Parse 'declare -p' etc. as commands, not assignments.

This fixes several errors in the wild tests.

TODO: Still need to implement -p and family.

osh/cmd_parse.py

@@ -510,6 +510,24 @@ def _MakeAssignment(self, assign_kw, suffix_words):

    return node

  # Flags that indicate an assignment should be parsed like a command.
  _ASSIGN_COMMANDS = set([
      (Id.Assign_Declare, '-f'),  # function defs
      (Id.Assign_Declare, '-F'),  # function names
      (Id.Assign_Declare, '-p'),  # print

      (Id.Assign_Typeset, '-f'),
      (Id.Assign_Typeset, '-F'),
      (Id.Assign_Typeset, '-p'),

      (Id.Assign_Local, '-p'),
      (Id.Assign_Readonly, '-p'),
      # Hm 'export -p' is more like a command.  But we're parsing it
      # dynamically now because of some wrappers.
      # Maybe we could change this.
      #(Id.Assign_Export, '-p'),
  ])

  def ParseSimpleCommand(self):
    """
    Fixed transcription of the POSIX grammar (TODO: port to grammar/Shell.g)
@@ -609,30 +627,45 @@ def ParseSimpleCommand(self):
      node.spids.append(left_spid)  # no keyword spid to skip past
      return node

    # NOTE: Could also detect break/continue/return here?  Parse time or
    # runtime?

    kind, kw_token = word.KeywordToken(suffix_words[0])

    if kind == Kind.Assign:
      if redirects:
        # Attach the error location to the keyword.  It would be more precise
        # to attach it to the
        self.AddErrorContext('Got redirects in assignment', token=kw_token)
        return None
      # Here we StaticEval suffix_words[1] to see if it's a command like
      # 'typeset -p'.  Then it becomes a SimpleCommand node instead of an
      # Assignment.  Note we're not handling duplicate flags like 'typeset
      # -pf'.  I see this in bashdb (bash debugger) but it can just be changed
      # to 'typeset -p -f'.
      is_command = False
      if len(suffix_words) > 1:
        ok, val, _ = word.StaticEval(suffix_words[1])
        if ok and (kw_token.id, val) in self._ASSIGN_COMMANDS:
          is_command = True

      if is_command:  # declare -f, declare -p, typeset -p, etc.
        node = self._MakeSimpleCommand(prefix_bindings, suffix_words,
                                       redirects)
        return node

      if prefix_bindings:  # FOO=bar local spam=eggs not allowed
        # Use the location of the first value.  TODO: Use the whole word before
        # splitting.
        _, _, v0, _ = prefix_bindings[0]
        self.AddErrorContext(
            'Invalid prefix bindings in assignment: %s', prefix_bindings,
            word=v0)
        return None
      else:  # declare str='', declare -a array=()
        if redirects:
          # Attach the error location to the keyword.  It would be more precise
          # to attach it to the
          self.AddErrorContext('Got redirects in assignment', token=kw_token)
          return None

      node = self._MakeAssignment(kw_token.id, suffix_words)
      if not node: return None
      node.spids.append(kw_token.span_id)
      return node
        if prefix_bindings:  # FOO=bar local spam=eggs not allowed
          # Use the location of the first value.  TODO: Use the whole word before
          # splitting.
          _, _, v0, _ = prefix_bindings[0]
          self.AddErrorContext(
              'Invalid prefix bindings in assignment: %s', prefix_bindings,
              word=v0)
          return None

        node = self._MakeAssignment(kw_token.id, suffix_words)
        if not node: return None
        node.spids.append(kw_token.span_id)
        return node

    elif kind == Kind.ControlFlow:
      if redirects: