New warnings for METAD adn WALKERS_MPI

regtest/basic/rt-errormessages/Makefile

@@ -0,0 +1 @@
+include ../../scripts/test.make

regtest/basic/rt-errormessages/config

@@ -0,0 +1,3 @@
+type=make
+# this is needed because we are explicitly checking some exception message
+export PLUMED_STACK_TRACE=no

regtest/basic/rt-errormessages/output.reference

@@ -0,0 +1 @@
+METAD WALKER_MPI : Exception thrown, correct message

regtest/basic/rt-errormessages/testWALKERS_MPI.cpp

@@ -0,0 +1,77 @@
+#include <fstream>
+
+#include "plumed/wrapper/Plumed.h"
+#include "plumed/tools/Communicator.h"
+
+constexpr unsigned nat=10;
+//it is a struct because we don't need getter/setters (for now)
+struct plumedThrowChecker{
+  unsigned natoms=nat;
+  std::vector<double> positions=[](unsigned natoms){
+    std::vector<double> toret(natoms*3,0.0);
+    for(unsigned i=0; i<3*natoms; i++) toret[i]=i;
+    return toret;
+  }(nat);
+  std::vector<double> masses{nat,1.0};
+  std::vector<double> forces{3*nat,0.0};
+  std::vector<double> box{9,0.0};
+  std::vector<double> virial{9,0.0};
+  ///This initializes a new plumed to test each throw in the cleanliest way possible
+  int checkThrow (std::ostream& out,std::string name, std::string cmd, std::string expectedMessage){
+    //GIVEN an initialized Plumed interface
+    PLMD::Plumed plumed;
+
+    plumed.cmd("setNatoms",&natoms);
+    int step=0;
+    plumed.cmd("setLogFile","test.log");
+    plumed.cmd("init");
+    plumed.cmd("setStep",&step);
+    plumed.cmd("setPositions",positions.data());
+    plumed.cmd("setBox",box.data());
+    plumed.cmd("setForces",forces.data());
+    plumed.cmd("setVirial",virial.data());
+    plumed.cmd("setMasses",masses.data());
+
+    plumed.cmd("readInputLine","d: DISTANCE ATOMS=1,2");
+    plumed.cmd("readInputLine","d1: DISTANCE ATOMS={1 2}");
+    ///TODO: expand with a "readInputLines" to give the possibility to test in more situations
+    try {
+      //WHEN the user ask for the given input
+      plumed.cmd("readInputLine",cmd.c_str());
+      //THEN plumed should gracefully exit with a clear error message
+    } catch(PLMD::Plumed::ExceptionError &e) { //correct throw, we are happy
+      std::string exceptionText{e.what()};
+      out << name << " : ";
+      if (exceptionText.find(expectedMessage) != std::string::npos) {
+        out << "Exception thrown, correct message\n";
+        return 0;
+      }
+
+      out << "Exception thrown, wrong message: "
+                << e.what() ;
+      out << "\tExpected message should contain: \""
+                << expectedMessage << "\"\n";
+      return 1;
+    }
+    out  << "Exception not thrown\n";
+    return 1;
+  }
+};
+
+int main(int, char**) {
+  std::ofstream out("output");
+  plumedThrowChecker ptc;
+  //When the user aks for a WALKERS_MPI in the METAD action,
+  //if MPI is not installed then the user must be informed
+  //if MPI is installed then the comunications must be already set up
+  //WHEN PLUMED is not compiled with MPI or the MPI routines are not initialized
+  std::string expectedMessage="WALKERS_MPI flag requires MPI compilation";
+  if (PLMD::Communicator::plumedHasMPI()) {
+    expectedMessage="WALKERS_MPI needs the communicator correctly initialized";
+  }
+  ptc.checkThrow(out,"METAD WALKER_MPI",
+    "METAD ARG=d,d1 SIGMA=0.1,0.2 HEIGHT=0.1 PACE=2 RESTART=YES WALKERS_MPI",
+    expectedMessage);
+
+  //add other throw messages checks
+}

regtest/scripts/run

@@ -172,8 +172,10 @@ fi
 
 if $plumed --is-installed ; then
   export PLUMED_KERNEL="$root/../lib${PLUMED_PROGRAM_NAME:-plumed}Kernel.$($plumed info --soext)"
+  export PLUMED_LIB="$root/../lib${PLUMED_PROGRAM_NAME:-plumed}.$($plumed info --soext)"
 else
   export PLUMED_KERNEL="$root/src/lib/libplumedKernel.$($plumed info --soext)"
+  export PLUMED_LIB="$root/src/lib/libplumed.$($plumed info --soext)"
 fi
 if type -t plumed_regtest_before 1>/dev/null ; then
   plumed_regtest_before

src/bias/MetaD.cpp

@@ -878,6 +878,12 @@ MetaD::MetaD(const ActionOptions& ao):
   // MPI version
   parseFlag("WALKERS_MPI",walkers_mpi_);
 
+  //If this Action is not compiled with MPI the user is informed and we exit gracefully
+  if(walkers_mpi_) {
+    plumed_assert(Communicator::plumedHasMPI()) << "Invalid walkers configuration: WALKERS_MPI flag requires MPI compilation";
+    plumed_assert(Communicator::initialized()) << "Invalid walkers configuration: WALKERS_MPI needs the communicator correctly initialized.";
+  }
+
   // Flying Gaussian
   parseFlag("FLYING_GAUSSIAN", flying_);
 

src/tools/Communicator.cpp

@@ -28,6 +28,14 @@
 
 namespace PLMD {
 
+bool Communicator::plumedHasMPI() {
+#ifdef __PLUMED_HAS_MPI
+  return true;
+#else
+  return false;
+#endif
+}
+
 Communicator::Communicator()
 #ifdef __PLUMED_HAS_MPI
   : communicator(MPI_COMM_SELF)

src/tools/Communicator.h

@@ -121,6 +121,9 @@ class Communicator {
     }
   };
 public:
+  ///Runtime acces to the __PLUMED_HAS_MPI definition
+  static bool plumedHasMPI();
+
 /// Wrapper class for MPI_Status
   class Status {
     int Get_count(MPI_Datatype)const;