--- a/agent/src/os/bsd/libproc_impl.c	Wed Mar 13 17:34:29 2013 -0400
+++ b/agent/src/os/bsd/libproc_impl.c	Thu Mar 14 00:33:08 2013 -0700
@@ -21,12 +21,6 @@
  * questions.
  *
  */
-#include <stdarg.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <fcntl.h>
-#include <thread_db.h>
 #include "libproc_impl.h"
 
 static const char* alt_root = NULL;
@@ -34,61 +28,65 @@
 
 #define SA_ALTROOT "SA_ALTROOT"
 
+off_t ltell(int fd) {
+  return lseek(fd, 0, SEEK_CUR);
+}
+
 static void init_alt_root() {
-   if (alt_root_len == -1) {
-      alt_root = getenv(SA_ALTROOT);
-      if (alt_root) {
-         alt_root_len = strlen(alt_root);
-      } else {
-         alt_root_len = 0;
-      }
-   }
+  if (alt_root_len == -1) {
+    alt_root = getenv(SA_ALTROOT);
+    if (alt_root) {
+      alt_root_len = strlen(alt_root);
+    } else {
+      alt_root_len = 0;
+    }
+  }
 }
 
 int pathmap_open(const char* name) {
-   int fd;
-   char alt_path[PATH_MAX + 1];
+  int fd;
+  char alt_path[PATH_MAX + 1];
+
+  init_alt_root();
 
-   init_alt_root();
-   fd = open(name, O_RDONLY);
-   if (fd >= 0) {
+  if (alt_root_len > 0) {
+    strcpy(alt_path, alt_root);
+    strcat(alt_path, name);
+    fd = open(alt_path, O_RDONLY);
+    if (fd >= 0) {
+      print_debug("path %s substituted for %s\n", alt_path, name);
       return fd;
-   }
+    }
 
-   if (alt_root_len > 0) {
+    if (strrchr(name, '/')) {
       strcpy(alt_path, alt_root);
-      strcat(alt_path, name);
+      strcat(alt_path, strrchr(name, '/'));
       fd = open(alt_path, O_RDONLY);
       if (fd >= 0) {
-         print_debug("path %s substituted for %s\n", alt_path, name);
-         return fd;
+        print_debug("path %s substituted for %s\n", alt_path, name);
+        return fd;
       }
-
-      if (strrchr(name, '/')) {
-         strcpy(alt_path, alt_root);
-         strcat(alt_path, strrchr(name, '/'));
-         fd = open(alt_path, O_RDONLY);
-         if (fd >= 0) {
-            print_debug("path %s substituted for %s\n", alt_path, name);
-            return fd;
-         }
-      }
-   }
-
-   return -1;
+    }
+  } else {
+    fd = open(name, O_RDONLY);
+    if (fd >= 0) {
+      return fd;
+    }
+  }
+  return -1;
 }
 
 static bool _libsaproc_debug;
 
 void print_debug(const char* format,...) {
-   if (_libsaproc_debug) {
-     va_list alist;
+  if (_libsaproc_debug) {
+    va_list alist;
 
-     va_start(alist, format);
-     fputs("libsaproc DEBUG: ", stderr);
-     vfprintf(stderr, format, alist);
-     va_end(alist);
-   }
+    va_start(alist, format);
+    fputs("libsaproc DEBUG: ", stderr);
+    vfprintf(stderr, format, alist);
+    va_end(alist);
+  }
 }
 
