Merge remote-tracking branch 'upstream/master' into usermarksusermarks

1 files changed, 510 insertions, 574 deletions

diff --git a/src/nvim/ex_eval.c b/src/nvim/ex_eval.c
index 69d509abb7..f76e60f6c5 100644
--- a/src/nvim/ex_eval.c
+++ b/src/nvim/ex_eval.c
@@ -1,8 +1,6 @@
 // This is an open source non-commercial project. Dear PVS-Studio, please check
 // it. PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
 
-// TODO(ZyX-I): move to eval/executor
-
 /// @file ex_eval.c
 ///
 /// Functions for Ex command line for the +eval feature.
@@ -10,19 +8,30 @@
 #include <inttypes.h>
 #include <limits.h>
 #include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
 
 #include "nvim/ascii.h"
 #include "nvim/charset.h"
 #include "nvim/debugger.h"
 #include "nvim/eval.h"
+#include "nvim/eval/typval.h"
+#include "nvim/eval/typval_defs.h"
 #include "nvim/eval/userfunc.h"
+#include "nvim/ex_cmds_defs.h"
 #include "nvim/ex_docmd.h"
 #include "nvim/ex_eval.h"
+#include "nvim/ex_eval_defs.h"
+#include "nvim/gettext.h"
+#include "nvim/globals.h"
 #include "nvim/memory.h"
 #include "nvim/message.h"
+#include "nvim/option_defs.h"
+#include "nvim/pos.h"
 #include "nvim/regexp.h"
 #include "nvim/runtime.h"
 #include "nvim/strings.h"
+#include "nvim/types.h"
 #include "nvim/vim.h"
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
@@ -45,20 +54,19 @@
 // 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
+// the preprocessor macros below evaluate to false, an error (did_emsg) or
 // interrupt (got_int) under an active try conditional terminates the script
 // after the non-active finally clauses of all active try conditionals have been
 // executed.  Otherwise, errors and/or interrupts are converted into catchable
-// exceptions, which terminate the script only if not caught.  For user
-// exceptions, only current_exception is set.  (Note: got_int can be set
-// asynchronously afterwards by a SIGINT, so current_exception && got_int is not
+// exceptions (did_throw additionally set), which terminate the script only if
+// not caught.  For user exceptions, only did_throw is set.  (Note: got_int can
+// be set asynchronously afterwards by a SIGINT, so did_throw && got_int is not
 // a reliant test that the exception currently being thrown is an interrupt
 // exception.  Similarly, did_emsg can be set afterwards on an error in an
-// (unskipped) conditional command inside an inactive conditional, so
-// current_exception && did_emsg is not a reliant test that the exception
-// currently being thrown is an error exception.)  -  The macros can be defined
-// as expressions checking for a variable that is allowed to be changed during
-// execution of a script.
+// (unskipped) conditional command inside an inactive conditional, so did_throw
+// && did_emsg is not a reliant test that the exception currently being thrown
+// is an error exception.)  -  The macros can be defined as expressions checking
+// for a variable that is allowed to be changed during execution of a script.
 
 // Values used for the Vim release.
 #define THROW_ON_ERROR true
@@ -71,7 +79,7 @@
 #define CHECK_SKIP \
   (did_emsg \
    || got_int \
-   || current_exception \
+   || did_throw \
    || (cstack->cs_idx > 0 \
        && !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE)))
 
@@ -80,16 +88,14 @@ static void discard_pending_return(typval_T *p)
   tv_free(p);
 }
 
-/*
- * When several errors appear in a row, setting "force_abort" is delayed until
- * the failing command returned.  "cause_abort" is set to TRUE meanwhile, in
- * order to indicate that situation.  This is useful when "force_abort" was set
- * during execution of a function call from an expression: the aborting of the
- * expression evaluation is done without producing any error messages, but all
- * error messages on parsing errors during the expression evaluation are given
- * (even if a try conditional is active).
- */
-static int cause_abort = FALSE;
+// When several errors appear in a row, setting "force_abort" is delayed until
+// the failing command returned.  "cause_abort" is set to true meanwhile, in
+// order to indicate that situation.  This is useful when "force_abort" was set
+// during execution of a function call from an expression: the aborting of the
+// expression evaluation is done without producing any error messages, but all
+// error messages on parsing errors during the expression evaluation are given
+// (even if a try conditional is active).
+static int cause_abort = false;
 
 /// @return  true when immediately aborting on error, or when an interrupt
 ///          occurred or an exception was thrown but not caught.
@@ -104,7 +110,7 @@ static int cause_abort = FALSE;
 /// value. "got_int" is also set by calling interrupt().
 int aborting(void)
 {
-  return (did_emsg && force_abort) || got_int || current_exception;
+  return (did_emsg && force_abort) || got_int || did_throw;
 }
 
