X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/27f7006d3136f93a67086f125afca174554c3f5e..d011cb8a5566e78daba9b90c6a370dca07b74c5a:/src/simgrid/sg_config.cpp

diff --git a/src/simgrid/sg_config.cpp b/src/simgrid/sg_config.cpp
index 19e7b14506..11bd7dd3bb 100644
--- a/src/simgrid/sg_config.cpp
+++ b/src/simgrid/sg_config.cpp
@@ -1,99 +1,106 @@
-/* Copyright (c) 2009-2017. The SimGrid Team. All rights reserved.          */
+/* Copyright (c) 2009-2019. The SimGrid Team. All rights reserved.          */
 
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
 
 /* sg_config: configuration infrastructure for the simulation world         */
 
-#include "simgrid/sg_config.h"
-#include "instr/instr_interface.h"
-#include "mc/mc.h"
+#include "simgrid/sg_config.hpp"
 #include "simgrid/instr.h"
-#include "simgrid/simix.h"
-#include "simgrid_config.h" /* what was compiled in? */
+#include "simgrid/version.h"
+#include "src/instr/instr_private.hpp"
+#include "src/internal_config.h"
 #include "src/kernel/lmm/maxmin.hpp"
+#include "src/mc/mc_config.hpp"
 #include "src/mc/mc_replay.hpp"
 #include "src/surf/surf_interface.hpp"
 #include "surf/surf.hpp"
-#include "xbt/config.h"
 #include "xbt/config.hpp"
-#include "xbt/log.h"
-#include "xbt/mallocator.h"
-#include "xbt/misc.h"
-#include "xbt/sysdep.h"
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_config, surf, "About the configuration of SimGrid");
 
+static simgrid::config::Flag<bool> cfg_continue_after_help
+  {"help-nostop", "Do not stop the execution when --help is found", false};
 
-/* 0: beginning of time (config cannot be changed yet);
- * 1: initialized: cfg_set created (config can now be changed);
+/** @brief Allow other libraries to react to the --help flag, too
+ *
+ * When finding --help on the command line, simgrid usually stops right after displaying its help message.
+ * If you are writing a library using simgrid, you may want to display your own help message before everything stops.
+ * If so, just call this function before having simgrid parsing the command line, and you will be given the control
+ * even if the user is asking for help.
+ */
+void sg_config_continue_after_help()
+{
+  cfg_continue_after_help = true;
+}
+
+/* 0: beginning of time (config cannot be changed yet)
+ * 1: initialized: cfg_set created (config can now be changed)
  * 2: configured: command line parsed and config part of platform file was
  *    integrated also, platform construction ongoing or done.
  *    (Config cannot be changed anymore!)
  */
 int _sg_cfg_init_status = 0;
 
-/* instruct the upper layer (simix or simdag) to exit as soon as possible */
-int _sg_cfg_exit_asap = 0;
-
-#define sg_cfg_exit_early() do { _sg_cfg_exit_asap = 1; return; } while (0)
-
 /* Parse the command line, looking for options */
 static void sg_config_cmd_line(int *argc, char **argv)
 {
-  int shall_exit = 0;
+  bool shall_exit = false;
   int i;
   int j;
+  bool parse_args = true; // Stop parsing the parameters once we found '--'
 
   for (j = i = 1; i < *argc; i++) {
-    if (not strncmp(argv[i], "--cfg=", strlen("--cfg="))) {
+    if (not strcmp("--", argv[i])) {
+      parse_args = false;
+      // Remove that '--' from the arguments
+    } else if (parse_args && not strncmp(argv[i], "--cfg=", strlen("--cfg="))) {
       char *opt = strchr(argv[i], '=');
       opt++;
 
-      xbt_cfg_set_parse(opt);
+      simgrid::config::set_parse(opt);
       XBT_DEBUG("Did apply '%s' as config setting", opt);
-    } else if (not strcmp(argv[i], "--version")) {
-      printf("%s\n", SIMGRID_VERSION_STRING);
-      shall_exit = 1;
-    } else if (not strcmp(argv[i], "--cfg-help") || not strcmp(argv[i], "--help")) {
-      printf("Description of the configuration accepted by this simulator:\n");
-      xbt_cfg_help();
-      printf(
-          "\n"
-          "Each of these configurations can be used by adding\n"
-          "    --cfg=<option name>:<option value>\n"
-          "to the command line.\n"
-          "\n"
-          "For more information, please refer to:\n"
-          "   --help-aliases for the list of all option aliases.\n"
-          "   --help-logs and --help-log-categories for the details of logging output.\n"
-          "   --help-models for a list of all models known by this simulator.\n"
-          "   --help-tracing for the details of all tracing options known by this simulator.\n"
-          "   --version to get SimGrid version information.\n"
-          "\n"
-        );
-      shall_exit = 1;
-    } else if (not strcmp(argv[i], "--help-aliases")) {
-      printf("Here is a list of all deprecated option names, with their replacement.\n");
-      xbt_cfg_aliases();
-      printf("Please consider using the recent names\n");
-      shall_exit = 1;
-    } else if (not strcmp(argv[i], "--help-models")) {
+    } else if (parse_args && not strcmp(argv[i], "--version")) {
+      sg_version();
+      shall_exit = true;
+    } else if (parse_args && (not strcmp(argv[i], "--cfg-help") || not strcmp(argv[i], "--help"))) {
+      XBT_HELP("Description of the configuration accepted by this simulator:");
+      simgrid::config::help();
+      XBT_HELP("\n"
+               "Each of these configurations can be used by adding\n"
+               "    --cfg=<option name>:<option value>\n"
+               "to the command line. Try passing \"help\" as a value\n"
+               "to get the list of values accepted by a given option.\n"
+               "For example, \"--cfg=plugin:help\" gives you the list of\n"
+               "plugins available in your installation of SimGrid.\n"
+               "\n"
+               "For more information, please refer to:\n"
+               "   --help-aliases for the list of all option aliases.\n"
+               "   --help-logs and --help-log-categories for the details of logging output.\n"
+               "   --help-models for a list of all models known by this simulator.\n"
+               "   --help-tracing for the details of all tracing options known by this simulator.\n"
+               "   --version to get SimGrid version information.\n");
+      shall_exit = not cfg_continue_after_help;
+      argv[j++]  = argv[i]; // Preserve the --help in argv just in case someone else wants to see it
+    } else if (parse_args && not strcmp(argv[i], "--help-aliases")) {
+      XBT_HELP("Here is a list of all deprecated option names, with their replacement.");
+      simgrid::config::show_aliases();
+      XBT_HELP("Please consider using the recent names");
+      shall_exit = true;
+    } else if (parse_args && not strcmp(argv[i], "--help-models")) {
       model_help("host", surf_host_model_description);
-      printf("\n");
+      XBT_HELP("%s", "");
       model_help("CPU", surf_cpu_model_description);
-      printf("\n");
+      XBT_HELP("%s", "");
       model_help("network", surf_network_model_description);
-      printf("\nLong description of all optimization levels accepted by the models of this simulator:\n");
-      for (int k = 0; surf_optimization_mode_description[k].name; k++)
-        printf("  %s: %s\n",
-               surf_optimization_mode_description[k].name,
-               surf_optimization_mode_description[k].description);
-      printf("Both network and CPU models have 'Lazy' as default optimization level\n\n");
-      shall_exit = 1;
-    } else if (not strcmp(argv[i], "--help-tracing")) {
-      TRACE_help (1);
-      shall_exit = 1;
+      XBT_HELP("\nLong description of all optimization levels accepted by the models of this simulator:");
+      for (auto const& item : surf_optimization_mode_description)
+        XBT_HELP("  %s: %s", item.name, item.description);
+      XBT_HELP("Both network and CPU models have 'Lazy' as default optimization level\n");
+      shall_exit = true;
+    } else if (parse_args && not strcmp(argv[i], "--help-tracing")) {
+      TRACE_help();
+      shall_exit = true;
     } else {
       argv[j++] = argv[i];
     }
@@ -103,151 +110,109 @@ static void sg_config_cmd_line(int *argc, char **argv)
     *argc = j;
   }
   if (shall_exit)
-    sg_cfg_exit_early();
+    exit(0);
 }
 
