implement reallocarray on macOS

.idea/misc.xml

@@ -1,4 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="CMakePythonSetting">
+    <option name="pythonIntegrationState" value="YES" />
+  </component>
   <component name="CMakeWorkspace" PROJECT_DIR="$PROJECT_DIR$" />
 </project>

include/lfmacos.h

@@ -3,6 +3,8 @@
 
 #if defined(__APPLE__) || defined(__MACH__)
 
+#include <time.h>
+
 typedef struct {
     double total_user_time;
     double total_kernel_time;
@@ -18,6 +20,7 @@ typedef struct {
 
 ProcessData *new_ProcessData();
 int update_process(pid_t pid, ProcessData *proc);
+void *reallocarray(void *optr, size_t nmemb, size_t size);
 
 #endif /* defined(__APPLE__) || defined(__MACH__) */
 #endif /* LIBFLINT_MACOS_H */

src/macos.c

@@ -1,6 +1,7 @@
 #include <libproc.h>
 #include <time.h>
 #include <mach/mach_time.h>
+#include <sys/errno.h>
 #include <stdlib.h>
 
 #include "lfmacos.h"
@@ -43,3 +44,39 @@ int update_process(pid_t pid, ProcessData *proc) {
 
     return 0;
 }
+
+/* reallocarray is reimplemented here for macOS because Apple doesn't expose
+ * their implementation. This is taken straight from the OpenBSD source as
+ * shown in the below copyright notice
+ */
+
+/*	$OpenBSD: reallocarray.c,v 1.2 2014/12/08 03:45:00 bcook Exp $	*/
+/*
+ * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* OPENBSD ORIGINAL: lib/libc/stdlib/reallocarray.c */
+
+#define MUL_NO_OVERFLOW	((size_t)1 << (sizeof(size_t) * 4))
+
+void *reallocarray(void *optr, size_t nmemb, size_t size)
+{
+    if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
+        nmemb > 0 && SIZE_MAX / nmemb < size) {
+        errno = ENOMEM;
+        return NULL;
+    }
+    return realloc(optr, size * nmemb);
+}

src/vector.c

@@ -5,6 +5,10 @@
 #include <bsd/stdlib.h>
 #endif
 
+#if defined(__APPLE__) || defined(__MACH__)
+#include "lfmacos.h"
+#endif
+
 #include "lfvector.h"
 
 #define VEC_INIT_CAP 2
@@ -32,11 +36,7 @@ int vec_init_with_capacity(Vector *vec, void (*destroy)(void *data), size_t capa
 static int vec_grow(Vector *const vec) {
     vec->capacity *= 2;
 
-#ifdef __OpenBSD__
     vec->elements = reallocarray(vec->elements, vec->capacity, sizeof(void *));
-#else
-    vec->elements = reallocf(vec->elements, sizeof(void *) * vec->capacity);
-#endif
 
     if (vec->elements == NULL) {
         return -1;