Simplify Fcall_interactively

* src/callint.c (Fcall_interactively): Use C99 constructs to
simplify the code a bit.  Stop worrying about circa-1990
compiler bugs.

1 files changed, 109 insertions, 177 deletions

diff --git a/src/callint.c b/src/callint.c
index 3d2ed0016cc..08a8bba4646 100644
--- a/src/callint.c
+++ b/src/callint.c
@@ -271,45 +271,16 @@ invoke it.  If KEYS is omitted or nil, the return value of
 `this-command-keys-vector' is used.  */)
   (Lisp_Object function, Lisp_Object record_flag, Lisp_Object keys)
 {
-  /* `args' will contain the array of arguments to pass to the function.
-     `visargs' will contain the same list but in a nicer form, so that if we
-     pass it to Fformat_message it will be understandable to a human.  */
-  Lisp_Object *args, *visargs;
-  Lisp_Object specs;
-  Lisp_Object filter_specs;
-  Lisp_Object teml;
-  Lisp_Object up_event;
-  Lisp_Object enable;
-  USE_SAFE_ALLOCA;
   ptrdiff_t speccount = SPECPDL_INDEX ();
 
-  /* The index of the next element of this_command_keys to examine for
-     the 'e' interactive code.  */
-  ptrdiff_t next_event;
-
-  Lisp_Object prefix_arg;
-  char *string, *string_end;
-  ptrdiff_t string_len;
-  const char *tem;
-
-  /* If varies[i] > 0, the i'th argument shouldn't just have its value
-     in this call quoted in the command history.  It should be
-     recorded as a call to the function named callint_argfuns[varies[i]].  */
-  signed char *varies;
-
-  ptrdiff_t i, nargs;
-  ptrdiff_t mark;
-  bool arg_from_tty = 0;
+  bool arg_from_tty = false;
   ptrdiff_t key_count;
-  bool record_then_fail = 0;
+  bool record_then_fail = false;
 
-  Lisp_Object save_this_command, save_last_command;
-  Lisp_Object save_this_original_command, save_real_this_command;
-
-  save_this_command = Vthis_command;
-  save_this_original_command = Vthis_original_command;
-  save_real_this_command = Vreal_this_command;
-  save_last_command = KVAR (current_kboard, Vlast_command);
+  Lisp_Object save_this_command = Vthis_command;
+  Lisp_Object save_this_original_command = Vthis_original_command;
+  Lisp_Object save_real_this_command = Vreal_this_command;
+  Lisp_Object save_last_command = KVAR (current_kboard, Vlast_command);
 
   if (NILP (keys))
     keys = this_command_keys, key_count = this_command_key_count;
@@ -320,55 +291,44 @@ invoke it.  If KEYS is omitted or nil, the return value of
     }
 
   /* Save this now, since use of minibuffer will clobber it.  */
-  prefix_arg = Vcurrent_prefix_arg;
-
-  if (SYMBOLP (function))
-    enable = Fget (function, Qenable_recursive_minibuffers);
-  else
-    enable = Qnil;
+  Lisp_Object prefix_arg = Vcurrent_prefix_arg;
 
-  specs = Qnil;
-  string = 0;
-  /* The idea of FILTER_SPECS is to provide a way to
-     specify how to represent the arguments in command history.
-     The feature is not fully implemented.  */
-  filter_specs = Qnil;
+  Lisp_Object enable = (SYMBOLP (function)
+                        ? Fget (function, Qenable_recursive_minibuffers)
+                        : Qnil);
 
   /* If k or K discard an up-event, save it here so it can be retrieved with
      U.  */
-  up_event = Qnil;
+  Lisp_Object up_event = Qnil;
 
   /* Set SPECS to the interactive form, or barf if not interactive.  */
-  {
-    Lisp_Object form;
-    form = Finteractive_form (function);
-    if (CONSP (form))
-      specs = filter_specs = Fcar (XCDR (form));
-    else
-      wrong_type_argument (Qcommandp, function);
-  }
+  Lisp_Object form = Finteractive_form (function);
+  if (! CONSP (form))
+    wrong_type_argument (Qcommandp, function);
+  Lisp_Object specs = Fcar (XCDR (form));
+
+  /* At this point the value of SPECS could help provide a way to
+     specify how to represent the arguments in command history.
+     The feature is not fully implemented.  */
 
