From 56f2447e5a9b8f28a4ca72a9290e8e2eac86bea3 Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Thu, 28 Mar 2013 15:55:05 +0000
Subject: [PATCH] mkmf.rb: force refererence in MAIN_DOES_NOTHING

* lib/mkmf.rb (MAIN_DOES_NOTHING): ensure symbols for tests to be
  preserved.  [ruby-core:53745] [Bug #8169]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39989 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog   |  5 +++++
 lib/mkmf.rb | 11 +++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index a0d4c16bc4..f6b6e3fa80 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Mar 29 00:54:54 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* lib/mkmf.rb (MAIN_DOES_NOTHING): ensure symbols for tests to be
+	  preserved.  [ruby-core:53745] [Bug #8169]
+
 Thu Mar 28 23:11:25 2013  Tanaka Akira  <akr@fsij.org>
 
 	* lib/resolv.rb: Test Windows platform by detecting LoadError when
diff --git a/lib/mkmf.rb b/lib/mkmf.rb
index 6f96f3ce1a..0fd930b47c 100644
--- a/lib/mkmf.rb
+++ b/lib/mkmf.rb
@@ -2421,7 +2421,14 @@ MESSAGE
 
   def MAIN_DOES_NOTHING(*refs)
     src = MAIN_DOES_NOTHING
-    src = src.sub(/\{/) {$&+refs.map {|n|"(void)#{n}; "}.join("")}
+    unless refs.empty?
+      src = src.sub(/\{/) do
+        $& +
+          "\n  if (argc > 1000000) {\n" +
+          refs.map {|n|"    printf(\"%p\", &#{n});\n"}.join("") +
+          "  }\n"
+      end
+    end
     src
   end
 
@@ -2532,7 +2539,7 @@ MESSAGE
   ##
   # A C main function which does no work
 
-  MAIN_DOES_NOTHING = config_string('MAIN_DOES_NOTHING') || 'int main(void) {return 0;}'
+  MAIN_DOES_NOTHING = config_string('MAIN_DOES_NOTHING') || "int main(int argc, char **argv)\n{\n  return 0;\n}"
   UNIVERSAL_INTS = config_string('UNIVERSAL_INTS') {|s| Shellwords.shellwords(s)} ||
     %w[int short long long\ long]