Merge #8371 'API: more reliable/descriptive VimL errors'

runtime/autoload/msgpack.vim

@@ -40,9 +40,10 @@ function s:msgpack_init_python() abort
     return s:msgpack_python_type
   endif
   let s:msgpack_python_initialized = 1
-  for suf in ['', '3']
+  for suf in (has('win32') ? ['3'] : ['', '3'])
     try
       execute 'python' . suf
+              \. "\n"
               \. "def shada_dict_strftime():\n"
               \. "  import datetime\n"
               \. "  import vim\n"
@@ -60,12 +61,15 @@ function s:msgpack_init_python() abort
               \. "  fmt = vim.eval('a:format')\n"
               \. "  timestr = vim.eval('a:string')\n"
               \. "  timestamp = datetime.datetime.strptime(timestr, fmt)\n"
-              \. "  timestamp = int(timestamp.timestamp())\n"
+              \. "  try:\n"
+              \. "    timestamp = int(timestamp.timestamp())\n"
+              \. "  except:\n"
+              \. "    timestamp = int(timestamp.strftime('%s'))\n"
               \. "  if timestamp > 2 ** 31:\n"
-              \. "    tsabs = abs(timestamp)"
+              \. "    tsabs = abs(timestamp)\n"
               \. "    return ('{\"_TYPE\": v:msgpack_types.integer,'\n"
               \. "            + '\"_VAL\": [{sign},{v1},{v2},{v3}]}').format(\n"
-              \. "              sign=1 if timestamp >= 0 else -1,\n"
+              \. "              sign=(1 if timestamp >= 0 else -1),\n"
               \. "              v1=((tsabs >> 62) & 0x3),\n"
               \. "              v2=((tsabs >> 31) & (2 ** 31 - 1)),\n"
               \. "              v3=(tsabs & (2 ** 31 - 1)))\n"

src/nvim/api/private/helpers.c

@@ -120,9 +120,7 @@ bool try_end(Error *err)
   // try_enter/try_leave.
   trylevel--;
 
-  // Without this it stops processing all subsequent VimL commands and
-  // generates strange error messages if I e.g. try calling Test() in a
-  // cycle
+  // Set by emsg(), affects aborting().  See also enter_cleanup().
   did_emsg = false;
 
   if (got_int) {

src/nvim/api/vim.c

@@ -46,8 +46,7 @@
 
 /// Executes an ex-command.
 ///
-/// On parse error: forwards the Vim error; does not update v:errmsg.
-/// On runtime error: forwards the Vim error; does not update v:errmsg.
+/// On execution error: fails with VimL error, does not update v:errmsg.
 ///
 /// @param command  Ex-command string
 /// @param[out] err Error details (Vim error), if any
@@ -103,7 +102,8 @@ Dictionary nvim_get_hl_by_id(Integer hl_id, Boolean rgb, Error *err)
 }
 
 /// Passes input keys to Nvim.
-/// On VimL error: Does not fail, but updates v:errmsg.
+///
+/// On execution error: does not fail, but updates v:errmsg.
 ///
 /// @param keys         to be typed
 /// @param mode         mapping options
@@ -169,7 +169,8 @@ void nvim_feedkeys(String keys, String mode, Boolean escape_csi)
 }
 
 /// Passes keys to Nvim as raw user-input.
-/// On VimL error: Does not fail, but updates v:errmsg.
+///
+/// On execution error: does not fail, but updates v:errmsg.
 ///
 /// Unlike `nvim_feedkeys`, this uses a lower-level input buffer and the call
 /// is not deferred. This is the most reliable way to send real user input.
@@ -213,8 +214,7 @@ String nvim_replace_termcodes(String str, Boolean from_part, Boolean do_lt,
 /// Executes an ex-command and returns its (non-error) output.
 /// Shell |:!| output is not captured.
 ///
-/// On parse error: forwards the Vim error; does not update v:errmsg.
-/// On runtime error: forwards the Vim error; does not update v:errmsg.
+/// On execution error: fails with VimL error, does not update v:errmsg.
 ///
 /// @param command  Ex-command string
 /// @param[out] err Error details (Vim error), if any
@@ -259,30 +259,51 @@ String nvim_command_output(String command, Error *err)
 
 /// Evaluates a VimL expression (:help expression).
 /// Dictionaries and Lists are recursively expanded.
-/// On VimL error: Returns a generic error; v:errmsg is not updated.
+///
+/// On execution error: fails with VimL error, does not update v:errmsg.
 ///
 /// @param expr     VimL expression string
 /// @param[out] err Error details, if any
 /// @return         Evaluation result or expanded object
 Object nvim_eval(String expr, Error *err)
   FUNC_API_SINCE(1)
 {
+  static int recursive = 0;  // recursion depth
   Object rv = OBJECT_INIT;
-  // Evaluate the expression
+
+  // `msg_list` controls the collection of abort-causing non-exception errors,
+  // which would otherwise be ignored.  This pattern is from do_cmdline().
+  struct msglist **saved_msg_list = msg_list;
+  struct msglist *private_msg_list;
+  msg_list = &private_msg_list;
+  private_msg_list = NULL;
+
+  // Initialize `force_abort`  and `suppress_errthrow` at the top level.
+  if (!recursive) {
+    force_abort = false;
+    suppress_errthrow = false;
+    current_exception = NULL;
+    // `did_emsg` is set by emsg(), which cancels execution.
+    did_emsg = false;
+  }
+  recursive++;
   try_start();
 
