From de3700e1fd5fc8c005fd8048e3ef979e19b2ec2e Mon Sep 17 00:00:00 2001
From: Dan Liew <daniel.liew@imperial.ac.uk>
Date: Wed, 25 Oct 2017 11:13:25 +0100
Subject: [PATCH] [CMake] Try to unbreak the C example build with older GCC
 versions by forcing the language version to be C99.

---
 examples/c/CMakeLists.txt | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/examples/c/CMakeLists.txt b/examples/c/CMakeLists.txt
index bac08e460..c47a4947a 100644
--- a/examples/c/CMakeLists.txt
+++ b/examples/c/CMakeLists.txt
@@ -7,6 +7,19 @@
 # the C++ standard library in resulting in a link failure.
 project(Z3_C_EXAMPLE C CXX)
 cmake_minimum_required(VERSION 2.8.12)
+
+# Set C version required to C99
+if ("${CMAKE_VERSION}" VERSION_LESS "3.1")
+  if (("${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU") OR
+      ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang"))
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c99 ")
+  endif()
+else()
+  set(CMAKE_C_STANDARD_REQUIRED ON)
+  set(CMAKE_C_STANDARD 99)
+  set(CMAKE_C_EXTENSIONS OFF)
+endif()
+
 find_package(Z3
   REQUIRED
   CONFIG