Fixed errors getting printed to stdout instead of stderr.

CL: Fixed additional stack overflow error when there's an error in the "fileerror" message handler.

Author: ReFreezed

preprocess-cl.lua

@@ -144,7 +144,7 @@ local args = arg
 
 local major, minor = _VERSION:match"Lua (%d+)%.(%d+)"
 if not major then
-	print("[LuaPreprocess] Warning: Could not detect Lua version.") -- Note: This line does not obey the --silent option.
+	io.stderr:write("[LuaPreprocess] Warning: Could not detect Lua version.\n") -- Note: This line does not obey the --silent option.
 else
 	major = tonumber(major)
 	minor = tonumber(minor)
@@ -177,10 +177,10 @@ local validate             = true
 --==============================================================
 --= Local Functions ============================================
 --==============================================================
-local errorline
+local errorLine
 local F, formatBytes, formatInt
 local loadLuaFile
-local printf, printfNoise
+local printf, printfNoise, printError, printfError
 
 F = string.format
 function formatBytes(n)
@@ -210,8 +210,15 @@ function printf(s, ...)
 end
 printfNoise = printf
 
-function errorline(err)
-	print("Error: "..tostring(err))
+function printError(s)
+	io.stderr:write(s, "\n")
+end
+function printfError(s, ...)
+	io.stderr:write(s:format(...), "\n")
+end
+
+function errorLine(err)
+	printError("Error: "..tostring(err))
 	os.exit(1)
 end
 
@@ -283,16 +290,16 @@ for _, arg in ipairs(args) do
 
 	elseif arg:find"^%-%-outputextension=" then
 		if hasOutputPaths then
-			errorline("Cannot specify both --outputextension and --outputpaths")
+			errorLine("Cannot specify both --outputextension and --outputpaths")
 		end
 		hasOutputExtension = true
 		outputExtension    = arg:match"^%-%-outputextension=(.*)$"
 
 	elseif arg == "--outputpaths" or arg == "-o" then
 		if hasOutputExtension then
-			errorline("Cannot specify both --outputpaths and --outputextension")
+			errorLine("Cannot specify both --outputpaths and --outputextension")
 		elseif pathsIn[1] then
-			errorline(arg.." must appear before any paths.")
+			errorLine(arg.." must appear before any path.")
 		end
 		hasOutputPaths = true
 
@@ -303,7 +310,7 @@ for _, arg in ipairs(args) do
 		silent = true
 
 	else
-		errorline("Unknown option '"..arg:gsub("=.*", "").."'.")
+		errorLine("Unknown option '"..arg:gsub("=.*", "").."'.")
 	end
 end
 
@@ -317,7 +324,7 @@ printfNoise("%s", header)
 printfNoise(("="):rep(#header))
 
 if hasOutputPaths and #pathsOut < #pathsIn then
-	errorline("Missing output path for "..pathsIn[#pathsIn])
+	errorLine("Missing output path for "..pathsIn[#pathsIn])
 end
 
 
@@ -370,7 +377,7 @@ if messageHandlerPath ~= "" then
 	-- This way the message handler can easily define globals that the metaprogram uses.
 	local mainChunk, err = loadLuaFile(messageHandlerPath, pp.metaEnvironment)
 	if not mainChunk then
-		errorline("Could not load message handler: "..err)
+		errorLine("Could not load message handler...\n"..pp.tryToFormatError(err))
 	end
 
 	messageHandler = mainChunk()
@@ -380,13 +387,13 @@ if messageHandlerPath ~= "" then
 	elseif type(messageHandler) == "table" then
 		for message, _messageHandler in pairs(messageHandler) do
 			if type(message) ~= "string" then
-				errorline(messageHandlerPath..": Table of handlers must only contain messages as keys.")
+				errorLine(messageHandlerPath..": Table of handlers must only contain messages as keys.")
 			elseif type(_messageHandler) ~= "function" then
-				errorline(messageHandlerPath..": Table of handlers must only contain functions as values.")
+				errorLine(messageHandlerPath..": Table of handlers must only contain functions as values.")
 			end
 		end
 	else
-		errorline(messageHandlerPath..": File did not return a table or a function.")
+		errorLine(messageHandlerPath..": File did not return a table or a function.")
 	end
 end
 