   /* If SPECS is not a string, invent one.  */
   if (! STRINGP (specs))
     {
-      Lisp_Object input;
       Lisp_Object funval = Findirect_function (function, Qt);
       uintmax_t events = num_input_events;
-      input = specs;
+      Lisp_Object input = specs;
       /* Compute the arg values using the user's expression.  */
       specs = Feval (specs,
                      CONSP (funval) && EQ (Qclosure, XCAR (funval))
                      ? CAR_SAFE (XCDR (funval)) : Qnil);
       if (events != num_input_events || !NILP (record_flag))
         {
-          /* We should record this command on the command history.  */
-          Lisp_Object values;
-          Lisp_Object this_cmd;
-          /* Make a copy of the list of values, for the command history,
+          /* We should record this command on the command history.
+             Make a copy of the list of values, for the command history,
              and turn them into things we can eval.  */
-          values = quotify_args (Fcopy_sequence (specs));
+          Lisp_Object values = quotify_args (Fcopy_sequence (specs));
           fix_command (input, values);
-          this_cmd = Fcons (function, values);
+          Lisp_Object this_cmd = Fcons (function, values);
           if (history_delete_duplicates)
             Vcommand_history = Fdelete (this_cmd, Vcommand_history);
           Vcommand_history = Fcons (this_cmd, Vcommand_history);
@@ -376,7 +336,7 @@ invoke it.  If KEYS is omitted or nil, the return value of
           /* Don't keep command history around forever.  */
           if (INTEGERP (Vhistory_length) && XINT (Vhistory_length) > 0)
             {
-              teml = Fnthcdr (Vhistory_length, Vcommand_history);
+              Lisp_Object teml = Fnthcdr (Vhistory_length, Vcommand_history);
               if (CONSP (teml))
                 XSETCDR (teml, Qnil);
             }
@@ -387,48 +347,42 @@ invoke it.  If KEYS is omitted or nil, the return value of
       Vreal_this_command = save_real_this_command;
       kset_last_command (current_kboard, save_last_command);
 
-      Lisp_Object result
-        = unbind_to (speccount, CALLN (Fapply, Qfuncall_interactively,
-                                       function, specs));
-      SAFE_FREE ();
-      return result;
+      return unbind_to (speccount, CALLN (Fapply, Qfuncall_interactively,
+                                          function, specs));
     }
 
   /* SPECS is set to a string; use it as an interactive prompt.
      Copy it so that STRING will be valid even if a GC relocates SPECS.  */
-  SAFE_ALLOCA_STRING (string, specs);
-  string_len = SBYTES (specs);
-  string_end = string + string_len;
-
-  /* Here if function specifies a string to control parsing the defaults.  */
+  USE_SAFE_ALLOCA;
+  ptrdiff_t string_len = SBYTES (specs);
+  char *string = SAFE_ALLOCA (string_len + 1);
+  memcpy (string, SDATA (specs), string_len + 1);
+  char *string_end = string + string_len;
 
-  /* Set next_event to point to the first event with parameters.  */
+  /* The index of the next element of this_command_keys to examine for
+     the 'e' interactive code.  Initialize it to point to the first
+     event with parameters.  */
+  ptrdiff_t next_event;
   for (next_event = 0; next_event < key_count; next_event++)
     if (EVENT_HAS_PARAMETERS (AREF (keys, next_event)))
       break;
 
