From b5dacf019169a98e6264dd5937c432d70eb01524 Mon Sep 17 00:00:00 2001
From: Arnaud Giersch <arnaud.giersch@univ-fcomte.fr>
Date: Tue, 13 Jun 2023 10:49:01 +0200
Subject: [PATCH] Implement smpirun --help-coll.

---
 src/smpi/colls/smpi_coll.cpp       | 25 +++++++++++++++++++++++++
 src/smpi/include/smpi_coll.hpp     |  1 +
 src/smpi/internals/smpi_global.cpp |  4 ++++
 src/smpi/smpirun.in                |  4 ++++
 teshsuite/smpi/CMakeLists.txt      |  2 ++
 5 files changed, 36 insertions(+)

diff --git a/src/smpi/colls/smpi_coll.cpp b/src/smpi/colls/smpi_coll.cpp
index b9d1680faa..4daa1d5b80 100644
--- a/src/smpi/colls/smpi_coll.cpp
+++ b/src/smpi/colls/smpi_coll.cpp
@@ -13,7 +13,10 @@
 #include "smpi_request.hpp"
 #include "xbt/config.hpp"
 
+#include <iomanip>
 #include <map>
+#include <numeric>
+#include <sstream>
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(smpi_coll, smpi, "Logging specific to SMPI collectives.");
 
@@ -242,6 +245,28 @@ std::vector<s_mpi_coll_description_t>* colls::get_smpi_coll_descriptions(const s
   return &iter->second;
 }
 
+std::string colls::get_smpi_coll_help()
+{
+  size_t max_name_len =
+      std::accumulate(begin(smpi_coll_descriptions), end(smpi_coll_descriptions), 0, [](auto len, auto const& coll) {
+        return std::max(len, std::accumulate(begin(coll.second), end(coll.second), 0, [](auto len, auto const& descr) {
+                          return std::max<size_t>(len, descr.name.length());
+                        }));
+      });
+  std::ostringstream oss;
+  std::string title = "Available collective algorithms (select them with \"smpi/collective_name:algo_name\"):";
+  oss << title << '\n' << std::setfill('=') << std::setw(title.length() + 1);
+  for (auto const& [coll, algos] : smpi_coll_descriptions) {
+    std::string line = "Collective: \"" + coll + "\"";
+    oss << '\n' << line << '\n' << std::setfill('-') << std::setw(line.length() + 1) << '\n';
+    oss << std::setfill(' ') << std::left;
+    for (auto const& [name, descr, _] : algos)
+      oss << "  " << std::setw(max_name_len) << name << " " << descr << "\n";
+    oss << std::right;
+  }
+  return oss.str();
+}
+
 static s_mpi_coll_description_t* find_coll_description(const std::string& collective, const std::string& algo)
 {
   std::vector<s_mpi_coll_description_t>* table = colls::get_smpi_coll_descriptions(collective);
diff --git a/src/smpi/include/smpi_coll.hpp b/src/smpi/include/smpi_coll.hpp
index b8822099d4..786a5e825c 100644
--- a/src/smpi/include/smpi_coll.hpp
+++ b/src/smpi/include/smpi_coll.hpp
@@ -57,6 +57,7 @@ struct s_mpi_coll_description_t {
 namespace colls {
 void set_collectives();
 XBT_PUBLIC std::vector<s_mpi_coll_description_t>* get_smpi_coll_descriptions(const std::string& name);
+std::string get_smpi_coll_help();
 
 void set_gather(const std::string& name);
 void set_allgather(const std::string& name);
diff --git a/src/smpi/internals/smpi_global.cpp b/src/smpi/internals/smpi_global.cpp
index b7d4dce316..36a3e39101 100644
--- a/src/smpi/internals/smpi_global.cpp
+++ b/src/smpi/internals/smpi_global.cpp
@@ -520,6 +520,10 @@ int smpi_main(const char* executable, int argc, char* argv[])
      * configuration tools */
     return 0;
   }
+  if (argv[0] == std::string("--help-coll")) {
+    std::cerr << simgrid::smpi::colls::get_smpi_coll_help();
+    return 0;
+  }
 
   smpi_init_options_internal(true);
   simgrid::s4u::Engine engine(&argc, argv);
diff --git a/src/smpi/smpirun.in b/src/smpi/smpirun.in
index 2e949968d3..b52c5e1b98 100755
--- a/src/smpi/smpirun.in
+++ b/src/smpi/smpirun.in
@@ -240,6 +240,10 @@ while true; do
             usage
             exit 0
             ;;
+        "--help-coll")
+            ${WRAPPER} "@SMPIMAIN@" --help-coll
+            exit 0
+            ;;
         "-version" | "--version" | "-v")
             printf '%b\n' "$SIMGRID_VERSION"
             exit 0
diff --git a/teshsuite/smpi/CMakeLists.txt b/teshsuite/smpi/CMakeLists.txt
index ce735edf2a..25b8ce35f8 100644
--- a/teshsuite/smpi/CMakeLists.txt
+++ b/teshsuite/smpi/CMakeLists.txt
@@ -57,6 +57,8 @@ set(bin_files       ${bin_files}    ${CMAKE_CURRENT_SOURCE_DIR}/hostfile
 
 
 if(enable_smpi)
+  ADD_TEST(test-smpi-help-coll ${CMAKE_BINARY_DIR}/smpi_script/bin/smpirun -wrapper "${VALGRIND_WRAPPER_NO_LEAK_CHECK}" --help-coll)
+
   ADD_TESH_FACTORIES(tesh-smpi-macro-shared "*" --setenv platfdir=${CMAKE_HOME_DIRECTORY}/examples/platforms --setenv platfdir=${CMAKE_HOME_DIRECTORY}/examples/platforms --setenv bindir=${CMAKE_BINARY_DIR}/teshsuite/smpi/macro-shared --cd ${CMAKE_BINARY_DIR}/teshsuite/smpi/macro-shared ${CMAKE_HOME_DIRECTORY}/teshsuite/smpi/macro-shared/macro-shared.tesh)
   ADD_TESH_FACTORIES(tesh-smpi-auto-shared "*" --setenv platfdir=${CMAKE_HOME_DIRECTORY}/examples/platforms --setenv bindir=${CMAKE_BINARY_DIR}/teshsuite/smpi/auto-shared --cd ${CMAKE_BINARY_DIR}/teshsuite/smpi/auto-shared ${CMAKE_HOME_DIRECTORY}/teshsuite/smpi/auto-shared/auto-shared.tesh)
   ADD_TESH_FACTORIES(tesh-smpi-macro-partial-shared "*" --setenv platfdir=${CMAKE_HOME_DIRECTORY}/examples/platforms --setenv bindir=${CMAKE_BINARY_DIR}/teshsuite/smpi/macro-partial-shared --cd ${CMAKE_BINARY_DIR}/teshsuite/smpi/macro-partial-shared ${CMAKE_HOME_DIRECTORY}/teshsuite/smpi/macro-partial-shared/macro-partial-shared.tesh)
-- 
2.20.1