QPID-3500 C++ qpidd broker --help should work despite parse errors

This patch finds and processes --version before anything else.
Then it finds --help before fully parsing command line options. 
In the event of a parse error, help usage may be shown as requested.



git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1388032 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 29 insertions, 9 deletions

diff --git a/qpid/cpp/src/qpidd.cpp b/qpid/cpp/src/qpidd.cpp
index b5686c6ab8..920009580c 100644
--- a/qpid/cpp/src/qpidd.cpp
+++ b/qpid/cpp/src/qpidd.cpp
@@ -41,6 +41,18 @@ int run_broker(int argc, char *argv[], bool hidden)
     {
         BootstrapOptions bootOptions(argv[0]);
         string           defaultPath (bootOptions.module.loadDir);
+
+        // --version causes print and exit
+        if (bootOptions.findArg(argc, argv, "version")) {
+            cout << "qpidd (" << qpid::product << ") version "
+                << qpid::version << endl;
+            return 0;
+        }
+
+        // --help sets a flag so that its presence is known despite
+        // subsequent parse problems.
+        bool helpArgSeen = bootOptions.findArg(argc, argv, "help");
+
         // Parse only the common, load, and log options to see which
         // modules need to be loaded.  Once the modules are loaded,
         // the command line will be re-parsed with all of the
@@ -51,8 +63,12 @@ int run_broker(int argc, char *argv[], bool hidden)
                 bootOptions.log.sinkOptions->detached();
             qpid::log::Logger::instance().configure(bootOptions.log);
         } catch (const std::exception& e) {
+            if (helpArgSeen) {
+                // provide help even when parsing fails
+                 bootOptions.usage();
+            }
             // Couldn't configure logging so write the message direct to stderr.
-            cerr << "Unexpected error: " << e.what() << endl;
+            cerr << endl << "Unexpected error: " << e.what() << endl;
             return 1;
         }
 
@@ -67,16 +83,20 @@ int run_broker(int argc, char *argv[], bool hidden)
         }
 
         // Parse options
-        options.reset(new QpiddOptions(argv[0]));
-        options->parse(argc, argv, options->common.config);
+        try {
+            options.reset(new QpiddOptions(argv[0]));
+            options->parse(argc, argv, options->common.config);
+        } catch (const std::exception& /*e*/) {
+            if (helpArgSeen) {
+                 // provide help even when parsing fails
+                options->usage();
+            }
+            throw;
+        }
 
         // Options that just print information.
-        if (options->common.help || options->common.version) {
-            if (options->common.version) 
-                cout << "qpidd (" << qpid::product << ") version "
-                     << qpid::version << endl;
-            else if (options->common.help)
-                options->usage();
+        if (helpArgSeen) {
+            options->usage();
             return 0;
         }