patch 9.0.0634: evaluating "expr" options has more overhead than needed

Problem:    Evaluating "expr" options has more overhead than needed.
Solution:   Use call_simple_func() for 'foldtext', 'includeexpr', 'printexpr',
            "expr" of 'spellsuggest', 'diffexpr', 'patchexpr', 'balloonexpr',
            'formatexpr', 'indentexpr' and 'charconvert'.

runtime/doc/diff.txt

@@ -376,6 +376,9 @@ Additionally, 'diffexpr' should take care of "icase" and "iwhite" in the
 'diffopt' option.  'diffexpr' cannot change the value of 'lines' and
 'columns'.
 
+The advantage of using a function call without arguments is that it is faster,
+see |expr-option-function|.
+
 Example (this does almost the same as 'diffexpr' being empty): >
 
 	set diffexpr=MyDiff()
@@ -441,6 +444,9 @@ will have the same effect.  These variables are set to the file names used:
 	v:fname_diff		patch file
 	v:fname_out		resulting patched file
 
+The advantage of using a function call without arguments is that it is faster,
+see |expr-option-function|.
+
 Example (this does the same as 'patchexpr' being empty): >
 
 	set patchexpr=MyPatch()

runtime/doc/options.txt

@@ -1626,6 +1626,9 @@ A jump table for the options with a short description can be found at |Q_op|.
 	Note that v:charconvert_from and v:charconvert_to may be different
 	from 'encoding'.  Vim internally uses UTF-8 instead of UCS-2 or UCS-4.
 
+	The advantage of using a function call without arguments is that it is
+	faster, see |expr-option-function|.
+
 	Encryption is not done by Vim when using 'charconvert'.  If you want
 	to encrypt the file after conversion, 'charconvert' should take care
 	of this.
@@ -3664,6 +3667,9 @@ A jump table for the options with a short description can be found at |Q_op|.
 <	This will invoke the mylang#Format() function in the
 	autoload/mylang.vim file in 'runtimepath'. |autoload|
 
+	The advantage of using a function call without arguments is that it is
+	faster, see |expr-option-function|.
+
 	The expression is also evaluated when 'textwidth' is set and adding
 	text beyond that limit.  This happens under the same conditions as
 	when internal formatting is used.  Make sure the cursor is kept in the
@@ -4534,11 +4540,14 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 	If the expression starts with s: or |<SID>|, then it is replaced with
 	the script ID (|local-function|). Example: >
-		set includeexpr=s:MyIncludeExpr(v:fname)
+		set includeexpr=s:MyIncludeExpr()
-		set includeexpr=<SID>SomeIncludeExpr(v:fname)
+		set includeexpr=<SID>SomeIncludeExpr()
 <	Otherwise, the expression is evaluated in the context of the script
 	where the option was set, thus script-local items are available.
 
+	It is more efficient if the value is just a function call without
+	arguments, see |expr-option-function|.
+
 	The expression will be evaluated in the |sandbox| when set from a
 	modeline, see |sandbox-option|.
 	This option cannot be set in a modeline when 'modelineexpr' is off.
@@ -4620,6 +4629,9 @@ A jump table for the options with a short description can be found at |Q_op|.
 <	Otherwise, the expression is evaluated in the context of the script
 	where the option was set, thus script-local items are available.
 
+	The advantage of using a function call without arguments is that it is
+	faster, see |expr-option-function|.
+
 	The expression must return the number of spaces worth of indent.  It
 	can return "-1" to keep the current indent (this means 'autoindent' is
 	used for the indent).
@@ -7470,9 +7482,11 @@ A jump table for the options with a short description can be found at |Q_op|.
 			The file is used for all languages.
 
 	expr:{expr}	Evaluate expression {expr}.  Use a function to avoid
-			trouble with spaces.  |v:val| holds the badly spelled
+			trouble with spaces.  Best is to call a function
-			word.  The expression must evaluate to a List of
+			without arguments, see |expr-option-function|.
-			Lists, each with a suggestion and a score.
+			|v:val| holds the badly spelled word.  The expression
+			must evaluate to a List of Lists, each with a
+			suggestion and a score.
 			Example:
 				[['the', 33], ['that', 44]] ~
 			Set 'verbose' and use |z=| to see the scores that the

runtime/doc/print.txt

@@ -158,13 +158,16 @@ currently specified printdevice: >
 If you change this option, using a function is an easy way to avoid having to
 escape all the spaces.  Example: >
 
