Fixed files to support FreeBSD amd64 based on patches at:

http://www.freebsd.org/cgi/cvsweb.cgi/ports/devel/glog/files/

Since FreeBSD do not have gettid system call unlikely to MacOSX, I
modified utilities.h not to use that on FreeBSD:
* FreeBSD lacks gettid syscall.
http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/kern/syscalls.master?rev=1.276;content-type=text%2Fplain
* MacOSX gettid == 286.
http://www.opensource.apple.com/source/xnu/xnu-1504.3.12/bsd/kern/syscalls.master
   
As for the fix of stacktrace, we use a different approach.
Even in FreeBSD, package gcc44/gcc46 has unwind.h.
As a result, checking unwind.h should be natural solution.

This patch was given by yyanagisawa



git-svn-id: https://google-glog.googlecode.com/svn/trunk@116 eb4d4688-79bd-11dd-afb4-1d65580434c0

configure.ac

@@ -44,6 +44,8 @@ AC_CHECK_HEADERS(pwd.h)
 AC_CHECK_HEADERS(syslog.h)
 AC_CHECK_HEADERS(sys/time.h)
 AC_CHECK_HEADERS(glob.h)
+# For backtrace with gcc.
+AC_CHECK_HEADERS(unwind.h)
 
 AC_CHECK_SIZEOF(void *)
 

src/utilities.cc

@@ -233,8 +233,8 @@ bool PidHasChanged() {
 }
 
 pid_t GetTID() {
-  // On Linux and FreeBSD, we try to use gettid().
-#if defined OS_LINUX || defined OS_FREEBSD || defined OS_MACOSX
+  // On Linux and MacOSX, we try to use gettid().
+#if defined OS_LINUX || defined OS_MACOSX
 #ifndef __NR_gettid
 #ifdef OS_MACOSX
 #define __NR_gettid SYS_gettid
@@ -256,7 +256,7 @@ pid_t GetTID() {
     // the value change to "true".
     lacks_gettid = true;
   }
-#endif  // OS_LINUX || OS_FREEBSD
+#endif  // OS_LINUX || OS_MACOSX
 
   // If gettid() could not be used, we use one of the following.
 #if defined OS_LINUX

src/utilities.h

@@ -106,7 +106,7 @@
 #elif !defined(NO_FRAME_POINTER)
 # if defined(__i386__) && __GNUC__ >= 2
 #  define STACKTRACE_H "stacktrace_x86-inl.h"
-# elif defined(__x86_64__) && __GNUC__ >= 2
+# elif defined(__x86_64__) && __GNUC__ >= 2 && HAVE_UNWIND_H
 #  define STACKTRACE_H "stacktrace_x86_64-inl.h"
 # elif (defined(__ppc__) || defined(__PPC__)) && __GNUC__ >= 2
 #  define STACKTRACE_H "stacktrace_powerpc-inl.h"