feat: add option printMessageEndPos

src/Lean/Elab/Frontend.lean

@@ -82,6 +82,12 @@ def process (input : String) (env : Environment) (opts : Options) (fileName : Op
   let s ← IO.processCommands inputCtx { : Parser.ModuleParserState } (Command.mkState env {} opts)
   pure (s.commandState.env, s.commandState.messages)
 
+builtin_initialize
+  registerOption `printMessageEndPos { defValue := false, descr := "print end position of each message in addition to start position" }
+
+def getPrintMessageEndPos (opts : Options) : Bool :=
+  opts.getBool `printMessageEndPos false
+
 @[export lean_run_frontend]
 def runFrontend (input : String) (opts : Options) (fileName : String) (mainModuleName : Name) : IO (Environment × Bool) := do
   let inputCtx := Parser.mkInputContext input fileName
@@ -90,7 +96,7 @@ def runFrontend (input : String) (opts : Options) (fileName : String) (mainModul
   let env := env.setMainModule mainModuleName
   let s ← IO.processCommands inputCtx parserState (Command.mkState env messages opts)
   for msg in s.commandState.messages.toList do
-    IO.print (← msg.toString)
+    IO.print (← msg.toString (includeEndPos := getPrintMessageEndPos opts))
   pure (s.commandState.env, !s.commandState.messages.hasErrors)
 
 end Lean.Elab

src/Lean/Message.lean

@@ -14,8 +14,11 @@ import Lean.Util.PPExt
 
 namespace Lean
 
-def mkErrorStringWithPos (fileName : String) (line col : Nat) (msg : String) : String :=
-  fileName ++ ":" ++ toString line ++ ":" ++ toString col ++ ": " ++ toString msg
+def mkErrorStringWithPos (fileName : String) (pos : Position) (msg : String) (endPos : Option Position := none) : String :=
+  let endPos := match endPos with
+    | some endPos => s!"-{endPos.line}:{endPos.column}"
+    | none        => ""
+  s!"{fileName}:{pos.line}:{pos.column}{endPos}: {msg}"
 
 inductive MessageSeverity where
   | information | warning | error
@@ -149,14 +152,15 @@ def mkMessageEx (fileName : String) (pos : Position) (endPos : Option Position)
   { fileName := fileName, pos := pos, endPos := endPos, severity := severity, caption := caption, data := text }
 namespace Message
 
-protected def toString (msg : Message) : IO String := do
+protected def toString (msg : Message) (includeEndPos := false) : IO String := do
   let mut str ← msg.data.toString
+  let endPos := if includeEndPos then msg.endPos else none
   unless msg.caption == "" do
     str := msg.caption ++ ":\n" ++ str
   match msg.severity with
   | MessageSeverity.information => pure ()
-  | MessageSeverity.warning     => str := mkErrorStringWithPos msg.fileName msg.pos.line msg.pos.column "warning: " ++ str
-  | MessageSeverity.error       => str := mkErrorStringWithPos msg.fileName msg.pos.line msg.pos.column "error: " ++ str
+  | MessageSeverity.warning     => str := mkErrorStringWithPos msg.fileName msg.pos (endPos := endPos) "warning: " ++ str
+  | MessageSeverity.error       => str := mkErrorStringWithPos msg.fileName msg.pos (endPos := endPos) "error: " ++ str
   if str.isEmpty || str.back != '\n' then
     str := str ++ "\n"
   return str

src/Lean/Parser/Basic.lean

@@ -208,7 +208,7 @@ def toErrorMsg (ctx : ParserContext) (s : ParserState) : String :=
   | none     => ""
   | some msg =>
     let pos := ctx.fileMap.toPosition s.pos
-    mkErrorStringWithPos ctx.fileName pos.line pos.column (toString msg)
+    mkErrorStringWithPos ctx.fileName pos (toString msg)
 
 def mkNode (s : ParserState) (k : SyntaxNodeKind) (iniStackSz : Nat) : ParserState :=
   match s with