Mesa (master): c99: in c99_math.h check that _USE_MATH_DEFINES is defined with MSVC

[Brian Paul]

Module: Mesa
Branch: master
Commit: 688d7656c58ea4775dbd55fe56193a27f4799c00
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=688d7656c58ea4775dbd55fe56193a27f4799c00

Author: Brian Paul <brianp at vmware.com>
Date:   Thu Feb 26 10:19:37 2015 -0700

c99: in c99_math.h check that _USE_MATH_DEFINES is defined with MSVC

Reviewed-by: Jose Fonseca <jfonseca at vmware.com>

---

 include/c99_math.h |    5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/c99_math.h b/include/c99_math.h
index 5d4f535..0a359eb 100644
--- a/include/c99_math.h
+++ b/include/c99_math.h
@@ -40,6 +40,11 @@
 
 #if defined(_MSC_VER)
 
+/* This is to ensure that we get M_PI, etc. definitions */
+#if !defined(_USE_MATH_DEFINES)
+#error _USE_MATH_DEFINES define required when building with MSVC
+#endif 
+
 #if _MSC_VER < 1800
 #define isfinite(x) _finite((double)(x))
 #define isnan(x) _isnan((double)(x))