 /// The value of "force_abort" is temporarily reset by the first emsg() call
@@ -114,11 +120,11 @@ int aborting(void)
 void update_force_abort(void)
 {
   if (cause_abort) {
-    force_abort = TRUE;
+    force_abort = true;
   }
 }
 
-/// @return  TRUE if a command with a subcommand resulting in "retcode" should
+/// @return  true if a command with a subcommand resulting in "retcode" should
 /// abort the script processing.  Can be used to suppress an autocommand after
 /// execution of a failing subcommand as long as the error message has not been
 /// displayed and actually caused the abortion.
@@ -127,7 +133,7 @@ int should_abort(int retcode)
   return (retcode == FAIL && trylevel != 0 && !emsg_silent) || aborting();
 }
 
-/// @return  TRUE if a function with the "abort" flag should not be considered
+/// @return  true if a function with the "abort" flag should not be considered
 /// ended on an error.  This means that parsing commands is continued in order
 /// to find finally clauses to be executed, and that some errors in skipped
 /// commands are still reported.
@@ -154,70 +160,58 @@ bool cause_errthrow(const char *mesg, bool severe, bool *ignore)
   msglist_T *elem;
   msglist_T **plist;
 
-  /*
-   * Do nothing when displaying the interrupt message or reporting an
-   * uncaught exception (which has already been discarded then) at the top
-   * level.  Also when no exception can be thrown.  The message will be
-   * displayed by emsg().
-   */
+  // Do nothing when displaying the interrupt message or reporting an
+  // uncaught exception (which has already been discarded then) at the top
+  // level.  Also when no exception can be thrown.  The message will be
+  // displayed by emsg().
   if (suppress_errthrow) {
     return false;
   }
 
-  /*
-   * If emsg() has not been called previously, temporarily reset
-   * "force_abort" until the throw point for error messages has been
-   * reached.  This ensures that aborting() returns the same value for all
-   * errors that appear in the same command.  This means particularly that
-   * for parsing errors during expression evaluation emsg() will be called
-   * multiply, even when the expression is evaluated from a finally clause
-   * that was activated due to an aborting error, interrupt, or exception.
-   */
+  // If emsg() has not been called previously, temporarily reset
+  // "force_abort" until the throw point for error messages has been
+  // reached.  This ensures that aborting() returns the same value for all
+  // errors that appear in the same command.  This means particularly that
+  // for parsing errors during expression evaluation emsg() will be called
+  // multiply, even when the expression is evaluated from a finally clause
+  // that was activated due to an aborting error, interrupt, or exception.
   if (!did_emsg) {
     cause_abort = force_abort;
-    force_abort = FALSE;
-  }
-
-  /*
-   * If no try conditional is active and no exception is being thrown and
-   * there has not been an error in a try conditional or a throw so far, do
-   * nothing (for compatibility of non-EH scripts).  The message will then
-   * be displayed by emsg().  When ":silent!" was used and we are not
-   * currently throwing an exception, do nothing.  The message text will
-   * then be stored to v:errmsg by emsg() without displaying it.
-   */
-  if (((trylevel == 0 && !cause_abort) || emsg_silent) && !current_exception) {
+    force_abort = false;
+  }
+
+  // If no try conditional is active and no exception is being thrown and
+  // there has not been an error in a try conditional or a throw so far, do
+  // nothing (for compatibility of non-EH scripts).  The message will then
+  // be displayed by emsg().  When ":silent!" was used and we are not
+  // currently throwing an exception, do nothing.  The message text will
+  // then be stored to v:errmsg by emsg() without displaying it.
+  if (((trylevel == 0 && !cause_abort) || emsg_silent) && !did_throw) {
     return false;
   }
 
-  /*
-   * Ignore an interrupt message when inside a try conditional or when an
-   * exception is being thrown or when an error in a try conditional or
-   * throw has been detected previously.  This is important in order that an
-   * interrupt exception is catchable by the innermost try conditional and
-   * not replaced by an interrupt message error exception.
-   */
+  // Ignore an interrupt message when inside a try conditional or when an
+  // exception is being thrown or when an error in a try conditional or
+  // throw has been detected previously.  This is important in order that an
+  // interrupt exception is catchable by the innermost try conditional and
+  // not replaced by an interrupt message error exception.
   if (mesg == _(e_interr)) {
     *ignore = true;
     return true;
   }
 
