introduces netbsd's reallocarr overriding.

and couple of tests.

include/mimalloc-override.h

@@ -48,6 +48,7 @@ not accidentally mix pointers from different allocators).
 #define valloc(n)               mi_valloc(n)
 #define pvalloc(n)              mi_pvalloc(n)
 #define reallocarray(p,s,n)     mi_reallocarray(p,s,n)
+#define reallocarr(p,s,n)       mi_reallocarr(p,s,n)
 #define memalign(a,n)           mi_memalign(a,n)
 #define aligned_alloc(a,n)      mi_aligned_alloc(a,n)
 #define posix_memalign(p,a,n)   mi_posix_memalign(p,a,n)

include/mimalloc.h

@@ -351,6 +351,7 @@ mi_decl_nodiscard mi_decl_export mi_decl_restrict void* mi_pvalloc(size_t size)
 mi_decl_nodiscard mi_decl_export mi_decl_restrict void* mi_aligned_alloc(size_t alignment, size_t size) mi_attr_noexcept mi_attr_malloc mi_attr_alloc_size(2) mi_attr_alloc_align(1);
 
 mi_decl_nodiscard mi_decl_export void* mi_reallocarray(void* p, size_t count, size_t size) mi_attr_noexcept mi_attr_alloc_size2(2,3);
+mi_decl_nodiscard mi_decl_export int   mi_reallocarr(void* p, size_t count, size_t size) mi_attr_noexcept mi_attr_alloc_size2(2,3);
 mi_decl_nodiscard mi_decl_export void* mi_aligned_recalloc(void* p, size_t newcount, size_t size, size_t alignment) mi_attr_noexcept;
 mi_decl_nodiscard mi_decl_export void* mi_aligned_offset_recalloc(void* p, size_t newcount, size_t size, size_t alignment, size_t offset) mi_attr_noexcept;
 

src/alloc-override.c

@@ -183,6 +183,7 @@ size_t malloc_usable_size(const void *p) MI_FORWARD1(mi_usable_size,p);
 void* valloc(size_t size)                                     { return mi_valloc(size); }
 void* pvalloc(size_t size)                                    { return mi_pvalloc(size); }
 void* reallocarray(void* p, size_t count, size_t size)        { return mi_reallocarray(p, count, size); }
+int   reallocarr(void* p, size_t count, size_t size)          { return mi_reallocarr(&p, count, size); }
 void* memalign(size_t alignment, size_t size)                 { return mi_memalign(alignment, size); }
 int   posix_memalign(void** p, size_t alignment, size_t size) { return mi_posix_memalign(p, alignment, size); }
 void* _aligned_malloc(size_t alignment, size_t size)          { return mi_aligned_alloc(alignment, size); }

src/alloc-posix.c

@@ -90,6 +90,20 @@ void* mi_reallocarray( void* p, size_t count, size_t size ) mi_attr_noexcept {
   return newp;
 }
 
+int mi_reallocarr( void* p, size_t count, size_t size ) mi_attr_noexcept { // NetBSD
+  void** op = (void** )p;
+  int serrno = errno;
+  void* newp = mi_reallocn(p,count,size);
+  if (mi_unlikely(newp == NULL)) {
+    errno = ENOMEM;
+    return errno;
+  } else {
+    *op = newp;
+    errno = serrno;
+    return 0;
+  }
+}
+
 void* mi__expand(void* p, size_t newsize) mi_attr_noexcept {  // Microsoft
   void* res = mi_expand(p, newsize);
   if (res == NULL) errno = ENOMEM;

test/main-override.c

@@ -3,7 +3,7 @@
 #include <assert.h>
 #include <string.h>
 
-#include <mimalloc.h>
+#include <mimalloc-override.h>
 
 int main() {
   mi_version();       // ensure mimalloc library is linked
@@ -25,6 +25,12 @@ int main() {
   //free(p1);
   //p2 = malloc(32);
   //mi_free(p2);
+  p1 = malloc(24);
+  p2 = reallocarray(p1, 16, 16);
+  free(p2);
+  p1 = malloc(24);
+  assert(reallocarr(&p1, 16, 16) == 0);
+  free(p1);
   mi_stats_print(NULL);
   return 0;
 }