 void print_error(const char* format,...) {
@@ -100,172 +98,235 @@
 }
 
 bool is_debug() {
-   return _libsaproc_debug;
+  return _libsaproc_debug;
 }
 
+#ifdef __APPLE__
+// get arch offset in file
+bool get_arch_off(int fd, cpu_type_t cputype, off_t *offset) {
+  struct fat_header fatheader;
+  struct fat_arch fatarch;
+  off_t img_start = 0;
+
+  off_t pos = ltell(fd);
+  if (read(fd, (void *)&fatheader, sizeof(struct fat_header)) != sizeof(struct fat_header)) {
+    return false;
+  }
+  if (fatheader.magic == FAT_CIGAM) {
+    int i;
+    for (i = 0; i < ntohl(fatheader.nfat_arch); i++) {
+      if (read(fd, (void *)&fatarch, sizeof(struct fat_arch)) != sizeof(struct fat_arch)) {
+        return false;
+      }
+      if (ntohl(fatarch.cputype) == cputype) {
+        print_debug("fat offset=%x\n", ntohl(fatarch.offset));
+        img_start = ntohl(fatarch.offset);
+        break;
+      }
+    }
+    if (img_start == 0) {
+      return false;
+    }
+  }
+  lseek(fd, pos, SEEK_SET);
+  *offset = img_start;
+  return true;
+}
+
+bool is_macho_file(int fd) {
+  mach_header_64 fhdr;
+  off_t x86_64_off;
+
+  if (fd < 0) {
+    print_debug("Invalid file handle passed to is_macho_file\n");
+    return false;
+  }
+
+  off_t pos = ltell(fd);
+  // check fat header
+  if (!get_arch_off(fd, CPU_TYPE_X86_64, &x86_64_off)) {
+    print_debug("failed to get fat header\n");
+    return false;
+  }
+  lseek(fd, x86_64_off, SEEK_SET);
+  if (read(fd, (void *)&fhdr, sizeof(mach_header_64)) != sizeof(mach_header_64)) {
+     return false;
+  }
+  lseek(fd, pos, SEEK_SET);               // restore
+  print_debug("fhdr.magic %x\n", fhdr.magic);
+  return (fhdr.magic == MH_MAGIC_64 || fhdr.magic == MH_CIGAM_64);
+}
+
+#endif //__APPLE__
+
 // initialize libproc
 bool init_libproc(bool debug) {
-   // init debug mode
    _libsaproc_debug = debug;
-
+#ifndef __APPLE__
    // initialize the thread_db library
    if (td_init() != TD_OK) {
      print_debug("libthread_db's td_init failed\n");
      return false;
    }
-
+#endif // __APPLE__
    return true;
 }
 
-static void destroy_lib_info(struct ps_prochandle* ph) {
-   lib_info* lib = ph->libs;
-   while (lib) {
-     lib_info *next = lib->next;
-     if (lib->symtab) {
-        destroy_symtab(lib->symtab);
-     }
-     free(lib);
-     lib = next;
-   }
+void destroy_lib_info(struct ps_prochandle* ph) {
+  lib_info* lib = ph->libs;
+  while (lib) {
+    lib_info* next = lib->next;
+    if (lib->symtab) {
+      destroy_symtab(lib->symtab);
+    }
+    free(lib);
+    lib = next;
+  }
 }
 
-static void destroy_thread_info(struct ps_prochandle* ph) {
-   thread_info* thr = ph->threads;
-   while (thr) {
-     thread_info *next = thr->next;
-     free(thr);
-     thr = next;
-   }
+void destroy_thread_info(struct ps_prochandle* ph) {
+  sa_thread_info* thr = ph->threads;
+  while (thr) {
+    sa_thread_info* n = thr->next;
+    free(thr);
+    thr = n;
+  }
 }
 
 // ps_prochandle cleanup
-
-// ps_prochandle cleanup
 void Prelease(struct ps_prochandle* ph) {
-   // do the "derived class" clean-up first
-   ph->ops->release(ph);
-   destroy_lib_info(ph);
-   destroy_thread_info(ph);
-   free(ph);
+  // do the "derived class" clean-up first
+  ph->ops->release(ph);
+  destroy_lib_info(ph);
+  destroy_thread_info(ph);
+  free(ph);
 }
 
 lib_info* add_lib_info(struct ps_prochandle* ph, const char* libname, uintptr_t base) {
-   return add_lib_info_fd(ph, libname, -1, base);
+  return add_lib_info_fd(ph, libname, -1, base);
 }
 
 lib_info* add_lib_info_fd(struct ps_prochandle* ph, const char* libname, int fd, uintptr_t base) {
    lib_info* newlib;
+  print_debug("add_lib_info_fd %s\n", libname);
 
