make the Body struct standalone so we can use a forward declaration

src/MC/fix_hmc.cpp

@@ -30,7 +30,7 @@
 #include "domain.h"
 #include "error.h"
 #include "fix.h"
-#include "fix_rigid_nve_small.h"
+#include "fix_rigid_small.h"
 #include "force.h"
 #include "group.h"
 #include "improper.h"
@@ -771,7 +771,7 @@ void FixHMC::save_current_state()
     stored_nghost_body = fix_rigid->nghost_body;
     stored_ntotal_body = stored_nlocal_body + stored_nghost_body;
     delete stored_body;
-    stored_body = new FixRigidSmall::Body[stored_ntotal_body];
+    stored_body = new RigidSmallBody[stored_ntotal_body];
     for (int i = 0; i < stored_ntotal_body; i++) stored_body[i] = fix_rigid->body[i];
   }
 
@@ -919,14 +919,14 @@ void FixHMC::random_velocities()
 
 void FixHMC::rigid_body_random_velocities()
 {
-  FixRigidSmall::Body *body = fix_rigid->body;
+  RigidSmallBody *body = fix_rigid->body;
   int nlocal = fix_rigid->nlocal_body;
   int ntotal = nlocal + fix_rigid->nghost_body;
   int *mask = atom->mask;
 
   double stdev, bmass, wbody[3], mbody[3];
   double total_mass = 0;
-  FixRigidSmall::Body *b;
+  RigidSmallBody *b;
   double vcm[] = {0.0, 0.0, 0.0};
 
   for (int ibody = 0; ibody < nlocal; ibody++) {
@@ -985,10 +985,10 @@ void FixHMC::rigid_body_random_velocities()
 int FixHMC::pack_forward_comm(int n, int *list, double *buf, int /*pbc_flag*/, int * /*pbc*/)
 {
   int *bodyown = fix_rigid->bodyown;
-  FixRigidSmall::Body *body = fix_rigid->body;
+  RigidSmallBody *body = fix_rigid->body;
 
   int i, m, ibody;
-  FixRigidSmall::Body *b;
+  RigidSmallBody *b;
 
   m = 0;
   for (i = 0; i < n; i++) {
@@ -1021,10 +1021,10 @@ int FixHMC::pack_forward_comm(int n, int *list, double *buf, int /*pbc_flag*/, i
 void FixHMC::unpack_forward_comm(int n, int first, double *buf)
 {
   int *bodyown = fix_rigid->bodyown;
-  FixRigidSmall::Body *body = fix_rigid->body;
+  RigidSmallBody *body = fix_rigid->body;
 
   int i, m, last;
-  FixRigidSmall::Body *b;
+  RigidSmallBody *b;
 
   m = 0;
   last = first + n;
@@ -1210,7 +1210,7 @@ double FixHMC::memory_usage()
     }
   }
 
-  bytes += stored_ntotal_body * sizeof(FixRigidSmall::Body);
+  bytes += stored_ntotal_body * sizeof(RigidSmallBody);
 
   bytes += nvalues * atom->nmax * sizeof(double);
   return bytes;

src/MC/fix_hmc.h

@@ -12,9 +12,9 @@
 ------------------------------------------------------------------------- */
 
 #ifdef FIX_CLASS
-
-FixStyle(hmc, FixHMC)
-
+// clang-format off
+FixStyle(hmc,FixHMC)
+// clang-format on
 #else
 
 #ifndef LMP_FIX_HMC_H
@@ -22,31 +22,30 @@ FixStyle(hmc, FixHMC)
 
 #include "atom.h"
 #include "fix.h"
-#include "fix_rigid_small.h"
 
 namespace LAMMPS_NS {
 
 class FixHMC : public Fix {
  public:
   FixHMC(class LAMMPS *, int, char **);
-  ~FixHMC();
-  void post_constructor();
-  int setmask();
-  void init();
-  void setup(int);
-  void end_of_step();
-  double compute_scalar();
-  double compute_vector(int);
+  ~FixHMC() override;
+  void post_constructor() override;
+  int setmask() override;
+  void init() override;
+  void setup(int) override;
+  void end_of_step() override;
+  double compute_scalar() override;
+  double compute_vector(int) override;
 
-  int pack_forward_comm(int, int *, double *, int, int *);
-  void unpack_forward_comm(int, int, double *);
-  int pack_reverse_comm(int, int, double *);
-  void unpack_reverse_comm(int, int *, double *);
-  void grow_arrays(int);
-  void copy_arrays(int, int, int);
-  int pack_exchange(int, double *);
-  int unpack_exchange(int, double *);
-  double memory_usage();
+  int pack_forward_comm(int, int *, double *, int, int *) override;
+  void unpack_forward_comm(int, int, double *) override;
+  int pack_reverse_comm(int, int, double *) override;
+  void unpack_reverse_comm(int, int *, double *) override;
+  void grow_arrays(int) override;
+  void copy_arrays(int, int, int) override;
+  int pack_exchange(int, double *) override;
+  int unpack_exchange(int, double *) override;
+  double memory_usage() override;
 