-  /*
-   * Ensure that all commands in nested function calls and sourced files
-   * are aborted immediately.
-   */
-  cause_abort = TRUE;
-
-  /*
-   * When an exception is being thrown, some commands (like conditionals) are
-   * not skipped.  Errors in those commands may affect what of the subsequent
-   * commands are regarded part of catch and finally clauses.  Catching the
-   * exception would then cause execution of commands not intended by the
-   * user, who wouldn't even get aware of the problem.  Therefore, discard the
-   * exception currently being thrown to prevent it from being caught.  Just
-   * execute finally clauses and terminate.
-   */
-  if (current_exception) {
+  // Ensure that all commands in nested function calls and sourced files
+  // are aborted immediately.
+  cause_abort = true;
+
+  // When an exception is being thrown, some commands (like conditionals) are
+  // not skipped.  Errors in those commands may affect what of the subsequent
+  // commands are regarded part of catch and finally clauses.  Catching the
+  // exception would then cause execution of commands not intended by the
+  // user, who wouldn't even get aware of the problem.  Therefore, discard the
+  // exception currently being thrown to prevent it from being caught.  Just
+  // execute finally clauses and terminate.
+  if (did_throw) {
     // When discarding an interrupt exception, reset got_int to prevent the
     // same interrupt being converted to an exception again and discarding
     // the error exception we are about to throw here.
@@ -229,25 +223,21 @@ bool cause_errthrow(const char *mesg, bool severe, bool *ignore)
 
 #ifdef THROW_TEST
   if (!THROW_ON_ERROR) {
-    /*
-     * Print error message immediately without searching for a matching
-     * catch clause; just finally clauses are executed before the script
-     * is terminated.
-     */
+    // Print error message immediately without searching for a matching
+    // catch clause; just finally clauses are executed before the script
+    // is terminated.
     return false;
   } else  // NOLINT(readability/braces)
 #endif
   {
-    /*
-     * Prepare the throw of an error exception, so that everything will
-     * be aborted (except for executing finally clauses), until the error
-     * exception is caught; if still uncaught at the top level, the error
-     * message will be displayed and the script processing terminated
-     * then.  -  This function has no access to the conditional stack.
-     * Thus, the actual throw is made after the failing command has
-     * returned.  -  Throw only the first of several errors in a row, except
-     * a severe error is following.
-     */
+    // Prepare the throw of an error exception, so that everything will
+    // be aborted (except for executing finally clauses), until the error
+    // exception is caught; if still uncaught at the top level, the error
+    // message will be displayed and the script processing terminated
+    // then.  -  This function has no access to the conditional stack.
+    // Thus, the actual throw is made after the failing command has
+    // returned.  -  Throw only the first of several errors in a row, except
+    // a severe error is following.
     if (msg_list != NULL) {
       plist = msg_list;
       while (*plist != NULL) {
@@ -264,7 +254,7 @@ bool cause_errthrow(const char *mesg, bool severe, bool *ignore)
 
         // Skip the extra "Vim " prefix for message "E458".
         tmsg = elem->msg;
-        if (STRNCMP(tmsg, "Vim E", 5) == 0
+        if (strncmp(tmsg, "Vim E", 5) == 0
             && ascii_isdigit(tmsg[5])
             && ascii_isdigit(tmsg[6])
             && ascii_isdigit(tmsg[7])
@@ -313,13 +303,11 @@ void free_global_msglist(void)
 /// has returned (see do_one_cmd()).
 void do_errthrow(cstack_T *cstack, char *cmdname)
 {
-  /*
-   * Ensure that all commands in nested function calls and sourced files
-   * are aborted immediately.
-   */
+  // Ensure that all commands in nested function calls and sourced files
+  // are aborted immediately.
   if (cause_abort) {
-    cause_abort = FALSE;
-    force_abort = TRUE;
+    cause_abort = false;
+    force_abort = true;
   }
 
   // If no exception is to be thrown or the conversion should be done after
@@ -334,7 +322,7 @@ void do_errthrow(cstack_T *cstack, char *cmdname)
     if (cstack != NULL) {
       do_throw(cstack);
     } else {
-      need_rethrow = TRUE;
+      need_rethrow = true;
     }
   }
   *msg_list = NULL;
@@ -343,13 +331,13 @@ void do_errthrow(cstack_T *cstack, char *cmdname)
 /// do_intthrow(): Replace the current exception by an interrupt or interrupt
 /// exception if appropriate.
 ///
-/// @return  TRUE if the current exception is discarded or,
-///          FALSE otherwise.
+/// @return  true if the current exception is discarded or,
+///          false otherwise.
 int do_intthrow(cstack_T *cstack)
 {
   // If no interrupt occurred or no try conditional is active and no exception
   // is being thrown, do nothing (for compatibility of non-EH scripts).
-  if (!got_int || (trylevel == 0 && !current_exception)) {
+  if (!got_int || (trylevel == 0 && !did_throw)) {
     return false;
   }
 
@@ -358,7 +346,7 @@ int do_intthrow(cstack_T *cstack)
     // The interrupt aborts everything except for executing finally clauses.
     // Discard any user or error or interrupt exception currently being
     // thrown.
-    if (current_exception) {
+    if (did_throw) {
       discard_current_exception();
     }
   } else {
@@ -369,7 +357,7 @@ int do_intthrow(cstack_T *cstack)
   // will be terminated then.  -  If an interrupt exception is already
   // being thrown, do nothing.
 
