions, 0 deletions
diff --git a/atk16_asm/asm_pass3.py b/atk16_asm/asm_pass3.py
new file mode 100644
index 0000000..9c8cb34
--- /dev/null
+++ b/atk16_asm/asm_pass3.py
@@ -0,0 +1,78 @@
+from dataclasses import dataclass
+from asm_ops import *
+from asm_eval import *
+from asm_pass2 import *
+
+@dataclass
+class Result3Line:
+  line_num: int
+  src_file: str
+  address: int
+  parts: list[str]
+  original_parts: list[str]
+
+@dataclass
+class Result3:
+  lines: list[Result3Line]
+  operations: OpExpansionDict
+  symbols: dict[str, int]
+
+def pass_3(result2: Result2) -> Result3:
+  result_lines: list[Result3Line] = []
+  symbols: dict[str, int] = {}
+  address = 0
+
+  for line in result2.lines:
+    keyword, *args = line.parts
+    match keyword:
+      case "@address":
+        address = eval_expr(symbols, args[0])
+        continue
+      case "@label":
+        label = args[0]
+        if label in symbols:
+          raise Exception(f"When defining label {label} as {address:>04x}, symbol {label} already defined as {symbols[label]:>04x}")
+        symbols[args[0]] = address
+        continue
+      case "@let":
+        symbols[args[0]] = eval_expr(symbols, args[1])
+        continue
+      case _:
+        result_lines.append(Result3Line(
+          line_num=line.line_num,
+          src_file=line.src_file,
+          parts=line.parts,
+          address=address,
+          original_parts=line.original_parts,
+        ))
+        address += 1
+
+  result_lines.sort(key=lambda l: l.address)
+  for result_line in result_lines:
+    rows_with_same_addr = list(filter(lambda l: l.address == result_line.address, result_lines))
+    n = len(rows_with_same_addr)
+    if n > 1:
+      formatted = format_overlapping_rows(rows_with_same_addr)
+      raise Exception(f"Overlapping segments: address 0x{result_line.address:>04x} has conflicting definitions:\n{formatted}")
+  return Result3(
+    operations=result2.operations,
+    lines=result_lines,
+    symbols=symbols,
+  )
+
+def format_overlapping_rows(rows: list[Result3Line]) -> str:
+  longest_val = 0
+  for row in rows:
+    joined = " ".join(row.parts)
+    if len(joined) > longest_val:
+      longest_val = len(joined)
+
+  first_col_width = longest_val + 4
+
+  results: list[str] = []
+  for row in rows:
+    joined = " ".join(row.parts)
+    result = joined + (first_col_width - len(joined)) * " " + f" ({row.src_file}:{row.line_num})"
+    results.append(result)
+
+  return "\n".join(results)