patch 9.1.0984: exception handling can be improved

Problem:  exception handling can be improved
Solution: add v:stacktrace and getstacktrace()

closes: #16360

Co-authored-by: Naruhiko Nishino <naru123456789@gmail.com>
Signed-off-by: ichizok <gclient.gaap@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/doc/builtin.txt

@@ -279,6 +279,7 @@ getregionpos({pos1}, {pos2} [, {opts}])
 				List	get a list of positions for a region
 getregtype([{regname}])		String	type of a register
 getscriptinfo([{opts}])		List	list of sourced scripts
+getstacktrace()			List	get current stack trace of Vim scripts
 gettabinfo([{expr}])		List	list of tab pages
 gettabvar({nr}, {varname} [, {def}])
 				any	variable {varname} in tab {nr} or {def}
@@ -4997,6 +4998,21 @@ getscriptinfo([{opts}])					*getscriptinfo()*
 		Return type: list<dict<any>>
 
 
+getstacktrace()						*getstacktrace()*
+		Returns the current stack trace of Vim scripts.
+		Stack trace is a |List|, of which each item is a |Dictionary|
+		with the following items:
+		    funcref	The funcref if the stack is at the function,
+				otherwise this item is not exist.
+		    event	The string of the event description if the
+				stack is at autocmd event, otherwise this item
+				is not exist.
+		    lnum	The line number of the script on the stack.
+		    filepath	The file path of the script on the stack.
+
+		Return type: list<dict<any>>
+
+
 gettabinfo([{tabnr}])					*gettabinfo()*
 		If {tabnr} is not specified, then information about all the
 		tab pages is returned as a |List|. Each List item is a

runtime/doc/eval.txt

@@ -1,4 +1,4 @@
-*eval.txt*	For Vim version 9.1.  Last change: 2024 Dec 23
+*eval.txt*	For Vim version 9.1.  Last change: 2025 Jan 02
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -1953,7 +1953,8 @@ variables for each buffer.  Use local buffer variables instead |b:var|.
 
 PREDEFINED VIM VARIABLES			*vim-variable* *v:var* *v:*
 							*E963* *E1063*
-Some variables can be set by the user, but the type cannot be changed.
+Most variables are read-only, when a variable can be set by the user, it will
+be mentioned at the variable description below. The type cannot be changed.
 
 					*v:argv* *argv-variable*
 v:argv		The command line arguments Vim was invoked with.  This is a
@@ -2172,7 +2173,8 @@ v:event		Dictionary containing information about the current
 <
 					*v:exception* *exception-variable*
 v:exception	The value of the exception most recently caught and not
-		finished.  See also |v:throwpoint| and |throw-variables|.
+		finished.  See also |v:stacktrace|, |v:throwpoint|, and
+		|throw-variables|.
 		Example: >
 	:try
 	:  throw "oops"
@@ -2548,6 +2550,12 @@ v:sizeofpointer	Number of bytes in a pointer.  Depends on how Vim was compiled.
 		This is only useful for deciding whether a test will give the
 		expected result.
 
+					*v:stacktrace* *stacktrace-variable*
+v:stacktrace	The stack trace of the exception most recently caught and
+		not finished.  Refer to |getstacktrace()| for the structure of
+		stack trace.  See also |v:exception|, |v:throwpoint|, and
+		|throw-variables|.
+
 					*v:statusmsg* *statusmsg-variable*
 v:statusmsg	Last given status message.  It's allowed to set this variable.
 
