* math.c (math_atan2): you should know that M_PI is not the feature

of C90.
  fixed build failure caused by r29115.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@29119 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Fri Aug 27 15:24:20 2010  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* math.c (math_atan2): you should know that M_PI is not the feature
+	  of C90.
+	  fixed build failure caused by r29115.
+
 Fri Aug 27 15:26:33 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* file.c (null_device): move from io.c.

math.c

@@ -51,6 +51,9 @@ extern VALUE rb_to_float(VALUE val);
 static VALUE
 math_atan2(VALUE obj, VALUE y, VALUE x)
 {
+#ifndef M_PI
+# define M_PI 3.14159265358979323846
+#endif
     double dx, dy;
     Need_Float2(y, x);
     dx = RFLOAT_VALUE(x);