-	:set printexpr=PrintFile(v:fname_in)
+	:set printexpr=PrintFile()
-	:function PrintFile(fname)
+	:function PrintFile()
-	:  call system("ghostview " .. a:fname)
+	:  call system("ghostview " .. v:fname_in)
-	:  call delete(a:fname)
+	:  call delete(v:fname_in)
 	:  return v:shell_error
 	:endfunc
 
+It is more efficient if the option is set to just a function call,
+see |expr-option-function|.
+
 Be aware that some print programs return control before they have read the
 file.  If you delete the file too soon it will not be printed.  These programs
 usually offer an option to have them remove the file when printing is done.

src/beval.c

@@ -278,7 +278,7 @@ bexpr_eval(
 	current_sctx = curbuf->b_p_script_ctx[BV_BEXPR];
 
     vim_free(result);
-    result = eval_to_string(bexpr, TRUE);
+    result = eval_to_string(bexpr, TRUE, TRUE);
 
     // Remove one trailing newline, it is added when the result was a
     // list and it's hardly ever useful.  If the user really wants a

src/buffer.c

@@ -4246,7 +4246,7 @@ build_stl_str_hl(
 	tv.vval.v_number = wp->w_id;
 	set_var((char_u *)"g:statusline_winid", &tv, FALSE);
 
-	usefmt = eval_to_string_safe(fmt + 2, use_sandbox, FALSE);
+	usefmt = eval_to_string_safe(fmt + 2, use_sandbox, FALSE, FALSE);
 	if (usefmt == NULL)
 	    usefmt = fmt;
 
@@ -4633,7 +4633,7 @@ build_stl_str_hl(
 	    if (curwin != save_curwin)
 		VIsual_active = FALSE;
 
-	    str = eval_to_string_safe(p, use_sandbox, FALSE);
+	    str = eval_to_string_safe(p, use_sandbox, FALSE, FALSE);
 
 	    curwin = save_curwin;
 	    curbuf = save_curbuf;

src/clientserver.c

@@ -86,7 +86,7 @@ eval_client_expr_to_string(char_u *expr)
     // to be typed.  Do generate errors so that try/catch works.
     ++emsg_silent;
 
-    res = eval_to_string(expr, TRUE);
+    res = eval_to_string(expr, TRUE, FALSE);
 
     debug_break_level = save_dbl;
     redir_off = save_ro;

src/eval.c

@@ -143,17 +143,23 @@ eval_to_bool(
     char_u	*arg,
     int		*error,
     exarg_T	*eap,
-    int		skip)	    // only parse, don't execute
+    int		skip,	    // only parse, don't execute
+    int		use_simple_function)
 {
     typval_T	tv;
     varnumber_T	retval = FALSE;
     evalarg_T	evalarg;
+    int		r;
 
     fill_evalarg_from_eap(&evalarg, eap, skip);
 
     if (skip)
 	++emsg_skip;
-    if (eval0(arg, &tv, eap, &evalarg) == FAIL)
+    if (use_simple_function)
+	r = eval0_simple_funccal(arg, &tv, eap, &evalarg);
+    else
+	r = eval0(arg, &tv, eap, &evalarg);
+    if (r == FAIL)
 	*error = TRUE;
     else
     {
@@ -601,14 +607,20 @@ typval2string(typval_T *tv, int convert)
 eval_to_string_eap(
     char_u	*arg,
     int		convert,
-    exarg_T	*eap)
+    exarg_T	*eap,
+    int		use_simple_function)
 {
     typval_T	tv;
     char_u	*retval;
     evalarg_T	evalarg;
+    int		r;
 
