plugin: Add new onBufferOptionChanged callback

internal/buffer/settings.go

@@ -5,7 +5,9 @@ import (
 	"reflect"
 
 	"github.com/zyedidia/micro/v2/internal/config"
+	ulua "github.com/zyedidia/micro/v2/internal/lua"
 	"github.com/zyedidia/micro/v2/internal/screen"
+	luar "layeh.com/gopher-luar"
 )
 
 func (b *Buffer) ReloadSettings(reloadFiletype bool) {
@@ -46,7 +48,8 @@ func (b *Buffer) ReloadSettings(reloadFiletype bool) {
 }
 
 func (b *Buffer) DoSetOptionNative(option string, nativeValue interface{}) {
-	if reflect.DeepEqual(b.Settings[option], nativeValue) {
+	oldValue := b.Settings[option]
+	if reflect.DeepEqual(oldValue, nativeValue) {
 		return
 	}
 
@@ -117,6 +120,12 @@ func (b *Buffer) DoSetOptionNative(option string, nativeValue interface{}) {
 	if b.OptionCallback != nil {
 		b.OptionCallback(option, nativeValue)
 	}
+
+	if err := config.RunPluginFn("onBufferOptionChanged",
+		luar.New(ulua.L, b), luar.New(ulua.L, option),
+		luar.New(ulua.L, oldValue), luar.New(ulua.L, nativeValue)); err != nil {
+		screen.TermMessage(err)
+	}
 }
 
 func (b *Buffer) SetOptionNative(option string, nativeValue interface{}) error {

runtime/help/plugins.md

@@ -62,6 +62,10 @@ that micro defines:
 * `onBufferOpen(buf)`: runs when a buffer is opened. The input contains
    the buffer object.
 
+* `onBufferOptionChanged(buf, option, old, new)`: runs when an option of the
+   buffer has changed. The input contains the buffer object, the option name,
+   the old and the new value.
+
 * `onBufPaneOpen(bufpane)`: runs when a bufpane is opened. The input
    contains the bufpane object.
 

runtime/plugins/linter/linter.lua

@@ -66,7 +66,7 @@ function preinit()
     end
 
     makeLinter("gcc", "c", "gcc", {"-fsyntax-only", "-Wall", "-Wextra", "%f"}, "%f:%l:%c:.+: %m")
-    makeLinter("g++", "c++", "gcc", {"-fsyntax-only","-std=c++14", "-Wall", "-Wextra", "%f"}, "%f:%l:%c:.+: %m")
+    makeLinter("g++", "c++", "g++", {"-fsyntax-only","-Wall", "-Wextra", "%f"}, "%f:%l:%c:.+: %m")
     makeLinter("dmd", "d", "dmd", {"-color=off", "-o-", "-w", "-wi", "-c", "%f"}, "%f%(%l%):.+: %m")
     makeLinter("eslint", "javascript", "eslint", {"-f","compact","%f"}, "%f: line %l, col %c, %m")
     makeLinter("gobuild", "go", "go", {"build", "-o", devnull, "%d"}, "%f:%l:%c:? %m")
@@ -107,26 +107,29 @@ function contains(list, element)
     return false
 end
 
+function checkFtMatch(ft, v)
+    local ftmatch = ft == v.filetype
+    if v.domatch then
+        ftmatch = string.match(ft, v.filetype)
+    end
+
+    local hasOS = contains(v.os, runtime.GOOS)
+    if not hasOS and v.whitelist then
+        ftmatch = false
+    end
+    if hasOS and not v.whitelist then
+        ftmatch = false
+    end
+    return ftmatch
+end
+
 function runLinter(buf)
     local ft = buf:FileType()
     local file = buf.Path
     local dir = "." .. util.RuneStr(os.PathSeparator) .. filepath.Dir(file)
 
     for k, v in pairs(linters) do
-        local ftmatch = ft == v.filetype
-        if v.domatch then
-            ftmatch = string.match(ft, v.filetype)
-        end
-
-        local hasOS = contains(v.os, runtime.GOOS)
-        if not hasOS and v.whitelist then
-            ftmatch = false
-        end
-        if hasOS and not v.whitelist then
-            ftmatch = false
-        end
-
-        if ftmatch then
+        if checkFtMatch(ft, v) then
             local args = {}
             for k, arg in pairs(v.args) do
                 args[k] = arg:gsub("%%f", file):gsub("%%d", dir)
@@ -141,6 +144,19 @@ function onSave(bp)
     return true
 end
 
+function onBufferOptionChanged(buf, option, old, new)
+    if option == "filetype" then
+        if old ~= new then
+            for k, v in pairs(linters) do
+                if checkFtMatch(old, v) then
+                    buf:ClearMessages(k)
+                end
+            end
+        end
+    end
+    return true
+end
+
 function lint(buf, linter, cmd, args, errorformat, loff, coff, callback)
     buf:ClearMessages(linter)