   typval_T rettv;
-  if (eval0((char_u *)expr.data, &rettv, NULL, true) == FAIL) {
-    api_set_error(err, kErrorTypeException, "Failed to evaluate expression");
-  }
+  int ok = eval0((char_u *)expr.data, &rettv, NULL, true);
 
   if (!try_end(err)) {
-    // No errors, convert the result
-    rv = vim_to_object(&rettv);
+    if (ok == FAIL) {
+      // Should never happen, try_end() should get the error. #8371
+      api_set_error(err, kErrorTypeException, "Failed to evaluate expression");
+    } else {
+      rv = vim_to_object(&rettv);
+    }
   }
 
-  // Free the Vim object
   tv_clear(&rettv);
+  msg_list = saved_msg_list;  // Restore the exception context.
+  recursive--;
 
   return rv;
 }
@@ -314,7 +335,9 @@ Object nvim_execute_lua(String code, Array args, Error *err)
 /// @return Result of the function call
 static Object _call_function(String fn, Array args, dict_T *self, Error *err)
 {
+  static int recursive = 0;  // recursion depth
   Object rv = OBJECT_INIT;
+
   if (args.size > MAX_FUNC_ARGS) {
     api_set_error(err, kErrorTypeValidation,
                   "Function called with too many arguments");
@@ -330,20 +353,36 @@ static Object _call_function(String fn, Array args, dict_T *self, Error *err)
     }
   }
 
+  // `msg_list` controls the collection of abort-causing non-exception errors,
+  // which would otherwise be ignored.  This pattern is from do_cmdline().
+  struct msglist **saved_msg_list = msg_list;
+  struct msglist *private_msg_list;
+  msg_list = &private_msg_list;
+  private_msg_list = NULL;
+
+  // Initialize `force_abort`  and `suppress_errthrow` at the top level.
+  if (!recursive) {
+    force_abort = false;
+    suppress_errthrow = false;
+    current_exception = NULL;
+    // `did_emsg` is set by emsg(), which cancels execution.
+    did_emsg = false;
+  }
+  recursive++;
   try_start();
-  // Call the function
   typval_T rettv;
   int dummy;
-  int r = call_func((char_u *)fn.data, (int)fn.size, &rettv, (int)args.size,
-                    vim_args, NULL, curwin->w_cursor.lnum,
-                    curwin->w_cursor.lnum, &dummy, true, NULL, self);
-  if (r == FAIL) {
-    api_set_error(err, kErrorTypeException, "Error calling function");
-  }
+  // call_func() retval is deceptive, ignore it.  Instead we set `msg_list`
+  // (see above) to capture abort-causing non-exception errors.
+  (void)call_func((char_u *)fn.data, (int)fn.size, &rettv, (int)args.size,
+                  vim_args, NULL, curwin->w_cursor.lnum, curwin->w_cursor.lnum,
+                  &dummy, true, NULL, self);
   if (!try_end(err)) {
     rv = vim_to_object(&rettv);
   }
   tv_clear(&rettv);
+  msg_list = saved_msg_list;  // Restore the exception context.
+  recursive--;
 
 free_vim_args:
   while (i > 0) {
@@ -355,7 +394,7 @@ static Object _call_function(String fn, Array args, dict_T *self, Error *err)
 
 /// Calls a VimL function with the given arguments.
 ///
-/// On VimL error: Returns a generic error; v:errmsg is not updated.
+/// On execution error: fails with VimL error, does not update v:errmsg.
 ///
 /// @param fn       Function to call
 /// @param args     Function arguments packed in an Array
@@ -369,6 +408,8 @@ Object nvim_call_function(String fn, Array args, Error *err)
 
 /// Calls a VimL |Dictionary-function| with the given arguments.
 ///
+/// On execution error: fails with VimL error, does not update v:errmsg.
+///
 /// @param dict Dictionary, or String evaluating to a VimL |self| dict
 /// @param fn Name of the function defined on the VimL dict
 /// @param args Function arguments packed in an Array
@@ -934,27 +975,26 @@ Array nvim_get_api_info(uint64_t channel_id)
   return rv;
 }
 