     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
-    if (eval0(arg, &tv, NULL, &evalarg) == FAIL)
+    if (use_simple_function)
+	r = eval0_simple_funccal(arg, &tv, NULL, &evalarg);
+    else
+	r = eval0(arg, &tv, NULL, &evalarg);
+    if (r == FAIL)
 	retval = NULL;
     else
     {
@@ -623,9 +635,10 @@ eval_to_string_eap(
     char_u *
 eval_to_string(
     char_u	*arg,
-    int		convert)
+    int		convert,
+    int		use_simple_function)
 {
-    return eval_to_string_eap(arg, convert, NULL);
+    return eval_to_string_eap(arg, convert, NULL, use_simple_function);
 }
 
 /*
@@ -637,7 +650,8 @@ eval_to_string(
 eval_to_string_safe(
     char_u	*arg,
     int		use_sandbox,
-    int		keep_script_version)
+    int		keep_script_version,
+    int		use_simple_function)
 {
     char_u	*retval;
     funccal_entry_T funccal_entry;
@@ -651,7 +665,7 @@ eval_to_string_safe(
 	++sandbox;
     ++textlock;
     may_garbage_collect = FALSE;
-    retval = eval_to_string(arg, FALSE);
+    retval = eval_to_string(arg, FALSE, use_simple_function);
     if (use_sandbox)
 	--sandbox;
     --textlock;
@@ -667,15 +681,20 @@ eval_to_string_safe(
  * Returns -1 for an error.
  */
     varnumber_T
-eval_to_number(char_u *expr)
+eval_to_number(char_u *expr, int use_simple_function)
 {
     typval_T	rettv;
     varnumber_T	retval;
     char_u	*p = skipwhite(expr);
+    int		r = NOTDONE;
 
     ++emsg_off;
 
-    if (eval1(&p, &rettv, &EVALARG_EVALUATE) == FAIL)
+    if (use_simple_function)
+	r = may_call_simple_func(expr, &rettv);
+    if (r == NOTDONE)
+	r = eval1(&p, &rettv, &EVALARG_EVALUATE);
+    if (r == FAIL)
 	retval = -1;
     else
     {
@@ -694,6 +713,12 @@ eval_to_number(char_u *expr)
  */
     typval_T *
 eval_expr(char_u *arg, exarg_T *eap)
+{
+    return eval_expr_ext(arg, eap, FALSE);
+}
+
+    typval_T *
+eval_expr_ext(char_u *arg, exarg_T *eap, int use_simple_function)
 {
     typval_T	*tv;
     evalarg_T	evalarg;
@@ -701,8 +726,18 @@ eval_expr(char_u *arg, exarg_T *eap)
     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
 
     tv = ALLOC_ONE(typval_T);
-    if (tv != NULL && eval0(arg, tv, eap, &evalarg) == FAIL)
+    if (tv != NULL)
-	VIM_CLEAR(tv);
+    {
+	int	r = NOTDONE;
+
+	if (use_simple_function)
+	    r = eval0_simple_funccal(arg, tv, eap, &evalarg);
+	if (r == NOTDONE)
+	    r = eval0(arg, tv, eap, &evalarg);
+
+	if (r == FAIL)
+	    VIM_CLEAR(tv);
+    }
 
     clear_evalarg(&evalarg, eap);
     return tv;
@@ -899,12 +934,11 @@ eval_foldexpr(win_T *wp, int *cp)
 {
     char_u	*arg;
     typval_T	tv;
-    int		r = NOTDONE;
     varnumber_T	retval;
     char_u	*s;
     sctx_T	saved_sctx = current_sctx;
     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
-								   OPT_LOCAL);
+								    OPT_LOCAL);
 
     arg = skipwhite(wp->w_p_fde);
     current_sctx = wp->w_p_script_ctx[WV_FDE];
@@ -915,20 +949,9 @@ eval_foldexpr(win_T *wp, int *cp)
     ++textlock;
     *cp = NUL;
 