-   if ( (newlib = (lib_info*) calloc(1, sizeof(struct lib_info))) == NULL) {
-      print_debug("can't allocate memory for lib_info\n");
-      return NULL;
-   }
-
-   strncpy(newlib->name, libname, sizeof(newlib->name));
-   newlib->base = base;
+  if ( (newlib = (lib_info*) calloc(1, sizeof(struct lib_info))) == NULL) {
+    print_debug("can't allocate memory for lib_info\n");
+    return NULL;
+  }
 
-   if (fd == -1) {
-      if ( (newlib->fd = pathmap_open(newlib->name)) < 0) {
-         print_debug("can't open shared object %s\n", newlib->name);
-         free(newlib);
-         return NULL;
-      }
-   } else {
-      newlib->fd = fd;
-   }
+  strncpy(newlib->name, libname, sizeof(newlib->name));
+  newlib->base = base;
 
-   // check whether we have got an ELF file. /proc/<pid>/map
-   // gives out all file mappings and not just shared objects
-   if (is_elf_file(newlib->fd) == false) {
-      close(newlib->fd);
+  if (fd == -1) {
+    if ( (newlib->fd = pathmap_open(newlib->name)) < 0) {
+      print_debug("can't open shared object %s\n", newlib->name);
       free(newlib);
       return NULL;
-   }
-
-   newlib->symtab = build_symtab(newlib->fd);
-   if (newlib->symtab == NULL) {
-      print_debug("symbol table build failed for %s\n", newlib->name);
-   }
-   else {
-      print_debug("built symbol table for %s\n", newlib->name);
-   }
+    }
+  } else {
+    newlib->fd = fd;
+  }
 
-   // even if symbol table building fails, we add the lib_info.
-   // This is because we may need to read from the ELF file for core file
-   // address read functionality. lookup_symbol checks for NULL symtab.
-   if (ph->libs) {
-      ph->lib_tail->next = newlib;
-      ph->lib_tail = newlib;
-   }  else {
-      ph->libs = ph->lib_tail = newlib;
-   }
-   ph->num_libs++;
+#ifdef __APPLE__
+  // check whether we have got an Macho file.
+  if (is_macho_file(newlib->fd) == false) {
+    close(newlib->fd);
+    free(newlib);
+    print_debug("not a mach-o file\n");
+    return NULL;
+  }
+#else
+  // check whether we have got an ELF file. /proc/<pid>/map
+  // gives out all file mappings and not just shared objects
+  if (is_elf_file(newlib->fd) == false) {
+    close(newlib->fd);
+    free(newlib);
+    return NULL;
+  }
+#endif // __APPLE__
 
-   return newlib;
+  newlib->symtab = build_symtab(newlib->fd);
+  if (newlib->symtab == NULL) {
+    print_debug("symbol table build failed for %s\n", newlib->name);
+  } else {
+    print_debug("built symbol table for %s\n", newlib->name);
+  }
+
+  // even if symbol table building fails, we add the lib_info.
+  // This is because we may need to read from the ELF file or MachO file for core file
+  // address read functionality. lookup_symbol checks for NULL symtab.
+  if (ph->libs) {
+    ph->lib_tail->next = newlib;
+    ph->lib_tail = newlib;
+  }  else {
+    ph->libs = ph->lib_tail = newlib;
+  }
+  ph->num_libs++;
+  return newlib;
 }
 