-  if (current_exception) {
+  if (did_throw) {
     if (current_exception->type == ET_INTERRUPT) {
       return false;
     }
@@ -397,13 +385,13 @@ char *get_exception_string(void *value, except_type_T type, char *cmdname, int *
     *should_free = true;
     mesg = ((msglist_T *)value)->throw_msg;
     if (cmdname != NULL && *cmdname != NUL) {
-      size_t cmdlen = STRLEN(cmdname);
-      ret = xstrnsave("Vim(", 4 + cmdlen + 2 + STRLEN(mesg));
+      size_t cmdlen = strlen(cmdname);
+      ret = xstrnsave("Vim(", 4 + cmdlen + 2 + strlen(mesg));
       STRCPY(&ret[4], cmdname);
       STRCPY(&ret[4 + cmdlen], "):");
       val = ret + 4 + cmdlen + 2;
     } else {
-      ret = xstrnsave("Vim:", 4 + STRLEN(mesg));
+      ret = xstrnsave("Vim:", 4 + strlen(mesg));
       val = ret + 4;
     }
 
@@ -431,7 +419,7 @@ char *get_exception_string(void *value, except_type_T type, char *cmdname, int *
 
           STRCAT(val, p);
           p[-2] = NUL;
-          snprintf(val + STRLEN(p), strlen(" (%s)"), " (%s)", &mesg[1]);
+          snprintf(val + strlen(p), strlen(" (%s)"), " (%s)", &mesg[1]);
           p[-2] = '"';
         }
         break;
@@ -456,15 +444,13 @@ static int throw_exception(void *value, except_type_T type, char *cmdname)
   except_T *excp;
   int should_free;
 
-  /*
-   * Disallow faking Interrupt or error exceptions as user exceptions.  They
-   * would be treated differently from real interrupt or error exceptions
-   * when no active try block is found, see do_cmdline().
-   */
+  // Disallow faking Interrupt or error exceptions as user exceptions.  They
+  // would be treated differently from real interrupt or error exceptions
+  // when no active try block is found, see do_cmdline().
   if (type == ET_USER) {
-    if (STRNCMP((char_u *)value, "Vim", 3) == 0
-        && (((char_u *)value)[3] == NUL || ((char_u *)value)[3] == ':'
-            || ((char_u *)value)[3] == '(')) {
+    if (strncmp(value, "Vim", 3) == 0
+        && (((char *)value)[3] == NUL || ((char *)value)[3] == ':'
+            || ((char *)value)[3] == '(')) {
       emsg(_("E608: Cannot :throw exceptions with 'Vim' prefix"));
       goto fail;
     }
@@ -501,13 +487,13 @@ static int throw_exception(void *value, except_type_T type, char *cmdname)
     int save_msg_silent = msg_silent;
 
     if (debug_break_level > 0) {
-      msg_silent = FALSE;               // display messages
+      msg_silent = false;               // display messages
     } else {
       verbose_enter();
     }
     no_wait_return++;
     if (debug_break_level > 0 || *p_vfile == NUL) {
-      msg_scroll = TRUE;            // always scroll up, don't overwrite
+      msg_scroll = true;            // always scroll up, don't overwrite
     }
     smsg(_("Exception thrown: %s"), excp->value);
     msg_puts("\n");  // don't overwrite this either
@@ -552,19 +538,17 @@ static void discard_exception(except_T *excp, bool was_finished)
   if (p_verbose >= 13 || debug_break_level > 0) {
     int save_msg_silent = msg_silent;
 
-    saved_IObuff = (char *)vim_strsave(IObuff);
+    saved_IObuff = xstrdup(IObuff);
     if (debug_break_level > 0) {
-      msg_silent = FALSE;               // display messages
+      msg_silent = false;               // display messages
     } else {
       verbose_enter();
     }
     no_wait_return++;
     if (debug_break_level > 0 || *p_vfile == NUL) {
-      msg_scroll = TRUE;            // always scroll up, don't overwrite
+      msg_scroll = true;            // always scroll up, don't overwrite
     }
-    smsg(was_finished ? _("Exception finished: %s")
-                      : _("Exception discarded: %s"),
-         excp->value);
+    smsg(was_finished ? _("Exception finished: %s") : _("Exception discarded: %s"), excp->value);
     msg_puts("\n");  // don't overwrite this either
     if (debug_break_level > 0 || *p_vfile == NUL) {
       cmdline_row = msg_row;
@@ -575,7 +559,7 @@ static void discard_exception(except_T *excp, bool was_finished)
     } else {
       verbose_leave();
     }
-    STRLCPY(IObuff, saved_IObuff, IOSIZE);
+    xstrlcpy(IObuff, saved_IObuff, IOSIZE);
     xfree(saved_IObuff);
   }
   if (excp->type != ET_INTERRUPT) {
@@ -596,6 +580,7 @@ void discard_current_exception(void)
   }
   // Note: all globals manipulated here should be saved/restored in
   // try_enter/try_leave.
+  did_throw = false;
   need_rethrow = false;
 }
 