 /* callback of the plugin variable */
-static void _sg_cfg_cb__plugin(const char *name)
+static void _sg_cfg_cb__plugin(const std::string& value)
 {
   xbt_assert(_sg_cfg_init_status < 2, "Cannot load a plugin after the initialization");
 
-  std::string val = xbt_cfg_get_string(name);
-  if (val.empty())
+  if (value.empty())
     return;
 
-  if (val == "help") {
-    model_help("plugin", surf_plugin_description);
-    sg_cfg_exit_early();
+  if (value == "help") {
+    model_help("plugin", *surf_plugin_description);
+    exit(0);
   }
 
-  int plugin_id = find_model_description(surf_plugin_description, val);
-  surf_plugin_description[plugin_id].model_init_preparse();
+  int plugin_id = find_model_description(*surf_plugin_description, value);
+  (*surf_plugin_description)[plugin_id].model_init_preparse();
 }
 
 /* callback of the host/model variable */
-static void _sg_cfg_cb__host_model(const char *name)
+static void _sg_cfg_cb__host_model(const std::string& value)
 {
   xbt_assert(_sg_cfg_init_status < 2, "Cannot change the model after the initialization");
 
-  std::string val = xbt_cfg_get_string(name);
-  if (val == "help") {
+  if (value == "help") {
     model_help("host", surf_host_model_description);
-    sg_cfg_exit_early();
+    exit(0);
   }
 
   /* Make sure that the model exists */
-  find_model_description(surf_host_model_description, val);
+  find_model_description(surf_host_model_description, value);
 }
 
 /* callback of the cpu/model variable */
-static void _sg_cfg_cb__cpu_model(const char *name)
+static void _sg_cfg_cb__cpu_model(const std::string& value)
 {
   xbt_assert(_sg_cfg_init_status < 2, "Cannot change the model after the initialization");
 
-  std::string val = xbt_cfg_get_string(name);
-  if (val == "help") {
+  if (value == "help") {
     model_help("CPU", surf_cpu_model_description);
-    sg_cfg_exit_early();
+    exit(0);
   }
 
   /* New Module missing */
-  find_model_description(surf_cpu_model_description, val);
+  find_model_description(surf_cpu_model_description, value);
 }
 
 /* callback of the cpu/model variable */
-static void _sg_cfg_cb__optimization_mode(const char *name)
+static void _sg_cfg_cb__optimization_mode(const std::string& value)
 {
   xbt_assert(_sg_cfg_init_status < 2, "Cannot change the model after the initialization");
 
-  std::string val = xbt_cfg_get_string(name);
-  if (val == "help") {
+  if (value == "help") {
     model_help("optimization", surf_optimization_mode_description);
-    sg_cfg_exit_early();
+    exit(0);
   }
 
   /* New Module missing */
-  find_model_description(surf_optimization_mode_description, val);
+  find_model_description(surf_optimization_mode_description, value);
 }
 
-/* callback of the cpu/model variable */
-static void _sg_cfg_cb__storage_mode(const char *name)
+static void _sg_cfg_cb__disk_model(const std::string& value)
 {
   xbt_assert(_sg_cfg_init_status < 2, "Cannot change the model after the initialization");
 
-  std::string val = xbt_cfg_get_string(name);
-  if (val == "help") {
-    model_help("storage", surf_storage_model_description);
-    sg_cfg_exit_early();
+  if (value == "help") {
+    model_help("disk", surf_disk_model_description);
+    exit(0);
   }
 
-  find_model_description(surf_storage_model_description, val);
+  find_model_description(surf_disk_model_description, value);
 }
 
-/* callback of the network_model variable */
-static void _sg_cfg_cb__network_model(const char *name)
+/* callback of the cpu/model variable */
+static void _sg_cfg_cb__storage_model(const std::string& value)
 {
   xbt_assert(_sg_cfg_init_status < 2, "Cannot change the model after the initialization");
 
-  std::string val = xbt_cfg_get_string(name);
-  if (val == "help") {
-    model_help("network", surf_network_model_description);
-    sg_cfg_exit_early();
+  if (value == "help") {
+    model_help("storage", surf_storage_model_description);
+    exit(0);
   }
 
-  /* New Module missing */
-  find_model_description(surf_network_model_description, val);
-}
-/* callback to decide if we want to use the model-checking */
-#include "src/xbt_modinter.h"
-
-static void _sg_cfg_cb_model_check_replay(const char *name) {
-  MC_record_path = xbt_cfg_get_string(name);
+  find_model_description(surf_storage_model_description, value);
 }
 
