gopls: add long forms for all the 1 rune flags

Also modify the printing so that it groups flags that work on the same
value into the same flag usage line.

For #41860

Change-Id: I97fdd3e64f24b22c15780b636789f512eb46ed2c
Reviewed-on: https://go-review.googlesource.com/c/tools/+/367838
Trust: Ian Cottrell <iancottrell@google.com>
Run-TryBot: Ian Cottrell <iancottrell@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>

internal/lsp/cmd/cmd.go

@@ -16,6 +16,7 @@ import (
 	"log"
 	"os"
 	"reflect"
+	"sort"
 	"strings"
 	"sync"
 	"text/tabwriter"
@@ -63,10 +64,10 @@ type Application struct {
 	Remote string `flag:"remote" help:"forward all commands to a remote lsp specified by this flag. With no special prefix, this is assumed to be a TCP address. If prefixed by 'unix;', the subsequent address is assumed to be a unix domain socket. If 'auto', or prefixed by 'auto;', the remote address is automatically resolved based on the executing environment."`
 
 	// Verbose enables verbose logging.
-	Verbose bool `flag:"v" help:"verbose output"`
+	Verbose bool `flag:"v,verbose" help:"verbose output"`
 
 	// VeryVerbose enables a higher level of verbosity in logging output.
-	VeryVerbose bool `flag:"vv" help:"very verbose output"`
+	VeryVerbose bool `flag:"vv,veryverbose" help:"very verbose output"`
 
 	// Control ocagent export of telemetry
 	OCAgent string `flag:"ocagent" help:"the address of the ocagent (e.g. http://localhost:55678), or off"`
@@ -138,9 +139,32 @@ command:
 
 // this is a slightly modified version of flag.PrintDefaults to give us control
 func printFlagDefaults(s *flag.FlagSet) {
+	var flags [][]*flag.Flag
+	seen := map[flag.Value]int{}
 	s.VisitAll(func(f *flag.Flag) {
+		if i, ok := seen[f.Value]; !ok {
+			seen[f.Value] = len(flags)
+			flags = append(flags, []*flag.Flag{f})
+		} else {
+			flags[i] = append(flags[i], f)
+		}
+	})
+	for _, entry := range flags {
+		sort.SliceStable(entry, func(i, j int) bool {
+			return len(entry[i].Name) < len(entry[j].Name)
+		})
 		var b strings.Builder
-		fmt.Fprintf(&b, "  -%s", f.Name) // Two spaces before -; see next two comments.
+		for i, f := range entry {
+			switch i {
+			case 0:
+				b.WriteString("  -")
+			default:
+				b.WriteString(",-")
+			}
+			b.WriteString(f.Name)
+		}
+
+		f := entry[0]
 		name, usage := flag.UnquoteUsage(f)
 		if len(name) > 0 {
 			b.WriteString(" ")
@@ -164,7 +188,7 @@ func printFlagDefaults(s *flag.FlagSet) {
 			}
 		}
 		fmt.Fprint(s.Output(), b.String(), "\n")
-	})
+	}
 }
 
 // isZeroValue is copied from the flags package

internal/lsp/cmd/format.go

@@ -19,9 +19,9 @@ import (
 
 // format implements the format verb for gopls.
 type format struct {
-	Diff  bool `flag:"d" help:"display diffs instead of rewriting files"`
-	Write bool `flag:"w" help:"write result to (source) file instead of stdout"`
-	List  bool `flag:"l" help:"list files whose formatting differs from gofmt's"`
+	Diff  bool `flag:"d,diff" help:"display diffs instead of rewriting files"`
+	Write bool `flag:"w,write" help:"write result to (source) file instead of stdout"`
+	List  bool `flag:"l,list" help:"list files whose formatting differs from gofmt's"`
 
 	app *Application
 }

internal/lsp/cmd/imports.go

@@ -20,8 +20,8 @@ import (
 
 // imports implements the import verb for gopls.
 type imports struct {
-	Diff  bool `flag:"d" help:"display diffs instead of rewriting files"`
-	Write bool `flag:"w" help:"write result to (source) file instead of stdout"`
+	Diff  bool `flag:"d,diff" help:"display diffs instead of rewriting files"`
+	Write bool `flag:"w,write" help:"write result to (source) file instead of stdout"`
 
