From 2bd95bd13bbf56cd674fa890e1d91e9bf3fd3c93 Mon Sep 17 00:00:00 2001
From: Alex Elder <elder@linaro.org>
Date: Fri, 1 Oct 2021 18:23:37 -0500
Subject: [PATCH] parser: introduce token_name()

Create a new function token_name() that returns a printable string
representing a given token id.  Use it to simplify token_expect(),
eliminating its switch statement.

Signed-off-by: Alex Elder <elder@linaro.org>
Message-Id: <20211001232338.769309-34-elder@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
 parser.c | 58 +++++++++++++++++++++++++++++++++-----------------------
 1 file changed, 34 insertions(+), 24 deletions(-)

diff --git a/parser.c b/parser.c
index 7c47cf5..8de8555 100644
--- a/parser.c
+++ b/parser.c
@@ -129,6 +129,30 @@ static struct symbol *symbol_find(const char *name)
 	return NULL;
 }
 
+static const char *token_name(enum token_id token_id)
+{
+	struct symbol *sym;
+
+	switch (token_id) {
+	case TOK_ID:
+		return "identifier";
+	case TOK_MESSAGE:
+		return "(message)";
+	case TOK_NUM:
+		return "(number)";
+	case TOK_EOF:
+		return "(EOF)";
+	default:
+		break;
+	}
+
+	list_for_each_entry(sym, &symbols, node)
+		if (token_id == sym->token_id)
+			return sym->name;
+
+	return NULL;
+}
+
 static bool symbol_valid(const char *name)
 {
 	const char *p = name;
@@ -355,30 +379,16 @@ static bool token_accept(enum token_id token_id, struct token *tok)
 
 static void token_expect(enum token_id token_id, struct token *tok)
 {
-	if (!token_accept(token_id, tok)) {
-		switch (token_id) {
-		case TOK_CONST:
-			yyerror("expected const");
-		case TOK_ID:
-			yyerror("expected identifier");
-		case TOK_MESSAGE:
-			yyerror("expected message");
-		case TOK_NUM:
-			yyerror("expected num");
-		case TOK_PACKAGE:
-			yyerror("expected package");
-		case TOK_STRUCT:
-			yyerror("expected struct");
-		case TOK_TYPE:
-			yyerror("expected type");
-		case TOK_REQUIRED:
-			yyerror("expected required");
-		case TOK_OPTIONAL:
-			yyerror("expected optional");
-		default:
-			yyerror("expected '%c'", token_id);
-		}
-	}
+	const char *want;
+
+	if (token_accept(token_id, tok))
+		return;
+
+	want = token_name(token_id);
+	if (want)
+		yyerror("expected %s", want);
+	else
+		yyerror("expected '%c'", token_id);
 }
 
 static void qmi_package_parse(void)