-#if SIMGRID_HAVE_MC
-extern int _sg_do_model_check_record;
-static void _sg_cfg_cb_model_check_record(const char *name) {
-  _sg_do_model_check_record = xbt_cfg_get_boolean(name);
-}
-#endif
-
-extern int _sg_do_verbose_exit;
-static void _sg_cfg_cb_verbose_exit(const char *name)
-{
-  _sg_do_verbose_exit = xbt_cfg_get_boolean(name);
-}
-
-extern int _sg_do_clean_atexit;
-static void _sg_cfg_cb_clean_atexit(const char *name)
-{
-  _sg_do_clean_atexit = xbt_cfg_get_boolean(name);
-}
-
-static void _sg_cfg_cb_context_stack_size(const char *name)
-{
-  smx_context_stack_size_was_set = 1;
-  smx_context_stack_size = xbt_cfg_get_int(name) * 1024;
-}
-
-static void _sg_cfg_cb_context_guard_size(const char *name)
+/* callback of the network_model variable */
+static void _sg_cfg_cb__network_model(const std::string& value)
 {
-  smx_context_guard_size_was_set = 1;
-  smx_context_guard_size = xbt_cfg_get_int(name) * xbt_pagesize;
-}
+  xbt_assert(_sg_cfg_init_status < 2, "Cannot change the model after the initialization");
 
-static void _sg_cfg_cb_contexts_nthreads(const char *name)
-{
-  SIMIX_context_set_nthreads(xbt_cfg_get_int(name));
-}
+  if (value == "help") {
+    model_help("network", surf_network_model_description);
+    exit(0);
+  }
 
-static void _sg_cfg_cb_contexts_parallel_threshold(const char *name)
-{
-  SIMIX_context_set_parallel_threshold(xbt_cfg_get_int(name));
+  /* New Module missing */
+  find_model_description(surf_network_model_description, value);
 }
 
-static void _sg_cfg_cb_contexts_parallel_mode(const char *name)
+static void _sg_cfg_cb_contexts_parallel_mode(const std::string& mode_name)
 {
-  std::string mode_name = xbt_cfg_get_string(name);
   if (mode_name == "posix") {
     SIMIX_context_set_parallel_mode(XBT_PARMAP_POSIX);
   } else if (mode_name == "futex") {
@@ -260,34 +225,25 @@ static void _sg_cfg_cb_contexts_parallel_mode(const char *name)
   }
 }
 
-static void _sg_cfg_cb__surf_network_crosstraffic(const char *name)
-{
-  sg_network_crosstraffic = xbt_cfg_get_boolean(name);
-}
-
 /* build description line with possible values */
-static void describe_model(char *result,int resultsize,
-                           const s_surf_model_description_t model_description[],
-                           const char *name,
-                           const char *description)
+static void declare_model_flag(const std::string& name, const std::string& value,
+                               const std::function<void(std::string const&)>& callback,
+                               const std::vector<surf_model_description_t>& model_description, const std::string& type,
+                               const std::string& descr)
 {
-  result[0] = '\0';
-  char *p = result;
-  p += snprintf(result,resultsize-1, "%s. Possible values: %s", description,
-            model_description[0].name ? model_description[0].name : "n/a");
-  for (int i = 1; model_description[i].name; i++)
-    p += snprintf(p,resultsize-(p-result)-1, ", %s", model_description[i].name);
-  p += snprintf(p,resultsize-(p-result)-1, ".\n       (use 'help' as a value to see the long description of each %s)", name);
-
-  xbt_assert(p<result+resultsize-1,"Buffer too small to display the model description of %s",name);
+  std::string description = descr + ". Possible values: ";
+  std::string sep         = "";
+  for (auto const& item : model_description) {
+    description += sep + item.name;
+    sep = ", ";
+  }
+  description += ".\n       (use 'help' as a value to see the long description of each " + type + ")";
+  simgrid::config::declare_flag<std::string>(name, description, value, callback);
 }
 
 /* create the config set, register what should be and parse the command line*/
 void sg_config_init(int *argc, char **argv)
 {
-  const int descsize = 1024;
-  char description[descsize];
-
   /* Create the configuration support */
   if (_sg_cfg_init_status != 0) { /* Only create stuff if not already inited */
     XBT_WARN("Call to sg_config_init() after initialization ignored");
@@ -295,277 +251,243 @@ void sg_config_init(int *argc, char **argv)
   }
 
   /* Plugins configuration */
-  describe_model(description, descsize, surf_plugin_description, "plugin", "The plugins");
-  xbt_cfg_register_string("plugin", "", &_sg_cfg_cb__plugin, description);
-
-  describe_model(description, descsize, surf_cpu_model_description, "model", "The model to use for the CPU");
-  xbt_cfg_register_string("cpu/model", "Cas01", &_sg_cfg_cb__cpu_model, description);
+  declare_model_flag("plugin", "", &_sg_cfg_cb__plugin, *surf_plugin_description, "plugin", "The plugins");
 
-  describe_model(description, descsize, surf_optimization_mode_description, "optimization mode",
-                 "The optimization modes to use for the CPU");
-  xbt_cfg_register_string("cpu/optim", "Lazy", &_sg_cfg_cb__optimization_mode, description);
+  declare_model_flag("cpu/model", "Cas01", &_sg_cfg_cb__cpu_model, surf_cpu_model_description, "model",
+                     "The model to use for the CPU");
 
-  describe_model(description, descsize, surf_storage_model_description, "model", "The model to use for the storage");
-  xbt_cfg_register_string("storage/model", "default", &_sg_cfg_cb__storage_mode, description);
+  declare_model_flag("disk/model", "default", &_sg_cfg_cb__disk_model, surf_disk_model_description, "model",
+                     "The model to use for the disk");
 
-  describe_model(description, descsize, surf_network_model_description, "model", "The model to use for the network");
-  xbt_cfg_register_string("network/model", "LV08", &_sg_cfg_cb__network_model, description);
+  declare_model_flag("storage/model", "default", &_sg_cfg_cb__storage_model, surf_storage_model_description, "model",
+                     "The model to use for the storage");
 