   /* Handle special starting chars `*' and `@'.  Also `-'.  */
   /* Note that `+' is reserved for user extensions.  */
-  while (1)
+  for (;; string++)
     {
       if (*string == '+')
         error ("`+' is not used in `interactive' for ordinary commands");
       else if (*string == '*')
         {
-          string++;
           if (!NILP (BVAR (current_buffer, read_only)))
             {
               if (!NILP (record_flag))
                 {
-                  char *p = string;
-                  while (p < string_end)
-                    {
-                      if (! (*p == 'r' || *p == 'p' || *p == 'P'
-                             || *p == '\n'))
-                        Fbarf_if_buffer_read_only (Qnil);
-                      p++;
-                    }
-                  record_then_fail = 1;
+                  for (char *p = string + 1; p < string_end; p++)
+                    if (! (*p == 'r' || *p == 'p' || *p == 'P' || *p == '\n'))
+                      Fbarf_if_buffer_read_only (Qnil);
+                  record_then_fail = true;
                 }
               else
                 Fbarf_if_buffer_read_only (Qnil);
@@ -436,14 +390,12 @@ invoke it.  If KEYS is omitted or nil, the return value of
         }
       /* Ignore this for semi-compatibility with Lucid.  */
       else if (*string == '-')
-        string++;
+        ;
       else if (*string == '@')
         {
-          Lisp_Object event, w;
-
-          event = (next_event < key_count
-                   ? AREF (keys, next_event)
-                   : Qnil);
+          Lisp_Object w, event = (next_event < key_count
+                                  ? AREF (keys, next_event)
+                                  : Qnil);
           if (EVENT_HAS_PARAMETERS (event)
               && (w = XCDR (event), CONSP (w))
               && (w = XCAR (w), CONSP (w))
@@ -458,32 +410,23 @@ invoke it.  If KEYS is omitted or nil, the return value of
 
               Fselect_window (w, Qnil);
             }
-          string++;
         }
       else if (*string == '^')
-        {
-          call0 (Qhandle_shift_selection);
-          string++;
-        }
+        call0 (Qhandle_shift_selection);
       else break;
     }
 
   /* Count the number of arguments, which is two (the function itself and
      `funcall-interactively') plus the number of arguments the interactive spec
      would have us give to the function.  */
-  tem = string;
-  for (nargs = 2; tem < string_end; )
+  ptrdiff_t nargs = 2;
+  for (char const *tem = string; tem < string_end; tem++)
     {
       /* 'r' specifications ("point and mark as 2 numeric args")
          produce *two* arguments.  */
-      if (*tem == 'r')
-        nargs += 2;
-      else
-        nargs++;
+      nargs += 1 + (*tem == 'r');
       tem = memchr (tem, '\n', string_len - (tem - string));
-      if (tem)
-        ++tem;
-      else
+      if (!tem)
         break;
     }
 
@@ -491,11 +434,18 @@ invoke it.  If KEYS is omitted or nil, the return value of
       && MOST_POSITIVE_FIXNUM < nargs)
     memory_full (SIZE_MAX);
 
-  /* Allocate them all at one go.  This wastes a bit of memory, but
+  /* ARGS will contain the array of arguments to pass to the function.
+     VISARGS will contain the same list but in a nicer form, so that if we
+     pass it to Fformat_message it will be understandable to a human.
+     Allocate them all at one go.  This wastes a bit of memory, but
      it's OK to trade space for speed.  */
+  Lisp_Object *args;
   SAFE_NALLOCA (args, 3, nargs);
-  visargs = args + nargs;
-  varies = (signed char *) (visargs + nargs);
+  Lisp_Object *visargs = args + nargs;
+  /* If varies[I] > 0, the Ith argument shouldn't just have its value
+     in this call quoted in the command history.  It should be
+     recorded as a call to the function named callint_argfuns[varies[I]].  */
+  signed char *varies = (signed char *) (visargs + nargs);
 
   memclear (args, nargs * (2 * word_size + 1));
   args = ptr_bounds_clip (args, nargs * sizeof *args);
@@ -505,8 +455,8 @@ invoke it.  If KEYS is omitted or nil, the return value of
   if (!NILP (enable))
     specbind (Qenable_recursive_minibuffers, Qt);
 