@@ -607,12 +592,12 @@ static void catch_exception(except_T *excp)
   set_vim_var_string(VV_EXCEPTION, excp->value, -1);
   if (*excp->throw_name != NUL) {
     if (excp->throw_lnum != 0) {
-      vim_snprintf((char *)IObuff, IOSIZE, _("%s, line %" PRId64),
+      vim_snprintf(IObuff, IOSIZE, _("%s, line %" PRId64),
                    excp->throw_name, (int64_t)excp->throw_lnum);
     } else {
-      vim_snprintf((char *)IObuff, IOSIZE, "%s", excp->throw_name);
+      vim_snprintf(IObuff, IOSIZE, "%s", excp->throw_name);
     }
-    set_vim_var_string(VV_THROWPOINT, (char *)IObuff, -1);
+    set_vim_var_string(VV_THROWPOINT, IObuff, -1);
   } else {
     // throw_name not set on an exception from a command that was typed.
     set_vim_var_string(VV_THROWPOINT, NULL, -1);
@@ -622,13 +607,13 @@ static void catch_exception(except_T *excp)
     int save_msg_silent = msg_silent;
 
     if (debug_break_level > 0) {
-      msg_silent = FALSE;               // display messages
+      msg_silent = false;               // display messages
     } else {
       verbose_enter();
     }
     no_wait_return++;
     if (debug_break_level > 0 || *p_vfile == NUL) {
-      msg_scroll = TRUE;            // always scroll up, don't overwrite
+      msg_scroll = true;            // always scroll up, don't overwrite
     }
     smsg(_("Exception caught: %s"), excp->value);
     msg_puts("\n");  // don't overwrite this either
@@ -656,14 +641,14 @@ static void finish_exception(except_T *excp)
     set_vim_var_string(VV_EXCEPTION, caught_stack->value, -1);
     if (*caught_stack->throw_name != NUL) {
       if (caught_stack->throw_lnum != 0) {
-        vim_snprintf((char *)IObuff, IOSIZE,
+        vim_snprintf(IObuff, IOSIZE,
                      _("%s, line %" PRId64), caught_stack->throw_name,
                      (int64_t)caught_stack->throw_lnum);
       } else {
-        vim_snprintf((char *)IObuff, IOSIZE, "%s",
+        vim_snprintf(IObuff, IOSIZE, "%s",
                      caught_stack->throw_name);
       }
-      set_vim_var_string(VV_THROWPOINT, (char *)IObuff, -1);
+      set_vim_var_string(VV_THROWPOINT, IObuff, -1);
     } else {
       // throw_name not set on an exception from a command that was
       // typed.
@@ -678,9 +663,7 @@ static void finish_exception(except_T *excp)
   discard_exception(excp, true);
 }
 
-/*
- * Flags specifying the message displayed by report_pending.
- */
+// Flags specifying the message displayed by report_pending.
 #define RP_MAKE         0
 #define RP_RESUME       1
 #define RP_DISCARD      2
@@ -726,14 +709,14 @@ static void report_pending(int action, int pending, void *value)
     break;
   case CSTP_RETURN:
     // ":return" command producing value, allocated
-    s = (char *)get_return_cmd(value);
+    s = get_return_cmd(value);
     break;
 
   default:
     if (pending & CSTP_THROW) {
-      vim_snprintf((char *)IObuff, IOSIZE,
+      vim_snprintf(IObuff, IOSIZE,
                    mesg, _("Exception"));
-      mesg = (char *)concat_str(IObuff, (char_u *)": %s");
+      mesg = concat_str(IObuff, ": %s");
       s = ((except_T *)value)->value;
     } else if ((pending & CSTP_ERROR) && (pending & CSTP_INTERRUPT)) {
       s = _("Error and interrupt");
@@ -746,7 +729,7 @@ static void report_pending(int action, int pending, void *value)
 
   save_msg_silent = msg_silent;
   if (debug_break_level > 0) {
-    msg_silent = FALSE;         // display messages
+    msg_silent = false;         // display messages
   }
   no_wait_return++;
   msg_scroll = true;            // always scroll up, don't overwrite
@@ -830,7 +813,7 @@ void ex_if(exarg_T *eap)
   if (cstack->cs_idx == CSTACK_LEN - 1) {
     eap->errmsg = _("E579: :if nesting too deep");
   } else {
-    ++cstack->cs_idx;
+    cstack->cs_idx++;
     cstack->cs_flags[cstack->cs_idx] = 0;
 
     skip = CHECK_SKIP;
@@ -870,14 +853,14 @@ void ex_endif(exarg_T *eap)
       (void)do_intthrow(eap->cstack);
     }
 
