Basic implementation of alias and unalias hooked up.

Also: added spec tests for alias semantics, which are quite subtle. - Still need to do the actual expansion in the parser. - Still need spec tests for the usage of the builtins.
oilshell · Aug 31, 2018 · 46640afddc74af6b803c766d1926f4d115bab5f4 · 46640af
1 parent 86888cf
commit 46640afddc74af6b803c766d1926f4d115bab5f4
diff --git a/bin/oil.py b/bin/oil.py
@@ -229,12 +229,13 @@ def OshMain(argv0, argv, login_shell):
    # TODO: NullLookup?
    comp_lookup = None

+  fd_state = process.FdState()
  exec_opts = state.ExecOpts(mem)
  builtin.SetExecOpts(exec_opts, opts.opt_changes)
+  aliases = {}  # feedback between runtime and parser

-  fd_state = process.FdState()
  ex = cmd_exec.Executor(mem, fd_state, status_lines, funcs, readline,
-                         completion, comp_lookup, exec_opts, arena)
+                         completion, comp_lookup, exec_opts, arena, aliases)

  # NOTE: The rc file can contain both commands and functions... ideally we
  # would only want to save nodes/lines for the functions.
@@ -243,7 +244,7 @@ def OshMain(argv0, argv, login_shell):
    arena.PushSource(rc_path)
    with open(rc_path) as f:
      rc_line_reader = reader.FileLineReader(f, arena)
-      _, rc_c_parser = parse_lib.MakeParser(rc_line_reader, arena)
+      _, rc_c_parser = parse_lib.MakeParser(rc_line_reader, arena, aliases)
      try:
        rc_node = rc_c_parser.ParseWholeFile()
        if not rc_node:
@@ -291,7 +292,7 @@ def OshMain(argv0, argv, login_shell):

  # TODO: assert arena.NumSourcePaths() == 1
  # TODO: .rc file needs its own arena.
-  w_parser, c_parser = parse_lib.MakeParser(line_reader, arena)
+  w_parser, c_parser = parse_lib.MakeParser(line_reader, arena, aliases)

  if exec_opts.interactive:
    # NOTE: We're using a different evaluator here.  The completion system can
diff --git a/core/builtin.py b/core/builtin.py
@@ -109,6 +109,9 @@
    "declare": builtin_e.DECLARE,
    "typeset": builtin_e.TYPESET,

+    "alias": builtin_e.ALIAS,
+    "unalias": builtin_e.UNALIAS,
+
    "help": builtin_e.HELP,
    "debug-line": builtin_e.DEBUG_LINE,
 }
@@ -983,6 +986,51 @@ def DeclareTypeset(argv, mem, funcs):
  return status


+ALIAS_SPEC = _Register('alias')
+
+
+# TODO: Test out all the details here
+def Alias(argv, aliases):
+  if not argv:
+    for name, alias_exp in aliases.iteritems():
+      # TODO: Print this better
+      print('%s %s' % (name, alias_exp))
+    return 0
+
+  for arg in argv:
+    parts = arg.split('=', 1)
+    log(' p %s', parts)
+    if len(parts) == 1:
+      name = parts[0]
+      alias_exp = aliases.get(name)
+      if alias_exp is None:
+        print('alias %r is not defined' % name)  # TODO: error?
+      else:
+        print('%s %s' % (name, alias_exp))
+    else:
+      name, alias_exp = parts
+      aliases[name] = alias_exp
+
+  print(argv)
+  print(aliases)
+  return 0
+
+
+UNALIAS_SPEC = _Register('unalias')
+
+
+# TODO: Test out all the details here
+def UnAlias(argv, aliases):
+  status = 0
+  for name in argv:
+    try:
+      del aliases[name]
+    except KeyError:
+      print('alias %r is not defined' % name)  # TODO: error?
+      status = 1
+  return status
+
+
 import signal


diff --git a/core/cmd_exec.py b/core/cmd_exec.py
@@ -106,7 +106,7 @@ class Executor(object):
  CompoundWord/WordPart.
  """
  def __init__(self, mem, fd_state, status_lines, funcs, readline, completion,
-               comp_lookup, exec_opts, arena):
+               comp_lookup, exec_opts, arena, aliases):
    """
    Args:
      mem: Mem instance for storing variables
@@ -141,8 +141,7 @@ def __init__(self, mem, fd_state, status_lines, funcs, readline, completion,
    self.nodes_to_run = []  # list of nodes, appended to by signal handlers
    self.dir_stack = state.DirStack()

