diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 01539f5b64790dc7879021682f53a61b45066d50..d2775fd9751368cfe2f717dc38dbc7b512c1d39d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+2002-06-29  Neil Booth  <neil@daikokuya.demon.co.uk>
+
+	* config/i386/crtdll.h: Define EXTRA_OS_CPP_BUILTINS.
+	Don't use CPP_PREDEFINES.
+	* config/i386/cygwin.h (EXTRA_OS_CPP_BUILTINS): New.
+	Used TARGET_OS_CPP_BUILTINS in preference to CPP_PREDEFINES.
+	* config/i386/djgpp.h, config/i386/i386-coff.h,
+	config/i386/i386-interix.h, config/i386/i386-interix3.h,
+	config/i386/lynx-ng.h, config/i386/lynx.h, config/i386/mingw32.h,
+	config/i386/openbsd.h, config/i386/ptx4-i.h, config/i386/sysv3.h,
+	config/i386/uwin.h: Similarly.
+
 2002-06-29  Herman A.J. ten Brugge <Haj.Ten.Brugge@net.HCC.nl>
 
         * c4x.h: (TARGET_CPU_CPP_BUILTINS): Check flag_inline_functions and
diff --git a/gcc/config/i386/crtdll.h b/gcc/config/i386/crtdll.h
index f3eae8471a71bb4b77076b6a96253400c3404442..dab60c19ca2380ab46e5ac684a3f2596107f9ed7 100644
--- a/gcc/config/i386/crtdll.h
+++ b/gcc/config/i386/crtdll.h
@@ -20,10 +20,9 @@ along with GNU CC; see the file COPYING.  If not, write to
 the Free Software Foundation, 59 Temple Place - Suite 330,
 Boston, MA 02111-1307, USA.  */
 
-#undef CPP_PREDEFINES
-#define CPP_PREDEFINES "-D_WIN32 -DWIN32 \
-  -D__MINGW32__=0.2 -DWINNT  -D_X86_=1 \
-  -Asystem=winnt"
+#undef EXTRA_OS_CPP_BUILTINS
+#define EXTRA_OS_CPP_BUILTINS() \
+  do { builtin_define ("__MINGW32__=0.2"); } while (0)
 
 #undef LIBGCC_SPEC
 #define LIBGCC_SPEC \
diff --git a/gcc/config/i386/cygwin.h b/gcc/config/i386/cygwin.h
index 15a5cdbb925c7ee33f8a3140bb45713260b3baf1..e849c9b800d48b18cc3b72047907ec980208c06b 100644
--- a/gcc/config/i386/cygwin.h
+++ b/gcc/config/i386/cygwin.h
@@ -54,8 +54,23 @@ Boston, MA 02111-1307, USA.  */
 { "no-nop-fun-dllimport", -MASK_NOP_FUN_DLLIMPORT, "" },	\
 { "threads",		  0, N_("Use Mingw-specific thread support") },
 
-#undef CPP_PREDEFINES
-#define CPP_PREDEFINES "-D_X86_=1 -Asystem=winnt"
+#define MAYBE_UWIN_CPP_BUILTINS() /* Nothing.  */
+#define TARGET_OS_CPP_BUILTINS()					\
+  do									\
+    {									\
+	builtin_define ("_X86_=1");					\
+	builtin_assert ("system=winnt");				\
+	builtin_define ("__stdcall=__attribute__((__stdcall__))");	\
+	builtin_define ("__cdecl=__attribute__((__cdecl__))");		\
+	builtin_define ("__declspec(x)=__attribute__((x))");		\
+	if (!flag_iso)							\
+	  {								\
+	    builtin_define ("_stdcall=__attribute__((__stdcall__))");	\
+	    builtin_define ("_cdecl=__attribute__((__cdecl__))");	\
+	  }								\
+	MAYBE_UWIN_CPP_BUILTINS ();					\
+    }									\
+  while (0)
 
 #ifdef CROSS_COMPILE
 #define CYGWIN_INCLUDES "%{!nostdinc:-idirafter " CYGWIN_CROSS_DIR "/include}"
@@ -97,12 +112,6 @@ Boston, MA 02111-1307, USA.  */
 
