From 8d182b04ed04378877e743535658be41a05aef74 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E5=8D=9C=E9=83=A8=E6=98=8C=E5=B9=B3?=
 <shyouhei@ruby-lang.org>
Date: Thu, 11 Jun 2020 13:23:56 +0900
Subject: [PATCH] builtin_lookup: do not goto into a branch

I'm not necessarily against every goto in general, but jumping into a
branch is definitely a bad idea.  Better refactor.
---
 builtin.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/builtin.c b/builtin.c
index 6de77228d0..7c3653dab7 100644
--- a/builtin.c
+++ b/builtin.c
@@ -12,27 +12,24 @@
 
 #include "builtin_binary.inc"
 
+static const unsigned char *
+bin4feature(const struct builtin_binary *bb, const char *feature, size_t *psize)
+{
+    *psize = bb->bin_size;
+    return strcmp(bb->feature, feature) ? NULL : bb->bin;
+}
+
 static const unsigned char*
 builtin_lookup(const char *feature, size_t *psize)
 {
     static int index = 0;
-    int i = index++;
+    const unsigned char *bin = bin4feature(&builtin_binary[index++], feature, psize);
 
     // usually, `builtin_binary` order is loading order at miniruby.
-    if (LIKELY(strcmp(builtin_binary[i].feature, feature) == 0)) {
-      found:
-        *psize = builtin_binary[i].bin_size;
-        return builtin_binary[i].bin;
+    for (const struct builtin_binary *bb = &builtin_binary[0]; bb->feature &&! bin; bb++) {
+        bin = bin4feature(bb++, feature, psize);
     }
-    else {
-        if (0) fprintf(stderr, "builtin_lookup: cached index miss (index:%d)\n", i);
-        for (i=0; i<BUILTIN_BINARY_SIZE; i++) {
-            if (strcmp(builtin_binary[i].feature, feature) == 0) {
-                goto found;
-            }
-        }
-    }
-    rb_bug("builtin_lookup: can not find %s\n", feature);
+    return bin;
 }
 
 void
@@ -41,6 +38,9 @@ rb_load_with_builtin_functions(const char *feature_name, const struct rb_builtin
     // search binary
     size_t size;
     const unsigned char *bin = builtin_lookup(feature_name, &size);
+    if (! bin) {
+        rb_bug("builtin_lookup: can not find %s\n", feature_name);
+    }
 
     // load binary
     rb_vm_t *vm = GET_VM();