-  describe_model(description, descsize, surf_optimization_mode_description, "optimization mode",
-                 "The optimization modes to use for the network");
-  xbt_cfg_register_string("network/optim", "Lazy", &_sg_cfg_cb__optimization_mode, description);
+  declare_model_flag("network/model", "LV08", &_sg_cfg_cb__network_model, surf_network_model_description, "model",
+                     "The model to use for the network");
 
-  describe_model(description, descsize, surf_host_model_description, "model", "The model to use for the host");
-  xbt_cfg_register_string("host/model", "default", &_sg_cfg_cb__host_model, description);
+  declare_model_flag("network/optim", "Lazy", &_sg_cfg_cb__optimization_mode, surf_optimization_mode_description,
+                     "optimization mode", "The optimization modes to use for the network");
 
-  sg_tcp_gamma = 4194304.0;
-  simgrid::config::bindFlag(sg_tcp_gamma, {"network/TCP-gamma", "network/TCP_gamma"},
-                            "Size of the biggest TCP window (cat /proc/sys/net/ipv4/tcp_[rw]mem for recv/send window; "
-                            "Use the last given value, which is the max window size)");
+  declare_model_flag("host/model", "default", &_sg_cfg_cb__host_model, surf_host_model_description, "model",
+                     "The model to use for the host");
 
-  simgrid::config::bindFlag(sg_surf_precision, "surf/precision",
-                            "Numerical precision used when updating simulation times (in seconds)");
+  simgrid::config::bind_flag(sg_surf_precision, "surf/precision",
+                             "Numerical precision used when updating simulation times (in seconds)");
 
-  simgrid::config::bindFlag(sg_maxmin_precision, "maxmin/precision",
-                            "Numerical precision used when computing resource sharing (in flops/sec or bytes/sec)");
+  simgrid::config::bind_flag(sg_maxmin_precision, "maxmin/precision",
+                             "Numerical precision used when computing resource sharing (in flops/sec or bytes/sec)");
 
-  simgrid::config::bindFlag(sg_concurrency_limit, "maxmin/concurrency-limit",
-                            "Maximum number of concurrent variables in the maxmim system. Also limits the number of "
-                            "processes on each host, at higher level. (default: -1 means no such limitation)");
-  xbt_cfg_register_alias("maxmin/concurrency-limit", "maxmin/concurrency_limit");
+  simgrid::config::bind_flag(sg_concurrency_limit, "maxmin/concurrency-limit", {"maxmin/concurrency_limit"},
+                             "Maximum number of concurrent variables in the maxmim system. Also limits the number of "
+                             "processes on each host, at higher level. (default: -1 means no such limitation)");
 
   /* The parameters of network models */
 
   sg_latency_factor = 13.01; // comes from the default LV08 network model
-  simgrid::config::bindFlag(sg_latency_factor, {"network/latency-factor", "network/latency_factor"},
-                            "Correction factor to apply to the provided latency (default value set by network model)");
+  simgrid::config::bind_flag(sg_latency_factor, "network/latency-factor", {"network/latency_factor"},
+                             "Correction factor to apply to the provided latency (default value set by network model)");
 
   sg_bandwidth_factor = 0.97; // comes from the default LV08 network model
-  simgrid::config::bindFlag(
-      sg_bandwidth_factor, {"network/bandwidth-factor", "network/bandwidth_factor"},
+  simgrid::config::bind_flag(
+      sg_bandwidth_factor, "network/bandwidth-factor", {"network/bandwidth_factor"},
       "Correction factor to apply to the provided bandwidth (default value set by network model)");
 
   sg_weight_S_parameter = 20537; // comes from the default LV08 network model
-  simgrid::config::bindFlag(
-      sg_weight_S_parameter, {"network/weight-S", "network/weight_S"},
+  simgrid::config::bind_flag(
+      sg_weight_S_parameter, "network/weight-S", {"network/weight_S"},
       "Correction factor to apply to the weight of competing streams (default value set by network model)");
 
