all: add more uses of stringer

By grepping for ]string{$, one can find many manual implementations of
stringer. The debug/dwarf ones needed the new -trimprefix flag, too.

html/template was fairly simple, just implementing the fallback as
stringer would. The changes there are trivial.

The ones in debug/dwarf needed a bit of extra logic since the GoString
wants to use its own format, depending on whether or not the value is
one of the known constants.

Change-Id: I501ea7deaa538fa425c8e9c2bb895f480169273f
Reviewed-on: https://go-review.googlesource.com/77253
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

2 files changed, 18 insertions, 16 deletions

diff --git a/src/html/template/attr_string.go b/src/html/template/attr_string.go
new file mode 100644
index 0000000000..babe70c08b
--- /dev/null
+++ b/src/html/template/attr_string.go
@@ -0,0 +1,16 @@
+// Code generated by "stringer -type attr"; DO NOT EDIT.
+
+package template
+
+import "strconv"
+
+const _attr_name = "attrNoneattrScriptattrScriptTypeattrStyleattrURLattrSrcset"
+
+var _attr_index = [...]uint8{0, 8, 18, 32, 41, 48, 58}
+
+func (i attr) String() string {
+	if i >= attr(len(_attr_index)-1) {
+		return "attr(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _attr_name[_attr_index[i]:_attr_index[i+1]]
+}
diff --git a/src/html/template/context.go b/src/html/template/context.go
index 50730d3f2b..7e28cf47e2 100644
--- a/src/html/template/context.go
+++ b/src/html/template/context.go
@@ -314,6 +314,8 @@ func (e element) String() string {
 	return fmt.Sprintf("illegal element %d", int(e))
 }
 
+//go:generate stringer -type attr
+
 // attr identifies the current HTML attribute when inside the attribute,
 // that is, starting from stateAttrName until stateTag/stateText (exclusive).
 type attr uint8
@@ -332,19 +334,3 @@ const (
 	// attrSrcset corresponds to a srcset attribute.
 	attrSrcset
 )
-
-var attrNames = [...]string{
-	attrNone:       "attrNone",
-	attrScript:     "attrScript",
-	attrScriptType: "attrScriptType",
-	attrStyle:      "attrStyle",
-	attrURL:        "attrURL",
-	attrSrcset:     "attrSrcset",
-}
-
-func (a attr) String() string {
-	if int(a) < len(attrNames) {
-		return attrNames[a]
-	}
-	return fmt.Sprintf("illegal attr %d", int(a))
-}