From a2b67973d64d22704ed29ef9f58708a13b2b1bad Mon Sep 17 00:00:00 2001
From: Rafael Haenel <rhaenel@quera.com>
Date: Thu, 16 Oct 2025 11:57:32 -0700
Subject: [PATCH 1/3] Add debug logging to writeln method in EmitStimMain class

---
 src/bloqade/stim/emit/stim_str.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/bloqade/stim/emit/stim_str.py b/src/bloqade/stim/emit/stim_str.py
index 640d97a1f..7a7cdaee5 100644
--- a/src/bloqade/stim/emit/stim_str.py
+++ b/src/bloqade/stim/emit/stim_str.py
@@ -43,6 +43,12 @@ def get_output(self) -> str:
         self.file.seek(0)
         return self.file.read()
 
+    def writeln(self, frame: EmitStrFrame, *args):
+        if self.debug:
+            self.newline(frame)
+            self.file.write(f"# v-- {frame.code.source or 'unknown source'}")
+        super().writeln(frame, *args)
+
 
 @func.dialect.register(key="emit.stim")
 class FuncEmit(interp.MethodTable):

From a048ec2a660bd967a55476b18e9487971384743b Mon Sep 17 00:00:00 2001
From: Rafael Haenel <rhaenel@quera.com>
Date: Thu, 16 Oct 2025 12:21:40 -0700
Subject: [PATCH 2/3] Add unit test

---
 test/stim/emit/__init__.py      |  0
 test/stim/emit/test_stim_str.py | 26 ++++++++++++++++++++++++++
 2 files changed, 26 insertions(+)
 create mode 100644 test/stim/emit/__init__.py
 create mode 100644 test/stim/emit/test_stim_str.py

diff --git a/test/stim/emit/__init__.py b/test/stim/emit/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/test/stim/emit/test_stim_str.py b/test/stim/emit/test_stim_str.py
new file mode 100644
index 000000000..20082caf7
--- /dev/null
+++ b/test/stim/emit/test_stim_str.py
@@ -0,0 +1,26 @@
+import pytest
+
+from bloqade import squin
+from bloqade.squin import qubit, kernel
+from bloqade.stim.emit import EmitStimMain
+from bloqade.stim.passes import SquinToStimPass
+
+
+@pytest.mark.parametrize("debug", [True, False])
+def test_debug_emit_with_source_info(debug: bool):
+    @kernel
+    def test():
+        q = qubit.new(2)
+        squin.cx(q[0], q[1])
+
+    SquinToStimPass(test.dialects)(test)
+
+    emit = EmitStimMain(debug=debug)
+    emit.initialize()
+    emit.run(mt=test, args=())
+    output = emit.get_output()
+
+    if debug:
+        assert "# v--" in output
+    else:
+        assert "# v--" not in output

From 20bfb7485ba299e28233767e81ed788ab3445ebe Mon Sep 17 00:00:00 2001
From: Rafael Haenel <rhaenel@quera.com>
Date: Tue, 21 Oct 2025 11:49:35 -0700
Subject: [PATCH 3/3] Writeln with correct source info with offset

---
 src/bloqade/stim/emit/stim_str.py | 16 ++++++++++++++--
 test/stim/emit/test_stim_str.py   | 12 ++++--------
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/src/bloqade/stim/emit/stim_str.py b/src/bloqade/stim/emit/stim_str.py
index 7a7cdaee5..354f14f2c 100644
--- a/src/bloqade/stim/emit/stim_str.py
+++ b/src/bloqade/stim/emit/stim_str.py
@@ -27,6 +27,12 @@ def initialize(self):
         self.file.seek(0)
         return self
 
+    def run_method(
+        self, method: ir.Method, args: tuple[str, ...]
+    ) -> tuple[EmitStrFrame, str]:
+        self._current_method = method
+        return super().run_method(method, args)
+
     def eval_stmt_fallback(
         self, frame: EmitStrFrame, stmt: ir.Statement
     ) -> tuple[str, ...]:
@@ -34,6 +40,7 @@ def eval_stmt_fallback(
 
     def emit_block(self, frame: EmitStrFrame, block: ir.Block) -> str | None:
         for stmt in block.stmts:
+            frame.current_stmt = stmt
             result = self.eval_stmt(frame, stmt)
             if isinstance(result, tuple):
                 frame.set_values(stmt.results, result)
@@ -46,7 +53,13 @@ def get_output(self) -> str:
     def writeln(self, frame: EmitStrFrame, *args):
         if self.debug:
             self.newline(frame)
-            self.file.write(f"# v-- {frame.code.source or 'unknown source'}")
+            source = frame.current_stmt.source
+            if source is not None:
+                self.file.write(
+                    f"# v-- {source.file}:{source.lineno + self._current_method.lineno_begin -1}"
+                )
+            else:
+                self.file.write("# v-- unknown source")
         super().writeln(frame, *args)
 
 
@@ -56,5 +69,4 @@ class FuncEmit(interp.MethodTable):
     @interp.impl(func.Function)
     def emit_func(self, emit: EmitStimMain, frame: EmitStrFrame, stmt: func.Function):
         _ = emit.run_ssacfg_region(frame, stmt.body, ())
-        # emit.output = "\n".join(frame.body)
         return ()
diff --git a/test/stim/emit/test_stim_str.py b/test/stim/emit/test_stim_str.py
index 20082caf7..67043a114 100644
--- a/test/stim/emit/test_stim_str.py
+++ b/test/stim/emit/test_stim_str.py
@@ -1,19 +1,14 @@
 import pytest
 
-from bloqade import squin
-from bloqade.squin import qubit, kernel
+from bloqade import stim
 from bloqade.stim.emit import EmitStimMain
-from bloqade.stim.passes import SquinToStimPass
 
 
 @pytest.mark.parametrize("debug", [True, False])
 def test_debug_emit_with_source_info(debug: bool):
-    @kernel
+    @stim.main
     def test():
-        q = qubit.new(2)
-        squin.cx(q[0], q[1])
-
-    SquinToStimPass(test.dialects)(test)
+        stim.cx((0, 1), (2, 3))
 
     emit = EmitStimMain(debug=debug)
     emit.initialize()
@@ -22,5 +17,6 @@ def test():
 
     if debug:
         assert "# v--" in output
+        assert ".py:" in output
     else:
         assert "# v--" not in output