@@ -2676,7 +2684,7 @@ v:this_session	Full filename of the last loaded or saved session file.  See
 					*v:throwpoint* *throwpoint-variable*
 v:throwpoint	The point where the exception most recently caught and not
 		finished was thrown.  Not set when commands are typed.  See
-		also |v:exception| and |throw-variables|.
+		also |v:exception|, |v:stacktrace|, and |throw-variables|.
 		Example: >
 	:try
 	:  throw "oops"
@@ -3856,7 +3864,8 @@ in the variable |v:exception|: >
 	:    echo "Number thrown.  Value is" v:exception
 
 You may also be interested where an exception was thrown.  This is stored in
-|v:throwpoint|.  Note that "v:exception" and "v:throwpoint" are valid for the
+|v:throwpoint|.  And you can obtain the stack trace from |v:stacktrace|.
+Note that "v:exception", "v:stacktrace" and "v:throwpoint" are valid for the
 exception most recently caught as long it is not finished.
    Example: >
 

runtime/doc/tags

@@ -7908,6 +7908,7 @@ getscript-history	pi_getscript.txt	/*getscript-history*
 getscript-plugins	pi_getscript.txt	/*getscript-plugins*
 getscript-start	pi_getscript.txt	/*getscript-start*
 getscriptinfo()	builtin.txt	/*getscriptinfo()*
+getstacktrace()	builtin.txt	/*getstacktrace()*
 gettabinfo()	builtin.txt	/*gettabinfo()*
 gettabvar()	builtin.txt	/*gettabvar()*
 gettabwinvar()	builtin.txt	/*gettabwinvar()*
@@ -10218,6 +10219,7 @@ sqrt()	builtin.txt	/*sqrt()*
 squirrel.vim	syntax.txt	/*squirrel.vim*
 srand()	builtin.txt	/*srand()*
 sscanf	eval.txt	/*sscanf*
+stacktrace-variable	eval.txt	/*stacktrace-variable*
 standard-plugin	usr_05.txt	/*standard-plugin*
 standard-plugin-list	help.txt	/*standard-plugin-list*
 standout	syntax.txt	/*standout*
@@ -11038,6 +11040,7 @@ v:shell_error	eval.txt	/*v:shell_error*
 v:sizeofint	eval.txt	/*v:sizeofint*
 v:sizeoflong	eval.txt	/*v:sizeoflong*
 v:sizeofpointer	eval.txt	/*v:sizeofpointer*
+v:stacktrace	eval.txt	/*v:stacktrace*
 v:statusmsg	eval.txt	/*v:statusmsg*
 v:swapchoice	eval.txt	/*v:swapchoice*
 v:swapcommand	eval.txt	/*v:swapcommand*

runtime/doc/usr_41.txt

@@ -1,4 +1,4 @@
-*usr_41.txt*	For Vim version 9.1.  Last change: 2024 Dec 30
+*usr_41.txt*	For Vim version 9.1.  Last change: 2025 Jan 02
 
 		     VIM USER MANUAL - by Bram Moolenaar
 
@@ -1399,7 +1399,8 @@ Various:					*various-functions*
 	eventhandler()		check if invoked by an event handler
 	getcellpixels()		get List of cell pixel size
 	getpid()		get process ID of Vim
-	getscriptinfo()		get list of sourced vim scripts
+	getscriptinfo()		get list of sourced Vim scripts
+	getstacktrace()		get current stack trace of Vim scripts
 	getimstatus()		check if IME status is active
 	interrupt()		interrupt script execution
 	windowsversion()	get MS-Windows version

runtime/doc/version9.txt

@@ -41623,6 +41623,8 @@ Changed~
   for the ghostty terminal emulator (using kitty protocol)
 - |complete_info()| returns the list of matches shown in the poppu menu via
   the "matches" key
+- |v:stacktrace| The stack trace of the exception most recently caught and
+  not finished
 
 							*added-9.2*
 Added ~
@@ -41642,6 +41644,7 @@ Functions: ~
 |getcmdprompt()|	get prompt for input()/confirm()
 |getregion()|		get a region of text from a buffer
 |getregionpos()|	get a list of positions for a region
+|getstacktrace()|	get current stack trace of Vim scripts
 |id()|			get unique identifier for a Dict, List, Object,
 			Channel or Blob variable
 |matchbufline()|	all the matches of a pattern in a buffer