-  tem = string;
-  for (i = 2; tem < string_end; i++)
+  char const *tem = string;
+  for (ptrdiff_t i = 2; tem < string_end; i++)
     {
       char *pnl = memchr (tem + 1, '\n', string_len - (tem + 1 - string));
       ptrdiff_t sz = pnl ? pnl - (tem + 1) : string_end - (tem + 1);
@@ -520,9 +470,7 @@ invoke it.  If KEYS is omitted or nil, the return value of
           visargs[i] = Fcompleting_read (callint_message,
                                          Vobarray, Qfboundp, Qt,
                                          Qnil, Qnil, Qnil, Qnil);
-          /* Passing args[i] directly stimulates compiler bug.  */
-          teml = visargs[i];
-          args[i] = Fintern (teml, Qnil);
+          args[i] = Fintern (visargs[i], Qnil);
           break;
 
         case 'b':               /* Name of existing buffer.  */
@@ -534,7 +482,8 @@ invoke it.  If KEYS is omitted or nil, the return value of
 
         case 'B':               /* Name of buffer, possibly nonexistent.  */
           args[i] = Fread_buffer (callint_message,
-                                  Fother_buffer (Fcurrent_buffer (), Qnil, Qnil),
+                                  Fother_buffer (Fcurrent_buffer (),
+                                                 Qnil, Qnil),
                                   Qnil, Qnil);
           break;
 
@@ -545,20 +494,17 @@ invoke it.  If KEYS is omitted or nil, the return value of
                               Qface, Qminibuffer_prompt, callint_message);
           args[i] = Fread_char (callint_message, Qnil, Qnil);
           message1_nolog (0);
-          /* Passing args[i] directly stimulates compiler bug.  */
-          teml = args[i];
           /* See bug#8479.  */
-          if (! CHARACTERP (teml)) error ("Non-character input-event");
-          visargs[i] = Fchar_to_string (teml);
+          if (! CHARACTERP (args[i]))
+            error ("Non-character input-event");
+          visargs[i] = Fchar_to_string (args[i]);
           break;
 
         case 'C':             /* Command: symbol with interactive function.  */
           visargs[i] = Fcompleting_read (callint_message,
                                          Vobarray, Qcommandp,
                                          Qt, Qnil, Qnil, Qnil, Qnil);
-          /* Passing args[i] directly stimulates compiler bug.  */
-          teml = visargs[i];
-          args[i] = Fintern (teml, Qnil);
+          args[i] = Fintern (visargs[i], Qnil);
           break;
 
         case 'd':               /* Value of point.  Does not do I/O.  */
@@ -569,8 +515,8 @@ invoke it.  If KEYS is omitted or nil, the return value of
           break;
 
         case 'D':               /* Directory name.  */
-          args[i] = read_file_name (BVAR (current_buffer, directory), Qlambda, Qnil,
-                                    Qfile_directory_p);
+          args[i] = read_file_name (BVAR (current_buffer, directory), Qlambda,
+                                    Qnil, Qfile_directory_p);
           break;
 
         case 'f':               /* Existing file name.  */
@@ -601,21 +547,19 @@ invoke it.  If KEYS is omitted or nil, the return value of
             args[i] = Fread_key_sequence (callint_message,
                                           Qnil, Qnil, Qnil, Qnil);
             unbind_to (speccount1, Qnil);
-            teml = args[i];
-            visargs[i] = Fkey_description (teml, Qnil);
+            visargs[i] = Fkey_description (args[i], Qnil);
 
             /* If the key sequence ends with a down-event,
                discard the following up-event.  */
-            teml = Faref (args[i], make_number (XINT (Flength (args[i])) - 1));
+            Lisp_Object teml
+              = Faref (args[i], make_number (XINT (Flength (args[i])) - 1));
             if (CONSP (teml))
               teml = XCAR (teml);
             if (SYMBOLP (teml))
               {
-                Lisp_Object tem2;
-
                 teml = Fget (teml, Qevent_symbol_elements);
                 /* Ignore first element, which is the base key.  */
-                tem2 = Fmemq (Qdown, Fcdr (teml));
+                Lisp_Object tem2 = Fmemq (Qdown, Fcdr (teml));
                 if (! NILP (tem2))
                   up_event = Fread_event (Qnil, Qnil, Qnil);
               }
@@ -632,22 +576,20 @@ invoke it.  If KEYS is omitted or nil, the return value of
                                 Qface, Qminibuffer_prompt, callint_message);
             args[i] = Fread_key_sequence_vector (callint_message,
                                                  Qnil, Qt, Qnil, Qnil);
-            teml = args[i];
-            visargs[i] = Fkey_description (teml, Qnil);
+            visargs[i] = Fkey_description (args[i], Qnil);
             unbind_to (speccount1, Qnil);
 
