At compile time, packages linking to 'ergm' will now store the C API …

…version numbers of the 'ergm' installation they were built against in global variables built_ERGM_API_MAJOR and built_ERGM_API_MINOR; model and proposal initialization code will then check whether the linking package was compiled under a wrong version and issue a warning.

inst/include/ergm_Rutil.h

@@ -71,4 +71,6 @@ static inline void *R_calloc_helper(size_t n, size_t size){
 
 #define R_CheckUserInterruptEvery(freq, iter) if((iter)%(freq) == 0) R_CheckUserInterrupt();
 
+void warn_API_version(const char *sn);
+
 #endif 

inst/include/ergm_stubs.c

@@ -8,6 +8,11 @@
  *  Copyright 2003-2024 Statnet Commons
  */
 
+#include "ergm_constants.h"
+
+unsigned int built_ERGM_API_MAJOR = ERGM_API_MAJOR;
+unsigned int built_ERGM_API_MINOR = ERGM_API_MINOR;
+
 #define STUBFILE
 #include <stddef.h>
 #include <R_ext/Rdynload.h>
@@ -77,6 +82,16 @@ static void (*fun)(Vertex,Vertex,double,void *,WtNetwork *,double) = NULL;
 if(fun==NULL) fun = (void (*)(Vertex,Vertex,double,void *,WtNetwork *,double)) R_FindSymbol("WtDyadGenUpdate", "ergm", NULL);
 fun(tail,head,weight,gen,nwp,edgestate);
 }
+void AddOnDyadGenInit(OnDyadGenInit callback, void *payload){
+static void (*fun)(OnDyadGenInit,void *) = NULL;
+if(fun==NULL) fun = (void (*)(OnDyadGenInit,void *)) R_FindSymbol("AddOnDyadGenInit", "ergm", NULL);
+fun(callback,payload);
+}
+void DeleteOnDyadGenInit(OnDyadGenInit callback, void *payload){
+static void (*fun)(OnDyadGenInit,void *) = NULL;
+if(fun==NULL) fun = (void (*)(OnDyadGenInit,void *)) R_FindSymbol("DeleteOnDyadGenInit", "ergm", NULL);
+fun(callback,payload);
+}
 
 #define STUBFILE
 #include <stddef.h>

src/MHproposal.c

@@ -31,6 +31,10 @@ MHProposal *MHProposalInitialize(SEXP pR, Network *nwp, void **aux_storage){
   /* Extract the required string information from the relevant sources */
   const char *fname = FIRSTCHAR(getListElement(pR, "name")),
     *sn = FIRSTCHAR(getListElement(pR, "pkgname"));
+
+  /* Check if the package is compiled against a different version of 'ergm'. */
+  warn_API_version(sn);
+
   char *fn = R_Calloc(strlen(fname)+4, char);
   fn[0]='M';
   fn[1]='H';

src/ergm_Rutil.c

@@ -0,0 +1,34 @@
+#include "ergm_Rutil.h"
+#include "ergm_constants.h"
+#include "ergm_kvec.h"
+#include "ergm_khash.h"
+
+unsigned int built_ERGM_API_MAJOR = ERGM_API_MAJOR;
+unsigned int built_ERGM_API_MINOR = ERGM_API_MINOR;
+
+static kvec_t(khint_t) build_version_warned = kv_blank;
+
+void warn_API_version(const char *sn){
+
+  /* Here, we are saving the hash of the library name rather than the
+     name itself, since keeping track of strings allocated from the
+     heap is a hassle, and we don't want to assume that sn will always
+     be around. Chances of collision are negligible. */
+  khint_t snhash = kh_str_hash_func(sn);
+  unsigned int i = 0;
+  while(i < kv_size(build_version_warned) && kv_A(build_version_warned, i) != snhash) i++;
+  if(i < kv_size(build_version_warned)) return;
+
+  kv_push(khint_t, build_version_warned, snhash);
+
+  void *bv = R_FindSymbol("built_ERGM_API_MAJOR",sn,NULL);
+  unsigned int bv_major = bv ? *(unsigned int *)bv : 0;
+  if(bv_major){
+    unsigned int bv_minor = *(unsigned int *)R_FindSymbol("built_ERGM_API_MINOR",sn,NULL);
+    if(bv_major != ERGM_API_MAJOR || bv_minor != ERGM_API_MINOR)
+      warningcall_immediate(R_NilValue, "Package '%s' was compiled against 'ergm' with C API version\n    %d.%d, but it is being loaded by 'ergm' with C API version %d.%d. Inconsistent\n    versions may result in malfunctions ranging from incorrect results to R\n    crashing. Please rebuild the package against the current 'ergm' version.",
+              sn, bv_major, bv_minor, ERGM_API_MAJOR, ERGM_API_MINOR);
+  }else
+    warningcall_immediate(R_NilValue, "Package '%s' was compiled against an older version of 'ergm'\n    that did not store '%s''s C API version information. Inconsistent\n    versions may cause malfunctions ranging from incorrect results to R\n    crashing. Please rebuild the package against the current 'ergm' version.",
+                          sn, sn);
+}

src/model.c

@@ -162,6 +162,10 @@ Model* ModelInitialize(SEXP mR, SEXP ext_state, Network *nwp, Rboolean noinit_s)
       the respective functions.*/
       const char *fname = FIRSTCHAR(getListElement(thisterm->R, "name")),
         *sn = FIRSTCHAR(getListElement(thisterm->R, "pkgname"));
+
+      /* Check if the package is compiled against a different version of 'ergm'. */
+      warn_API_version(sn);
+
       /* Extract the required string information from the relevant sources */
       char *fn = R_Calloc(strlen(fname)+3, char);
       fn[1]='_';

src/wtMHproposal.c

@@ -30,6 +30,10 @@ WtMHProposal *WtMHProposalInitialize(SEXP pR, WtNetwork *nwp, void **aux_storage
   /* Extract the required string information from the relevant sources */
   const char *fname = FIRSTCHAR(getListElement(pR, "name")),
     *sn = FIRSTCHAR(getListElement(pR, "pkgname"));
+
+  /* Check if the package is compiled against a different version of 'ergm'. */
+  warn_API_version(sn);
+
   char *fn = R_Calloc(strlen(fname)+4, char);
   fn[0]='M';
   fn[1]='H';

src/wtmodel.c

@@ -162,6 +162,10 @@ WtModel* WtModelInitialize (SEXP mR, SEXP ext_state, WtNetwork *nwp, Rboolean no
       the respective functions.*/
       const char *fname = FIRSTCHAR(getListElement(thisterm->R, "name")),
         *sn = FIRSTCHAR(getListElement(thisterm->R, "pkgname"));
+
+      /* Check if the package is compiled against a different version of 'ergm'. */
+      warn_API_version(sn);
+
       /* Extract the required string information from the relevant sources */
       char *fn = R_Calloc(strlen(fname)+3, char);
       fn[1]='_';