   /* Inclusion path */
-  simgrid::config::declareFlag<std::string>("path", "Lookup path for inclusions in platform and deployment XML files",
-                                            "", [](std::string const& path) {
-                                              if (path[0] != '\0') {
-                                                surf_path.push_back(path);
-                                              }
-                                            });
-
-  xbt_cfg_register_boolean("cpu/maxmin-selective-update", "no", nullptr, "Update the constraint set propagating "
+  simgrid::config::declare_flag<std::string>("path", "Lookup path for inclusions in platform and deployment XML files",
+                                             "", [](std::string const& path) {
+                                               if (not path.empty())
+                                                 surf_path.push_back(path);
+                                             });
+
+  simgrid::config::declare_flag<bool>("cpu/maxmin-selective-update",
+                                      "Update the constraint set propagating recursively to others constraints "
+                                      "(off by default unless optim is set to lazy)",
+                                      "no");
+  simgrid::config::alias("cpu/maxmin-selective-update", {"cpu/maxmin_selective_update"});
+  simgrid::config::declare_flag<bool>("network/maxmin-selective-update", "Update the constraint set propagating "
                                                                          "recursively to others constraints (off by "
-                                                                         "default when optim is set to lazy)");
-  xbt_cfg_register_alias("cpu/maxmin-selective-update", "cpu/maxmin_selective_update");
-  xbt_cfg_register_boolean("network/maxmin-selective-update", "no", nullptr, "Update the constraint set propagating "
-                                                                             "recursively to others constraints (off "
-                                                                             "by default when optim is set to lazy)");
-  xbt_cfg_register_alias("network/maxmin-selective-update", "network/maxmin_selective_update");
-  /* Replay (this part is enabled even if MC it disabled) */
-  xbt_cfg_register_string("model-check/replay", nullptr, _sg_cfg_cb_model_check_replay,
-                          "Model-check path to replay (as reported by SimGrid when a violation is reported)");
-
-#if SIMGRID_HAVE_MC
-    /* do model-checking-record */
-    xbt_cfg_register_boolean("model-check/record", "no", _sg_cfg_cb_model_check_record, "Record the model-checking paths");
-
-    xbt_cfg_register_int("model-check/checkpoint", 0, _mc_cfg_cb_checkpoint,
-        "Specify the amount of steps between checkpoints during stateful model-checking (default: 0 => stateless verification). "
-        "If value=1, one checkpoint is saved for each step => faster verification, but huge memory consumption; higher values are good compromises between speed and memory consumption.");
-
-    xbt_cfg_register_boolean("model-check/sparse-checkpoint", "no", _mc_cfg_cb_sparse_checkpoint, "Use sparse per-page snapshots.");
-    xbt_cfg_register_boolean("model-check/ksm", "no", _mc_cfg_cb_ksm, "Kernel same-page merging");
-
-    xbt_cfg_register_string("model-check/property", "", _mc_cfg_cb_property,
-                            "Name of the file containing the property, as formatted by the ltl2ba program.");
-    xbt_cfg_register_boolean("model-check/communications-determinism", "no", _mc_cfg_cb_comms_determinism,
-        "Whether to enable the detection of communication determinism");
-    xbt_cfg_register_alias("model-check/communications-determinism","model-check/communications_determinism");
-
-    xbt_cfg_register_boolean("model-check/send-determinism", "no", _mc_cfg_cb_send_determinism,
-        "Enable/disable the detection of send-determinism in the communications schemes");
-    xbt_cfg_register_alias("model-check/send-determinism","model-check/send_determinism");
-
-    /* Specify the kind of model-checking reduction */
-    xbt_cfg_register_string("model-check/reduction", "dpor", _mc_cfg_cb_reduce,
-        "Specify the kind of exploration reduction (either none or DPOR)");
-    xbt_cfg_register_boolean("model-check/timeout", "no",  _mc_cfg_cb_timeout,
-        "Whether to enable timeouts for wait requests");
-
-    xbt_cfg_register_boolean("model-check/hash", "no", _mc_cfg_cb_hash, "Whether to enable state hash for state comparison (experimental)");
-    xbt_cfg_register_boolean("model-check/snapshot-fds", "no",  _mc_cfg_cb_snapshot_fds,
-        "Whether file descriptors must be snapshoted (currently unusable)");
-    xbt_cfg_register_alias("model-check/snapshot-fds","model-check/snapshot_fds");
-    xbt_cfg_register_int("model-check/max-depth", 1000, _mc_cfg_cb_max_depth, "Maximal exploration depth (default: 1000)");
-    xbt_cfg_register_alias("model-check/max-depth","model-check/max_depth");
-    xbt_cfg_register_int("model-check/visited", 0, _mc_cfg_cb_visited,
-        "Specify the number of visited state stored for state comparison reduction. If value=5, the last 5 visited states are stored. If value=0 (the default), all states are stored.");
-
-    xbt_cfg_register_string("model-check/dot-output", "", _mc_cfg_cb_dot_output, "Name of dot output file corresponding to graph state");
-    xbt_cfg_register_alias("model-check/dot-output","model-check/dot_output");
-    xbt_cfg_register_boolean("model-check/termination", "no", _mc_cfg_cb_termination, "Whether to enable non progressive cycle detection");
-#endif
-
-    xbt_cfg_register_boolean("verbose-exit", "yes", _sg_cfg_cb_verbose_exit, "Activate the \"do nothing\" mode in Ctrl-C");
+                                                                         "default unless optim is set to lazy)",
+                                      "no");
+  simgrid::config::alias("network/maxmin-selective-update", {"network/maxmin_selective_update"});
 
-    xbt_cfg_register_int("contexts/stack-size", 8*1024, _sg_cfg_cb_context_stack_size, "Stack size of contexts in KiB");
-    /* (FIXME: this is unpleasant) Reset this static variable that was altered when setting the default value. */
-    smx_context_stack_size_was_set = 0;
-    xbt_cfg_register_alias("contexts/stack-size","contexts/stack_size");
+  simgrid::config::declare_flag<int>("contexts/stack-size", "Stack size of contexts in KiB (not with threads)",
+                                     8 * 1024, [](int value) { smx_context_stack_size = value * 1024; });
+  simgrid::config::alias("contexts/stack-size", {"contexts/stack_size"});
 
