From c09beb1418e59013006746d8eb7919418c1ece5c Mon Sep 17 00:00:00 2001
From: Oliver Jowett <oliver@mutability.co.uk>
Date: Tue, 16 Apr 2019 17:20:23 +0800
Subject: [PATCH] Handle exceptions from SoapySDR during stream setup more
 cleanly.

---
 dump978_main.cc | 10 ++++++----
 exception.h     | 20 ++++++++++++++++++++
 soapy_source.cc | 25 ++++++++++++++++++-------
 3 files changed, 44 insertions(+), 11 deletions(-)
 create mode 100644 exception.h

diff --git a/dump978_main.cc b/dump978_main.cc
index de75ac2..4cb8bd5 100644
--- a/dump978_main.cc
+++ b/dump978_main.cc
@@ -14,6 +14,7 @@
 
 #include "convert.h"
 #include "demodulator.h"
+#include "exception.h"
 #include "message_dispatch.h"
 #include "sample_source.h"
 #include "soapy_source.h"
@@ -246,14 +247,15 @@ static int realmain(int argc, char **argv) {
 }
 
 int main(int argc, char **argv) {
-#ifndef DEBUG_EXCEPTIONS
     try {
         return realmain(argc, argv);
+    } catch (const config_error &e) {
+        std::cerr << "Configuration error: " << e.what() << std::endl;
+        return 2;
+#ifndef DEBUG_EXCEPTIONS
     } catch (...) {
         std::cerr << "Uncaught exception: " << boost::current_exception_diagnostic_information() << std::endl;
         return 2;
-    }
-#else
-    return realmain(argc, argv);
 #endif
+    }
 }
diff --git a/exception.h b/exception.h
new file mode 100644
index 0000000..2dfc429
--- /dev/null
+++ b/exception.h
@@ -0,0 +1,20 @@
+// -*- c++ -*-
+
+// Copyright (c) 2019, FlightAware LLC.
+// All rights reserved.
+// Licensed under the 2-clause BSD license; see the LICENSE file
+
+#ifndef DUMP978_EXCEPTION_H
+#define DUMP978_EXCEPTION_H
+
+#include <stdexcept>
+
+namespace flightaware::uat {
+    class config_error : public std::runtime_error {
+      public:
+        explicit config_error(const std::string &what_arg) : runtime_error(what_arg) {}
+        explicit config_error(const char *what_arg) : runtime_error(what_arg) {}
+    };
+}; // namespace flightaware::uat
+
+#endif
diff --git a/soapy_source.cc b/soapy_source.cc
index 6c29dd3..47d9888 100644
--- a/soapy_source.cc
+++ b/soapy_source.cc
@@ -3,6 +3,7 @@
 // Licensed under the 2-clause BSD license; see the LICENSE file
 
 #include "soapy_source.h"
+#include "exception.h"
 
 #include <iomanip>
 #include <iostream>
@@ -100,9 +101,14 @@ SoapySampleSource::SoapySampleSource(boost::asio::io_service &service, const std
 SoapySampleSource::~SoapySampleSource() { Stop(); }
 
 void SoapySampleSource::Init() {
-    device_ = {SoapySDR::Device::make(device_name_), &SoapySDR::Device::unmake};
+    try {
+        device_ = {SoapySDR::Device::make(device_name_), &SoapySDR::Device::unmake};
+    } catch (const std::runtime_error &err) {
+        throw config_error(std::string("No matching SoapySDR device found (cause: ") + err.what() + ")");
+    }
+
     if (!device_) {
-        throw std::runtime_error("no suitable device found");
+        throw config_error("No matching SoapySDR device found");
     }
 
     // hacky mchackerson
@@ -112,7 +118,7 @@ void SoapySampleSource::Init() {
 
     if (options_.count("sdr-auto-gain")) {
         if (!device_->hasGainMode(SOAPY_SDR_RX, 0)) {
-            throw std::runtime_error("device does not support automatic gain mode");
+            throw config_error("Device does not support automatic gain mode");
         }
         std::cerr << "SoapySDR: using automatic gain" << std::endl;
         device_->setGainMode(SOAPY_SDR_RX, 0, true);
@@ -171,12 +177,12 @@ void SoapySampleSource::Init() {
         soapy_format = device_->getNativeStreamFormat(SOAPY_SDR_RX, 0, fullScale);
         format_ = SoapyToFormat(soapy_format);
         if (format_ == SampleFormat::UNKNOWN) {
-            throw std::runtime_error("Unsupported native SDR format: " + soapy_format + "; try specifying --format");
+            throw config_error("Unsupported native SDR format: " + soapy_format + "; try specifying --format");
         }
     } else {
         soapy_format = FormatToSoapy(format_);
         if (soapy_format.empty()) {
-            throw std::runtime_error("unsupported sample format");
+            throw config_error("Unsupported sample format");
         }
     }
 
@@ -199,9 +205,14 @@ void SoapySampleSource::Init() {
 #endif
     }
 
-    stream_ = {device_->setupStream(SOAPY_SDR_RX, soapy_format, channels, stream_settings), std::bind(&SoapySDR::Device::closeStream, device_, std::placeholders::_1)};
+    try {
+        stream_ = {device_->setupStream(SOAPY_SDR_RX, soapy_format, channels, stream_settings), std::bind(&SoapySDR::Device::closeStream, device_, std::placeholders::_1)};
+    } catch (const std::runtime_error &err) {
+        throw config_error(std::string("Failed to construct soapysdr stream (cause: ") + err.what() + ")");
+    }
+
     if (!stream_) {
-        throw std::runtime_error("failed to construct stream");
+        throw config_error("Failed to construct soapysdr stream");
     }
 }