patch 8.1.1195: Vim script debugger functionality needs cleanupv8.1.1195

Problem:    Vim script debugger functionality needs cleanup.
Solution:   Move debugger code to a separate file.  Add more tests. (Yegappan
            Lakshmanan, closes #4285)

17 files changed, 1063 insertions, 1001 deletions

diff --git a/Filelist b/Filelist
index 1e18c67e30..fc6374bacb 100644
--- a/Filelist
+++ b/Filelist
@@ -23,6 +23,7 @@ SRC_ALL =	\
 		src/charset.c \
 		src/crypt.c \
 		src/crypt_zip.c \
+		src/debugger.c \
 		src/dict.c \
 		src/diff.c \
 		src/digraph.c \
@@ -156,6 +157,7 @@ SRC_ALL =	\
 		src/proto/charset.pro \
 		src/proto/crypt.pro \
 		src/proto/crypt_zip.pro \
+		src/proto/debugger.pro \
 		src/proto/dict.pro \
 		src/proto/diff.pro \
 		src/proto/digraph.pro \
diff --git a/src/Make_bc5.mak b/src/Make_bc5.mak
index 1c13931d31..62d03972e8 100644
--- a/src/Make_bc5.mak
+++ b/src/Make_bc5.mak
@@ -516,6 +516,7 @@ vimobj =  \
 	$(OBJDIR)\charset.obj \
 	$(OBJDIR)\crypt.obj \
 	$(OBJDIR)\crypt_zip.obj \
+	$(OBJDIR)\debugger.obj \
 	$(OBJDIR)\dict.obj \
 	$(OBJDIR)\diff.obj \
 	$(OBJDIR)\digraph.obj \
diff --git a/src/Make_cyg_ming.mak b/src/Make_cyg_ming.mak
index bfc5545536..3c01e63fe0 100644
--- a/src/Make_cyg_ming.mak
+++ b/src/Make_cyg_ming.mak
@@ -703,6 +703,7 @@ OBJ = \
 	$(OUTDIR)/charset.o \
 	$(OUTDIR)/crypt.o \
 	$(OUTDIR)/crypt_zip.o \
+	$(OUTDIR)/debugger.o \
 	$(OUTDIR)/dict.o \
 	$(OUTDIR)/diff.o \
 	$(OUTDIR)/digraph.o \
diff --git a/src/Make_dice.mak b/src/Make_dice.mak
index 5bad80b850..93e960a8db 100644
--- a/src/Make_dice.mak
+++ b/src/Make_dice.mak
@@ -33,6 +33,7 @@ SRC = \
 	charset.c \
 	crypt.c \
 	crypt_zip.c \
+	debugger.c \
 	dict.c \
 	diff.c \
 	digraph.c \
@@ -93,6 +94,7 @@ OBJ =	o/arabic.o \
 	o/charset.o \
 	o/crypt.o \
 	o/crypt_zip.o \
+	o/debugger.o \
 	o/dict.o \
 	o/diff.o \
 	o/digraph.o \
@@ -179,6 +181,8 @@ o/crypt.o:	crypt.c  $(SYMS)
 
 o/crypt_zip.o:	crypt_zip.c  $(SYMS)
 
+o/debugger.o:	debugger.c  $(SYMS)
+
 o/dict.o:	dict.c	$(SYMS)
 
 o/diff.o:	diff.c	$(SYMS)
diff --git a/src/Make_ivc.mak b/src/Make_ivc.mak
index 27b2c336d7..08bd87451f 100644
--- a/src/Make_ivc.mak
+++ b/src/Make_ivc.mak
@@ -217,6 +217,7 @@ LINK32_OBJS= \
 	"$(INTDIR)/charset.obj" \
 	"$(INTDIR)/crypt.obj" \
 	"$(INTDIR)/crypt_zip.obj" \
+	"$(INTDIR)/debugger.obj" \
 	"$(INTDIR)/dict.obj" \
 	"$(INTDIR)/diff.obj" \
 	"$(INTDIR)/digraph.obj" \
@@ -369,6 +370,10 @@ SOURCE=.\crypt_zip.c
 # End Source File
 # Begin Source File
 
+SOURCE=.\debugger.c
+# End Source File
+# Begin Source File
+
 SOURCE=.\dict.c
 # End Source File
 # Begin Source File
diff --git a/src/Make_manx.mak b/src/Make_manx.mak
index d150e4b6fc..6eb7bfa684 100644
--- a/src/Make_manx.mak
+++ b/src/Make_manx.mak
@@ -43,6 +43,7 @@ SRC =	arabic.c \
 	charset.c \
 	crypt.c \
 	crypt_zip.c \
+	debugger.c \
 	dict.c \
 	diff.c \
 	digraph.c \
@@ -105,6 +106,7 @@ OBJ =	obj/arabic.o \
 	obj/charset.o \
 	obj/crypt.o \
 	obj/crypt_zip.o \
+	obj/debugger.o \
 	obj/dict.o \
 	obj/diff.o \
 	obj/digraph.o \
@@ -165,6 +167,7 @@ PRO =	proto/arabic.pro \
 	proto/charset.pro \
 	proto/crypt.pro \
 	proto/crypt_zip.pro \
+	proto/debugger.pro \
 	proto/dict.pro \
 	proto/diff.pro \
 	proto/digraph.pro \
@@ -283,6 +286,9 @@ obj/crypt.o:	crypt.c
 obj/crypt_zip.o: crypt_zip.c
 	$(CCSYM) $@ crypt_zip.c
 