-    /* guard size for contexts stacks in memory pages */
-    xbt_cfg_register_int("contexts/guard-size",
+  /* guard size for contexts stacks in memory pages */
 #if defined(_WIN32) || (PTH_STACKGROWTH != -1)
-        0,
+  int default_guard_size = 0;
 #else
-        1,
+  int default_guard_size = 1;
 #endif
-    _sg_cfg_cb_context_guard_size, "Guard size for contexts stacks in memory pages");
-    /* No, it was not set yet (the above setdefault() changed this to 1). */
-    smx_context_guard_size_was_set = 0;
-    xbt_cfg_register_alias("contexts/guard-size","contexts/guard_size");
-    xbt_cfg_register_int("contexts/nthreads", 1, _sg_cfg_cb_contexts_nthreads, "Number of parallel threads used to execute user contexts");
-
-    xbt_cfg_register_int("contexts/parallel-threshold", 2, _sg_cfg_cb_contexts_parallel_threshold,
-        "Minimal number of user contexts to be run in parallel (raw contexts only)");
-    xbt_cfg_register_alias("contexts/parallel-threshold","contexts/parallel_threshold");
-
-    /* synchronization mode for parallel user contexts */
+  simgrid::config::declare_flag<int>("contexts/guard-size", "Guard size for contexts stacks in memory pages",
+                                     default_guard_size,
+                                     [](int value) { smx_context_guard_size = value * xbt_pagesize; });
+  simgrid::config::alias("contexts/guard-size", {"contexts/guard_size"});
+  simgrid::config::declare_flag<int>("contexts/nthreads", "Number of parallel threads used to execute user contexts", 1,
+                                     &SIMIX_context_set_nthreads);
+
+  simgrid::config::declare_flag<int>("contexts/parallel-threshold",
+                                     "Minimal number of user contexts to be run in parallel (raw contexts only)", 2,
+                                     &SIMIX_context_set_parallel_threshold);
+  simgrid::config::alias("contexts/parallel-threshold", {"contexts/parallel_threshold"});
+
+  /* synchronization mode for parallel user contexts */
 #if HAVE_FUTEX_H
-    xbt_cfg_register_string("contexts/synchro", "futex",     _sg_cfg_cb_contexts_parallel_mode,
-        "Synchronization mode to use when running contexts in parallel (either futex, posix or busy_wait)");
-#else //No futex on mac and posix is unimplememted yet
-    xbt_cfg_register_string("contexts/synchro", "busy_wait", _sg_cfg_cb_contexts_parallel_mode,
-        "Synchronization mode to use when running contexts in parallel (either futex, posix or busy_wait)");
+  std::string default_synchro_mode = "futex";
+#else // No futex on mac and posix is unimplemented yet
+  std::string default_synchro_mode = "busy_wait";
 #endif
-
-    xbt_cfg_register_boolean("network/crosstraffic", "yes", _sg_cfg_cb__surf_network_crosstraffic,
-        "Activate the interferences between uploads and downloads for fluid max-min models (LV08, CM02)");
-
-    // For smpi/bw-factor and smpi/lat-factor
-    // SMPI model can be used without enable_smpi, so keep this out of the ifdef.
-    xbt_cfg_register_string("smpi/bw-factor",
-        "65472:0.940694;15424:0.697866;9376:0.58729;5776:1.08739;3484:0.77493;1426:0.608902;732:0.341987;257:0.338112;0:0.812084", nullptr,
-        "Bandwidth factors for smpi. Format: 'threshold0:value0;threshold1:value1;...;thresholdN:valueN', meaning if(size >=thresholdN ) return valueN.");
-    xbt_cfg_register_alias("smpi/bw-factor","smpi/bw_factor");
-
-    xbt_cfg_register_string("smpi/lat-factor",
-        "65472:11.6436;15424:3.48845;9376:2.59299;5776:2.18796;3484:1.88101;1426:1.61075;732:1.9503;257:1.95341;0:2.01467", nullptr, "Latency factors for smpi.");
-    xbt_cfg_register_alias("smpi/lat-factor","smpi/lat_factor");
-
-    xbt_cfg_register_string("smpi/IB-penalty-factors", "0.965;0.925;1.35", nullptr,
-        "Correction factor to communications using Infiniband model with contention (default value based on Stampede cluster profiling)");
-    xbt_cfg_register_alias("smpi/IB-penalty-factors","smpi/IB_penalty_factors");
+  simgrid::config::declare_flag<std::string>("contexts/synchro", "Synchronization mode to use when running contexts in "
+                                                                 "parallel (either futex, posix or busy_wait)",
+                                             default_synchro_mode, &_sg_cfg_cb_contexts_parallel_mode);
+
+  // For smpi/bw-factor and smpi/lat-factor
+  // SMPI model can be used without enable_smpi, so keep this out of the ifdef.
+  simgrid::config::declare_flag<std::string>("smpi/bw-factor",
+                                             "Bandwidth factors for smpi. Format: "
+                                             "'threshold0:value0;threshold1:value1;...;thresholdN:valueN', "
+                                             "meaning if(size >=thresholdN ) return valueN.",
+                                             "65472:0.940694;15424:0.697866;9376:0.58729;5776:1.08739;3484:0.77493;"
+                                             "1426:0.608902;732:0.341987;257:0.338112;0:0.812084");
+  simgrid::config::alias("smpi/bw-factor", {"smpi/bw_factor"});
+
+  simgrid::config::declare_flag<std::string>("smpi/lat-factor", "Latency factors for smpi.",
+                                             "65472:11.6436;15424:3.48845;9376:2.59299;5776:2.18796;3484:1.88101;"
+                                             "1426:1.61075;732:1.9503;257:1.95341;0:2.01467");
+  simgrid::config::alias("smpi/lat-factor", {"smpi/lat_factor"});
+  simgrid::config::declare_flag<std::string>("smpi/IB-penalty-factors",
+                                             "Correction factor to communications using Infiniband model with "
+                                             "contention (default value based on Stampede cluster profiling)",
+                                             "0.965;0.925;1.35");
+  simgrid::config::alias("smpi/IB-penalty-factors", {"smpi/IB_penalty_factors"});
 
