feat(lint): abi0 register-args rule and go-asm width model

lint/abi.go

@@ -25,18 +25,53 @@ func abiExpectedArgSize(doc string) (int64, bool) {
 	if sig == "" {
 		return 0, false
 	}
-	fset := token.NewFileSet()
-	f, err := parser.ParseFile(fset, "sig.go", "package p\n"+sig+" {}\n", 0)
-	if err != nil || len(f.Decls) == 0 {
-		return 0, false
-	}
-	fn, ok := f.Decls[0].(*ast.FuncDecl)
-	if !ok || fn.Type == nil {
+	fn, ok := parseSignature(sig)
+	if !ok || fn == nil {
 		return 0, false
 	}
 	return signatureSize(fn.Type.Params, fn.Type.Results)
 }
 
+// abiParamNames returns the parameter names declared by the `// func …`
+// signature in a doc comment, in declaration order.  Shared names
+// (`left, right []int32`) expand to one entry per name; a nameless parameter
+// (`[]int32`) contributes an empty placeholder so offsets stay aligned.
+func abiParamNames(doc string) ([]string, bool) {
+	sig := signatureLine(doc)
+	if sig == "" {
+		return nil, false
+	}
+	fn, ok := parseSignature(sig)
+	if !ok || fn == nil || fn.Type.Params == nil {
+		return nil, false
+	}
+	var names []string
+	for _, field := range fn.Type.Params.List {
+		if len(field.Names) == 0 {
+			names = append(names, "")
+			continue
+		}
+		for _, n := range field.Names {
+			names = append(names, n.Name)
+		}
+	}
+	return names, true
+}
+
+// parseSignature parses a `func …` line into a Go FuncDecl.
+func parseSignature(sig string) (*ast.FuncDecl, bool) {
+	fset := token.NewFileSet()
+	f, err := parser.ParseFile(fset, "sig.go", "package p\n"+sig+" {}\n", 0)
+	if err != nil || len(f.Decls) == 0 {
+		return nil, false
+	}
+	fn, ok := f.Decls[0].(*ast.FuncDecl)
+	if !ok || fn.Type == nil {
+		return nil, false
+	}
+	return fn, true
+}
+
 // signatureLine returns the first `func …` line from a doc comment, trimmed.
 func signatureLine(doc string) string {
 	for _, line := range strings.Split(doc, "\n") {