From 5812cc3c8ba705b2cf380ebf54837f3f9a367104 Mon Sep 17 00:00:00 2001
From: Gareth Rees <gdr@ravenbrook.com>
Date: Thu, 28 Jun 2018 16:07:56 +0100
Subject: [PATCH] Try to avoid "eventpy.c:164:3: error: comparison of unsigned
 expression < 0 is always false" from gcc 4.8.4 (the version on the travis
 buildbots). see https://travis-ci.org/ravenbrook/mps/jobs/397813493

Copied from Perforce
 Change: 194282
---
 mps/code/eventpy.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/mps/code/eventpy.c b/mps/code/eventpy.c
index 67587045994..d67986ea66e 100644
--- a/mps/code/eventpy.c
+++ b/mps/code/eventpy.c
@@ -107,9 +107,12 @@ int main(int argc, char *argv[])
   puts("\n# Namespace containing an EventDesc for every event.");
   puts("class Event:");
 #define PAD_TO(OFFSET)                                  \
-  if (prev_sort != 'S' && prev_offset < (OFFSET))       \
-    printf("%ux", (unsigned)((OFFSET) - prev_offset));  \
-  prev_offset = (OFFSET);
+  BEGIN {                                               \
+    size_t offset = (OFFSET);                           \
+    if (prev_sort != 'S' && prev_offset < offset)       \
+      printf("%ux", (unsigned)(offset - prev_offset));  \
+    prev_offset = offset;                               \
+  } END
 #define EVENT_PARAM(X, INDEX, SORT, NAME)                       \
   puts("        EventParam('" #SORT "', '" #NAME "'),");        \
   prev_sort = #SORT[0];