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

6 files changed, 89 insertions, 27 deletions

diff --git a/qpid/cpp/include/qpid/Options.h b/qpid/cpp/include/qpid/Options.h
index 0bbe7b704f..feef5d8b98 100644
--- a/qpid/cpp/include/qpid/Options.h
+++ b/qpid/cpp/include/qpid/Options.h
@@ -149,6 +149,11 @@ struct Options : public po::options_description {
                const std::string& configfile=std::string(),
                bool  allowUnknown = false);
 
+    /**
+     * Tests for presence of argc/argv switch
+     */
+    QPID_COMMON_EXTERN bool findArg(int argc, char const* const* argv,
+                                       const std::string& theArg);
 
   boost::program_options::options_description_easy_init addOptions() {
       return add_options();
diff --git a/qpid/cpp/src/posix/QpiddBroker.cpp b/qpid/cpp/src/posix/QpiddBroker.cpp
index 76e3bb6674..f1f9009568 100644
--- a/qpid/cpp/src/posix/QpiddBroker.cpp
+++ b/qpid/cpp/src/posix/QpiddBroker.cpp
@@ -48,6 +48,10 @@ BootstrapOptions::BootstrapOptions(const char* argv0)
     add(log);
 }
 
+void BootstrapOptions::usage() const {
+    cout << "Usage: qpidd [OPTIONS]" << endl << endl << *this << endl;
+}
+
 namespace {
 const std::string TCP = "tcp";
 }
@@ -111,17 +115,17 @@ void QpiddOptions::usage() const {
 // Set the broker pointer on the signal handler, then reset at end of scope.
 // This is to ensure that the signal handler doesn't keep a broker
 // reference after main() has returned.
-// 
+//
 struct ScopedSetBroker {
     ScopedSetBroker(const boost::intrusive_ptr<Broker>& broker) {
         qpid::broker::SignalHandler::setBroker(broker.get());
     }
     ~ScopedSetBroker() { qpid::broker::SignalHandler::setBroker(0); }
 };
-    
+
 struct QpiddDaemon : public Daemon {
     QpiddPosixOptions *options;
-  
+
     QpiddDaemon(std::string pidDir, QpiddPosixOptions *opts)
       : Daemon(pidDir), options(opts) {}
 
@@ -129,7 +133,7 @@ struct QpiddDaemon : public Daemon {
     void parent() {
         uint16_t port = wait(options->daemon.wait);
         if (options->parent->broker.port == 0 || options->daemon.transport != TCP)
-            cout << port << endl; 
+            cout << port << endl;
     }
 
     /** Code for forked child process */
@@ -162,12 +166,12 @@ int QpiddBroker::execute (QpiddOptions *options) {
             QPID_LOG(notice, "Cannot stop broker: " << e.what());
             return 1;
         }
-        if (pid < 0) 
+        if (pid < 0)
             return 1;
         if (myOptions->daemon.check)
             cout << pid << endl;
         if (myOptions->daemon.quit) {
-            if (kill(pid, SIGINT) < 0) 
+            if (kill(pid, SIGINT) < 0)
                 throw Exception("Failed to stop daemon: " + qpid::sys::strError(errno));
             // Wait for the process to die before returning
             int retry=10000;    // Try up to 10 seconds
diff --git a/qpid/cpp/src/qpid/Options.cpp b/qpid/cpp/src/qpid/Options.cpp
index 35787aa8f3..9813dda697 100644
--- a/qpid/cpp/src/qpid/Options.cpp
+++ b/qpid/cpp/src/qpid/Options.cpp
@@ -41,13 +41,13 @@ struct EnvOptMapper {
         return desc->long_name().size() == env.size() &&
             std::equal(env.begin(), env.end(), desc->long_name().begin(), &matchChar);
     }
-            
+
     static bool matchCase(const string& env, boost::shared_ptr<po::option_description> desc) {
         return env == desc->long_name();
     }
-            
+
     EnvOptMapper(const Options& o) : opts(o) {}
-    
+
     string operator()(const string& envVar) {
         static const std::string prefix("QPID_");
         if (envVar.substr(0, prefix.size()) == prefix) {
@@ -75,7 +75,7 @@ struct EnvOptMapper {
 
 
     string configFileLine (string& line) {
-        
+
         if ( isComment ( line ) )
           return string();
 