+obj/debugger.o:	debugger.c
+	$(CCSYM) $@ debugger.c
+
 obj/dict.o:	dict.c
 	$(CCSYM) $@ dict.c
 
diff --git a/src/Make_morph.mak b/src/Make_morph.mak
index b224c67adc..65cf8447be 100644
--- a/src/Make_morph.mak
+++ b/src/Make_morph.mak
@@ -31,6 +31,7 @@ SRC =	arabic.c						\
 	charset.c						\
 	crypt.c							\
 	crypt_zip.c						\
+	debugger.c						\
 	dict.c							\
 	diff.c							\
 	digraph.c						\
diff --git a/src/Make_mvc.mak b/src/Make_mvc.mak
index b6a1ac0d1c..7da56bc2d8 100644
--- a/src/Make_mvc.mak
+++ b/src/Make_mvc.mak
@@ -711,6 +711,7 @@ OBJ = \
 	$(OUTDIR)\charset.obj \
 	$(OUTDIR)\crypt.obj \
 	$(OUTDIR)\crypt_zip.obj \
+	$(OUTDIR)\debugger.obj \
 	$(OUTDIR)\dict.obj \
 	$(OUTDIR)\diff.obj \
 	$(OUTDIR)\digraph.obj \
@@ -1367,6 +1368,8 @@ $(OUTDIR)/crypt.obj:	$(OUTDIR) crypt.c  $(INCL)
 
 $(OUTDIR)/crypt_zip.obj: $(OUTDIR) crypt_zip.c  $(INCL)
 
+$(OUTDIR)/debugger.obj:	$(OUTDIR) debugger.c  $(INCL)
+
 $(OUTDIR)/dict.obj:	$(OUTDIR) dict.c  $(INCL)
 
 $(OUTDIR)/diff.obj:	$(OUTDIR) diff.c  $(INCL)
@@ -1638,6 +1641,7 @@ proto.h: \
 	proto/charset.pro \
 	proto/crypt.pro \
 	proto/crypt_zip.pro \
+	proto/debugger.pro \
 	proto/dict.pro \
 	proto/diff.pro \
 	proto/digraph.pro \
diff --git a/src/Make_sas.mak b/src/Make_sas.mak
index 09650c31f6..78d6d2a93f 100644
--- a/src/Make_sas.mak
+++ b/src/Make_sas.mak
@@ -96,6 +96,7 @@ SRC = \
 	charset.c \
 	crypt.c \
 	crypt_zip.c \
+	debugger.c \
 	dict.c \
 	diff.c \
 	digraph.c \
@@ -157,6 +158,7 @@ OBJ = \
 	charset.o \
 	crypt.o \
 	crypt_zip.o \
+	debugger.o \
 	dict.o \
 	diff.o \
 	digraph.o \
@@ -218,6 +220,7 @@ PRO = \
 	proto/charset.pro \
 	proto/crypt.pro \
 	proto/crypt_zip.pro \
+	proto/debugger.pro \
 	proto/dict.pro \
 	proto/diff.pro \
 	proto/digraph.pro \
@@ -340,6 +343,8 @@ crypt.o:		crypt.c
 proto/crypt.pro:	crypt.c
 crypt_zip.o:		crypt_zip.c
 proto/crypt_zip.pro:	crypt_zip.c
+debugger.o:		debugger.c
+proto/debugger.pro:	debugger.c
 dict.o:			dict.c
 proto/dict.pro:		dict.c
 diff.o:			diff.c
diff --git a/src/Make_vms.mms b/src/Make_vms.mms
index bc8aee69f6..edf77cb6bd 100644
--- a/src/Make_vms.mms
+++ b/src/Make_vms.mms
@@ -308,30 +308,30 @@ ALL_LIBS = $(LIBS) $(GUI_LIB_DIR) $(GUI_LIB) \
 	   $(PERL_LIB) $(PYTHON_LIB) $(TCL_LIB) $(RUBY_LIB)
 