-    // If the expression is "FuncName()" then we can skip a lot of overhead.
+    // Evaluate the expression.  If the expression is "FuncName()" call the
-    char_u *parens = (char_u *)strstr((char *)arg, "()");
+    // function directly.
-    if (parens != NULL && *skipwhite(parens + 2) == NUL)
+    if (eval0_simple_funccal(arg, &tv, NULL, &EVALARG_EVALUATE) == FAIL)
-    {
-	char_u *p = STRNCMP(arg, "<SNR>", 5) == 0 ? skipdigits(arg + 5) : arg;
-
-	if (to_name_end(p, TRUE) == parens)
-	    r = call_simple_func(arg, (int)(parens - arg), &tv);
-    }
-
-    if (r == NOTDONE)
-	r = eval0(arg, &tv, NULL, &EVALARG_EVALUATE);
-
-    if (r == FAIL)
 	retval = 0;
     else
     {
@@ -2428,9 +2451,10 @@ skipwhite_and_linebreak(char_u *arg, evalarg_T *evalarg)
 }
 
 /*
- * The "evaluate" argument: When FALSE, the argument is only parsed but not
+ * The "eval" functions have an "evalarg" argument: When NULL or
- * executed.  The function may return OK, but the rettv will be of type
+ * "evalarg->eval_flags" does not have EVAL_EVALUATE, then the argument is only
- * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
+ * parsed but not executed.  The functions may return OK, but the rettv will be
+ * of type VAR_UNKNOWN.  The functions still returns FAIL for a syntax error.
  */
 
 /*
@@ -2451,6 +2475,47 @@ eval0(
     return eval0_retarg(arg, rettv, eap, evalarg, NULL);
 }
 
+/*
+ * If "arg" is a simple function call without arguments then call it and return
+ * the result.  Otherwise return NOTDONE.
+ */
+    int
+may_call_simple_func(
+    char_u	*arg,
+    typval_T	*rettv)
+{
+    char_u  *parens = (char_u *)strstr((char *)arg, "()");
+    int	    r = NOTDONE;
+
+    // If the expression is "FuncName()" then we can skip a lot of overhead.
+    if (parens != NULL && *skipwhite(parens + 2) == NUL)
+    {
+	char_u *p = STRNCMP(arg, "<SNR>", 5) == 0 ? skipdigits(arg + 5) : arg;
+
+	if (to_name_end(p, TRUE) == parens)
+	    r = call_simple_func(arg, (int)(parens - arg), rettv);
+    }
+    return r;
+}
+
+/*
+ * Handle zero level expression with optimization for a simple function call.
+ * Same arguments and return value as eval0().
+ */
+    int
+eval0_simple_funccal(
+    char_u	*arg,
+    typval_T	*rettv,
+    exarg_T	*eap,
+    evalarg_T	*evalarg)
+{
+    int	    r = may_call_simple_func(arg, rettv);
+
+    if (r == NOTDONE)
+	r = eval0_retarg(arg, rettv, eap, evalarg, NULL);
+    return r;
+}
+
 /*
  * Like eval0() but when "retarg" is not NULL store the pointer to after the
  * expression and don't check what comes after the expression.
@@ -6283,7 +6348,7 @@ make_expanded_name(
     c1 = *in_end;
     *in_end = NUL;
 
-    temp_result = eval_to_string(expr_start + 1, FALSE);
+    temp_result = eval_to_string(expr_start + 1, FALSE, FALSE);
     if (temp_result != NULL)
     {
 	retval = alloc(STRLEN(temp_result) + (expr_start - in_start)

src/evalvars.c

@@ -380,7 +380,7 @@ eval_charconvert(
     if (ctx != NULL)
 	current_sctx = *ctx;
 
-    if (eval_to_bool(p_ccv, &err, NULL, FALSE))
+    if (eval_to_bool(p_ccv, &err, NULL, FALSE, TRUE))
 	err = TRUE;
 
     set_vim_var_string(VV_CC_FROM, NULL, -1);
@@ -408,7 +408,7 @@ eval_printexpr(char_u *fname, char_u *args)
     if (ctx != NULL)
 	current_sctx = *ctx;
 
-    if (eval_to_bool(p_pexpr, &err, NULL, FALSE))
+    if (eval_to_bool(p_pexpr, &err, NULL, FALSE, TRUE))
 	err = TRUE;
 
     set_vim_var_string(VV_FNAME_IN, NULL, -1);
@@ -444,7 +444,7 @@ eval_diff(
 	current_sctx = *ctx;
 
