Remove `outer_final`

We don't need to know whether there's a outer finally block
that's already implicit in the current break and continue
target.

Signed-off-by: Michael Birtwell <michael.birtwell@oxionics.com>

artiq/compiler/transforms/artiq_ir_generator.py

@@ -113,7 +113,6 @@ class ARTIQIRGenerator(algorithm.Visitor):
         self.return_target = None
         self.unwind_target = None
         self.catch_clauses = []
-        self.outer_final = None
         self.final_branch = None
         self.function_map = dict()
         self.variable_map = dict()
@@ -468,7 +467,6 @@ class ARTIQIRGenerator(algorithm.Visitor):
             self.append(ir.BranchIf(cond, if_true, tail), block=head)
 
     def visit_While(self, node):
-        old_outer_final, self.outer_final = self.outer_final, None
         try:
             head = self.add_block("while.head")
             self.append(ir.Branch(head))
@@ -488,7 +486,6 @@ class ARTIQIRGenerator(algorithm.Visitor):
         finally:
             self.break_target = old_break
             self.continue_target = old_continue
-            self.outer_final = old_outer_final
 
         if any(node.orelse):
             else_tail = self.add_block("while.else")
@@ -563,7 +560,6 @@ class ARTIQIRGenerator(algorithm.Visitor):
             assert False
 
     def visit_ForT(self, node):
-        old_outer_final, self.outer_final = self.outer_final, None
         try:
             iterable = self.visit(node.iter)
             length = self.iterable_len(iterable)
@@ -601,7 +597,6 @@ class ARTIQIRGenerator(algorithm.Visitor):
         finally:
             self.break_target = old_break
             self.continue_target = old_continue
-            self.outer_final = old_outer_final
 
         if any(node.orelse):
             else_tail = self.add_block("for.else")
@@ -710,9 +705,7 @@ class ARTIQIRGenerator(algorithm.Visitor):
                 value = return_action.append(ir.GetLocal(self.current_private_env, "$return"))
                 return_action.append(ir.Return(value))
                 final_branch(return_action, return_proxy)
-
-            old_outer_final, self.outer_final = self.outer_final, final_branch
-        elif self.outer_final is None:
+        else:
             landingpad.has_cleanup = False
 
         # we should propagate the clauses to nested try catch blocks
@@ -777,7 +770,7 @@ class ARTIQIRGenerator(algorithm.Visitor):
                 self.continue_target = old_continue
             self.return_target = old_return
 
-        if any(node.finalbody) or self.outer_final is not None:
+        if any(node.finalbody):
             # create new unwind target for cleanup
             final_dispatcher = self.add_block("try.final.dispatch")
             final_landingpad = ir.LandingPad(cleanup)
@@ -790,16 +783,6 @@ class ARTIQIRGenerator(algorithm.Visitor):
             # if we have a while:try/finally continue must execute finally
             # before continuing the while
             redirect = final_branch
-        elif self.outer_final is not None:
-            # If we have while:try/finally:try then we need to execute that finally
-            # before the continuing the while
-            # If we have try/finally:while:try then we should just continue the
-            # while without having to execute the finally until later
-            # If we have try/finally:while:try/finally:try we should execute
-            # one but not the other
-            # This is achieved by reseting self.outer_final in while and for
-            # loops
-            redirect = self.outer_final
         else:
             redirect = lambda dest, proxy: proxy.append(ir.Branch(dest))
 
@@ -860,7 +843,6 @@ class ARTIQIRGenerator(algorithm.Visitor):
 
         if any(node.finalbody):
             # Finalize and continue after try statement.
-            self.outer_final = old_outer_final
             self.unwind_target = old_unwind
             # Exception path
             finalizer_reraise = self.add_block("finally.resume")
@@ -910,8 +892,6 @@ class ARTIQIRGenerator(algorithm.Visitor):
                         block.append(ir.SetLocal(final_state, "$cont", tail))
                         block.append(ir.Branch(finalizer))
         else:
-            if self.outer_final is not None:
-                self.unwind_target = old_unwind
             self.current_block = tail = self.add_block("try.tail")
             if not body.is_terminated():
                 body.append(ir.Branch(tail))

artiq/test/lit/try_loop/try_finally_while_try_finally_break.py

@@ -0,0 +1,42 @@
+# RUN: %python -m artiq.compiler.testbench.jit %s >%t
+# RUN: OutputCheck %s --file-to-check=%t
+# REQUIRES: exceptions
+
+def run():
+    loop = 0
+    print("start")
+    try:
+        while True:
+            print("loop")
+            try:
+                if loop == 0:
+                    loop += 1
+                    continue
+                func()
+                break
+            except RuntimeError:
+                print("except")
+                return False
+            finally:
+                print("finally2")
+        print("after-while")
+    finally:
+        print("finally1")
+    print("exit")
+    return True
+
+
+def func():
+    print("func")
+
+# CHECK-L: start
+# CHECK-NEXT-L: loop
+# CHECK-NEXT-L: finally2
+# CHECK-NEXT-L: loop
+# CHECK-NEXT-L: func
+# CHECK-NEXT-L: finally2
+# CHECK-NEXT-L: after-while
+# CHECK-NEXT-L: finally1
+# CHECK-NEXT-L: exit
+
+run()

artiq/test/lit/try_loop/try_finally_while_try_reraise.py

@@ -0,0 +1,42 @@
+# RUN: %python -m artiq.compiler.testbench.jit %s >%t
+# RUN: OutputCheck %s --file-to-check=%t
+# REQUIRES: exceptions
+
+def run():
+    print("start")
+    try:
+        try:
+            while True:
+                print("loop")
+                try:
+                    print("try")
+                    func()
+                    print("unreachable")
+                    return True
+                except RuntimeError:
+                    print("except1")
+                    raise
+            print("unreachable")
+        finally:
+            print("finally1")
+        print("unreachable")
+        return False
+    except RuntimeError:
+        print("except2")
+        raise
+    finally:
+        print("finally2")
+        return True
+
+
+def func():
+    raise RuntimeError("Test")
+
+# CHECK-L: start
+# CHECK-NEXT-L: loop
+# CHECK-NEXT-L: try
+# CHECK-NEXT-L: except1
+# CHECK-NEXT-L: finally1
+# CHECK-NEXT-L: except2
+# CHECK-NEXT-L: finally2
+run()

artiq/test/lit/try_loop/try_finally_while_try_return.py

@@ -0,0 +1,29 @@
+# RUN: %python -m artiq.compiler.testbench.jit %s >%t
+# RUN: OutputCheck %s --file-to-check=%t
+# REQUIRES: exceptions
+
+def run():
+    try:
+        while True:
+            try:
+                print("try")
+                func()
+                return True
+            except RuntimeError:
+                print("except")
+                return False
+        print("unreachable")
+    finally:
+        print("finally")
+    print("unreachable")
+    return False
+
+
+def func():
+    pass
+
+# CHECK-L: try
+# CHECK-NOT-L: except
+# CHECK-NOT-L: unreachable
+# CHECK-L: finally
+run()