 #if HAVE_SMPI
-    xbt_cfg_register_double("smpi/host-speed", 20000.0, nullptr, "Speed of the host running the simulation (in flop/s). Used to bench the operations.");
-    xbt_cfg_register_alias("smpi/host-speed","smpi/running_power");
-    xbt_cfg_register_alias("smpi/host-speed","smpi/running-power");
-
-    xbt_cfg_register_boolean("smpi/keep-temps", "no", nullptr, "Whether we should keep the generated temporary files.");
-
-    xbt_cfg_register_boolean("smpi/display-timing", "no", nullptr, "Whether we should display the timing after simulation.");
-    xbt_cfg_register_alias("smpi/display-timing", "smpi/display_timing");
-
-    xbt_cfg_register_boolean("smpi/simulate-computation", "yes", nullptr, "Whether the computational part of the simulated application should be simulated.");
-    xbt_cfg_register_alias("smpi/simulate-computation","smpi/simulate_computation");
-
-    xbt_cfg_register_string("smpi/shared-malloc", "global", nullptr,
-                            "Whether SMPI_SHARED_MALLOC is enabled. Disable it for debugging purposes.");
-    xbt_cfg_register_alias("smpi/shared-malloc", "smpi/use-shared-malloc");
-    xbt_cfg_register_alias("smpi/shared-malloc", "smpi/use_shared_malloc");
-    xbt_cfg_register_double("smpi/shared-malloc-blocksize", 1UL << 20, nullptr, "Size of the bogus file which will be created for global shared allocations");
-    xbt_cfg_register_string("smpi/shared-malloc-hugepage", "", nullptr,
-                            "Path to a mounted hugetlbfs, to use huge pages with shared malloc.");
-
-    xbt_cfg_register_double("smpi/cpu-threshold", 1e-6, nullptr, "Minimal computation time (in seconds) not discarded, or -1 for infinity.");
-    xbt_cfg_register_alias("smpi/cpu-threshold", "smpi/cpu_threshold");
-
-    xbt_cfg_register_int("smpi/async-small-thresh", 0, nullptr,
-        "Maximal size of messages that are to be sent asynchronously, without waiting for the receiver");
-    xbt_cfg_register_alias("smpi/async-small-thresh","smpi/async_small_thresh");
-    xbt_cfg_register_alias("smpi/async-small-thresh","smpi/async_small_thres");
-
-    xbt_cfg_register_boolean("smpi/trace-call-location", "no", nullptr, "Should filename and linenumber of MPI calls be traced?");
-
-    xbt_cfg_register_int("smpi/send-is-detached-thresh", 65536, nullptr,
-        "Threshold of message size where MPI_Send stops behaving like MPI_Isend and becomes MPI_Ssend");
-    xbt_cfg_register_alias("smpi/send-is-detached-thresh","smpi/send_is_detached_thresh");
-    xbt_cfg_register_alias("smpi/send-is-detached-thresh","smpi/send_is_detached_thres");
-
-    const char* default_privatization = std::getenv("SMPI_PRIVATIZATION");
-    if (default_privatization == nullptr)
-      default_privatization = "no";
-
-    xbt_cfg_register_string("smpi/privatization", default_privatization, nullptr,
-                            "How we should privatize global variable at runtime (no, yes, mmap, dlopen).");
-
-    xbt_cfg_register_alias("smpi/privatization", "smpi/privatize-global-variables");
-    xbt_cfg_register_alias("smpi/privatization", "smpi/privatize_global_variables");
-
-    xbt_cfg_register_boolean("smpi/grow-injected-times", "yes", nullptr, "Whether we want to make the injected time in MPI_Iprobe and MPI_Test grow, to allow faster simulation. This can make simulation less precise, though.");
+  simgrid::config::declare_flag<double>("smpi/host-speed", "Speed of the host running the simulation (in flop/s). "
+                                                           "Used to bench the operations.",
+                                        20000.0, [](const double& val) {
+      xbt_assert(val > 0.0, "Invalid value (%f) for 'smpi/host-speed': it must be positive.", val);
+    });
+  simgrid::config::alias("smpi/host-speed", {"smpi/running_power", "smpi/running-power"});
+
+  simgrid::config::declare_flag<bool>("smpi/keep-temps", "Whether we should keep the generated temporary files.",
+                                      false);
+
+  simgrid::config::declare_flag<bool>("smpi/display-timing", "Whether we should display the timing after simulation.",
+                                      false);
+  simgrid::config::alias("smpi/display-timing", {"smpi/display_timing"});
+
+  simgrid::config::declare_flag<bool>(
+      "smpi/simulate-computation", "Whether the computational part of the simulated application should be simulated.",
+      true);
+  simgrid::config::alias("smpi/simulate-computation", {"smpi/simulate_computation"});
+
+  simgrid::config::declare_flag<std::string>(
+      "smpi/shared-malloc", "Whether SMPI_SHARED_MALLOC is enabled. Disable it for debugging purposes.", "global");
+  simgrid::config::alias("smpi/shared-malloc", {"smpi/use_shared_malloc", "smpi/use-shared-malloc"});
+  simgrid::config::declare_flag<double>("smpi/shared-malloc-blocksize",
+                                        "Size of the bogus file which will be created for global shared allocations",
+                                        1UL << 20);
+  simgrid::config::declare_flag<double>("smpi/auto-shared-malloc-thresh",
+                                        "Threshold size for the automatic sharing of memory",
+                                        0);
+
+  simgrid::config::declare_flag<std::string>("smpi/shared-malloc-hugepage",
+                                             "Path to a mounted hugetlbfs, to use huge pages with shared malloc.", "");
+
+  simgrid::config::declare_flag<double>(
+      "smpi/cpu-threshold", "Minimal computation time (in seconds) not discarded, or -1 for infinity.", 1e-6);
+  simgrid::config::alias("smpi/cpu-threshold", {"smpi/cpu_threshold"});
+
+  simgrid::config::declare_flag<int>(
+      "smpi/async-small-thresh",
+      "Maximal size of messages that are to be sent asynchronously, without waiting for the receiver", 0);
+  simgrid::config::alias("smpi/async-small-thresh", {"smpi/async_small_thres", "smpi/async_small_thresh"});
+
+  simgrid::config::declare_flag<bool>("smpi/trace-call-location",
+                                      "Should filename and linenumber of MPI calls be traced?", false);
+  simgrid::config::declare_flag<bool>("smpi/trace-call-use-absolute-path",
+                                      "Should filenames for trace-call tracing be absolute or not?", false);
+  simgrid::config::declare_flag<int>(
+      "smpi/send-is-detached-thresh",
+      "Threshold of message size where MPI_Send stops behaving like MPI_Isend and becomes MPI_Ssend", 65536);
+  simgrid::config::alias("smpi/send-is-detached-thresh",
+                         {"smpi/send_is_detached_thres", "smpi/send_is_detached_thresh"});
+
+  const char* default_privatization = std::getenv("SMPI_PRIVATIZATION");
+  if (default_privatization == nullptr)
+    default_privatization = "no";
+
+  simgrid::config::declare_flag<std::string>(
+      "smpi/privatization", "How we should privatize global variable at runtime (no, yes, mmap, dlopen).",
+      default_privatization);
+  simgrid::config::alias("smpi/privatization", {"smpi/privatize_global_variables", "smpi/privatize-global-variables"});
+
+  simgrid::config::declare_flag<std::string>(
+      "smpi/privatize-libs", "Add libraries (; separated) to privatize (libgfortran for example). You need to provide the full names of the files (libgfortran.so.4), or its full path", "");
+
+  simgrid::config::declare_flag<bool>("smpi/grow-injected-times",
+                                      "Whether we want to make the injected time in MPI_Iprobe and MPI_Test grow, to "
+                                      "allow faster simulation. This can make simulation less precise, though.",
+                                      true);
 