@@ -85,7 +85,7 @@ struct EnvOptMapper {
         string key = line.substr (0, pos);
 #if (BOOST_VERSION >= 103300)
         typedef const std::vector< boost::shared_ptr<po::option_description> > OptDescs;
-        OptDescs::const_iterator i = 
+        OptDescs::const_iterator i =
             find_if(opts.options().begin(), opts.options().end(), boost::bind(matchCase, key, _1));
         if (i != opts.options().end())
             return string (line) + "\n";
@@ -109,8 +109,8 @@ std::string prettyArg(const std::string& name, const std::string& value) {
     return value.empty() ? name+" " : name+" ("+value+") ";
 }
 
-Options::Options(const string& name) : 
-  po::options_description(name) 
+Options::Options(const string& name) :
+  po::options_description(name)
 {
 }
 
@@ -197,5 +197,33 @@ CommonOptions::CommonOptions(const string& name, const string& configfile, const
 }
 
 
+
+bool Options::findArg(int argc, char const* const* argv, const std::string& theArg)
+{
+    const string parsing("command line options");
+    bool result(false);
+    try {
+        if (argc > 0 && argv != 0) {
+            po::command_line_parser clp = po::command_line_parser(argc, const_cast<char**>(argv)).
+            options(*this).allow_unregistered();
+            po::parsed_options opts     = clp.run();
+
+            for (std::vector< po::basic_option<char> >::iterator
+                i = opts.options.begin(); i != opts.options.end(); i++) {
+                if (theArg.compare(i->string_key) == 0) {
+                    result = true;
+                    break;
+                }
+            }
+        }
+        return result;
+    }
+    catch (const std::exception& e) {
+        ostringstream msg;
+        msg << "Error in " << parsing << ": " << e.what() << endl;
+        throw Exception(msg.str());
+    }
+}
+
 } // namespace qpid
 
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;
         }
 
diff --git a/qpid/cpp/src/qpidd.h b/qpid/cpp/src/qpidd.h
index f7f84d11da..08356ab29e 100644
--- a/qpid/cpp/src/qpidd.h
+++ b/qpid/cpp/src/qpidd.h
@@ -37,9 +37,10 @@ namespace broker {
 struct BootstrapOptions : public qpid::Options {
     qpid::CommonOptions common;
     qpid::ModuleOptions module;
-    qpid::log::Options log;     
+    qpid::log::Options log;
 
     BootstrapOptions(const char *argv0);
+    void usage() const;
 };
 
 // Each platform derives an options struct from QpiddOptionsPrivate, adding
diff --git a/qpid/cpp/src/windows/QpiddBroker.cpp b/qpid/cpp/src/windows/QpiddBroker.cpp
index 4ca3f3059c..de2e41dd4d 100644
--- a/qpid/cpp/src/windows/QpiddBroker.cpp
+++ b/qpid/cpp/src/windows/QpiddBroker.cpp
@@ -53,6 +53,10 @@ BootstrapOptions::BootstrapOptions(const char* argv0)
     add(log);
 }
 
+void BootstrapOptions::usage() const {
+    std::cout << "Usage: qpidd [OPTIONS]" << std::endl << std::endl << *this << std::endl;
+}
+
 // Local functions to set and get the pid via a LockFile.
 namespace {
 
@@ -225,10 +229,10 @@ VOID WINAPI SvcCtrlHandler(DWORD control)
         ::SetServiceStatus(svcStatusHandle, &svcStatus);
         CtrlHandler(CTRL_C_EVENT);
         break;
- 
+
     case SERVICE_CONTROL_INTERROGATE:
         break;
- 
+
     default:
         break;
     }
@@ -306,7 +310,7 @@ struct ServiceOptions : public qpid::Options {
     std::string password;
     std::string depends;
 
-    ServiceOptions() 
+    ServiceOptions()
         : qpid::Options("Service options"),
           install(false),
           start(false),
@@ -423,7 +427,7 @@ int QpiddBroker::execute (QpiddOptions *options) {
         // Relies on port number being set via --port or QPID_PORT env variable.
         NamedSharedMemory<BrokerInfo> info(brokerInfoName(options->broker.port));
         int pid = info.get().pid;
-        if (pid < 0) 
+        if (pid < 0)
             return 1;
         if (myOptions->control.check)
             std::cout << pid << std::endl;