             /* If the key sequence ends with a down-event,
                discard the following up-event.  */
-            teml = Faref (args[i], make_number (XINT (Flength (args[i])) - 1));
+            Lisp_Object teml
+              = Faref (args[i], make_number (XINT (Flength (args[i])) - 1));
             if (CONSP (teml))
               teml = XCAR (teml);
             if (SYMBOLP (teml))
               {
-                Lisp_Object tem2;
-
                 teml = Fget (teml, Qevent_symbol_elements);
                 /* Ignore first element, which is the base key.  */
-                tem2 = Fmemq (Qdown, Fcdr (teml));
+                Lisp_Object tem2 = Fmemq (Qdown, Fcdr (teml));
                 if (! NILP (tem2))
                   up_event = Fread_event (Qnil, Qnil, Qnil);
               }
@@ -659,8 +601,7 @@ invoke it.  If KEYS is omitted or nil, the return value of
             {
               args[i] = Fmake_vector (make_number (1), up_event);
               up_event = Qnil;
-              teml = args[i];
-              visargs[i] = Fkey_description (teml, Qnil);
+              visargs[i] = Fkey_description (args[i], Qnil);
             }
           break;
 
@@ -671,18 +612,18 @@ invoke it.  If KEYS is omitted or nil, the return value of
                     ? SSDATA (SYMBOL_NAME (function))
                     : "command"));
           args[i] = AREF (keys, next_event);
-          next_event++;
           varies[i] = -1;
 
           /* Find the next parameterized event.  */
-          while (next_event < key_count
-                 && !(EVENT_HAS_PARAMETERS (AREF (keys, next_event))))
+          do
             next_event++;
+          while (next_event < key_count
+                 && ! EVENT_HAS_PARAMETERS (AREF (keys, next_event)));
 
           break;
 
         case 'm':               /* Value of mark.  Does not do I/O.  */
-          check_mark (0);
+          check_mark (false);
           /* visargs[i] = Qnil; */
           args[i] = BVAR (current_buffer, mark);
           varies[i] = 2;
@@ -700,9 +641,7 @@ invoke it.  If KEYS is omitted or nil, the return value of
           FALLTHROUGH;
         case 'n':               /* Read number from minibuffer.  */
           args[i] = call1 (Qread_number, callint_message);
-          /* Passing args[i] directly stimulates compiler bug.  */
-          teml = args[i];
-          visargs[i] = Fnumber_to_string (teml);
+          visargs[i] = Fnumber_to_string (args[i]);
           break;
 
         case 'P':               /* Prefix arg in raw form.  Does no I/O.  */
@@ -719,15 +658,16 @@ invoke it.  If KEYS is omitted or nil, the return value of
           break;
 
         case 'r':               /* Region, point and mark as 2 args.  */
-          check_mark (1);
-          set_marker_both (point_marker, Qnil, PT, PT_BYTE);
-          /* visargs[i+1] = Qnil; */
-          mark = marker_position (BVAR (current_buffer, mark));
-          /* visargs[i] = Qnil; */
-          args[i] = PT < mark ? point_marker : BVAR (current_buffer, mark);
-          varies[i] = 3;
-          args[++i] = PT > mark ? point_marker : BVAR (current_buffer, mark);
-          varies[i] = 4;
+          {
+            check_mark (true);
+            set_marker_both (point_marker, Qnil, PT, PT_BYTE);
+            ptrdiff_t mark = marker_position (BVAR (current_buffer, mark));
+            /* visargs[i] = visargs[i + 1] = Qnil; */
+            args[i] = PT < mark ? point_marker : BVAR (current_buffer, mark);
+            varies[i] = 3;
+            args[++i] = PT > mark ? point_marker : BVAR (current_buffer, mark);
+            varies[i] = 4;
+          }
           break;
 