 	app *Application
 }

internal/lsp/cmd/references.go

@@ -17,7 +17,7 @@ import (
 
 // references implements the references verb for gopls
 type references struct {
-	IncludeDeclaration bool `flag:"d" help:"include the declaration of the specified identifier in the results"`
+	IncludeDeclaration bool `flag:"d,declaration" help:"include the declaration of the specified identifier in the results"`
 
 	app *Application
 }

internal/lsp/cmd/rename.go

@@ -23,8 +23,8 @@ import (
 
 // rename implements the rename verb for gopls.
 type rename struct {
-	Diff     bool `flag:"d" help:"display diffs instead of rewriting files"`
-	Write    bool `flag:"w" help:"write result to (source) file instead of stdout"`
+	Diff     bool `flag:"d,diff" help:"display diffs instead of rewriting files"`
+	Write    bool `flag:"w,write" help:"write result to (source) file instead of stdout"`
 	Preserve bool `flag:"preserve" help:"preserve original files"`
 
 	app *Application

internal/lsp/cmd/suggested_fix.go

@@ -20,9 +20,9 @@ import (
 
 // suggestedFix implements the fix verb for gopls.
 type suggestedFix struct {
-	Diff  bool `flag:"d" help:"display diffs instead of rewriting files"`
-	Write bool `flag:"w" help:"write result to (source) file instead of stdout"`
-	All   bool `flag:"a" help:"apply all fixes, not just preferred fixes"`
+	Diff  bool `flag:"d,diff" help:"display diffs instead of rewriting files"`
+	Write bool `flag:"w,write" help:"write result to (source) file instead of stdout"`
+	All   bool `flag:"a,all" help:"apply all fixes, not just preferred fixes"`
 
 	app *Application
 }

internal/lsp/cmd/usage/fix.hlp

@@ -7,6 +7,9 @@ Example: apply suggested fixes for this file
 	$ gopls fix -w internal/lsp/cmd/check.go
 
 fix-flags:
-  -a	apply all fixes, not just preferred fixes
-  -d	display diffs instead of rewriting files
-  -w	write result to (source) file instead of stdout
+  -a,-all
+    	apply all fixes, not just preferred fixes
+  -d,-diff
+    	display diffs instead of rewriting files
+  -w,-write
+    	write result to (source) file instead of stdout

internal/lsp/cmd/usage/format.hlp

@@ -10,6 +10,9 @@ Example: reformat this file:
 	$ gopls format -w internal/lsp/cmd/check.go
 
 format-flags:
-  -d	display diffs instead of rewriting files
-  -l	list files whose formatting differs from gofmt's
-  -w	write result to (source) file instead of stdout
+  -d,-diff
+    	display diffs instead of rewriting files
+  -l,-list
+    	list files whose formatting differs from gofmt's
+  -w,-write
+    	write result to (source) file instead of stdout

internal/lsp/cmd/usage/imports.hlp

@@ -8,5 +8,7 @@ Example: update imports statements in a file:
 	$ gopls imports -w internal/lsp/cmd/check.go
 
 imports-flags:
-  -d	display diffs instead of rewriting files
-  -w	write result to (source) file instead of stdout
+  -d,-diff
+    	display diffs instead of rewriting files
+  -w,-write
+    	write result to (source) file instead of stdout

internal/lsp/cmd/usage/references.hlp

@@ -10,4 +10,5 @@ Example:
 	$ gopls references helper/helper.go:#53
 
 references-flags:
-  -d	include the declaration of the specified identifier in the results
+  -d,-declaration
+    	include the declaration of the specified identifier in the results