 SRC =	arabic.c autocmd.c beval.c blob.c blowfish.c buffer.c charset.c \
-	crypt.c crypt_zip.c dict.c diff.c digraph.c edit.c eval.c evalfunc.c \
-	ex_cmds.c ex_cmds2.c ex_docmd.c ex_eval.c ex_getln.c if_cscope.c \
-	if_xcmdsrv.c fileio.c findfile.c fold.c getchar.c hardcopy.c \
-	hashtab.c indent.c insexpand.c json.c list.c main.c mark.c menu.c \
-	mbyte.c memfile.c memline.c message.c misc1.c misc2.c move.c normal.c \
-	ops.c option.c popupmnu.c quickfix.c regexp.c search.c sha256.c sign.c \
-	spell.c spellfile.c syntax.c tag.c term.c termlib.c textprop.c ui.c \
-	undo.c userfunc.c version.c screen.c window.c os_unix.c os_vms.c \
-	pathdef.c
+	crypt.c crypt_zip.c debugger.c dict.c diff.c digraph.c edit.c eval.c \
+	evalfunc.c ex_cmds.c ex_cmds2.c ex_docmd.c ex_eval.c ex_getln.c \
+	if_cscope.c if_xcmdsrv.c fileio.c findfile.c fold.c getchar.c \
+	hardcopy.c hashtab.c indent.c insexpand.c json.c list.c main.c mark.c \
+	menu.c mbyte.c memfile.c memline.c message.c misc1.c misc2.c move.c \
+	normal.c ops.c option.c popupmnu.c quickfix.c regexp.c search.c \
+	sha256.c sign.c spell.c spellfile.c syntax.c tag.c term.c termlib.c \
+	textprop.c ui.c undo.c userfunc.c version.c screen.c window.c \
+	os_unix.c os_vms.c pathdef.c \
 	$(GUI_SRC) $(PERL_SRC) $(PYTHON_SRC) $(TCL_SRC) \
  	$(RUBY_SRC) $(HANGULIN_SRC) $(MZSCH_SRC) $(XDIFF_SRC)
 
 OBJ = 	arabic.obj autocmd.obj beval.obj blob.obj blowfish.obj buffer.obj \
-	charset.obj crypt.obj crypt_zip.obj dict.obj diff.obj digraph.obj \
-	edit.obj eval.obj evalfunc.obj ex_cmds.obj ex_cmds2.obj ex_docmd.obj \
-	ex_eval.obj ex_getln.obj if_cscope.obj if_xcmdsrv.obj \
+	charset.obj crypt.obj crypt_zip.obj debugger.obj dict.obj diff.obj \
+	digraph.obj edit.obj eval.obj evalfunc.obj ex_cmds.obj ex_cmds2.obj \
+	ex_docmd.obj ex_eval.obj ex_getln.obj if_cscope.obj if_xcmdsrv.obj \
 	fileio.obj findfile.obj fold.obj getchar.obj hardcopy.obj hashtab.obj \
 	indent.obj insexpand.obj json.obj list.obj main.obj mark.obj \
 	menu.obj memfile.obj memline.obj message.obj misc1.obj misc2.obj \
 	move.obj mbyte.obj normal.obj ops.obj option.obj popupmnu.obj \
 	quickfix.obj regexp.obj search.obj sha256.obj sign.obj spell.obj \
 	spellfile.obj syntax.obj tag.obj term.obj termlib.obj textprop.obj \
-	ui.obj undo.obj userfunc.obj screen.obj version.obj window.obj \
-	os_unix.obj os_vms.obj pathdef.obj if_mzsch.obj \
+	ui.obj undo.obj userfunc.obj screen.obj version.obj \
+	window.obj os_unix.obj os_vms.obj pathdef.obj if_mzsch.obj \
 	$(GUI_OBJ) $(PERL_OBJ) $(PYTHON_OBJ) $(TCL_OBJ) \
  	$(RUBY_OBJ) $(HANGULIN_OBJ) $(MZSCH_OBJ) $(XDIFF_OBJ)
 
@@ -522,6 +522,10 @@ crypt_zip.obj : crypt_zip.c vim.h [.auto]config.h feature.h os_unix.h \
  ascii.h keymap.h term.h macros.h option.h structs.h \
  regexp.h gui.h beval.h [.proto]gui_beval.pro alloc.h ex_cmds.h spell.h \
  proto.h globals.h
+debugger.obj : debugger.c vim.h [.auto]config.h feature.h os_unix.h \
+ ascii.h keymap.h term.h macros.h structs.h regexp.h \
+ gui.h beval.h [.proto]gui_beval.pro option.h ex_cmds.h proto.h \
+ globals.h
 dict.obj : dict.c vim.h [.auto]config.h feature.h os_unix.h \
  ascii.h keymap.h term.h macros.h option.h structs.h regexp.h gui.h \
  beval.h [.proto]gui_beval.pro alloc.h ex_cmds.h spell.h proto.h \
diff --git a/src/Makefile b/src/Makefile
index bee20ae3e7..cf23ca816d 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -1579,6 +1579,7 @@ BASIC_SRC = \
 	charset.c \
 	crypt.c \
 	crypt_zip.c \
+	debugger.c \
 	dict.c \
 	diff.c \
 	digraph.c \
@@ -1693,6 +1694,7 @@ OBJ_COMMON = \
 	objects/blowfish.o \
 	objects/crypt.o \
 	objects/crypt_zip.o \
+	objects/debugger.o \
 	objects/dict.o \
 	objects/diff.o \
 	objects/digraph.o \
@@ -1820,6 +1822,7 @@ PRO_AUTO = \
 	charset.pro \
 	crypt.pro \
 	crypt_zip.pro \
+	debugger.pro \
 	dict.pro \
 	diff.pro \
 	digraph.pro \
@@ -2963,6 +2966,9 @@ objects/crypt.o: crypt.c
 objects/crypt_zip.o: crypt_zip.c
 	$(CCC) -o $@ crypt_zip.c
 
