From 5db9dbc71277ae780e64607832e50437801832a9 Mon Sep 17 00:00:00 2001
From: Nikolaus Demmel <nikolaus@nikolaus-demmel.de>
Date: Wed, 13 May 2020 19:38:31 +0200
Subject: [PATCH] fix compiler warning on __STDC_FORMAT_MACROS redef

Without this, if I include 2 libraries that define this macro, I get warnings like

```
warning: '__STDC_FORMAT_MACROS' macro redefined [-Wmacro-redefined]
```

This is on macos 10.15 with AppleClang 11.

See also upstream PR: https://github.com/kazuho/picojson/pull/127
---
 include/pangolin/utils/picojson.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/pangolin/utils/picojson.h b/include/pangolin/utils/picojson.h
index 3791ee6b7..85252691f 100644
--- a/include/pangolin/utils/picojson.h
+++ b/include/pangolin/utils/picojson.h
@@ -69,7 +69,9 @@ extern "C" {
 
 // experimental support for int64_t (see README.mkdn for detail)
 #ifdef PICOJSON_USE_INT64
-# define __STDC_FORMAT_MACROS
+# ifndef __STDC_FORMAT_MACROS
+#  define __STDC_FORMAT_MACROS
+# endif
 # include <errno.h>
 # include <inttypes.h>
 #endif // PICOJSON_USE_INT64