@@ -402,20 +409,20 @@ if not hasOutputPaths then
 end
 
 if not pathsIn[1] then
-	errorline("No path(s) specified.")
+	errorLine("No path(s) specified.")
 elseif #pathsIn ~= #pathsOut then
-	errorline(F("Number of input and output paths differ. (%d in, %d out)", #pathsIn, #pathsOut))
+	errorLine(F("Number of input and output paths differ. (%d in, %d out)", #pathsIn, #pathsOut))
 end
 
 local pathsSetIn  = {}
 local pathsSetOut = {}
 for i = 1, #pathsIn do
-	if pathsSetIn [pathsIn [i]] then  errorline("Duplicate input path: " ..pathsIn [i])  end
-	if pathsSetOut[pathsOut[i]] then  errorline("Duplicate output path: "..pathsOut[i])  end
+	if pathsSetIn [pathsIn [i]] then  errorLine("Duplicate input path: " ..pathsIn [i])  end
+	if pathsSetOut[pathsOut[i]] then  errorLine("Duplicate output path: "..pathsOut[i])  end
 	pathsSetIn [pathsIn [i]] = true
 	pathsSetOut[pathsOut[i]] = true
-	if pathsSetOut[pathsIn [i]] then  errorline("Path is both input and output: "..pathsIn [i])  end
-	if pathsSetIn [pathsOut[i]] then  errorline("Path is both input and output: "..pathsOut[i])  end
+	if pathsSetOut[pathsIn [i]] then  errorLine("Path is both input and output: "..pathsIn [i])  end
+	if pathsSetIn [pathsOut[i]] then  errorLine("Path is both input and output: "..pathsOut[i])  end
 end
 
 
@@ -444,7 +451,7 @@ for i, pathIn in ipairs(pathsIn) do
 		pathMeta = nil
 	end
 
-	local info = pp.processFile{
+	local info, err = pp.processFile{
 		pathIn          = pathIn,
 		pathMeta        = pathMeta,
 		pathOut         = pathOut,
@@ -485,13 +492,10 @@ for i, pathIn in ipairs(pathsIn) do
 				lua = luaModified
 
 			elseif luaModified ~= nil then
-				local err = F(
+				error(F(
 					"%s: Message handler did not return a string for 'aftermeta'. (Got %s)",
 					messageHandlerPath, type(luaModified)
-				)
-				print("Error @ "..err)
-				sendMessage("fileerror", pathIn, err)
-				os.exit(1)
+				))
 			end
 
 			return lua
@@ -502,15 +506,20 @@ for i, pathIn in ipairs(pathsIn) do
 		end,
 
 		onError = function(err)
-			sendMessage("fileerror", pathIn, err)
+			xpcall(function()
+				sendMessage("fileerror", pathIn, err)
+			end, function(err)
+				io.stderr:write("Additional error in 'fileerror' message handler...\n", pp.tryToFormatError(tostring(err)), "\n")
+			end)
 			os.exit(1)
 		end,
 	}
+	assert(info, err) -- The onError() handler above should have been called and we should have exited already.
 
-	byteCount     = byteCount+info.processedByteCount
-	lineCount     = lineCount+info.lineCount
-	lineCountCode = lineCountCode+info.linesOfCode
-	tokenCount    = tokenCount+info.tokenCount
+	byteCount     = byteCount     + info.processedByteCount
+	lineCount     = lineCount     + info.lineCount
+	lineCountCode = lineCountCode + info.linesOfCode
+	tokenCount    = tokenCount    + info.tokenCount
 
 	if processingInfoPath ~= "" then
 

preprocess.lua

@@ -216,7 +216,7 @@ local isToken, isTokenAndNotNil
 local loadLuaString, loadLuaFile
 local outputLineNumber, maybeOutputLineNumber
 local pack, unpack
-local printf, printTokens, printTraceback
+local printf, printTokens, printError, printfError, printErrorTraceback
 local pushErrorHandler, pushErrorHandlerIfOverridingDefault, popErrorHandler
 local serialize, toLua
 
@@ -256,18 +256,25 @@ function printTokens(tokens, filter)
 	end
 end
 
-function printTraceback(message, level)
-	print(message)
-	print("stack traceback:")
+function printError(s)
+	io.stderr:write(s, "\n")
+end
+function printfError(s, ...)
+	io.stderr:write(s:format(...), "\n")
+end
+
+function printErrorTraceback(message, level)
+	printError(message)
+	printError("stack traceback:")
 
 	for level = 1+(level or 1), 1/0 do
 		local info = debug.getinfo(level, "nSl")
 		if not info then  break  end
 
-		-- print(level, "source   ", info.source)
-		-- print(level, "short_src", info.short_src)
-		-- print(level, "name     ", info.name)
-		-- print(level, "what     ", info.what)
+		-- printError(level, "source   ", info.source)
+		-- printError(level, "short_src", info.short_src)
+		-- printError(level, "name     ", info.name)
+		-- printError(level, "what     ", info.what)
 
 		local where = info.source:match"^@(.+)" or info.short_src
 		local lnStr = info.currentline > 0 and ":"..info.currentline or ""
@@ -279,7 +286,7 @@ function printTraceback(message, level)
 			or info.what == "tail" and "tail call"
 			or "?"
 