+objects/debugger.o: debugger.c
+	$(CCC) -o $@ debugger.c
+
 objects/dict.o: dict.c
 	$(CCC) -o $@ dict.c
 
@@ -3425,6 +3431,9 @@ objects/crypt_zip.o: crypt_zip.c vim.h protodef.h auto/config.h feature.h \
  os_unix.h auto/osdef.h ascii.h keymap.h term.h macros.h option.h beval.h \
  proto/gui_beval.pro structs.h regexp.h gui.h alloc.h ex_cmds.h spell.h \
  proto.h globals.h
+objects/debugger.o: debugger.c vim.h protodef.h auto/config.h feature.h os_unix.h \
+  os_mac.h ascii.h keymap.h term.h macros.h option.h beval.h structs.h \
+  regexp.h gui.h alloc.h ex_cmds.h spell.h proto.h globals.h
 objects/dict.o: dict.c vim.h protodef.h auto/config.h feature.h os_unix.h \
  auto/osdef.h ascii.h keymap.h term.h macros.h option.h beval.h \
  proto/gui_beval.pro structs.h regexp.h gui.h alloc.h ex_cmds.h spell.h \
diff --git a/src/debugger.c b/src/debugger.c
new file mode 100644
index 0000000000..10dc86dcc6
--- /dev/null
+++ b/src/debugger.c
@@ -0,0 +1,990 @@
+/* vi:set ts=8 sts=4 sw=4 noet:
+ *
+ * VIM - Vi IMproved	by Bram Moolenaar
+ *
+ * Do ":help uganda"  in Vim to read copying and usage conditions.
+ * Do ":help credits" in Vim to see a list of people who contributed.
+ * See README.txt for an overview of the Vim source code.
+ */
+
+/*
+ * debugger.c: Vim script debugger functions
+ */
+
+#include "vim.h"
+
+#if defined(FEAT_EVAL) || defined(PROTO)
+static int debug_greedy = FALSE;	/* batch mode debugging: don't save
+					   and restore typeahead. */
+static void do_setdebugtracelevel(char_u *arg);
+static void do_checkbacktracelevel(void);
+static void do_showbacktrace(char_u *cmd);
+
+static char_u *debug_oldval = NULL;	/* old and newval for debug expressions */
+static char_u *debug_newval = NULL;
+static int     debug_expr   = 0;        /* use debug_expr */
+
+    int
+has_watchexpr(void)
+{
+    return debug_expr;
+}
+
+/*
+ * do_debug(): Debug mode.
+ * Repeatedly get Ex commands, until told to continue normal execution.
+ */
+    void
+do_debug(char_u *cmd)
+{
+    int		save_msg_scroll = msg_scroll;
+    int		save_State = State;
+    int		save_did_emsg = did_emsg;
+    int		save_cmd_silent = cmd_silent;
+    int		save_msg_silent = msg_silent;
+    int		save_emsg_silent = emsg_silent;
+    int		save_redir_off = redir_off;
+    tasave_T	typeaheadbuf;
+    int		typeahead_saved = FALSE;
+    int		save_ignore_script = 0;
+    int		save_ex_normal_busy;
+    int		n;
+    char_u	*cmdline = NULL;
+    char_u	*p;
+    char	*tail = NULL;
+    static int	last_cmd = 0;
+#define CMD_CONT	1
+#define CMD_NEXT	2
+#define CMD_STEP	3
+#define CMD_FINISH	4
+#define CMD_QUIT	5
+#define CMD_INTERRUPT	6
+#define CMD_BACKTRACE	7
+#define CMD_FRAME	8
+#define CMD_UP		9
+#define CMD_DOWN	10
+
+#ifdef ALWAYS_USE_GUI
+    /* Can't do this when there is no terminal for input/output. */
+    if (!gui.in_use)
+    {
+	/* Break as soon as possible. */
+	debug_break_level = 9999;
+	return;
+    }
+#endif
+
+    /* Make sure we are in raw mode and start termcap mode.  Might have side
+     * effects... */
+    settmode(TMODE_RAW);
+    starttermcap();
+
+    ++RedrawingDisabled;	/* don't redisplay the window */
+    ++no_wait_return;		/* don't wait for return */
+    did_emsg = FALSE;		/* don't use error from debugged stuff */
+    cmd_silent = FALSE;		/* display commands */
+    msg_silent = FALSE;		/* display messages */
+    emsg_silent = FALSE;	/* display error messages */
+    redir_off = TRUE;		/* don't redirect debug commands */
+
+    State = NORMAL;
+    debug_mode = TRUE;
+
+    if (!debug_did_msg)
+	msg(_("Entering Debug mode.  Type \"cont\" to continue."));
+    if (debug_oldval != NULL)
+    {
+	smsg(_("Oldval = \"%s\""), debug_oldval);
