List warnings & hints via --(hints|warnings):list

Hints and warnings can be now listed using --warnings:list and --hints:list
printing names and checkboxes indicating which of these are enabled.

compiler/commands.nim

@@ -128,6 +128,18 @@ proc processOnOffSwitch(op: TOptions, arg: string, pass: TCmdLinePass,
   of wOff: gOptions = gOptions - op
   else: localError(info, errOnOrOffExpectedButXFound, arg)
 
+proc processOnOffSwitchOrList(op: TOptions, arg: string, pass: TCmdLinePass,
+                              info: TLineInfo): bool =
+  result = false
+  case whichKeyword(arg)
+  of wOn: gOptions = gOptions + op
+  of wOff: gOptions = gOptions - op
+  else:
+    if arg == "list":
+      result = true
+    else:
+      localError(info, errOnOffOrListExpectedButXFound, arg)
+
 proc processOnOffSwitchG(op: TGlobalOptions, arg: string, pass: TCmdLinePass,
                          info: TLineInfo) =
   case whichKeyword(arg)
@@ -382,10 +394,12 @@ proc processSwitch(switch, arg: string, pass: TCmdLinePass, info: TLineInfo) =
       gSelectedGC = gcNone
       defineSymbol("nogc")
     else: localError(info, errNoneBoehmRefcExpectedButXFound, arg)
-  of "warnings", "w": processOnOffSwitch({optWarns}, arg, pass, info)
+  of "warnings", "w":
+    if processOnOffSwitchOrList({optWarns}, arg, pass, info): listWarnings()
   of "warning": processSpecificNote(arg, wWarning, pass, info, switch)
   of "hint": processSpecificNote(arg, wHint, pass, info, switch)
-  of "hints": processOnOffSwitch({optHints}, arg, pass, info)
+  of "hints":
+    if processOnOffSwitchOrList({optHints}, arg, pass, info): listHints()
   of "threadanalysis": processOnOffSwitchG({optThreadAnalysis}, arg, pass, info)
   of "stacktrace": processOnOffSwitch({optStackTrace}, arg, pass, info)
   of "linetrace": processOnOffSwitch({optLineTrace}, arg, pass, info)

compiler/msgs.nim

@@ -30,7 +30,8 @@ type
     errStmtInvalidAfterReturn, errStmtExpected, errInvalidLabel,
     errInvalidCmdLineOption, errCmdLineArgExpected, errCmdLineNoArgExpected,
     errInvalidVarSubstitution, errUnknownVar, errUnknownCcompiler,
-    errOnOrOffExpectedButXFound, errNoneBoehmRefcExpectedButXFound,
+    errOnOrOffExpectedButXFound, errOnOffOrListExpectedButXFound,
+    errNoneBoehmRefcExpectedButXFound,
     errNoneSpeedOrSizeExpectedButXFound, errGuiConsoleOrLibExpectedButXFound,
     errUnknownOS, errUnknownCPU, errGenOutExpectedButXFound,
     errArgsNeedRunOption, errInvalidMultipleAsgn, errColonOrEqualsExpected,
@@ -181,6 +182,7 @@ const
     errUnknownVar: "unknown variable: \'$1\'",
     errUnknownCcompiler: "unknown C compiler: \'$1\'",
     errOnOrOffExpectedButXFound: "\'on\' or \'off\' expected, but \'$1\' found",
+    errOnOffOrListExpectedButXFound: "\'on\', \'off\' or \'list\' expected, but \'$1\' found",
     errNoneBoehmRefcExpectedButXFound: "'none', 'boehm' or 'refc' expected, but '$1' found",
     errNoneSpeedOrSizeExpectedButXFound: "'none', 'speed' or 'size' expected, but '$1' found",
     errGuiConsoleOrLibExpectedButXFound: "'gui', 'console' or 'lib' expected, but '$1' found",
@@ -973,6 +975,22 @@ ropes.errorHandler = proc (err: RopesError, msg: string, useWarning: bool) =
   of rCannotOpenFile:
     rawMessage(if useWarning: warnCannotOpenFile else: errCannotOpenFile, msg)
 
+proc listWarnings*() =
+  msgWriteln("Warnings:")
+  for warn in warnMin..warnMax:
+    msgWriteln("  [$1] $2" % [
+      if warn in gNotes: "x" else: " ",
+      msgs.WarningsToStr[ord(warn) - ord(warnMin)]
+    ])
+
+proc listHints*() =
+  msgWriteln("Hints:")
+  for hint in hintMin..hintMax:
+    msgWriteln("  [$1] $2" % [
+      if hint in gNotes: "x" else: " ",
+      msgs.HintsToStr[ord(hint) - ord(hintMin)]
+    ])
+
 # enable colors by default on terminals
 if terminal.isatty(stdout):
   incl(gGlobalOptions, optUseColors)

doc/advopt.txt

@@ -18,9 +18,10 @@ Advanced options:
   --stdout                  output to stdout
   --colors:on|off           turn compiler messages coloring on|off
   --listFullPaths           list full paths in messages
-  -w, --warnings:on|off     turn all warnings on|off
+  -w:on|off|list, --warnings:on|off|list
+                            turn all warnings on|off or list all available
   --warning[X]:on|off       turn specific warning X on|off
-  --hints:on|off            turn all hints on|off
+  --hints:on|off|list       turn all hints on|off or list all available
   --hint[X]:on|off          turn specific hint X on|off
   --lib:PATH                set the system library path
   --import:PATH             add an automatically imported module