 // lookup for a specific symbol
 uintptr_t lookup_symbol(struct ps_prochandle* ph,  const char* object_name,
                        const char* sym_name) {
-   // ignore object_name. search in all libraries
-   // FIXME: what should we do with object_name?? The library names are obtained
-   // by parsing /proc/<pid>/maps, which may not be the same as object_name.
-   // What we need is a utility to map object_name to real file name, something
-   // dlopen() does by looking at LD_LIBRARY_PATH and /etc/ld.so.cache. For
-   // now, we just ignore object_name and do a global search for the symbol.
+  // ignore object_name. search in all libraries
+  // FIXME: what should we do with object_name?? The library names are obtained
+  // by parsing /proc/<pid>/maps, which may not be the same as object_name.
+  // What we need is a utility to map object_name to real file name, something
+  // dlopen() does by looking at LD_LIBRARY_PATH and /etc/ld.so.cache. For
+  // now, we just ignore object_name and do a global search for the symbol.
 
-   lib_info* lib = ph->libs;
-   while (lib) {
-      if (lib->symtab) {
-         uintptr_t res = search_symbol(lib->symtab, lib->base, sym_name, NULL);
-         if (res) return res;
-      }
-      lib = lib->next;
-   }
+  lib_info* lib = ph->libs;
+  while (lib) {
+    if (lib->symtab) {
+      uintptr_t res = search_symbol(lib->symtab, lib->base, sym_name, NULL);
+      if (res) return res;
+    }
+    lib = lib->next;
+  }
 
-   print_debug("lookup failed for symbol '%s' in obj '%s'\n",
+  print_debug("lookup failed for symbol '%s' in obj '%s'\n",
                           sym_name, object_name);
-   return (uintptr_t) NULL;
+  return (uintptr_t) NULL;
 }
 
-
 const char* symbol_for_pc(struct ps_prochandle* ph, uintptr_t addr, uintptr_t* poffset) {
-   const char* res = NULL;
-   lib_info* lib = ph->libs;
-   while (lib) {
-      if (lib->symtab && addr >= lib->base) {
-         res = nearest_symbol(lib->symtab, addr - lib->base, poffset);
-         if (res) return res;
-      }
-      lib = lib->next;
-   }
-   return NULL;
+  const char* res = NULL;
+  lib_info* lib = ph->libs;
+  while (lib) {
+    if (lib->symtab && addr >= lib->base) {
+      res = nearest_symbol(lib->symtab, addr - lib->base, poffset);
+      if (res) return res;
+    }
+    lib = lib->next;
+  }
+  return NULL;
 }
 
 // add a thread to ps_prochandle
-thread_info* add_thread_info(struct ps_prochandle* ph, pthread_t pthread_id, lwpid_t lwp_id) {
-   thread_info* newthr;
-   if ( (newthr = (thread_info*) calloc(1, sizeof(thread_info))) == NULL) {
-      print_debug("can't allocate memory for thread_info\n");
-      return NULL;
-   }
+sa_thread_info* add_thread_info(struct ps_prochandle* ph, pthread_t pthread_id, lwpid_t lwp_id) {
+  sa_thread_info* newthr;
+  if ( (newthr = (sa_thread_info*) calloc(1, sizeof(sa_thread_info))) == NULL) {
+    print_debug("can't allocate memory for thread_info\n");
+    return NULL;
+  }
 
-   // initialize thread info
-   newthr->pthread_id = pthread_id;
-   newthr->lwp_id = lwp_id;
+  // initialize thread info
+  newthr->pthread_id = pthread_id;
+  newthr->lwp_id = lwp_id;
 
-   // add new thread to the list
-   newthr->next = ph->threads;
-   ph->threads = newthr;
-   ph->num_threads++;
-   return newthr;
+  // add new thread to the list
+  newthr->next = ph->threads;
+  ph->threads = newthr;
+  ph->num_threads++;
+  return newthr;
 }
 
-
+#ifndef __APPLE__
 // struct used for client data from thread_db callback
 struct thread_db_client_data {
-   struct ps_prochandle* ph;
-   thread_info_callback callback;
+  struct ps_prochandle* ph;
+  thread_info_callback callback;
 };
 
