From 77d47c2fdd7ab348407795dc24dd05aabc615ec9 Mon Sep 17 00:00:00 2001
From: whitequark <whitequark@whitequark.org>
Date: Wed, 22 Jun 2016 00:56:39 +0000
Subject: [PATCH] =?UTF-8?q?transforms.artiq=5Fir=5Fgenerator:=20split=20ou?=
 =?UTF-8?q?t=20finally=E2=86=92reraise=20control=20flow.?=
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This makes it accessible to introspect by local access validator,
making some previously rejected code valid.

Fixes #331.
---
 .../compiler/transforms/artiq_ir_generator.py | 14 +++++++-----
 artiq/test/lit/exceptions/finally_reraise.py  | 22 +++++++++++++++++++
 2 files changed, 31 insertions(+), 5 deletions(-)
 create mode 100644 artiq/test/lit/exceptions/finally_reraise.py

diff --git a/artiq/compiler/transforms/artiq_ir_generator.py b/artiq/compiler/transforms/artiq_ir_generator.py
index 9d432acd6..35aa25616 100644
--- a/artiq/compiler/transforms/artiq_ir_generator.py
+++ b/artiq/compiler/transforms/artiq_ir_generator.py
@@ -690,6 +690,7 @@ class ARTIQIRGenerator(algorithm.Visitor):
             handlers.append((handler, post_handler))
 
         if any(node.finalbody):
+            # Finalize and continue after try statement.
             self.final_branch = old_final_branch
 
             finalizer = self.add_block("finally")
@@ -698,13 +699,17 @@ class ARTIQIRGenerator(algorithm.Visitor):
             self.visit(node.finalbody)
             post_finalizer = self.current_block
 
-            reraise = self.add_block('try.reraise')
-            reraise.append(ir.Reraise(self.unwind_target))
+            # Finalize and reraise. Separate from previous case to expose flow
+            # to LocalAccessValidator.
+            finalizer_reraise = self.add_block("finally.reraise")
+            self.current_block = finalizer_reraise
+
+            self.visit(node.finalbody)
+            self.terminate(ir.Reraise(self.unwind_target))
 
         self.current_block = tail = self.add_block("try.tail")
         if any(node.finalbody):
             final_targets.append(tail)
-            final_targets.append(reraise)
 
             for block in final_paths:
                 block.append(ir.Branch(finalizer))
@@ -713,8 +718,7 @@ class ARTIQIRGenerator(algorithm.Visitor):
                 body.append(ir.SetLocal(final_state, "$cont", tail))
                 body.append(ir.Branch(finalizer))
 
-            cleanup.append(ir.SetLocal(final_state, "$cont", reraise))
-            cleanup.append(ir.Branch(finalizer))
+            cleanup.append(ir.Branch(finalizer_reraise))
 
             for handler, post_handler in handlers:
                 if not post_handler.is_terminated():
diff --git a/artiq/test/lit/exceptions/finally_reraise.py b/artiq/test/lit/exceptions/finally_reraise.py
new file mode 100644
index 000000000..ef4da2af9
--- /dev/null
+++ b/artiq/test/lit/exceptions/finally_reraise.py
@@ -0,0 +1,22 @@
+# RUN: %python -m artiq.compiler.testbench.jit %s >%t
+# RUN: OutputCheck %s --file-to-check=%t
+# REQUIRES: exceptions
+
+x = 1
+
+def doit():
+    try:
+        if x > 0:
+            raise ZeroDivisionError
+        r = 0
+    finally:
+        print('final')
+    return r
+
+try:
+    doit()
+except ZeroDivisionError:
+    print('caught')
+
+# CHECK-L: final
+# CHECK-L: caught