-    --eap->cstack->cs_idx;
+    eap->cstack->cs_idx--;
   }
 }
 
 /// Handle ":else" and ":elseif".
 void ex_else(exarg_T *eap)
 {
-  int result;
+  bool result = false;
   cstack_T *const cstack = eap->cstack;
 
   bool skip = CHECK_SKIP;
@@ -925,13 +908,20 @@ void ex_else(exarg_T *eap)
 
   if (eap->cmdidx == CMD_elseif) {
     bool error;
-    result = eval_to_bool(eap->arg, &error, &eap->nextcmd, skip);
+    // When skipping we ignore most errors, but a missing expression is
+    // wrong, perhaps it should have been "else".
+    // A double quote here is the start of a string, not a comment.
+    if (skip && *eap->arg != '"' && ends_excmd(*eap->arg)) {
+      semsg(_(e_invexpr2), eap->arg);
+    } else {
+      result = eval_to_bool(eap->arg, &error, &eap->nextcmd, skip);
+    }
+
     // When throwing error exceptions, we want to throw always the first
     // of several errors in a row.  This is what actually happens when
     // a conditional error was detected above and there is another failure
     // when parsing the expression.  Since the skip flag is set in this
     // case, the parsing error will be ignored by emsg().
-
     if (!skip && !error) {
       if (result) {
         cstack->cs_flags[cstack->cs_idx] = CSF_ACTIVE | CSF_TRUE;
@@ -958,14 +948,12 @@ void ex_while(exarg_T *eap)
   if (cstack->cs_idx == CSTACK_LEN - 1) {
     eap->errmsg = _("E585: :while/:for nesting too deep");
   } else {
-    /*
-     * The loop flag is set when we have jumped back from the matching
-     * ":endwhile" or ":endfor".  When not set, need to initialise this
-     * cstack entry.
-     */
+    // The loop flag is set when we have jumped back from the matching
+    // ":endwhile" or ":endfor".  When not set, need to initialise this
+    // cstack entry.
     if ((cstack->cs_lflags & CSL_HAD_LOOP) == 0) {
-      ++cstack->cs_idx;
-      ++cstack->cs_looplevel;
+      cstack->cs_idx++;
+      cstack->cs_looplevel++;
       cstack->cs_line[cstack->cs_idx] = -1;
     }
     cstack->cs_flags[cstack->cs_idx] =
@@ -973,21 +961,17 @@ void ex_while(exarg_T *eap)
 
     skip = CHECK_SKIP;
     if (eap->cmdidx == CMD_while) {
-      /*
-       * ":while bool-expr"
-       */
+      // ":while bool-expr"
       result = eval_to_bool(eap->arg, &error, &eap->nextcmd, skip);
     } else {
       void *fi;
 
-      /*
-       * ":for var in list-expr"
-       */
+      // ":for var in list-expr"
       if ((cstack->cs_lflags & CSL_HAD_LOOP) != 0) {
         // Jumping here from a ":continue" or ":endfor": use the
         // previously evaluated list.
         fi = cstack->cs_forinfo[cstack->cs_idx];
-        error = FALSE;
+        error = false;
       } else {
         // Evaluate the argument and get the info in a structure.
         fi = eval_for_line(eap->arg, &error, &eap->nextcmd, skip);
@@ -998,7 +982,7 @@ void ex_while(exarg_T *eap)
       if (!error && fi != NULL && !skip) {
         result = next_for_item(fi, eap->arg);
       } else {
-        result = FALSE;
+        result = false;
       }
 
       if (!result) {
@@ -1007,11 +991,9 @@ void ex_while(exarg_T *eap)
       }
     }
 
-    /*
-     * If this cstack entry was just initialised and is active, set the
-     * loop flag, so do_cmdline() will set the line number in cs_line[].
-     * If executing the command a second time, clear the loop flag.
-     */
+    // If this cstack entry was just initialised and is active, set the
+    // loop flag, so do_cmdline() will set the line number in cs_line[].
+    // If executing the command a second time, clear the loop flag.
     if (!skip && !error && result) {
       cstack->cs_flags[cstack->cs_idx] |= (CSF_ACTIVE | CSF_TRUE);
       cstack->cs_lflags ^= CSL_HAD_LOOP;
@@ -1046,10 +1028,8 @@ void ex_continue(exarg_T *eap)
     if (cstack->cs_flags[idx] & (CSF_WHILE | CSF_FOR)) {
       rewind_conditionals(cstack, idx, CSF_TRY, &cstack->cs_trylevel);
 
