Adding support for passing command line options through the HPX_COMMA…

…NDLINE_OPTIONS environment variable

src/util/command_line_handling.cpp

@@ -32,6 +32,7 @@
 #include <boost/assign/std/vector.hpp>
 #include <boost/program_options/options_description.hpp>
 #include <boost/program_options/variables_map.hpp>
+#include <boost/tokenizer.hpp>
 
 #include <algorithm>
 #include <cstddef>
@@ -1250,6 +1251,19 @@ namespace hpx { namespace util
         return options;
     }
 
+    ///////////////////////////////////////////////////////////////////////////
+    std::vector<std::string> prepend_options(
+        std::vector<std::string>&& args, std::string&& options)
+    {
+        using tokenizer = boost::tokenizer<boost::escaped_list_separator<char>>;
+        boost::escaped_list_separator<char> sep('\\', ' ', '\"');
+        tokenizer tok(options, sep);
+
+        std::vector<std::string> result(tok.begin(), tok.end());
+        std::move(args.begin(), args.end(), std::back_inserter(result));
+        return result;
+    }
+
     ///////////////////////////////////////////////////////////////////////////
     int command_line_handling::call(
         boost::program_options::options_description const& desc_cmdline,
@@ -1274,6 +1288,14 @@ namespace hpx { namespace util
             error_mode |= util::rethrow_on_error;
         }
 
+        // The cfg registry may hold command line options to prepend to the
+        // real command line.
+        std::string prepend_command_line =
+            rtcfg_.get_entry("hpx.commandline.prepend_options");
+
+        args =
+            prepend_options(std::move(args), std::move(prepend_command_line));
+
         // Initial analysis of the command line options. This is
         // preliminary as it will not take into account any aliases as
         // defined in any of the runtime configuration files.

src/util/runtime_configuration.cpp

@@ -270,6 +270,10 @@ namespace hpx { namespace util
             // allow for unknown options to be passed through
             "allow_unknown = ${HPX_COMMANDLINE_ALLOW_UNKNOWN:0}",
 
+            // allow for command line options to to be passed through the
+            // environment
+            "prepend_options = ${HPX_COMMANDLINE_OPTIONS}",
+
             // predefine command line aliases
             "[hpx.commandline.aliases]",
             "-a = --hpx:agas",