From 7866e54e8d2ea3c723cbaf32eb53a878335de892 Mon Sep 17 00:00:00 2001
From: Jon Trulson <jtrulson@ics.com>
Date: Tue, 8 Sep 2015 17:02:10 -0600
Subject: [PATCH] mq303a: throw exception(s) on fatal errors

Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Mihai Tudor Panu <mihai.tudor.panu@intel.com>
---
 src/mq303a/mq303a.cxx | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/mq303a/mq303a.cxx b/src/mq303a/mq303a.cxx
index dda380e2..612ffd51 100644
--- a/src/mq303a/mq303a.cxx
+++ b/src/mq303a/mq303a.cxx
@@ -23,6 +23,8 @@
  */
 
 #include <iostream>
+#include <string>
+#include <stdexcept>
 
 #include "mq303a.h"
 
@@ -30,9 +32,19 @@ using namespace upm;
 
 MQ303A::MQ303A(int pin, int heaterPin)
 {
-  m_aio = mraa_aio_init(pin);
+  if ( !(m_aio = mraa_aio_init(pin)) ) 
+    {
+      throw std::invalid_argument(std::string(__FUNCTION__) +
+                                  ": mraa_aio_init() failed, invalid pin?");
+      return;
+    }
 
-  m_gpio = mraa_gpio_init(heaterPin);
+  if ( !(m_gpio = mraa_gpio_init(heaterPin)) ) 
+    {
+      throw std::invalid_argument(std::string(__FUNCTION__) +
+                                  ": mraa_gpio_init() failed, invalid pin?");
+      return;
+    }
   mraa_gpio_dir(m_gpio, MRAA_GPIO_OUT);
 }