         case 's':               /* String read via minibuffer without
@@ -739,9 +679,7 @@ invoke it.  If KEYS is omitted or nil, the return value of
         case 'S':               /* Any symbol.  */
           visargs[i] = Fread_string (callint_message,
                                      Qnil, Qnil, Qnil, Qnil);
-          /* Passing args[i] directly stimulates compiler bug.  */
-          teml = visargs[i];
-          args[i] = Fintern (teml, Qnil);
+          args[i] = Fintern (visargs[i], Qnil);
           break;
 
         case 'v':               /* Variable name: symbol that is
@@ -798,13 +736,14 @@ invoke it.  If KEYS is omitted or nil, the return value of
             else
               letter = *((unsigned char *) tem);
 
-            error ("Invalid control letter `%c' (#o%03o, #x%04x) in interactive calling string",
+            error (("Invalid control letter `%c' (#o%03o, #x%04x)"
+                    " in interactive calling string"),
                    (int) letter, letter, letter);
           }
         }
 
       if (varies[i] == 0)
-        arg_from_tty = 1;
+        arg_from_tty = true;
 
       if (NILP (visargs[i]) && STRINGP (args[i]))
         visargs[i] = args[i];
@@ -825,19 +764,16 @@ invoke it.  If KEYS is omitted or nil, the return value of
       /* We don't need `visargs' any more, so let's recycle it since we need
          an array of just the same size.  */
       visargs[1] = function;
-      for (i = 2; i < nargs; i++)
-        {
-          if (varies[i] > 0)
-            visargs[i] = list1 (intern (callint_argfuns[varies[i]]));
-          else
-            visargs[i] = quotify_arg (args[i]);
-        }
+      for (ptrdiff_t i = 2; i < nargs; i++)
+        visargs[i] = (varies[i] > 0
+                      ? list1 (intern (callint_argfuns[varies[i]]))
+                      : quotify_arg (args[i]));
       Vcommand_history = Fcons (Flist (nargs - 1, visargs + 1),
                                 Vcommand_history);
       /* Don't keep command history around forever.  */
       if (INTEGERP (Vhistory_length) && XINT (Vhistory_length) > 0)
         {
-          teml = Fnthcdr (Vhistory_length, Vcommand_history);
+          Lisp_Object teml = Fnthcdr (Vhistory_length, Vcommand_history);
           if (CONSP (teml))
             XSETCDR (teml, Qnil);
         }
@@ -845,7 +781,7 @@ invoke it.  If KEYS is omitted or nil, the return value of
 
   /* If we used a marker to hold point, mark, or an end of the region,
      temporarily, convert it to an integer now.  */
-  for (i = 2; i < nargs; i++)
+  for (ptrdiff_t i = 2; i < nargs; i++)
     if (varies[i] >= 1 && varies[i] <= 4)
       XSETINT (args[i], marker_position (args[i]));
 
@@ -857,15 +793,11 @@ invoke it.  If KEYS is omitted or nil, the return value of
   Vreal_this_command = save_real_this_command;
   kset_last_command (current_kboard, save_last_command);
 
-  {
-    Lisp_Object val;
-    specbind (Qcommand_debug_status, Qnil);
+  specbind (Qcommand_debug_status, Qnil);
 
-    val = Ffuncall (nargs, args);
-    val = unbind_to (speccount, val);
-    SAFE_FREE ();
-    return val;
-  }
+  Lisp_Object val = Ffuncall (nargs, args);
+  SAFE_FREE ();
+  return unbind_to (speccount, val);
 }
 
 DEFUN ("prefix-numeric-value", Fprefix_numeric_value, Sprefix_numeric_value,