     // errors are ignored
-    tv = eval_expr(p_dex, NULL);
+    tv = eval_expr_ext(p_dex, NULL, TRUE);
     free_tv(tv);
 
     set_vim_var_string(VV_FNAME_IN, NULL, -1);
@@ -472,7 +472,7 @@ eval_patch(
 	current_sctx = *ctx;
 
     // errors are ignored
-    tv = eval_expr(p_pex, NULL);
+    tv = eval_expr_ext(p_pex, NULL, TRUE);
     free_tv(tv);
 
     set_vim_var_string(VV_FNAME_IN, NULL, -1);
@@ -497,6 +497,7 @@ eval_spell_expr(char_u *badword, char_u *expr)
     char_u	*p = skipwhite(expr);
     sctx_T	saved_sctx = current_sctx;
     sctx_T	*ctx;
+    int		r;
 
     // Set "v:val" to the bad word.
     prepare_vimvar(VV_VAL, &save_val);
@@ -507,7 +508,10 @@ eval_spell_expr(char_u *badword, char_u *expr)
     if (ctx != NULL)
 	current_sctx = *ctx;
 
-    if (eval1(&p, &rettv, &EVALARG_EVALUATE) == OK)
+    r = may_call_simple_func(p, &rettv);
+    if (r == NOTDONE)
+	r = eval1(&p, &rettv, &EVALARG_EVALUATE);
+    if (r == OK)
     {
 	if (rettv.v_type != VAR_LIST)
 	    clear_tv(&rettv);
@@ -643,7 +647,7 @@ eval_one_expr_in_str(char_u *p, garray_T *gap, int evaluate)
     if (evaluate)
     {
 	*block_end = NUL;
-	expr_val = eval_to_string(block_start, TRUE);
+	expr_val = eval_to_string(block_start, TRUE, FALSE);
 	*block_end = '}';
 	if (expr_val == NULL)
 	    return NULL;

src/ex_docmd.c

@@ -5778,7 +5778,7 @@ ex_colorscheme(exarg_T *eap)
 	if (expr != NULL)
 	{
 	    ++emsg_off;
-	    p = eval_to_string(expr, FALSE);
+	    p = eval_to_string(expr, FALSE, FALSE);
 	    --emsg_off;
 	    vim_free(expr);
 	}

src/ex_eval.c

@@ -1047,7 +1047,7 @@ ex_if(exarg_T *eap)
 	skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0
 		&& !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE));
 
-	result = eval_to_bool(eap->arg, &error, eap, skip);
+	result = eval_to_bool(eap->arg, &error, eap, skip, FALSE);
 
 	if (!skip && !error)
 	{
@@ -1176,7 +1176,7 @@ ex_else(exarg_T *eap)
 	if (skip && ends_excmd(*eap->arg))
 	    semsg(_(e_invalid_expression_str), eap->arg);
 	else
-	    result = eval_to_bool(eap->arg, &error, eap, skip);
+	    result = eval_to_bool(eap->arg, &error, eap, skip, FALSE);
 
 	// When throwing error exceptions, we want to throw always the first
 	// of several errors in a row.  This is what actually happens when
@@ -1283,7 +1283,7 @@ ex_while(exarg_T *eap)
 	    /*
 	     * ":while bool-expr"
 	     */
-	    result = eval_to_bool(eap->arg, &error, eap, skip);
+	    result = eval_to_bool(eap->arg, &error, eap, skip, FALSE);
 	}
 	else
 	{

src/filepath.c

@@ -3354,7 +3354,7 @@ expand_backtick(
 
 #ifdef FEAT_EVAL
     if (*cmd == '=')	    // `={expr}`: Expand expression
-	buffer = eval_to_string(cmd + 1, TRUE);
+	buffer = eval_to_string(cmd + 1, TRUE, FALSE);
     else
 #endif
 	buffer = get_cmd_output(cmd, NULL,

src/findfile.c

@@ -2002,7 +2002,8 @@ eval_includeexpr(char_u *ptr, int len)
     current_sctx = curbuf->b_p_script_ctx[BV_INEX];
 
     res = eval_to_string_safe(curbuf->b_p_inex,
-		 was_set_insecurely((char_u *)"includeexpr", OPT_LOCAL), TRUE);
+	    was_set_insecurely((char_u *)"includeexpr", OPT_LOCAL),
+								   TRUE, TRUE);
 
