Implement $FUNCNAME (bash-only, used by Nix.)

Also make note of a var-ref issue where $? is not dynamic.

Addresses issue #26.

core/cmd_exec.py

@@ -983,7 +983,7 @@ def RunFunc(self, func_node, argv):
     if not self.fd_state.Push(def_redirects, self.waiter):
       return 1  # error
 
-    self.mem.Push(argv[1:])
+    self.mem.PushCall(func_node.name, argv[1:])
 
     # Redirects still valid for functions.
     # Here doc causes a pipe and Process(SubProgramThunk).
@@ -996,7 +996,7 @@ def RunFunc(self, func_node, argv):
         # break/continue used in the wrong place
         e_die('Unexpected %r (in function call)', e.token.val, token=e.token)
     finally:
-      self.mem.Pop()
+      self.mem.PopCall()
       self.fd_state.Pop()
 
     return status

core/completion_test.py

@@ -83,6 +83,7 @@ def testShellFuncExecution(self):
     pairs = [ast.assign_pair(ast.LhsName('COMPREPLY'), assign_op.Equal, w)]
     body_node = ast.Assignment(Id.Assign_None, [], pairs)
 
+    func_node.name = 'myfunc'
     func_node.body = body_node
 
     a = completion.ShellFuncAction(ex, func_node)

core/state.py

@@ -166,6 +166,10 @@ def __init__(self, argv0, argv, environ):
     self.var_stack = [top]
     self.argv0 = argv0
     self.argv_stack = [_ArgFrame(argv)]
+    # NOTE: could use deque and appendleft/popleft, but
+    # 1. ASDL type checking of StrArray doesn't allow it (could be fixed)
+    # 2. We don't otherwise depend on the collections module
+    self.func_name_stack = []
 
     self.last_status = 0  # Mutable public variable
     self.last_job_id = -1  # Uninitialized value mutable public variable
@@ -205,12 +209,17 @@ def _InitEnviron(self, environ):
   # Stack
   #
 
-  def Push(self, argv):
+  def PushCall(self, func_name, argv):
     """For function calls."""
+    # bash uses this order: top of stack first.
+    self.func_name_stack.append(func_name)
+
     self.var_stack.append({})
     self.argv_stack.append(_ArgFrame(argv))
 
-  def Pop(self):
+  def PopCall(self):
+    self.func_name_stack.pop()
+
     self.var_stack.pop()
     self.argv_stack.pop()
 
@@ -425,6 +434,16 @@ def SetVar(self, lval, value, new_flags, lookup_mode):
   # NOTE: Have a default for convenience
   def GetVar(self, name, lookup_mode=scope.Dynamic):
     assert isinstance(name, str), name
+
+    # Do lookup of system globals before looking at user variables.  Note: we
+    # could optimize this at compile-time like $?.  That would break
+    # ${!varref}, but it's already broken for $?.
+    if name == 'FUNCNAME':
+      # bash wants it in reverse order.  This is a little inefficient but we're
+      # not depending on deque().
+      strs = list(reversed(self.func_name_stack))
+      return runtime.StrArray(strs)
+
     cell, _ = self._FindCellAndNamespace(name, lookup_mode)
 
     if cell:

core/state_test.py

@@ -18,16 +18,16 @@ class MemTest(unittest.TestCase):
 
   def testGet(self):
     mem = state.Mem('', [], {})
-    mem.Push(['a', 'b'])
+    mem.PushCall('my-func', ['a', 'b'])
     print(mem.GetVar('HOME'))
-    mem.Pop()
+    mem.PopCall()
     print(mem.GetVar('NONEXISTENT'))
 
   def testSetVarClearFlag(self):
     mem = state.Mem('', [], {})
     print(mem)
 
-    mem.Push(['ONE'])
+    mem.PushCall('my-func', ['ONE'])
     self.assertEqual(2, len(mem.var_stack))  # internal details
 
     # local x=y
@@ -36,7 +36,7 @@ def testSetVarClearFlag(self):
     self.assertEqual('y', mem.var_stack[-1]['x'].val.s)
 
     # New frame
-    mem.Push(['TWO'])
+    mem.PushCall('my-func', ['TWO'])
     self.assertEqual(3, len(mem.var_stack))  # internal details
 
     # x=y -- test out dynamic scope
@@ -220,10 +220,10 @@ def testUnset(self):
 
   def testArgv(self):
     mem = state.Mem('', [], {})
-    mem.Push(['a', 'b'])
+    mem.PushCall('my-func', ['a', 'b'])
     self.assertEqual(['a', 'b'], mem.GetArgv())
 
-    mem.Push(['x', 'y'])
+    mem.PushCall('my-func', ['x', 'y'])
     self.assertEqual(['x', 'y'], mem.GetArgv())
 
     status = mem.Shift(1)
@@ -238,7 +238,7 @@ def testArgv(self):
     self.assertEqual([], mem.GetArgv())
     self.assertEqual(1, status)  # error
 
-    mem.Pop()
+    mem.PopCall()
     self.assertEqual(['a', 'b'], mem.GetArgv())
 
   def testArgv2(self):

spec/introspect.test.sh

@@ -5,15 +5,12 @@
 
 ### ${FUNCNAME[@]} array
 f() {
-  echo "begin: ${FUNCNAME[@]}"
+  argv.py "${FUNCNAME[@]}"
   g
-  echo "end: ${FUNCNAME[@]}"
+  argv.py "${FUNCNAME[@]}"
 }
 g() {
-  echo "func: ${FUNCNAME[@]}"
+  argv.py "${FUNCNAME[@]}"
 }
 f
-# stdout-json: "begin: f\nfunc: g f\nend: f\n"
-# N-I mksh stdout-json: "begin: \nfunc: \nend: \n"
-# N-I dash stdout-json: ""
-# N-I dash status: 2
+# stdout-json: "['f']\n['g', 'f']\n['f']\n"

spec/var-ref.test.sh

@@ -13,6 +13,16 @@ echo ref ${!a} ${a}
 # BUG mksh stdout: ref a b
 # N-I dash/zsh stdout-json: ""
 
+### var ref with special vars
+myfunc() {
+  local ref=$1
+  echo ${!ref}
+}
+myfunc FUNCNAME
+myfunc '?'  # osh doesn't do this dynamically
+# stdout-json: "myfunc\n0\n"
+# N-I mksh stdout-json: "ref\nref\n"
+
 ### declare -n and ${!a}
 declare -n a
 a=b
@@ -66,3 +76,4 @@ caller
 # BUG mksh stdout-json: ""
 # BUG mksh status: 1
 
+

test/spec.sh

@@ -457,7 +457,7 @@ extended-glob() {
 
 # ${!var} syntax -- oil should replace this with associative arrays.
 var-ref() {
-  sh-spec spec/var-ref.test.sh --osh-failures-allowed 4 \
+  sh-spec spec/var-ref.test.sh --osh-failures-allowed 5 \
     $BASH $MKSH $OSH "$@"
 }