Step 2 of the switch to support configuration with NPTL:

Define a new CPP symbol that the target OS is Linux, and use it where only the OS matters and not the threads Library.
Until now, 'HAVE_LINUXTHREADS' was used to indicate "Target is Linux" in many places.
When we support configuration with NPTL but no Linuxthreads, this misuse must cease.

configure.in

@@ -412,6 +412,7 @@ then
   MYSQLD_DEFAULT_SWITCHES="--skip-locking"
   TARGET_LINUX="true"
   AC_MSG_RESULT("yes");
+  AC_DEFINE([TARGET_OS_LINUX], [1], [Whether we build for Linux])
 else
   MYSQLD_DEFAULT_SWITCHES=""
   TARGET_LINUX="false"

include/my_global.h

@@ -97,7 +97,7 @@
 
 
 /* Fix problem with S_ISLNK() on Linux */
-#if defined(HAVE_LINUXTHREADS)
+#if defined(TARGET_OS_LINUX)
 #undef  _GNU_SOURCE
 #define _GNU_SOURCE 1
 #endif
@@ -214,13 +214,13 @@ C_MODE_START int __cxa_pure_virtual() {\
 #endif
 
 /* In Linux-alpha we have atomic.h if we are using gcc */
-#if defined(HAVE_LINUXTHREADS) && defined(__GNUC__) && defined(__alpha__) && (__GNUC__ > 2 || ( __GNUC__ == 2 &&  __GNUC_MINOR__ >= 95)) && !defined(HAVE_ATOMIC_ADD)
+#if defined(TARGET_OS_LINUX) && defined(__GNUC__) && defined(__alpha__) && (__GNUC__ > 2 || ( __GNUC__ == 2 &&  __GNUC_MINOR__ >= 95)) && !defined(HAVE_ATOMIC_ADD)
 #define HAVE_ATOMIC_ADD
 #define HAVE_ATOMIC_SUB
 #endif
 
 /* In Linux-ia64 including atomic.h will give us an error */
-#if (defined(HAVE_LINUXTHREADS) && defined(__GNUC__) && (defined(__ia64__)||defined(__powerpc64__))) || !defined(THREAD)
+#if (defined(TARGET_OS_LINUX) && defined(__GNUC__) && (defined(__ia64__)||defined(__powerpc64__))) || !defined(THREAD)
 #undef HAVE_ATOMIC_ADD
 #undef HAVE_ATOMIC_SUB
 #endif
@@ -755,7 +755,7 @@ typedef unsigned long	uint32; /* Short for unsigned integer >= 32 bits */
 error "Neither int or long is of 4 bytes width"
 #endif
 
-#if !defined(HAVE_ULONG) && !defined(HAVE_LINUXTHREADS) && !defined(__USE_MISC)
+#if !defined(HAVE_ULONG) && !defined(TARGET_OS_LINUX) && !defined(__USE_MISC)
 typedef unsigned long	ulong;		  /* Short for unsigned long */
 #endif
 #ifndef longlong_defined

mysys/thr_mutex.c

@@ -17,7 +17,7 @@
 /* This makes a wrapper for mutex handling to make it easier to debug mutex */
 
 #include <my_global.h>
-#if defined(HAVE_LINUXTHREADS) && !defined (__USE_UNIX98)
+#if defined(TARGET_OS_LINUX) && !defined (__USE_UNIX98)
 #define __USE_UNIX98			/* To get rw locks under Linux */
 #endif
 #if defined(THREAD) && defined(SAFE_MUTEX)

sql/stacktrace.c

@@ -43,7 +43,7 @@ void safe_print_str(const char* name, const char* val, int max_len)
   fputc('\n', stderr);
 }
 
-#ifdef HAVE_LINUXTHREADS
+#ifdef TARGET_OS_LINUX
 #define SIGRETURN_FRAME_COUNT  2
 
 #if defined(__alpha__) && defined(__GNUC__)
@@ -201,7 +201,7 @@ terribly wrong...\n");
 stack trace is much more helpful in diagnosing the problem, so please do \n\
 resolve it\n");
 }
-#endif /* HAVE_LINUXTHREADS */
+#endif /* TARGET_OS_LINUX */
 #endif /* HAVE_STACKTRACE */
 
 /* Produce a core for the thread */

sql/stacktrace.h

@@ -18,7 +18,7 @@
 extern "C" {
 #endif
 
-#ifdef HAVE_LINUXTHREADS
+#ifdef TARGET_OS_LINUX
 #if defined(HAVE_STACKTRACE) || (defined (__i386__) || (defined(__alpha__) && defined(__GNUC__)))
 #undef HAVE_STACKTRACE
 #define HAVE_STACKTRACE
@@ -30,7 +30,7 @@ extern char* heap_start;
 void print_stacktrace(gptr stack_bottom, ulong thread_stack);
 void safe_print_str(const char* name, const char* val, int max_len);
 #endif /* (defined (__i386__) || (defined(__alpha__) && defined(__GNUC__))) */
-#endif /* HAVE_LINUXTHREADS */
+#endif /* TARGET_OS_LINUX */
 
 /* Define empty prototypes for functions that are not implemented */
 #ifndef HAVE_STACKTRACE

tools/mysqlmanager.c

@@ -101,7 +101,7 @@ static CHARSET_INFO *cs= &my_charset_latin1;
   set by the user
 */
 
-#if defined(__i386__) && defined(HAVE_LINUXTHREADS)
+#if defined(__i386__) && defined(TARGET_OS_LINUX)
 #define DO_STACKTRACE 1
 #endif