 // callback function for libthread_db
@@ -314,6 +375,7 @@
   return true;
 }
 
+#endif // __APPLE__
 
 // get number of threads
 int get_num_threads(struct ps_prochandle* ph) {
@@ -322,18 +384,54 @@
 
 // get lwp_id of n'th thread
 lwpid_t get_lwp_id(struct ps_prochandle* ph, int index) {
-   int count = 0;
-   thread_info* thr = ph->threads;
-   while (thr) {
-      if (count == index) {
-         return thr->lwp_id;
-      }
-      count++;
-      thr = thr->next;
-   }
-   return -1;
+  int count = 0;
+  sa_thread_info* thr = ph->threads;
+  while (thr) {
+    if (count == index) {
+      return thr->lwp_id;
+    }
+    count++;
+    thr = thr->next;
+  }
+  return 0;
 }
 
+#ifdef __APPLE__
+// set lwp_id of n'th thread
+bool set_lwp_id(struct ps_prochandle* ph, int index, lwpid_t lwpid) {
+  int count = 0;
+  sa_thread_info* thr = ph->threads;
+  while (thr) {
+    if (count == index) {
+      thr->lwp_id = lwpid;
+      return true;
+    }
+    count++;
+    thr = thr->next;
+  }
+  return false;
+}
+
+// get regs of n-th thread, only used in fillThreads the first time called
+bool get_nth_lwp_regs(struct ps_prochandle* ph, int index, struct reg* regs) {
+  int count = 0;
+  sa_thread_info* thr = ph->threads;
+  while (thr) {
+    if (count == index) {
+      break;
+    }
+    count++;
+    thr = thr->next;
+  }
+  if (thr != NULL) {
+    memcpy(regs, &thr->regs, sizeof(struct reg));
+    return true;
+  }
+  return false;
+}
+
+#endif // __APPLE__
+
 // get regs for a given lwp
 bool get_lwp_regs(struct ps_prochandle* ph, lwpid_t lwp_id, struct reg* regs) {
   return ph->ops->get_lwp_regs(ph, lwp_id, regs);
@@ -341,35 +439,35 @@
 
 // get number of shared objects
 int get_num_libs(struct ps_prochandle* ph) {
-   return ph->num_libs;
+  return ph->num_libs;
 }
 
 // get name of n'th solib
 const char* get_lib_name(struct ps_prochandle* ph, int index) {
-   int count = 0;
-   lib_info* lib = ph->libs;
-   while (lib) {
-      if (count == index) {
-         return lib->name;
-      }
-      count++;
-      lib = lib->next;
-   }
-   return NULL;
+  int count = 0;
+  lib_info* lib = ph->libs;
+  while (lib) {
+    if (count == index) {
+      return lib->name;
+    }
+    count++;
+    lib = lib->next;
+  }
+  return NULL;
 }
 
 // get base address of a lib
 uintptr_t get_lib_base(struct ps_prochandle* ph, int index) {
-   int count = 0;
-   lib_info* lib = ph->libs;
-   while (lib) {
-      if (count == index) {
-         return lib->base;
-      }
-      count++;
-      lib = lib->next;
-   }
-   return (uintptr_t)NULL;
+  int count = 0;
+  lib_info* lib = ph->libs;
+  while (lib) {
+    if (count == index) {
+      return lib->base;
+    }
+    count++;
+    lib = lib->next;
+  }
+  return (uintptr_t)NULL;
 }
 
 bool find_lib(struct ps_prochandle* ph, const char *lib_name) {
@@ -425,6 +523,7 @@
   va_end(alist);
 }
 
+#ifndef __APPLE__
 // ------------------------------------------------------------------------
 // Functions below this point are not yet implemented. They are here only
 // to make the linker happy.
@@ -458,3 +557,4 @@
   print_debug("ps_pcontinue not implemented\n");
   return PS_OK;
 }
+#endif // __APPLE__