-		print("\t"..where..lnStr.."  ("..name..")")
+		printError("\t"..where..lnStr.."  ("..name..")")
 	end
 end
 
@@ -288,21 +295,21 @@ end
 function error(err, level)
 	-- @Check: Should we prepend the path? And, in all or just some cases?
 	level = 1+(level or 1)
-	printTraceback(tryToFormatError(err), level)
+	printErrorTraceback(tryToFormatError(err), level)
 	currentErrorHandler(err, level)
 end
 
 function errorLine(err)
-	print(tryToFormatError(err))
+	printError(tryToFormatError(err))
 	currentErrorHandler(err, 2)
 end
 
 function errorOnLine(path, ln, agent, s, ...)
 	s = s:format(...)
 	if agent then
-		printf("Error @ %s:%d: [%s] %s\n", path, ln, agent, s)
+		printfError("Error @ %s:%d: [%s] %s\n", path, ln, agent, s)
 	else
-		printf("Error @ %s:%d: %s\n",      path, ln,        s)
+		printfError("Error @ %s:%d: %s\n",      path, ln,        s)
 	end
 	currentErrorHandler(s, 2)
 	return s
@@ -336,7 +343,7 @@ do
 		local linePre1End   = findEndOfLine(contents, linePre1Start-1)
 		local linePre2Start = findStartOfLine(contents, linePre1Start-1, false)
 		local linePre2End   = findEndOfLine(contents, linePre2Start-1)
-		-- printf("pos %d | lines %d..%d, %d..%d, %d..%d", pos, linePre2Start,linePre2End+1, linePre1Start,linePre1End+1, lineStart,lineEnd+1) -- DEBUG
+		-- printfError("pos %d | lines %d..%d, %d..%d, %d..%d", pos, linePre2Start,linePre2End+1, linePre1Start,linePre1End+1, lineStart,lineEnd+1) -- DEBUG
 
 		local contextStr = F(">\n%s%s%s>-%s^",
 			(linePre2Start < linePre1Start and linePre2Start <= linePre2End) and F("> %s\n", (contents:sub(linePre2Start, linePre2End):gsub("\t", "    "))) or "",
@@ -346,8 +353,8 @@ do
 			nil
 		)
 
-		if agent then  printf("Error @ %s:%d: [%s] %s\n%s", path, ln, agent, s, contextStr)
-		else           printf("Error @ %s:%d: %s",          path, ln,        s, contextStr)
+		if agent then  printfError("Error @ %s:%d: [%s] %s\n%s", path, ln, agent, s, contextStr)
+		else           printfError("Error @ %s:%d: %s",          path, ln,        s, contextStr)
 		end
 
 		currentErrorHandler(s, 2)
@@ -904,7 +911,8 @@ end
 
 
 
--- luaString, error = toLua( value )
+-- luaString = toLua( value )
+-- Returns nil and a message on error.
 function toLua(v)
 	local buffer = {}
 
@@ -1140,7 +1148,7 @@ metaFuncs.printf = printf
 
 -- getFileContents()
 --   Get the entire contents of a binary file or text file. Returns nil and a message on error.
---   contents, error = getFileContents( path [, isTextFile=false ] )
+--   contents = getFileContents( path [, isTextFile=false ] )
 metaFuncs.getFileContents = getFileContents
 
 -- fileExists()
@@ -1150,8 +1158,8 @@ metaFuncs.fileExists = fileExists
 
 -- toLua()
 --   Convert a value to a Lua literal. Does not work with certain types, like functions or userdata.
---   Returns nil and a message if an error ocurred.
---   luaString, error = toLua( value )
+--   Returns nil and a message on error.
+--   luaString = toLua( value )
 metaFuncs.toLua = toLua
 
 -- serialize()
@@ -1295,7 +1303,7 @@ end
 
 -- tokenize()
 --   Convert Lua code to tokens. Returns nil and a message on error. (See newToken() for token types.)
---   tokens, error = tokenize( luaString [, allowPreprocessorCode=false ] )
+--   tokens = tokenize( luaString [, allowPreprocessorCode=false ] )
 --   token = {
 --     type=tokenType, representation=representation, value=value,
 --     line=lineNumber, lineEnd=lineNumber, position=bytePosition, file=filePath,
@@ -1557,6 +1565,9 @@ function metaFuncs.concatTokens(tokens)
 	return _concatTokens(tokens)
 end
 
+-- Extra stuff used by the command line program:
+metaFuncs.tryToFormatError = tryToFormatError
+
 
 
 for k, v in pairs(metaFuncs) do  metaEnv[k] = v  end
@@ -1872,7 +1883,7 @@ local function doExpansions(tokensRaw, fileBuffers, params, stats)
 												local startTok = depthStack[#depthStack].startToken
 												errorAtToken(
 													fileBuffers, tok, nil, "Macro",
-													"Expected '%s' (to end '%s' %s) but got '%s'.",
+													"Expected '%s' (to close '%s' %s) but got '%s'.",
 													depthStack[#depthStack][2], startTok.value, getRelativeLocationText(startTok, tok), tok.value
 												)
 											end
@@ -2473,7 +2484,7 @@ local function processFileOrString(params, isFile)
 		errorToReturn = err
 
 		if not levelFromOurError then
-			printTraceback(tryToFormatError(err), 2)
+			printErrorTraceback(tryToFormatError(err), 2)
 		end
 
 		if params.onError then  params.onError(errorToReturn)  end