-    # TODO: Pass these in from main()
-    self.aliases = {}  # alias name -> string
+    self.aliases = aliases  # alias name -> string
    self.targets = []  # make syntax enters stuff here -- Target()
                       # metaprogramming or regular target syntax
                       # Whether argv[0] is make determines if it is executed
@@ -203,7 +202,7 @@ def _Eval(self, argv):
    # TODO: set -o sane-eval should change eval to take a single string.
    code_str = ' '.join(argv)
    line_reader = reader.StringLineReader(code_str, self.arena)
-    _, c_parser = parse_lib.MakeParser(line_reader, self.arena)
+    _, c_parser = parse_lib.MakeParser(line_reader, self.arena, self.aliases)
    return self._EvalHelper(c_parser, '<eval string>')

  def ParseTrapCode(self, code_str):
@@ -380,6 +379,12 @@ def _RunBuiltin(self, builtin_id, argv):
      # These are synonyms
      status = builtin.DeclareTypeset(argv, self.mem, self.funcs)

+    elif builtin_id == builtin_e.ALIAS:
+      status = builtin.Alias(argv, self.aliases)
+
+    elif builtin_id == builtin_e.UNALIAS:
+      status = builtin.UnAlias(argv, self.aliases)
+
    elif builtin_id == builtin_e.HELP:
      loader = util.GetResourceLoader()
      status = builtin.Help(argv, loader)
diff --git a/core/cmd_exec_test.py b/core/cmd_exec_test.py
@@ -43,10 +43,11 @@ def InitExecutor(arena=None):
  status_lines = None  # not needed for what we're testing
  funcs = {}
  comp_funcs = {}
+  aliases = {}
  exec_opts = state.ExecOpts(mem)
  # For the tests, we do not use 'readline'.
  return cmd_exec.Executor(mem, fd_state, status_lines, funcs, None,
-                           completion, comp_funcs, exec_opts, arena)
+                           completion, comp_funcs, exec_opts, arena, aliases)


 def InitEvaluator():
diff --git a/core/runtime.asdl b/core/runtime.asdl
@@ -66,7 +66,7 @@ module runtime
  | COLON
  | TEST | BRACKET | GETOPTS
  | COMMAND | TYPE | HELP
-  | DECLARE | TYPESET
+  | DECLARE | TYPESET | ALIAS | UNALIAS
  | PWD

  -- word_eval.py: SliceParts is for ${a-} and ${a+}, Error is for ${a?}, and
diff --git a/osh/cmd_parse.py b/osh/cmd_parse.py
@@ -120,11 +120,12 @@ class CommandParser(object):
    lexer: for lookahead in function def, PushHint of ()
    line_reader: for here doc
  """
-  def __init__(self, w_parser, lexer, line_reader, arena):
+  def __init__(self, w_parser, lexer, line_reader, arena, aliases=None):
    self.w_parser = w_parser  # for normal parsing
    self.lexer = lexer  # for fast lookahead to (, for function defs
    self.line_reader = line_reader  # for here docs
-    self.arena = arena
+    self.arena = arena  # for adding here doc spans
+    self.aliases = aliases or {}  # aliases to expand at parse time

    self.Reset()

@@ -301,6 +302,7 @@ def _ScanSimpleCommand(self):

      else:
        break
+
      self._Next()
    return redirects, words

@@ -1183,11 +1185,25 @@ def ParseCommand(self):
      node = self.ParseCompoundCommand()
      assert node is not None
      if node.tag != command_e.TimeBlock:  # The only one without redirects
-        redirects = self._ParseRedirectList()
-        assert redirects is not None
-        node.redirects = redirects
+        node.redirects = self._ParseRedirectList()
+        assert node.redirects is not None
      return node

+    # TODO: Is this the natural place to check for aliases?  It's NOT a
+    # keyword.
+    # 1) check if self.cur_word is a plain word in self.aliases
+    # 2) Iteratively check next work based on trailing space
+    # 2) And then change state Then RECURSIVELY call ParseCommand?
+    #
+    # self.w_parser.PushAliasBuffer() -- this means the lexer reads from it?
+
+    # TODO: To this in a loop
+    ok, word_str, quoted = word.StaticEval(self.cur_word)
+    if ok and not quoted:
+      alias_exp = self.aliases.get(word_str)
+      if alias_exp is not None:
+        log('expand %s -> %s', word_str, alias_exp)
+
    # NOTE: I added this to fix cases in parse-errors.test.sh, but it doesn't
    # work because Lit_RBrace is in END_LIST below.

diff --git a/osh/parse_lib.py b/osh/parse_lib.py
@@ -36,12 +36,13 @@ def InitLexer(s, arena):
 #   you need somewhere to store the side effects -- errors for parsers, and the
 #   actual values for the evaluators/executors.

-def MakeParser(line_reader, arena):
+def MakeParser(line_reader, arena, aliases):
  """Top level parser."""
  line_lexer = lexer.LineLexer(match.MATCHER, '', arena)
  lx = lexer.Lexer(line_lexer, line_reader)
  w_parser = word_parse.WordParser(lx, line_reader)
-  c_parser = cmd_parse.CommandParser(w_parser, lx, line_reader, arena)
+  c_parser = cmd_parse.CommandParser(w_parser, lx, line_reader, arena,
+                                     aliases=aliases)
  return w_parser, c_parser


diff --git a/spec/alias.test.sh b/spec/alias.test.sh
@@ -6,17 +6,19 @@
 #
 # Bash is the only one that doesn't support aliases!