 #if HAVE_PAPI
-    xbt_cfg_register_string("smpi/papi-events", nullptr, nullptr, "This switch enables tracking the specified counters with PAPI");
+  simgrid::config::declare_flag<std::string>("smpi/papi-events",
+                                             "This switch enables tracking the specified counters with PAPI", "");
 #endif
-    xbt_cfg_register_string("smpi/comp-adjustment-file", nullptr, nullptr, "A file containing speedups or slowdowns for some parts of the code.");
-    xbt_cfg_register_string("smpi/os", "0:0:0:0:0", nullptr,  "Small messages timings (MPI_Send minimum time for small messages)");
-    xbt_cfg_register_string("smpi/ois", "0:0:0:0:0", nullptr, "Small messages timings (MPI_Isend minimum time for small messages)");
-    xbt_cfg_register_string("smpi/or", "0:0:0:0:0", nullptr,  "Small messages timings (MPI_Recv minimum time for small messages)");
-
-    xbt_cfg_register_double("smpi/iprobe-cpu-usage", 1, nullptr, "Maximum usage of CPUs by MPI_Iprobe() calls. We've observed that MPI_Iprobes consume significantly less power than the maximum of a specific application. This value is then (Iprobe_Usage/Max_Application_Usage).");
-
-    xbt_cfg_register_string("smpi/coll-selector", "default", nullptr, "Which collective selector to use");
-    xbt_cfg_register_alias("smpi/coll-selector","smpi/coll_selector");
-    xbt_cfg_register_string("smpi/gather",        nullptr, nullptr, "Which collective to use for gather");
-    xbt_cfg_register_string("smpi/allgather",     nullptr, nullptr, "Which collective to use for allgather");
-    xbt_cfg_register_string("smpi/barrier",       nullptr, nullptr, "Which collective to use for barrier");
-    xbt_cfg_register_string("smpi/reduce_scatter",nullptr, nullptr, "Which collective to use for reduce_scatter");
-    xbt_cfg_register_alias("smpi/reduce_scatter","smpi/reduce-scatter");
-    xbt_cfg_register_string("smpi/scatter",       nullptr, nullptr, "Which collective to use for scatter");
-    xbt_cfg_register_string("smpi/allgatherv",    nullptr, nullptr, "Which collective to use for allgatherv");
-    xbt_cfg_register_string("smpi/allreduce",     nullptr, nullptr, "Which collective to use for allreduce");
-    xbt_cfg_register_string("smpi/alltoall",      nullptr, nullptr, "Which collective to use for alltoall");
-    xbt_cfg_register_string("smpi/alltoallv",     nullptr, nullptr,"Which collective to use for alltoallv");
-    xbt_cfg_register_string("smpi/bcast",         nullptr, nullptr, "Which collective to use for bcast");
-    xbt_cfg_register_string("smpi/reduce",        nullptr, nullptr, "Which collective to use for reduce");
+  simgrid::config::declare_flag<std::string>("smpi/comp-adjustment-file",
+                                             "A file containing speedups or slowdowns for some parts of the code.", "");
+  simgrid::config::declare_flag<std::string>(
+      "smpi/os", "Small messages timings (MPI_Send minimum time for small messages)", "0:0:0:0:0");
+  simgrid::config::declare_flag<std::string>(
+      "smpi/ois", "Small messages timings (MPI_Isend minimum time for small messages)", "0:0:0:0:0");
+  simgrid::config::declare_flag<std::string>(
+      "smpi/or", "Small messages timings (MPI_Recv minimum time for small messages)", "0:0:0:0:0");
+
+  simgrid::config::declare_flag<double>("smpi/iprobe-cpu-usage",
+                                        "Maximum usage of CPUs by MPI_Iprobe() calls. We've observed that MPI_Iprobes "
+                                        "consume significantly less power than the maximum of a specific application. "
+                                        "This value is then (Iprobe_Usage/Max_Application_Usage).",
+                                        1.0);
+
+  simgrid::config::declare_flag<std::string>("smpi/coll-selector", "Which collective selector to use", "default");
+  simgrid::config::alias("smpi/coll-selector", {"smpi/coll_selector"});
+  simgrid::config::declare_flag<std::string>("smpi/gather", "Which collective to use for gather", "");
+  simgrid::config::declare_flag<std::string>("smpi/allgather", "Which collective to use for allgather", "");
+  simgrid::config::declare_flag<std::string>("smpi/barrier", "Which collective to use for barrier", "");
+  simgrid::config::declare_flag<std::string>("smpi/reduce_scatter", "Which collective to use for reduce_scatter", "");
+  simgrid::config::alias("smpi/reduce_scatter", {"smpi/reduce-scatter"});
+  simgrid::config::declare_flag<std::string>("smpi/scatter", "Which collective to use for scatter", "");
+  simgrid::config::declare_flag<std::string>("smpi/allgatherv", "Which collective to use for allgatherv", "");
+  simgrid::config::declare_flag<std::string>("smpi/allreduce", "Which collective to use for allreduce", "");
+  simgrid::config::declare_flag<std::string>("smpi/alltoall", "Which collective to use for alltoall", "");
+  simgrid::config::declare_flag<std::string>("smpi/alltoallv", "Which collective to use for alltoallv", "");
+  simgrid::config::declare_flag<std::string>("smpi/bcast", "Which collective to use for bcast", "");
+  simgrid::config::declare_flag<std::string>("smpi/reduce", "Which collective to use for reduce", "");
 #endif // HAVE_SMPI
 
-    /* Storage */
+  /* Others */
 
-    sg_storage_max_file_descriptors = 1024;
-    simgrid::config::bindFlag(sg_storage_max_file_descriptors, "storage/max_file_descriptors",
-      "Maximum number of concurrently opened files per host. Default is 1024");
+  simgrid::config::declare_flag<bool>(
+      "exception/cutpath", "Whether to cut all path information from call traces, used e.g. in exceptions.", false);
 
-    /* Others */
+  if (surf_path.empty())
+    simgrid::config::set_default<std::string>("path", "./");
 
-    xbt_cfg_register_boolean("exception/cutpath", "no", nullptr,
-        "Whether to cut all path information from call traces, used e.g. in exceptions.");
+  _sg_cfg_init_status = 1;
 
-    xbt_cfg_register_boolean("clean-atexit", "yes", _sg_cfg_cb_clean_atexit,
-        "Whether to cleanup SimGrid at exit. Disable it if your code segfaults after its end.");
-    xbt_cfg_register_alias("clean-atexit","clean_atexit");
+  sg_config_cmd_line(argc, argv);
 
-    if (surf_path.empty())
-      xbt_cfg_setdefault_string("path", "./");
-
-    _sg_cfg_init_status = 1;
-
-    sg_config_cmd_line(argc, argv);
-
-    xbt_mallocator_initialization_is_done(SIMIX_context_is_parallel());
+  xbt_mallocator_initialization_is_done(SIMIX_context_is_parallel());
 }
 
 void sg_config_finalize()
 {
-  if (not _sg_cfg_init_status)
-    return;                     /* Not initialized yet. Nothing to do */
-
-  xbt_cfg_free(&simgrid_config);
+  simgrid::config::finalize();
   _sg_cfg_init_status = 0;
 }