internal/lsp/cmd/usage/rename.hlp

@@ -10,7 +10,9 @@ Example:
 	$ gopls rename helper/helper.go:#53 Foo
 
 rename-flags:
-  -d	display diffs instead of rewriting files
+  -d,-diff
+    	display diffs instead of rewriting files
   -preserve
     	preserve original files
-  -w	write result to (source) file instead of stdout
+  -w,-write
+    	write result to (source) file instead of stdout

internal/lsp/cmd/usage/usage.hlp

@@ -69,6 +69,7 @@ flags:
     	when used with -remote=auto, the -logfile value used to start the daemon
   -rpc.trace
     	print the full rpc trace in lsp inspector format
-  -v	verbose output
-  -vv
+  -v,-verbose
+    	verbose output
+  -vv,-veryverbose
     	very verbose output

internal/tool/tool.go

@@ -15,6 +15,7 @@ import (
 	"runtime"
 	"runtime/pprof"
 	"runtime/trace"
+	"strings"
 	"time"
 )
 
@@ -28,8 +29,9 @@ import (
 //       (&Application{}).Main("myapp", "non-flag-command-line-arg-help", os.Args[1:])
 //     }
 // It recursively scans the application object for fields with a tag containing
-//     `flag:"flagname" help:"short help text"``
-// uses all those fields to build command line flags.
+//     `flag:"flagnames" help:"short help text"``
+// uses all those fields to build command line flags. It will split flagnames on
+// commas and add a flag per name.
 // It expects the Application type to have a method
 //     Run(context.Context, args...string) error
 // which it invokes only after all command line flag processing has been finished.
@@ -168,30 +170,44 @@ func addFlags(f *flag.FlagSet, field reflect.StructField, value reflect.Value) *
 		return nil
 	}
 	// now see if is actually a flag
-	flagName, isFlag := field.Tag.Lookup("flag")
+	flagNames, isFlag := field.Tag.Lookup("flag")
 	help := field.Tag.Get("help")
-	if !isFlag {
-		// not a flag, but it might be a struct with flags in it
-		value = resolve(value.Elem())
-		if value.Kind() != reflect.Struct {
-			return nil
-		}
-		p, _ := value.Addr().Interface().(*Profile)
-		// go through all the fields of the struct
-		for i := 0; i < value.Type().NumField(); i++ {
-			child := value.Type().Field(i)
-			v := value.Field(i)
-			// make sure we have a pointer
-			if v.Kind() != reflect.Ptr {
-				v = v.Addr()
-			}
-			// check if that field is a flag or contains flags
-			if fp := addFlags(f, child, v); fp != nil {
-				p = fp
+	if isFlag {
+		nameList := strings.Split(flagNames, ",")
+		// add the main flag
+		addFlag(f, value, nameList[0], help)
+		if len(nameList) > 1 {
+			// and now add any aliases using the same flag value
+			fv := f.Lookup(nameList[0]).Value
+			for _, flagName := range nameList[1:] {
+				f.Var(fv, flagName, help)
 			}
 		}
-		return p
+		return nil
 	}
+	// not a flag, but it might be a struct with flags in it
+	value = resolve(value.Elem())
+	if value.Kind() != reflect.Struct {
+		return nil
+	}
+	p, _ := value.Addr().Interface().(*Profile)
+	// go through all the fields of the struct
+	for i := 0; i < value.Type().NumField(); i++ {
+		child := value.Type().Field(i)
+		v := value.Field(i)
+		// make sure we have a pointer
+		if v.Kind() != reflect.Ptr {
+			v = v.Addr()
+		}
+		// check if that field is a flag or contains flags
+		if fp := addFlags(f, child, v); fp != nil {
+			p = fp
+		}
+	}
+	return p
+}
+
+func addFlag(f *flag.FlagSet, value reflect.Value, flagName string, help string) {
 	switch v := value.Interface().(type) {
 	case flag.Value:
 		f.Var(v, flagName, help)
@@ -214,7 +230,6 @@ func addFlags(f *flag.FlagSet, field reflect.StructField, value reflect.Value) *
 	default:
 		log.Fatalf("Cannot understand flag of type %T", v)
 	}
-	return nil
 }
 
 func resolve(v reflect.Value) reflect.Value {