From ca7d50a3fef8d4f2bfa199a0e334217978fd6483 Mon Sep 17 00:00:00 2001
From: Michael Forney <mforney@mforney.org>
Date: Mon, 9 Mar 2020 02:02:58 -0700
Subject: token: Add tokencheck utility function

This function is like expect(), but operates on a specific token
and does not read the following token.
---
 cc.h    |  2 +-
 pp.c    |  9 ++-------
 token.c | 15 ++++++++++++++-
 3 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/cc.h b/cc.h
index 96dde5e..05459e1 100644
--- a/cc.h
+++ b/cc.h
@@ -371,7 +371,7 @@ extern struct token tok;
 extern const char *tokstr[];
 
 void tokenprint(const struct token *);
-void tokendesc(char *, size_t, enum tokenkind, const char *);
+char *tokencheck(const struct token *, enum tokenkind, const char *);
 _Noreturn void error(const struct location *, const char *, ...);
 
 /* scan */
diff --git a/pp.c b/pp.c
index e62845f..4831cd6 100644
--- a/pp.c
+++ b/pp.c
@@ -133,14 +133,9 @@ peek(int kind)
 char *
 expect(enum tokenkind kind, const char *msg)
 {
-	char *lit, want[64], got[64];
+	char *lit;
 
-	if (tok.kind != kind) {
-		tokendesc(want, sizeof(want), kind, NULL);
-		tokendesc(got, sizeof(got), tok.kind, tok.lit);
-		error(&tok.loc, "expected %s %s, saw %s", want, msg, got);
-	}
-	lit = tok.lit;
+	lit = tokencheck(&tok, kind, msg);
 	next();
 
 	return lit;
diff --git a/token.c b/token.c
index 2397756..6d4484d 100644
--- a/token.c
+++ b/token.c
@@ -136,7 +136,7 @@ tokenprint(const struct token *t)
 	fputs(str, stdout);
 }
 
-void
+static void
 tokendesc(char *buf, size_t len, enum tokenkind kind, const char *lit)
 {
 	const char *class;
@@ -162,6 +162,19 @@ tokendesc(char *buf, size_t len, enum tokenkind kind, const char *lit)
 		snprintf(buf, len, "<unknown>");
 }
 
+char *
+tokencheck(const struct token *t, enum tokenkind kind, const char *msg)
+{
+	char want[64], got[64];
+
+	if (t->kind != kind) {
+		tokendesc(want, sizeof(want), kind, NULL);
+		tokendesc(got, sizeof(got), t->kind, t->lit);
+		error(&t->loc, "expected %s %s, saw %s", want, msg, got);
+	}
+	return t->lit;
+}
+
 _Noreturn void error(const struct location *loc, const char *fmt, ...)
 {
 	va_list ap;
-- 
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