+	vim_free(debug_oldval);
+	debug_oldval = NULL;
+    }
+    if (debug_newval != NULL)
+    {
+	smsg(_("Newval = \"%s\""), debug_newval);
+	vim_free(debug_newval);
+	debug_newval = NULL;
+    }
+    if (sourcing_name != NULL)
+	msg((char *)sourcing_name);
+    if (sourcing_lnum != 0)
+	smsg(_("line %ld: %s"), (long)sourcing_lnum, cmd);
+    else
+	smsg(_("cmd: %s"), cmd);
+    /*
+     * Repeat getting a command and executing it.
+     */
+    for (;;)
+    {
+	msg_scroll = TRUE;
+	need_wait_return = FALSE;
+
+	/* Save the current typeahead buffer and replace it with an empty one.
+	 * This makes sure we get input from the user here and don't interfere
+	 * with the commands being executed.  Reset "ex_normal_busy" to avoid
+	 * the side effects of using ":normal". Save the stuff buffer and make
+	 * it empty. Set ignore_script to avoid reading from script input. */
+	save_ex_normal_busy = ex_normal_busy;
+	ex_normal_busy = 0;
+	if (!debug_greedy)
+	{
+	    save_typeahead(&typeaheadbuf);
+	    typeahead_saved = TRUE;
+	    save_ignore_script = ignore_script;
+	    ignore_script = TRUE;
+	}
+
+	vim_free(cmdline);
+	cmdline = getcmdline_prompt('>', NULL, 0, EXPAND_NOTHING, NULL);
+
+	if (typeahead_saved)
+	{
+	    restore_typeahead(&typeaheadbuf);
+	    ignore_script = save_ignore_script;
+	}
+	ex_normal_busy = save_ex_normal_busy;
+
+	cmdline_row = msg_row;
+	msg_starthere();
+	if (cmdline != NULL)
+	{
+	    /* If this is a debug command, set "last_cmd".
+	     * If not, reset "last_cmd".
+	     * For a blank line use previous command. */
+	    p = skipwhite(cmdline);
+	    if (*p != NUL)
+	    {
+		switch (*p)
+		{
+		    case 'c': last_cmd = CMD_CONT;
+			      tail = "ont";
+			      break;
+		    case 'n': last_cmd = CMD_NEXT;
+			      tail = "ext";
+			      break;
+		    case 's': last_cmd = CMD_STEP;
+			      tail = "tep";
+			      break;
+		    case 'f':
+			      last_cmd = 0;
+			      if (p[1] == 'r')
+			      {
+				  last_cmd = CMD_FRAME;
+				  tail = "rame";
+			      }
+			      else
+			      {
+				  last_cmd = CMD_FINISH;
+				  tail = "inish";
+			      }
+			      break;
+		    case 'q': last_cmd = CMD_QUIT;
+			      tail = "uit";
+			      break;
+		    case 'i': last_cmd = CMD_INTERRUPT;
+			      tail = "nterrupt";
+			      break;
+		    case 'b': last_cmd = CMD_BACKTRACE;
+			      if (p[1] == 't')
+				  tail = "t";
+			      else
+				  tail = "acktrace";
+			      break;
+		    case 'w': last_cmd = CMD_BACKTRACE;
+			      tail = "here";
+			      break;
+		    case 'u': last_cmd = CMD_UP;
+			      tail = "p";
+			      break;
+		    case 'd': last_cmd = CMD_DOWN;
+			      tail = "own";
+			      break;
+		    default: last_cmd = 0;
+		}
+		if (last_cmd != 0)
+		{
+		    /* Check that the tail matches. */
+		    ++p;
+		    while (*p != NUL && *p == *tail)
+		    {
+			++p;
+			++tail;
+		    }
+		    if (ASCII_ISALPHA(*p) && last_cmd != CMD_FRAME)
+			last_cmd = 0;
+		}
+	    }
+
+	    if (last_cmd != 0)
+	    {
+		/* Execute debug command: decided where to break next and
+		 * return. */
+		switch (last_cmd)
+		{
+		    case CMD_CONT:
+			debug_break_level = -1;
+			break;
+		    case CMD_NEXT:
+			debug_break_level = ex_nesting_level;
+			break;
+		    case CMD_STEP:
+			debug_break_level = 9999;
+			break;
+		    case CMD_FINISH:
+			debug_break_level = ex_nesting_level - 1;
+			break;
+		    case CMD_QUIT:
+			got_int = TRUE;
+			debug_break_level = -1;
+			break;
+		    case CMD_INTERRUPT:
+			got_int = TRUE;
+			debug_break_level = 9999;
+			/* Do not repeat ">interrupt" cmd, continue stepping. */
+			last_cmd = CMD_STEP;
+			break;
+		    case CMD_BACKTRACE:
+			do_showbacktrace(cmd);
+			continue;
+		    case CMD_FRAME:
+			if (*p == NUL)
+			{
+			    do_showbacktrace(cmd);
+			}
+			else
+			{
+			    p = skipwhite(p);
+			    do_setdebugtracelevel(p);
+			}
+			continue;
+		    case CMD_UP:
+			debug_backtrace_level++;
+			do_checkbacktracelevel();
+			continue;
+		    case CMD_DOWN:
+			debug_backtrace_level--;
+			do_checkbacktracelevel();
+			continue;
+		}
+		/* Going out reset backtrace_level */
+		debug_backtrace_level = 0;
+		break;
+	    }
+
+	    /* don't debug this command */
+	    n = debug_break_level;
+	    debug_break_level = -1;
+	    (void)do_cmdline(cmdline, getexline, NULL,
+						DOCMD_VERBOSE|DOCMD_EXCRESET);
+	    debug_break_level = n;
+	}
+	lines_left = Rows - 1;
+    }
+    vim_free(cmdline);
+
+    --RedrawingDisabled;
+    --no_wait_return;
+    redraw_all_later(NOT_VALID);
+    need_wait_return = FALSE;
+    msg_scroll = save_msg_scroll;
+    lines_left = Rows - 1;
+    State = save_State;
+    debug_mode = FALSE;
+    did_emsg = save_did_emsg;
+    cmd_silent = save_cmd_silent;
+    msg_silent = save_msg_silent;
+    emsg_silent = save_emsg_silent;
+    redir_off = save_redir_off;
+
+    /* Only print the message again when typing a command before coming back
+     * here. */
+    debug_did_msg = TRUE;
+}
+
+    static int
+get_maxbacktrace_level(void)
+{
+    char	*p, *q;
+    int		maxbacktrace = 0;
+
+    if (sourcing_name != NULL)
+    {
+	p = (char *)sourcing_name;
+	while ((q = strstr(p, "..")) != NULL)
+	{
+	    p = q + 2;
+	    maxbacktrace++;
+	}
+    }
+    return maxbacktrace;
+}
+
+    static void
+do_setdebugtracelevel(char_u *arg)
+{
+    int level;
+
+    level = atoi((char *)arg);
+    if (*arg == '+' || level < 0)
+	debug_backtrace_level += level;
+    else
+	debug_backtrace_level = level;
+
+    do_checkbacktracelevel();
+}
+
+    static void
+do_checkbacktracelevel(void)
+{
+    if (debug_backtrace_level < 0)
+    {
+	debug_backtrace_level = 0;
+	msg(_("frame is zero"));
+    }
+    else
+    {
+	int max = get_maxbacktrace_level();
+
+	if (debug_backtrace_level > max)
+	{
+	    debug_backtrace_level = max;
+	    smsg(_("frame at highest level: %d"), max);
+	}
+    }
+}
+
+    static void
+do_showbacktrace(char_u *cmd)
+{
+    char    *cur;
+    char    *next;
+    int	    i = 0;
+    int	    max = get_maxbacktrace_level();
+
+    if (sourcing_name != NULL)
+    {
+	cur = (char *)sourcing_name;
+	while (!got_int)
+	{
+	    next = strstr(cur, "..");
+	    if (next != NULL)
+		*next = NUL;
+	    if (i == max - debug_backtrace_level)
+		smsg("->%d %s", max - i, cur);
+	    else
+		smsg("  %d %s", max - i, cur);
+	    ++i;
+	    if (next == NULL)
+		break;
+	    *next = '.';
+	    cur = next + 2;
+	}
+    }
+    if (sourcing_lnum != 0)
+       smsg(_("line %ld: %s"), (long)sourcing_lnum, cmd);
+    else
+       smsg(_("cmd: %s"), cmd);
+}
+
+/*
+ * ":debug".
+ */
+    void
+ex_debug(exarg_T *eap)
+{
+    int		debug_break_level_save = debug_break_level;
+
+    debug_break_level = 9999;
+    do_cmdline_cmd(eap->arg);
+    debug_break_level = debug_break_level_save;
+}
+
+static char_u	*debug_breakpoint_name = NULL;
+static linenr_T	debug_breakpoint_lnum;
+
+/*
+ * When debugging or a breakpoint is set on a skipped command, no debug prompt
+ * is shown by do_one_cmd().  This situation is indicated by debug_skipped, and
+ * debug_skipped_name is then set to the source name in the breakpoint case.  If
+ * a skipped command decides itself that a debug prompt should be displayed, it
+ * can do so by calling dbg_check_skipped().
+ */
+static int	debug_skipped;
+static char_u	*debug_skipped_name;
+
+/*
