cmd/compile: trim function name prefix from escape diagnostics

This information is redundant with the position information already
provided. Also, no other -m diagnostics print out function name.

While here, report parameter leak diagnostics against the parameter
declaration position rather than the function, and use Warnl for
"moved to heap" messages.

Test cases updated programmatically by removing the first word from
every "no match for" error emitted by run.go:

go run run.go |& \
  sed -E -n 's/^(.*):(.*): no match for `([^ ]* (.*))` in:$/\1!\2!\3!\4/p' | \
  while IFS='!' read -r fn line before after; do
    before=$(echo "$before" | sed 's/[.[\*^$()+?{|]/\\&/g')
    after=$(echo "$after" | sed -E 's/(\&|\\)/\\&/g')
    fn=$(find . -name "${fn}" | head -1)
    sed -i -E -e "${line}s/\"${before}\"/\"${after}\"/" "${fn}"
  done

Passes toolstash-check.

Change-Id: I6e02486b1409e4a8dbb2b9b816d22095835426b5
Reviewed-on: https://go-review.googlesource.com/c/go/+/195040
Run-TryBot: Matthew Dempsky <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>
Reviewed-by: Cherry Zhang <[email protected]>

Author: mdempsky

src/cmd/compile/internal/gc/esc.go

@@ -392,7 +392,7 @@ func moveToHeap(n *Node) {
 	n.Name.Param.Heapaddr = heapaddr
 	n.Esc = EscHeap
 	if Debug['m'] != 0 {
-		fmt.Printf("%v: moved to heap: %v\n", n.Line(), n)
+		Warnl(n.Pos, "moved to heap: %v", n)
 	}
 }
 
@@ -422,7 +422,7 @@ func (e *Escape) paramTag(fn *Node, narg int, f *types.Field) string {
 		// argument and pass those annotations along to importing code.
 		if f.Type.Etype == TUINTPTR {
 			if Debug['m'] != 0 {
-				Warnl(fn.Pos, "%v assuming %v is unsafe uintptr", funcSym(fn), name())
+				Warnl(f.Pos, "assuming %v is unsafe uintptr", name())
 			}
 			return unsafeUintptrTag
 		}
@@ -435,28 +435,28 @@ func (e *Escape) paramTag(fn *Node, narg int, f *types.Field) string {
 		// //go:noescape is given before the declaration.
 		if fn.Noescape() {
 			if Debug['m'] != 0 && f.Sym != nil {
-				Warnl(fn.Pos, "%S %v does not escape", funcSym(fn), name())
+				Warnl(f.Pos, "%v does not escape", name())
 			}
 			return mktag(EscNone)
 		}
 
 		if Debug['m'] != 0 && f.Sym != nil {
-			Warnl(fn.Pos, "leaking param: %v", name())
+			Warnl(f.Pos, "leaking param: %v", name())
 		}
 		return mktag(EscHeap)
 	}
 
 	if fn.Func.Pragma&UintptrEscapes != 0 {
 		if f.Type.Etype == TUINTPTR {
 			if Debug['m'] != 0 {
-				Warnl(fn.Pos, "%v marking %v as escaping uintptr", funcSym(fn), name())
+				Warnl(f.Pos, "marking %v as escaping uintptr", name())
 			}
 			return uintptrEscapesTag
 		}
 		if f.IsDDD() && f.Type.Elem().Etype == TUINTPTR {
 			// final argument is ...uintptr.
 			if Debug['m'] != 0 {
-				Warnl(fn.Pos, "%v marking %v as escaping ...uintptr", funcSym(fn), name())
+				Warnl(f.Pos, "marking %v as escaping ...uintptr", name())
 			}
 			return uintptrEscapesTag
 		}
@@ -477,17 +477,17 @@ func (e *Escape) paramTag(fn *Node, narg int, f *types.Field) string {
 
 	if Debug['m'] != 0 && !loc.escapes {
 		if esc == EscNone {
-			Warnl(n.Pos, "%S %S does not escape", funcSym(fn), n)
+			Warnl(f.Pos, "%v does not escape", name())
 		} else if esc == EscHeap {
-			Warnl(n.Pos, "leaking param: %S", n)
+			Warnl(f.Pos, "leaking param: %v", name())
 		} else {
 			if esc&EscContentEscapes != 0 {
-				Warnl(n.Pos, "leaking param content: %S", n)
+				Warnl(f.Pos, "leaking param content: %v", name())
 			}
 			for i := 0; i < numEscReturns; i++ {
 				if x := getEscReturn(esc, i); x >= 0 {
-					res := n.Name.Curfn.Type.Results().Field(i).Sym
-					Warnl(n.Pos, "leaking param: %S to result %v level=%d", n, res, x)
+					res := fn.Type.Results().Field(i).Sym
+					Warnl(f.Pos, "leaking param: %v to result %v level=%d", name(), res, x)
 				}
 			}
 		}

src/cmd/compile/internal/gc/escape.go

@@ -1289,7 +1289,7 @@ func (e *Escape) finish(fns []*Node) {
 			addrescapes(n)
 		} else {
 			if Debug['m'] != 0 && n.Op != ONAME && n.Op != OTYPESW && n.Op != ORANGE && n.Op != ODEFER {
-				Warnl(n.Pos, "%S %S does not escape", funcSym(loc.curfn), n)
+				Warnl(n.Pos, "%S does not escape", n)
 			}
 			n.Esc = EscNone
 			if loc.transient {