-#### basic alias
+#### Basic alias
 shopt -s expand_aliases  # bash requires this
 alias hi='echo hello world'
-hi
+hi || echo 'should not run this'
 echo hi  # second word is not
+'hi' || echo 'expected failure'
 ## STDOUT:
 hello world
 hi
+expected failure
 ## END

-#### alias with trailing space causes second alias expansion
+#### alias with trailing space causes alias expansion on second word
 shopt -s expand_aliases  # bash requires this

 alias hi='echo hello world '
@@ -33,7 +35,7 @@ hello world !!!
 hello world punct
 ## END

-#### iterative alias expansion of first word
+#### Recursive alias expansion of first word
 shopt -s expand_aliases  # bash requires this
 alias hi='echo hello world'
 alias echo='echo --; echo '
@@ -43,8 +45,7 @@ hi   # first hi is expanded to echo hello world; then echo is expanded.  gah.
 hello world
 ## END

-
-#### expansion of alias with variable
+#### Expansion of alias with variable
 shopt -s expand_aliases  # bash requires this
 x=x
 alias echo-x='echo $x'  # nothing is evaluated here
@@ -54,6 +55,18 @@ echo-x hi
 y hi
 ## END

+#### Alias must be an unquoted word, no expansions allowed
+shopt -s expand_aliases  # bash requires this
+alias echo_alias_='echo'
+cmd=echo_alias_
+echo_alias_ X  # this works
+$cmd X  # this fails because it's quoted
+echo status=$?
+## STDOUT:
+X
+status=127
+## END
+

 #### first and second word are the same
 shopt -s expand_aliases  # bash requires this
@@ -109,18 +122,6 @@ alias "$name$val"
 echo_alias_ X
 ## stdout: X

-#### Alias detection happens before expansion
-shopt -s expand_aliases  # bash requires this
-alias echo_alias_='echo'
-cmd=echo_alias_
-echo_alias_ X
-$cmd X
-echo status=$?
-## STDOUT:
-X
-status=127
-## END
-
 #### Alias name with punctuation
 # NOTE: / is not OK in bash, but OK in other shells.  Must less restrictive
 # than var names.
@@ -136,7 +137,7 @@ e_ x
 ## status: 2
 ## OK mksh/zsh status: 1

-#### Loop split across alias and arg
+#### Loop split across alias and arg works
 shopt -s expand_aliases  # bash requires this
 alias e_='for i in 1 2 3; do echo $i;'
 e_ done
@@ -146,10 +147,63 @@ e_ done
 3
 ## END

-#### Loop split across alias and arg 2
+#### Loop split across alias in another way is syntax error
 # For some reason this doesn't work, but the previous case does.
 shopt -s expand_aliases
 alias e_='for i in 1 2 3; do echo '
 e_ '$i done;'
 ## status: 2
 ## OK mksh/zsh status: 1
+
+#### Loop split across both iterative and recursive aliases
+shopt -s expand_aliases  # bash requires this
+alias FOR1='for '
+alias FOR2='FOR1 '
+alias eye1='i '
+alias eye2='eye1 '
+alias IN='in '
+alias onetwo='$one "2" '  # NOTE: this does NOT work in any shell except bash.
+one=1
+FOR2 eye2 IN onetwo 3; do echo $i; done
+## STDOUT:
+1
+2
+3
+## END
+## BUG zsh stdout-json: ""
+
+#### Alias with a quote in the middle is a syntax error
+shopt -s expand_aliases
+alias e_='echo "'
+var=x
+e_ '${var}"'
+## status: 2
+## OK mksh/zsh status: 1
+
+#### Alias with a newline
+# The second echo command is run in dash/mksh!
+shopt -s expand_aliases
+alias e_='echo 1
+'
+var='echo foo'
+e_ ${var}
+## stdout-json: "1\nfoo\n"
+## OK zsh stdout-json: "1\n"
+## OK zsh status: 127
+
+#### Two aliases in pipeline
+shopt -s expand_aliases
+alias SEQ='seq '
+alias THREE='3 '
+alias WC='wc '
+SEQ THREE | WC -l
+## stdout: 3
+
+#### Alias for { block
+shopt -s expand_aliases
+alias LBRACE='{ '
+LBRACE echo one; echo two; }
+## STDOUT:
+one
+two
+## END
diff --git a/test/spec.sh b/test/spec.sh
@@ -232,7 +232,7 @@ blog-other1() {
 }

 alias() {
-  sh-spec spec/alias.test.sh --osh-failures-allowed 13 \
+  sh-spec spec/alias.test.sh --osh-failures-allowed 18 \
    ${REF_SHELLS[@]} $ZSH $OSH_LIST "$@"
 }