+ * Go to debug mode when a breakpoint was encountered or "ex_nesting_level" is
+ * at or below the break level.  But only when the line is actually
+ * executed.  Return TRUE and set breakpoint_name for skipped commands that
+ * decide to execute something themselves.
+ * Called from do_one_cmd() before executing a command.
+ */
+    void
+dbg_check_breakpoint(exarg_T *eap)
+{
+    char_u	*p;
+
+    debug_skipped = FALSE;
+    if (debug_breakpoint_name != NULL)
+    {
+	if (!eap->skip)
+	{
+	    /* replace K_SNR with "<SNR>" */
+	    if (debug_breakpoint_name[0] == K_SPECIAL
+		    && debug_breakpoint_name[1] == KS_EXTRA
+		    && debug_breakpoint_name[2] == (int)KE_SNR)
+		p = (char_u *)"<SNR>";
+	    else
+		p = (char_u *)"";
+	    smsg(_("Breakpoint in \"%s%s\" line %ld"),
+		    p,
+		    debug_breakpoint_name + (*p == NUL ? 0 : 3),
+		    (long)debug_breakpoint_lnum);
+	    debug_breakpoint_name = NULL;
+	    do_debug(eap->cmd);
+	}
+	else
+	{
+	    debug_skipped = TRUE;
+	    debug_skipped_name = debug_breakpoint_name;
+	    debug_breakpoint_name = NULL;
+	}
+    }
+    else if (ex_nesting_level <= debug_break_level)
+    {
+	if (!eap->skip)
+	    do_debug(eap->cmd);
+	else
+	{
+	    debug_skipped = TRUE;
+	    debug_skipped_name = NULL;
+	}
+    }
+}
+
+/*
+ * Go to debug mode if skipped by dbg_check_breakpoint() because eap->skip was
+ * set.  Return TRUE when the debug mode is entered this time.
+ */
+    int
+dbg_check_skipped(exarg_T *eap)
+{
+    int		prev_got_int;
+
+    if (debug_skipped)
+    {
+	/*
+	 * Save the value of got_int and reset it.  We don't want a previous
+	 * interruption cause flushing the input buffer.
+	 */
+	prev_got_int = got_int;
+	got_int = FALSE;
+	debug_breakpoint_name = debug_skipped_name;
+	/* eap->skip is TRUE */
+	eap->skip = FALSE;
+	(void)dbg_check_breakpoint(eap);
+	eap->skip = TRUE;
+	got_int |= prev_got_int;
+	return TRUE;
+    }
+    return FALSE;
+}
+
+/*
+ * The list of breakpoints: dbg_breakp.
+ * This is a grow-array of structs.
+ */
+struct debuggy
+{
+    int		dbg_nr;		/* breakpoint number */
+    int		dbg_type;	/* DBG_FUNC, DBG_FILE or DBG_EXPR */
+    char_u	*dbg_name;	/* function, expression or file name */
+    regprog_T	*dbg_prog;	/* regexp program */
+    linenr_T	dbg_lnum;	/* line number in function or file */
+    int		dbg_forceit;	/* ! used */
+#ifdef FEAT_EVAL
+    typval_T    *dbg_val;       /* last result of watchexpression */
+#endif
+    int		dbg_level;      /* stored nested level for expr */
+};
+
+static garray_T dbg_breakp = {0, 0, sizeof(struct debuggy), 4, NULL};
+#define BREAKP(idx)		(((struct debuggy *)dbg_breakp.ga_data)[idx])
+#define DEBUGGY(gap, idx)	(((struct debuggy *)gap->ga_data)[idx])
+static int last_breakp = 0;	/* nr of last defined breakpoint */
+
+#ifdef FEAT_PROFILE
+/* Profiling uses file and func names similar to breakpoints. */
+static garray_T prof_ga = {0, 0, sizeof(struct debuggy), 4, NULL};
+#endif
+#define DBG_FUNC	1
+#define DBG_FILE	2
+#define DBG_EXPR	3
+
+static linenr_T debuggy_find(int file,char_u *fname, linenr_T after, garray_T *gap, int *fp);
+
+/*
+ * Parse the arguments of ":profile", ":breakadd" or ":breakdel" and put them
+ * in the entry just after the last one in dbg_breakp.  Note that "dbg_name"
+ * is allocated.
+ * Returns FAIL for failure.
+ */
+    static int
+dbg_parsearg(
+    char_u	*arg,
+    garray_T	*gap)	    /* either &dbg_breakp or &prof_ga */
+{
+    char_u	*p = arg;
+    char_u	*q;
+    struct debuggy *bp;
+    int		here = FALSE;
+
+    if (ga_grow(gap, 1) == FAIL)
+	return FAIL;
+    bp = &DEBUGGY(gap, gap->ga_len);
+
+    /* Find "func" or "file". */
+    if (STRNCMP(p, "func", 4) == 0)
