cmd/go: respect -short flag when documenting individual symbols

The -short flag was ignored when documenting individual symbols (functions,
types, or variables) with "go doc -short package.symbol". This change adds
short flag checks to symbolDoc, typeDoc, and valueDoc functions.

Fixes #77192

Change-Id: I66935ceb5ffb5836dbd3a2fd2c7a33dd31e82001
Reviewed-on: https://go-review.googlesource.com/c/go/+/764101
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Michael Matloob <matloob@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Matloob <matloob@golang.org>

2 files changed, 29 insertions, 2 deletions

diff --git a/src/cmd/go/internal/doc/pkg.go b/src/cmd/go/internal/doc/pkg.go
index bd4a2f6e4f..e35ad38ebc 100644
--- a/src/cmd/go/internal/doc/pkg.go
+++ b/src/cmd/go/internal/doc/pkg.go
@@ -808,9 +808,14 @@ func (pkg *Package) symbolDoc(symbol string) bool {
 	for _, fun := range pkg.findFuncs(symbol) {
 		// Symbol is a function.
 		decl := fun.Decl
+		found = true
+		if short {
+			pkg.Printf("%s\n", pkg.oneLineNode(decl))
+			pkg.exampleSummary(fun.Examples, false)
+			continue
+		}
 		pkg.emit(fun.Doc, decl)
 		pkg.exampleSummary(fun.Examples, true)
-		found = true
 	}
 	for _, ex := range pkg.findExamples(symbol) {
 		pkg.emitExample(ex)
@@ -886,8 +891,12 @@ func (pkg *Package) valueDoc(value *doc.Value, printed map[*ast.GenDecl]bool) {
 		return
 	}
 	value.Decl.Specs = specs
-	pkg.emit(value.Doc, value.Decl)
 	printed[value.Decl] = true
+	if short {
+		pkg.Printf("%s\n", pkg.oneLineNode(value.Decl))
+		return
+	}
+	pkg.emit(value.Doc, value.Decl)
 }
 
 // typeDoc prints the docs for a type, including constructors and other items
@@ -900,6 +909,10 @@ func (pkg *Package) typeDoc(typ *doc.Type) {
 	if len(decl.Specs) > 1 {
 		decl.Specs = []ast.Spec{spec}
 	}
+	if short {
+		pkg.Printf("%s\n", pkg.oneLineNode(spec))
+		return
+	}
 	pkg.emit(typ.Doc, decl)
 	pkg.newlines(2)
 	// Show associated methods, constants, etc.
diff --git a/src/cmd/go/testdata/script/mod_doc.txt b/src/cmd/go/testdata/script/mod_doc.txt
index cbfd9336dd..32edb4852a 100644
--- a/src/cmd/go/testdata/script/mod_doc.txt
+++ b/src/cmd/go/testdata/script/mod_doc.txt
@@ -8,6 +8,13 @@ env GOFLAGS=-mod=mod
 go doc y
 stdout 'Package y is.*alphabet'
 stdout 'import "x/y"'
+go doc -short y.Yell
+stdout '^func Yell\(\) string$'
+! stdout 'Yell returns the final letter'
+go doc -short y.Letter
+stdout '^const Letter = "z"$'
+go doc -short y.Alphabet
+stdout '^type Alphabet struct\{\}$'
 go doc x/y
 stdout 'Package y is.*alphabet'
 ! go doc quote.Hello
@@ -75,6 +82,13 @@ require rsc.io/quote v1.5.2
 // Package y is the next to last package of the alphabet.
 package y
 
+// Yell returns the final letter of the alphabet.
+func Yell() string { return "z" }
+
+const Letter = "z"
+
+type Alphabet struct{}
+
 -- x.go --
 package x