     set_vim_var_string(VV_FNAME, NULL, 0);
     current_sctx = save_sctx;

src/fold.c

@@ -1960,7 +1960,8 @@ get_foldtext(
 
 	    ++emsg_off; // handle exceptions, but don't display errors
 	    text = eval_to_string_safe(wp->w_p_fdt,
-		    was_set_insecurely((char_u *)"foldtext", OPT_LOCAL), TRUE);
+			   was_set_insecurely((char_u *)"foldtext", OPT_LOCAL),
+			   TRUE, TRUE);
 	    --emsg_off;
 
 	    if (text == NULL || did_emsg)

src/if_ole.cpp

@@ -381,7 +381,7 @@ CVim::Eval(BSTR expr, BSTR *result)
 
     /* Evaluate the expression */
     ++emsg_skip;
-    str = (char *)eval_to_string((char_u *)buffer, TRUE);
+    str = (char *)eval_to_string((char_u *)buffer, TRUE, FALSE);
     --emsg_skip;
     vim_free(buffer);
     if (str == NULL)

src/if_perl.xs

@@ -873,7 +873,8 @@ msg_split(
     char_u *
 eval_to_string(
     char_u	*arg UNUSED,
-    int		dolist UNUSED)
+    int		convert UNUSED,
+    int		use_simple_function UNUSED)
 {
     return NULL;
 }
@@ -1599,7 +1600,7 @@ Eval(str)
     PREINIT:
 	char_u *value;
     PPCODE:
-	value = eval_to_string((char_u *)str, TRUE);
+	value = eval_to_string((char_u *)str, TRUE, FALSE);
 	if (value == NULL)
 	{
 	    XPUSHs(sv_2mortal(newSViv(0)));

src/if_tcl.c

@@ -1397,7 +1397,7 @@ tclvimexpr(
 
 #ifdef FEAT_EVAL
     expr = Tcl_GetStringFromObj(objv[objn], NULL);
-    str = (char *)eval_to_string((char_u *)expr, TRUE);
+    str = (char *)eval_to_string((char_u *)expr, TRUE, FALSE);
     if (str == NULL)
 	Tcl_SetResult(interp, _("invalid expression"), TCL_STATIC);
     else

src/map.c

@@ -1711,7 +1711,7 @@ eval_map_expr(
     }
 
     // Note: the evaluation may make "mp" invalid.
-    p = eval_to_string(expr, FALSE);
+    p = eval_to_string(expr, FALSE, FALSE);
 
     --textlock;
     --ex_normal_lock;

