Change more errors to exceptions in cmd_parse.py

Addresses #27 and #103.

osh/cmd_parse.py

@@ -417,14 +417,12 @@ def _MakeAssignment(self, assign_kw, suffix_words):
        # It sets global variables.
        ok, static_val, quoted = word.StaticEval(w)
        if not ok or quoted:
           self.AddErrorContext(
               'Variable names must be constant strings, got %s', w, word=w)
           return None
          p_die("Variable names must be unquoted constants", word=w)

        # No value is equivalent to ''
        if not match.IsValidVarName(static_val):
          self.AddErrorContext('Invalid variable name %r', static_val, word=w)
          return None
          p_die('Invalid variable name %r', static_val, word=w)

        a = (static_val, assign_op_e.Equal, None, left_spid)

      assignments.append(a)
@@ -544,9 +542,7 @@ def ParseSimpleCommand(self):
      if redirects:
        binding1 = prefix_bindings[0]
        _, _, _, spid = binding1
        self.AddErrorContext('Got redirects in global assignment',
                             span_id=spid)
        return None
        p_die("Global assignment shouldn't have redirects", span_id=spid)

      pairs = []
      for lhs, op, rhs, spid in prefix_bindings:
@@ -582,17 +578,13 @@ def ParseSimpleCommand(self):
        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
          p_die("Assignments shouldn't have redirects", token=kw_token)

        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
          p_die("Assignments shouldn't have environment bindings", word=v0)

        node = self._MakeAssignment(kw_token.id, suffix_words)
        if not node: return None
@@ -605,24 +597,17 @@ def ParseSimpleCommand(self):
        return None

      if prefix_bindings:  # FOO=bar local spam=eggs not allowed
        # Use the location of the first value.  TODO: Use the whole word before
        # splitting.
        # TODO: Change location as above
        _, _, v0, _ = prefix_bindings[0]
        self.AddErrorContext(
            'Invalid prefix bindings in control flow: %s', prefix_bindings,
            word=v0)
        return None
        p_die("Control flow shouldn't have environment bindings", word=v0)

      # Attach the token for errors.  (Assignment may not need it.)
      if len(suffix_words) == 1:
        arg_word = None
      elif len(suffix_words) == 2:
        arg_word = suffix_words[1]
      else:
        # Underline the extra word.
        self.AddErrorContext(
            'Unexpected argument to %r', kw_token.val, word=suffix_words[2])
        return None
        p_die('Unexpected argument to %r', kw_token.val, word=suffix_words[2])

      return ast.ControlFlow(kw_token, arg_word)

test/parse-errors.sh

@@ -192,8 +192,20 @@ quoted-strings() {
cmd-parse() {
  set +o errexit

  _error-case 'FOO=1 break'
  _error-case 'break 1 2'
}

redirect() {
  set +o errexit

  _error-case 'echo < <<'
  _error-case 'echo $( echo > >>  )'

  _error-case 'FOO=1 BAR=2 > out'
  _error-case '> out FOO=1 BAR=2'

  _error-case 'local BAR=2 > out'
}

simple-command() {
@@ -207,8 +219,12 @@ simple-command() {

assign() {
  set +o errexit
  _error-case 'local name$x'
  _error-case 'local "ab"'
  _error-case 'local a.b'

  _error-case 'FOO=1 local foo=1'

}

# I can't think of any other here doc error conditions except arith/var/command
@@ -239,6 +255,8 @@ cases-in-strings() {

  cmd-parse
  simple-command
  redirect
  here-doc

  # Word
  word-parse