-      /*
-       * Set CSL_HAD_CONT, so do_cmdline() will jump back to the
-       * matching ":while".
-       */
+      // Set CSL_HAD_CONT, so do_cmdline() will jump back to the
+      // matching ":while".
       cstack->cs_lflags |= CSL_HAD_CONT;        // let do_cmdline() handle it
     } else {
       // If a try conditional not in its finally clause is reached first,
@@ -1118,8 +1098,8 @@ void ex_endwhile(exarg_T *eap)
         eap->errmsg = _(e_endtry);
       }
       // Try to find the matching ":while" and report what's missing.
-      for (idx = cstack->cs_idx; idx > 0; --idx) {
-        fl =  cstack->cs_flags[idx];
+      for (idx = cstack->cs_idx; idx > 0; idx--) {
+        fl = cstack->cs_flags[idx];
         if ((fl & CSF_TRY) && !(fl & CSF_FINALLY)) {
           // Give up at a try conditional not in its finally clause.
           // Ignore the ":endwhile"/":endfor".
@@ -1131,7 +1111,7 @@ void ex_endwhile(exarg_T *eap)
         }
       }
       // Cleanup and rewind all contained (and unclosed) conditionals.
-      (void)cleanup_conditionals(cstack, CSF_WHILE | CSF_FOR, FALSE);
+      (void)cleanup_conditionals(cstack, CSF_WHILE | CSF_FOR, false);
       rewind_conditionals(cstack, idx, CSF_TRY, &cstack->cs_trylevel);
     } else if (cstack->cs_flags[cstack->cs_idx] & CSF_TRUE
                && !(cstack->cs_flags[cstack->cs_idx] & CSF_ACTIVE)
@@ -1147,10 +1127,8 @@ void ex_endwhile(exarg_T *eap)
       (void)do_intthrow(cstack);
     }
 
-    /*
-     * Set loop flag, so do_cmdline() will jump back to the matching
-     * ":while" or ":for".
-     */
+    // Set loop flag, so do_cmdline() will jump back to the matching
+    // ":while" or ":for".
     cstack->cs_lflags |= CSL_HAD_ENDLOOP;
   }
 }
@@ -1172,7 +1150,7 @@ void ex_throw(exarg_T *eap)
   // On error or when an exception is thrown during argument evaluation, do
   // not throw.
   if (!eap->skip && value != NULL) {
-    if (throw_exception((char_u *)value, ET_USER, NULL) == FAIL) {
+    if (throw_exception(value, ET_USER, NULL) == FAIL) {
       xfree(value);
     } else {
       do_throw(eap->cstack);
@@ -1186,7 +1164,7 @@ void ex_throw(exarg_T *eap)
 void do_throw(cstack_T *cstack)
 {
   int idx;
-  int inactivate_try = FALSE;
+  int inactivate_try = false;
 
   //
   // Cleanup and deactivate up to the next surrounding try conditional that
@@ -1199,31 +1177,29 @@ void do_throw(cstack_T *cstack)
   //
 #ifndef THROW_ON_ERROR_TRUE
   if (did_emsg && !THROW_ON_ERROR) {
-    inactivate_try = TRUE;
-    did_emsg = FALSE;
+    inactivate_try = true;
+    did_emsg = false;
   }
 #endif
 #ifndef THROW_ON_INTERRUPT_TRUE
   if (got_int && !THROW_ON_INTERRUPT) {
-    inactivate_try = TRUE;
-    got_int = FALSE;
+    inactivate_try = true;
+    got_int = false;
   }
 #endif
   idx = cleanup_conditionals(cstack, 0, inactivate_try);
   if (idx >= 0) {
-    /*
-     * If this try conditional is active and we are before its first
-     * ":catch", set THROWN so that the ":catch" commands will check
-     * whether the exception matches.  When the exception came from any of
-     * the catch clauses, it will be made pending at the ":finally" (if
-     * present) and rethrown at the ":endtry".  This will also happen if
-     * the try conditional is inactive.  This is the case when we are
-     * throwing an exception due to an error or interrupt on the way from
-     * a preceding ":continue", ":break", ":return", ":finish", error or
-     * interrupt (not converted to an exception) to the finally clause or
-     * from a preceding throw of a user or error or interrupt exception to
-     * the matching catch clause or the finally clause.
-     */
+    // If this try conditional is active and we are before its first
+    // ":catch", set THROWN so that the ":catch" commands will check
+    // whether the exception matches.  When the exception came from any of
+    // the catch clauses, it will be made pending at the ":finally" (if
+    // present) and rethrown at the ":endtry".  This will also happen if
+    // the try conditional is inactive.  This is the case when we are
+    // throwing an exception due to an error or interrupt on the way from
+    // a preceding ":continue", ":break", ":return", ":finish", error or
+    // interrupt (not converted to an exception) to the finally clause or
+    // from a preceding throw of a user or error or interrupt exception to
+    // the matching catch clause or the finally clause.
     if (!(cstack->cs_flags[idx] & CSF_CAUGHT)) {
       if (cstack->cs_flags[idx] & CSF_ACTIVE) {
         cstack->cs_flags[idx] |= CSF_THROWN;
@@ -1237,6 +1213,8 @@ void do_throw(cstack_T *cstack)
     cstack->cs_flags[idx] &= ~CSF_ACTIVE;
     cstack->cs_exception[idx] = current_exception;
   }
+
+  did_throw = true;
 }
 