+	bp->dbg_type = DBG_FUNC;
+    else if (STRNCMP(p, "file", 4) == 0)
+	bp->dbg_type = DBG_FILE;
+    else if (
+#ifdef FEAT_PROFILE
+	    gap != &prof_ga &&
+#endif
+	    STRNCMP(p, "here", 4) == 0)
+    {
+	if (curbuf->b_ffname == NULL)
+	{
+	    emsg(_(e_noname));
+	    return FAIL;
+	}
+	bp->dbg_type = DBG_FILE;
+	here = TRUE;
+    }
+    else if (
+#ifdef FEAT_PROFILE
+	    gap != &prof_ga &&
+#endif
+	    STRNCMP(p, "expr", 4) == 0)
+	bp->dbg_type = DBG_EXPR;
+    else
+    {
+	semsg(_(e_invarg2), p);
+	return FAIL;
+    }
+    p = skipwhite(p + 4);
+
+    /* Find optional line number. */
+    if (here)
+	bp->dbg_lnum = curwin->w_cursor.lnum;
+    else if (
+#ifdef FEAT_PROFILE
+	    gap != &prof_ga &&
+#endif
+	    VIM_ISDIGIT(*p))
+    {
+	bp->dbg_lnum = getdigits(&p);
+	p = skipwhite(p);
+    }
+    else
+	bp->dbg_lnum = 0;
+
+    /* Find the function or file name.  Don't accept a function name with (). */
+    if ((!here && *p == NUL)
+	    || (here && *p != NUL)
+	    || (bp->dbg_type == DBG_FUNC && strstr((char *)p, "()") != NULL))
+    {
+	semsg(_(e_invarg2), arg);
+	return FAIL;
+    }
+
+    if (bp->dbg_type == DBG_FUNC)
+	bp->dbg_name = vim_strsave(p);
+    else if (here)
+	bp->dbg_name = vim_strsave(curbuf->b_ffname);
+    else if (bp->dbg_type == DBG_EXPR)
+    {
+	bp->dbg_name = vim_strsave(p);
+	if (bp->dbg_name != NULL)
+	    bp->dbg_val = eval_expr(bp->dbg_name, NULL);
+    }
+    else
+    {
+	/* Expand the file name in the same way as do_source().  This means
+	 * doing it twice, so that $DIR/file gets expanded when $DIR is
+	 * "~/dir". */
+	q = expand_env_save(p);
+	if (q == NULL)
+	    return FAIL;
+	p = expand_env_save(q);
+	vim_free(q);
+	if (p == NULL)
+	    return FAIL;
+	if (*p != '*')
+	{
+	    bp->dbg_name = fix_fname(p);
+	    vim_free(p);
+	}
+	else
+	    bp->dbg_name = p;
+    }
+
+    if (bp->dbg_name == NULL)
+	return FAIL;
+    return OK;
+}
+
+/*
+ * ":breakadd".  Also used for ":profile".
+ */
+    void
+ex_breakadd(exarg_T *eap)
+{
+    struct debuggy *bp;
+    char_u	*pat;
+    garray_T	*gap;
+
+    gap = &dbg_breakp;
+#ifdef FEAT_PROFILE
+    if (eap->cmdidx == CMD_profile)
+	gap = &prof_ga;
+#endif
+
+    if (dbg_parsearg(eap->arg, gap) == OK)
+    {
+	bp = &DEBUGGY(gap, gap->ga_len);
+	bp->dbg_forceit = eap->forceit;
+
+	if (bp->dbg_type != DBG_EXPR)
+	{
+	    pat = file_pat_to_reg_pat(bp->dbg_name, NULL, NULL, FALSE);
+	    if (pat != NULL)
+	    {
+		bp->dbg_prog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
+		vim_free(pat);
+	    }
+	    if (pat == NULL || bp->dbg_prog == NULL)
+		vim_free(bp->dbg_name);
+	    else
+	    {
+		if (bp->dbg_lnum == 0)	/* default line number is 1 */
+		    bp->dbg_lnum = 1;
+#ifdef FEAT_PROFILE
+		if (eap->cmdidx != CMD_profile)
+#endif
+		{
+		    DEBUGGY(gap, gap->ga_len).dbg_nr = ++last_breakp;
+		    ++debug_tick;
+		}
+		++gap->ga_len;
+	    }
+	}
+	else
+	{
+	    /* DBG_EXPR */
+	    DEBUGGY(gap, gap->ga_len++).dbg_nr = ++last_breakp;
+	    ++debug_tick;
+	}
+    }
+}
+
+/*
+ * ":debuggreedy".
+ */
+    void
+ex_debuggreedy(exarg_T *eap)
+{
+    if (eap->addr_count == 0 || eap->line2 != 0)
+	debug_greedy = TRUE;
+    else
+	debug_greedy = FALSE;
+}
+
+/*
+ * ":breakdel" and ":profdel".
+ */
+    void
+ex_breakdel(exarg_T *eap)
+{
+    struct debuggy *bp, *bpi;
+    int		nr;
+    int		todel = -1;
+    int		del_all = FALSE;
+    int		i;
+    linenr_T	best_lnum = 0;
+    garray_T	*gap;
+
+    gap = &dbg_breakp;
+    if (eap->cmdidx == CMD_profdel)
+    {
+#ifdef FEAT_PROFILE
+	gap = &prof_ga;
+#else
+	ex_ni(eap);
+	return;
+#endif
+    }
+
+    if (vim_isdigit(*eap->arg))
+    {
+	/* ":breakdel {nr}" */
+	nr = atol((char *)eap->arg);