-/// Call many api methods atomically
+/// Calls many API methods atomically.
 ///
-/// This has two main usages: Firstly, to perform several requests from an
-/// async context atomically, i.e. without processing requests from other rpc
-/// clients or redrawing or allowing user interaction in between. Note that api
-/// methods that could fire autocommands or do event processing still might do
-/// so. For instance invoking the :sleep command might call timer callbacks.
-/// Secondly, it can be used to reduce rpc overhead (roundtrips) when doing
-/// many requests in sequence.
+/// This has two main usages:
+/// 1. To perform several requests from an async context atomically, i.e.
+///    without interleaving redraws, RPC requests from other clients, or user
+///    interactions (however API methods may trigger autocommands or event
+///    processing which have such side-effects, e.g. |:sleep| may wake timers).
+/// 2. To minimize RPC overhead (roundtrips) of a sequence of many requests.
 ///
 /// @param calls an array of calls, where each call is described by an array
 /// with two elements: the request name, and an array of arguments.
 /// @param[out] err Details of a validation error of the nvim_multi_request call
-/// itself, i e malformatted `calls` parameter. Errors from called methods will
+/// itself, i.e. malformed `calls` parameter. Errors from called methods will
 /// be indicated in the return value, see below.
 ///
 /// @return an array with two elements. The first is an array of return
 /// values. The second is NIL if all calls succeeded. If a call resulted in
 /// an error, it is a three-element array with the zero-based index of the call
 /// which resulted in an error, the error type and the error message. If an
-/// error ocurred, the values from all preceding calls will still be returned.
+/// error occurred, the values from all preceding calls will still be returned.
 Array nvim_call_atomic(uint64_t channel_id, Array calls, Error *err)
   FUNC_API_SINCE(1) FUNC_API_REMOTE_ONLY
 {

src/nvim/eval.c

@@ -6241,20 +6241,21 @@ bool set_ref_in_func(char_u *name, ufunc_T *fp_in, int copyID)
 /// invoked function uses them. It is called like this:
 ///   new_argcount = argv_func(current_argcount, argv, called_func_argcount)
 ///
-/// Return FAIL when the function can't be called,  OK otherwise.
-/// Also returns OK when an error was encountered while executing the function.
+/// @return FAIL if function cannot be called, else OK (even if an error
+///         occurred while executing the function! Set `msg_list` to capture
+///         the error, see do_cmdline()).
 int
 call_func(
     const char_u *funcname,         // name of the function
     int len,                        // length of "name"
-    typval_T *rettv,                // return value goes here
+    typval_T *rettv,                // [out] value goes here
     int argcount_in,                // number of "argvars"
     typval_T *argvars_in,           // vars for arguments, must have "argcount"
                                     // PLUS ONE elements!
     ArgvFunc argv_func,             // function to fill in argvars
     linenr_T firstline,             // first line of range
     linenr_T lastline,              // last line of range
-    int *doesrange,                 // return: function handled range
+    int *doesrange,                 // [out] function handled range
     bool evaluate,
     partial_T *partial,             // optional, can be NULL
     dict_T *selfdict_in             // Dictionary for "self"
@@ -6428,21 +6429,25 @@ call_func(
   return ret;
 }
 
-/*
- * Give an error message with a function name.  Handle <SNR> things.
- * "ermsg" is to be passed without translation, use N_() instead of _().
- */
+/// Give an error message with a function name.  Handle <SNR> things.
+///
+/// @param ermsg must be passed without translation (use N_() instead of _()).
+/// @param name function name
 static void emsg_funcname(char *ermsg, char_u *name)
 {
-  char_u      *p;
+  char_u *p;
 
-  if (*name == K_SPECIAL)
+  if (*name == K_SPECIAL) {
     p = concat_str((char_u *)"<SNR>", name + 3);
-  else
+  } else {
     p = name;
+  }
+
   EMSG2(_(ermsg), p);
-  if (p != name)
+
+  if (p != name) {
     xfree(p);
+  }
 }
 
 /*

src/nvim/ex_eval.c

@@ -28,22 +28,21 @@
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "ex_eval.c.generated.h"
 #endif
-/*
- * Exception handling terms:
- *
- *	:try		":try" command		\
- *	    ...		try block		|
- *	:catch RE	":catch" command	|
- *	    ...		catch clause		|- try conditional
- *	:finally	":finally" command	|
- *	    ...		finally clause		|
- *	:endtry		":endtry" command	/
- *
- * The try conditional may have any number of catch clauses and at most one
- * finally clause.  A ":throw" command can be inside the try block, a catch
- * clause, the finally clause, or in a function called or script sourced from
- * there or even outside the try conditional.  Try conditionals may be nested.
- */
+
+// Exception handling terms:
+//
+//      :try            ":try" command         ─┐
+//          ...         try block               │
+//      :catch RE       ":catch" command        │
+//          ...         catch clause            ├─ try conditional
+//      :finally        ":finally" command      │
+//          ...         finally clause          │
+//      :endtry         ":endtry" command      ─┘
+//
+// The try conditional may have any number of catch clauses and at most one
+// finally clause.  A ":throw" command can be inside the try block, a catch
+// clause, the finally clause, or in a function called or script sourced from
+// there or even outside the try conditional.  Try conditionals may be nested.
 
 // Configuration whether an exception is thrown on error or interrupt.  When
 // the preprocessor macros below evaluate to FALSE, an error (did_emsg) or