 /// Handle ":try"
@@ -1248,8 +1226,8 @@ void ex_try(exarg_T *eap)
   if (cstack->cs_idx == CSTACK_LEN - 1) {
     eap->errmsg = _("E601: :try nesting too deep");
   } else {
-    ++cstack->cs_idx;
-    ++cstack->cs_trylevel;
+    cstack->cs_idx++;
+    cstack->cs_trylevel++;
     cstack->cs_flags[cstack->cs_idx] = CSF_TRY;
     cstack->cs_pending[cstack->cs_idx] = CSTP_NONE;
 
@@ -1261,22 +1239,20 @@ void ex_try(exarg_T *eap)
       // that the finally clause needs to be executed.
       cstack->cs_flags[cstack->cs_idx] |= CSF_ACTIVE | CSF_TRUE;
 
-      /*
-       * ":silent!", even when used in a try conditional, disables
-       * displaying of error messages and conversion of errors to
-       * exceptions.  When the silent commands again open a try
-       * conditional, save "emsg_silent" and reset it so that errors are
-       * again converted to exceptions.  The value is restored when that
-       * try conditional is left.  If it is left normally, the commands
-       * following the ":endtry" are again silent.  If it is left by
-       * a ":continue", ":break", ":return", or ":finish", the commands
-       * executed next are again silent.  If it is left due to an
-       * aborting error, an interrupt, or an exception, restoring
-       * "emsg_silent" does not matter since we are already in the
-       * aborting state and/or the exception has already been thrown.
-       * The effect is then just freeing the memory that was allocated
-       * to save the value.
-       */
+      // ":silent!", even when used in a try conditional, disables
+      // displaying of error messages and conversion of errors to
+      // exceptions.  When the silent commands again open a try
+      // conditional, save "emsg_silent" and reset it so that errors are
+      // again converted to exceptions.  The value is restored when that
+      // try conditional is left.  If it is left normally, the commands
+      // following the ":endtry" are again silent.  If it is left by
+      // a ":continue", ":break", ":return", or ":finish", the commands
+      // executed next are again silent.  If it is left due to an
+      // aborting error, an interrupt, or an exception, restoring
+      // "emsg_silent" does not matter since we are already in the
+      // aborting state and/or the exception has already been thrown.
+      // The effect is then just freeing the memory that was allocated
+      // to save the value.
       if (emsg_silent) {
         eslist_T *elem = xmalloc(sizeof(*elem));
         elem->saved_emsg_silent = emsg_silent;
@@ -1314,7 +1290,7 @@ void ex_catch(exarg_T *eap)
       eap->errmsg = get_end_emsg(cstack);
       skip = true;
     }
-    for (idx = cstack->cs_idx; idx > 0; --idx) {
+    for (idx = cstack->cs_idx; idx > 0; idx--) {
       if (cstack->cs_flags[idx] & CSF_TRY) {
         break;
       }
@@ -1333,27 +1309,26 @@ void ex_catch(exarg_T *eap)
   if (ends_excmd(*eap->arg)) {  // no argument, catch all errors
     pat = ".*";
     end = NULL;
-    eap->nextcmd = (char *)find_nextcmd((char_u *)eap->arg);
+    eap->nextcmd = find_nextcmd(eap->arg);
   } else {
     pat = eap->arg + 1;
-    end = (char *)skip_regexp((char_u *)pat, *eap->arg, true, NULL);
+    end = skip_regexp_err(pat, *eap->arg, true);
+    if (end == NULL) {
+      give_up = true;
+    }
   }
 
   if (!give_up) {
-    /*
-     * Don't do something when no exception has been thrown or when the
-     * corresponding try block never got active (because of an inactive
-     * surrounding conditional or after an error or interrupt or throw).
-     */
-    if (!current_exception || !(cstack->cs_flags[idx] & CSF_TRUE)) {
+    // Don't do something when no exception has been thrown or when the
+    // corresponding try block never got active (because of an inactive
+    // surrounding conditional or after an error or interrupt or throw).
+    if (!did_throw || !(cstack->cs_flags[idx] & CSF_TRUE)) {
       skip = true;
     }
 
-    /*
-     * Check for a match only if an exception is thrown but not caught by
-     * a previous ":catch".  An exception that has replaced a discarded
-     * exception is not checked (THROWN is not set then).
-     */
+    // Check for a match only if an exception is thrown but not caught by
+    // a previous ":catch".  An exception that has replaced a discarded
+    // exception is not checked (THROWN is not set then).
     if (!skip && (cstack->cs_flags[idx] & CSF_THROWN)
         && !(cstack->cs_flags[idx] & CSF_CAUGHT)) {
       if (end != NULL && *end != NUL && !ends_excmd(*skipwhite(end + 1))) {
@@ -1376,7 +1351,7 @@ void ex_catch(exarg_T *eap)
           *end = NUL;
         }