BSD support

gg.c

@@ -25,6 +25,71 @@
 #include <sys/stat.h>
 #include <unistd.h>
 
+#include <sys/types.h>
+
+/* sysctlbyname() is the portable way to query CPU count on every BSD family
+ * (FreeBSD, OpenBSD, NetBSD, DragonFly) and on macOS/Darwin. */
+#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) ||     defined(__DragonFly__) || defined(__APPLE__)
+#include <sys/sysctl.h>
+#endif
+
+/* On some libc implementations (e.g. FreeBSD) the d_type constants are only
+ * exposed when BSD visibility is enabled. Provide portable fallbacks matching
+ * <sys/dirent.h> so the directory-walk classification always compiles. */
+#ifndef DT_UNKNOWN
+#define DT_UNKNOWN 0
+#define DT_FIFO    1
+#define DT_CHR     2
+#define DT_DIR     4
+#define DT_BLK     6
+#define DT_REG     8
+#define DT_LNK     10
+#define DT_SOCK    12
+#define DT_WHT     14
+#endif
+
+/* memmem() is a BSD/GNU extension, not POSIX. glibc and the BSD/Darwin libcs
+ * all provide it, but only expose the prototype outside strict conformance
+ * mode, so declare it ourselves when the system has not already. Any libc that
+ * genuinely lacks it (rare) gets a small portable fallback. */
+#if defined(__GLIBC__) || defined(__FreeBSD__) || defined(__OpenBSD__) ||     defined(__NetBSD__) || defined(__DragonFly__) || defined(__APPLE__)
+#ifndef memmem
+void *memmem(const void *haystack, size_t haystacklen,
+             const void *needle, size_t needlelen);
+#endif
+#else
+static void *gg_memmem(const void *haystack, size_t haystacklen,
+                       const void *needle, size_t needlelen) {
+  if (needlelen == 0) return (void *)haystack;
+  if (haystacklen < needlelen) return NULL;
+  const unsigned char *h = (const unsigned char *)haystack;
+  const unsigned char *n = (const unsigned char *)needle;
+  const unsigned char *end = h + haystacklen - needlelen;
+  for (; h <= end; h++)
+    if (memcmp(h, n, needlelen) == 0) return (void *)h;
+  return NULL;
+}
+#define memmem gg_memmem
+#endif
+
+/* Number of online processors, portable across Linux, the BSDs and macOS. */
+static long gg_nproc(void) {
+#if defined(_SC_NPROCESSORS_ONLN)
+  long n = sysconf(_SC_NPROCESSORS_ONLN);
+  if (n > 0) return n;
+#elif defined(_SC_NPROCESSORS_CONF)
+  long n = sysconf(_SC_NPROCESSORS_CONF);
+  if (n > 0) return n;
+#endif
+#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) ||     defined(__DragonFly__) || defined(__APPLE__)
+  int ncpu = 1;
+  size_t len = sizeof(ncpu);
+  if (sysctlbyname("hw.ncpu", &ncpu, &len, NULL, 0) == 0 && ncpu > 0)
+    return (long)ncpu;
+#endif
+  return 1;
+}
+
 #ifndef PATH_MAX
 #define PATH_MAX 4096
 #endif
@@ -588,7 +653,7 @@ int main(int argc, char **argv) {
     push_dir(root, "", NULL);
   }
 
-  long nproc = sysconf(_SC_NPROCESSORS_ONLN);
+  long nproc = gg_nproc();
   if(nproc < 1)
     nproc = 1;
   int nth = (int)nproc;