  private:
   void setup_arrays_and_pointers();
@@ -64,7 +63,7 @@ class FixHMC : public Fix {
   tagint *stored_tag;
   int stored_nlocal, stored_nghost, stored_ntotal, stored_nmax;
   int stored_nbonds, stored_nangles, stored_ndihedrals, stored_nimpropers;
-  FixRigidSmall::Body *stored_body;
+  class RigidSmallBody *stored_body;
   int stored_nlocal_body, stored_nghost_body, stored_ntotal_body;
   int *stored_bodyown;
   tagint *stored_bodytag;

src/OPENMP/fix_rigid_small_omp.cpp

@@ -39,6 +39,7 @@ using namespace LAMMPS_NS;
 using namespace FixConst;
 using namespace MathConst;
 using namespace RigidConst;
+typedef RigidSmallBody Body;
 
 typedef struct {
   double x, y, z;

src/RIGID/compute_rigid_local.cpp

@@ -13,7 +13,7 @@
 ------------------------------------------------------------------------- */
 
 #include "compute_rigid_local.h"
-#include <cstring>
+
 #include "atom.h"
 #include "update.h"
 #include "domain.h"
@@ -22,6 +22,8 @@
 #include "memory.h"
 #include "error.h"
 
+#include <cstring>
+
 using namespace LAMMPS_NS;
 
 #define DELTA 10000
@@ -150,7 +152,7 @@ int ComputeRigidLocal::compute_rigid(int flag)
 {
   int i,m,n,ibody;
   double *ptr;
-  FixRigidSmall::Body *body;
+  RigidSmallBody *body;
 
   double xprd = domain->xprd;
   double yprd = domain->yprd;

src/RIGID/fix_rigid_nh_small.cpp

@@ -42,6 +42,7 @@ using namespace LAMMPS_NS;
 using namespace FixConst;
 using namespace MathExtra;
 using namespace RigidConst;
+typedef RigidSmallBody Body;
 
 /* ---------------------------------------------------------------------- */
 

src/RIGID/fix_rigid_small.cpp

@@ -48,6 +48,7 @@ using namespace LAMMPS_NS;
 using namespace FixConst;
 using namespace MathConst;
 using namespace RigidConst;
+typedef RigidSmallBody Body;
 
 #define RVOUS 1   // 0 for irregular, 1 for all2all
 

src/RIGID/fix_rigid_small.h

@@ -24,6 +24,29 @@ FixStyle(rigid/small,FixRigidSmall);
 
 namespace LAMMPS_NS {
 
+struct RigidSmallBody {
+  int natoms;            // total number of atoms in body
+  int ilocal;            // index of owning atom
+  double mass;           // total mass of body
+  double xcm[3];         // COM position
+  double xgc[3];         // geometric center position
+  double vcm[3];         // COM velocity
+  double fcm[3];         // force on COM
+  double torque[3];      // torque around COM
+  double quat[4];        // quaternion for orientation of body
+  double inertia[3];     // 3 principal components of inertia
+  double ex_space[3];    // principal axes in space coords
+  double ey_space[3];
+  double ez_space[3];
+  double xgc_body[3];    // geometric center relative to xcm in body coords
+  double angmom[3];      // space-frame angular momentum of body
+  double omega[3];       // space-frame omega of body
+  double conjqm[4];      // conjugate quaternion momentum
+  int remapflag[4];      // PBC remap flags
+  imageint image;        // image flags of xcm
+  imageint dummy;        // dummy entry for better alignment
+};
+
 class FixRigidSmall : public Fix {
   friend class ComputeRigidLocal;
   friend class FixHMC;
@@ -82,34 +105,11 @@ class FixRigidSmall : public Fix {
   tagint maxmol;       // max mol-ID
   double maxextent;    // furthest distance from body owner to body atom
 
-  struct Body {
-    int natoms;            // total number of atoms in body
-    int ilocal;            // index of owning atom
-    double mass;           // total mass of body
-    double xcm[3];         // COM position
-    double xgc[3];         // geometric center position
-    double vcm[3];         // COM velocity
-    double fcm[3];         // force on COM
-    double torque[3];      // torque around COM
-    double quat[4];        // quaternion for orientation of body
-    double inertia[3];     // 3 principal components of inertia
-    double ex_space[3];    // principal axes in space coords
-    double ey_space[3];
-    double ez_space[3];
-    double xgc_body[3];    // geometric center relative to xcm in body coords
-    double angmom[3];      // space-frame angular momentum of body
-    double omega[3];       // space-frame omega of body
-    double conjqm[4];      // conjugate quaternion momentum
-    int remapflag[4];      // PBC remap flags
-    imageint image;        // image flags of xcm
-    imageint dummy;        // dummy entry for better alignment
-  };
-
-  Body *body;         // list of rigid bodies, owned and ghost
-  int nlocal_body;    // # of owned rigid bodies
-  int nghost_body;    // # of ghost rigid bodies
-  int nmax_body;      // max # of bodies that body can hold
-  int bodysize;       // sizeof(Body) in doubles
+  RigidSmallBody *body;    // list of rigid bodies, owned and ghost
+  int nlocal_body;         // # of owned rigid bodies
+  int nghost_body;         // # of ghost rigid bodies
+  int nmax_body;           // max # of bodies that body can hold
+  int bodysize;            // sizeof(Body) in doubles
 
   // per-atom quantities
   // only defined for owned atoms, except bodyown for own+ghost