src/proto/eval.pro

@@ -4,7 +4,7 @@ varnumber_T num_modulus(varnumber_T n1, varnumber_T n2, int *failed);
 void eval_init(void);
 void eval_clear(void);
 void fill_evalarg_from_eap(evalarg_T *evalarg, exarg_T *eap, int skip);
-int eval_to_bool(char_u *arg, int *error, exarg_T *eap, int skip);
+int eval_to_bool(char_u *arg, int *error, exarg_T *eap, int skip, int use_simple_function);
 int eval_expr_valid_arg(typval_T *tv);
 funccall_T *eval_expr_get_funccal(typval_T *expr, typval_T *rettv);
 int eval_expr_typval(typval_T *expr, typval_T *argv, int argc, funccall_T *fc_arg, typval_T *rettv);
@@ -15,11 +15,12 @@ void clear_evalarg(evalarg_T *evalarg, exarg_T *eap);
 int skip_expr(char_u **pp, evalarg_T *evalarg);
 int skip_expr_concatenate(char_u **arg, char_u **start, char_u **end, evalarg_T *evalarg);
 char_u *typval2string(typval_T *tv, int convert);
-char_u *eval_to_string_eap(char_u *arg, int convert, exarg_T *eap);
+char_u *eval_to_string_eap(char_u *arg, int convert, exarg_T *eap, int use_simple_function);
-char_u *eval_to_string(char_u *arg, int convert);
+char_u *eval_to_string(char_u *arg, int convert, int use_simple_function);
-char_u *eval_to_string_safe(char_u *arg, int use_sandbox, int keep_script_version);
+char_u *eval_to_string_safe(char_u *arg, int use_sandbox, int keep_script_version, int use_simple_function);
-varnumber_T eval_to_number(char_u *expr);
+varnumber_T eval_to_number(char_u *expr, int use_simple_function);
 typval_T *eval_expr(char_u *arg, exarg_T *eap);
+typval_T *eval_expr_ext(char_u *arg, exarg_T *eap, int use_simple_function);
 int call_vim_function(char_u *func, int argc, typval_T *argv, typval_T *rettv);
 void *call_func_retstr(char_u *func, int argc, typval_T *argv);
 void *call_func_retlist(char_u *func, int argc, typval_T *argv);
@@ -38,6 +39,8 @@ char_u *eval_next_non_blank(char_u *arg, evalarg_T *evalarg, int *getnext);
 char_u *eval_next_line(char_u *arg, evalarg_T *evalarg);
 char_u *skipwhite_and_linebreak(char_u *arg, evalarg_T *evalarg);
 int eval0(char_u *arg, typval_T *rettv, exarg_T *eap, evalarg_T *evalarg);
+int may_call_simple_func(char_u *arg, typval_T *rettv);
+int eval0_simple_funccal(char_u *arg, typval_T *rettv, exarg_T *eap, evalarg_T *evalarg);
 int eval0_retarg(char_u *arg, typval_T *rettv, exarg_T *eap, evalarg_T *evalarg, char_u **retarg);
 int eval1(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
 void eval_addblob(typval_T *tv1, typval_T *tv2);

src/regexp.c

@@ -2125,7 +2125,7 @@ vim_regsub_both(
 		// Execute instructions from ISN_SUBSTITUTE.
 		eval_result[nested] = exe_substitute_instr();
 	    else
-		eval_result[nested] = eval_to_string(source + 2, TRUE);
+		eval_result[nested] = eval_to_string(source + 2, TRUE, FALSE);
 	    --nesting;
 
 	    if (eval_result[nested] != NULL)

src/register.c

@@ -151,7 +151,7 @@ get_expr_line(void)
 	return expr_copy;
 
     ++nested;
-    rv = eval_to_string_eap(expr_copy, TRUE, expr_eap);
+    rv = eval_to_string_eap(expr_copy, TRUE, expr_eap, FALSE);
     --nested;
     vim_free(expr_copy);
     return rv;

src/screen.c

@@ -1198,7 +1198,7 @@ get_keymap_str(
 	curwin = wp;
 	STRCPY(buf, "b:keymap_name");	// must be writable
 	++emsg_skip;
-	s = p = eval_to_string(buf, FALSE);
+	s = p = eval_to_string(buf, FALSE, FALSE);
 	--emsg_skip;
 	curbuf = old_curbuf;
 	curwin = old_curwin;
@@ -2976,7 +2976,7 @@ free_screenlines(void)
  * Clear the screen.
  * May delay if there is something the user should read.
  * Allocated the screen for resizing if needed.
- * Returns TRUE when the screen was actually claared, FALSE if all display
+ * Returns TRUE when the screen was actually cleared, FALSE if all display
  * cells were marked for updating.
  */
     int

src/scriptfile.c

@@ -810,7 +810,7 @@ load_pack_plugin(char_u *fname)
 
 	// If runtime/filetype.vim wasn't loaded yet, the scripts will be
 	// found when it loads.
-	if (cmd != NULL && eval_to_number(cmd) > 0)
+	if (cmd != NULL && eval_to_number(cmd, FALSE) > 0)
 	{
 	    do_cmdline_cmd((char_u *)"augroup filetypedetect");
 	    vim_snprintf((char *)pat, len, ftpat, ffname);

src/textformat.c

@@ -938,7 +938,7 @@ fex_format(
     // Evaluate the function.
     if (use_sandbox)
 	++sandbox;
-    r = (int)eval_to_number(fex);
+    r = (int)eval_to_number(fex, TRUE);
     if (use_sandbox)
 	--sandbox;
 

src/version.c

@@ -699,6 +699,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    634,
 /**/
     633,
 /**/