 #undef CPP_SPEC
 #define CPP_SPEC "%{posix:-D_POSIX_SOURCE} \
-  -D__stdcall=__attribute__((__stdcall__)) \
-  -D__cdecl=__attribute__((__cdecl__)) \
-  %{!ansi:-D_stdcall=__attribute__((__stdcall__)) \
-    -D_cdecl=__attribute__((__cdecl__))} \
-  -D__declspec(x)=__attribute__((x)) \
-  -D__i386__ -D__i386 \
   %{mno-win32:%{mno-cygwin: %emno-cygwin and mno-win32 are not compatible}} \
   %{mno-cygwin:-D__MSVCRT__ -D__MINGW32__ %{mthreads:-D_MT} "\
     MINGW_INCLUDES "} \
diff --git a/gcc/config/i386/djgpp.h b/gcc/config/i386/djgpp.h
index 15c1531a9c82ecc2a5302c41ff2a4db0bcc09019..3afafd0ae3c7e81720482898f954c18bc0572d29 100644
--- a/gcc/config/i386/djgpp.h
+++ b/gcc/config/i386/djgpp.h
@@ -82,13 +82,18 @@ Boston, MA 02111-1307, USA.  */
         (((NAME)[0] == '/') || ((NAME)[0] == '\\') || \
         (((NAME)[0] >= 'A') && ((NAME)[0] <= 'z') && ((NAME)[1] == ':')))
 
-#undef CPP_PREDEFINES
-#define CPP_PREDEFINES "-D__MSDOS__ -D__GO32__ -Asystem=msdos"
+#define TARGET_OS_CPP_BUILTINS()		\
+  do						\
+    {						\
+	builtin_define_std ("MSDOS");		\
+	builtin_define_std ("GO32");		\
+	builtin_assert ("system=msdos");	\
+    }						\
+  while (0)
 
 /* Include <sys/version.h> so __DJGPP__ and __DJGPP_MINOR__ are defined.  */
 #undef CPP_SPEC
 #define CPP_SPEC "-remap %{posix:-D_POSIX_SOURCE} \
-  %{!ansi:%{!std=c*:%{!std=i*:-DMSDOS}}} %{!ansi:%{!std=c*:%{!std=i*:-DGO32}}} \
   -imacros %s../include/sys/version.h"
 
 /* We need to override link_command_spec in gcc.c so support -Tdjgpp.djl.
diff --git a/gcc/config/i386/i386-coff.h b/gcc/config/i386/i386-coff.h
index 5f3ed142866d4ff8abafefacc9ab8d0d0dc06f3c..d4d155323e5672ef1c84323e678e2660c7203e2c 100644
--- a/gcc/config/i386/i386-coff.h
+++ b/gcc/config/i386/i386-coff.h
@@ -21,12 +21,9 @@ the Free Software Foundation, 59 Temple Place - Suite 330,
 Boston, MA 02111-1307, USA.  */
 
 
-#define TARGET_VERSION fprintf (stderr, " (80386, COFF BSD syntax)"); 
+#define TARGET_VERSION fprintf (stderr, " (80386, COFF BSD syntax)");
 
-/* Specify predefined symbols in preprocessor.  */
-
-#undef CPP_PREDEFINES
-#define CPP_PREDEFINES ""
+#define TARGET_OS_CPP_BUILTINS() /* Sweet FA.  */
 
 /* We want to be able to get DBX debugging information via -gstabs.  */
 
diff --git a/gcc/config/i386/i386-interix.h b/gcc/config/i386/i386-interix.h
index 101f812c3621c7f207b3d30679de0c5aa4ebc675..6d74150d704a2f4b8653f8d86a4b1cdb5213190b 100644
--- a/gcc/config/i386/i386-interix.h
+++ b/gcc/config/i386/i386-interix.h
@@ -53,30 +53,37 @@ Boston, MA 02111-1307, USA.  */
 #define ASM_LOAD_ADDR(loc, reg)   "     leal " #loc "," #reg "\n"
 
 /* cpp handles __STDC__ */
-#undef CPP_PREDEFINES
-#define CPP_PREDEFINES " \
-  -D__INTERIX \
-  -D__OPENNT \
-  -D_M_IX86=300 -D_X86_=1 \
-  -D__stdcall=__attribute__((__stdcall__)) \
-  -D__cdecl=__attribute__((__cdecl__)) \
-  -D__declspec(x)=__attribute__((x)) \
-  -Asystem=unix -Asystem=interix"
+#define TARGET_OS_CPP_BUILTINS()					\
+  do									\
+    {									\
+	builtin_define ("__INTERIX");					\
+	builtin_define ("__OPENNT");					\
+	builtin_define ("_M_IX86=300");					\
+	builtin_define ("_X86_=1");					\
+	builtin_define ("__stdcall=__attribute__((__stdcall__))");	\
+	builtin_define ("__cdecl=__attribute__((__cdecl__))");		\
+	builtin_define ("__declspec(x)=__attribute__((x))");		\
+	builtin_assert ("system=unix");					\
+	builtin_assert ("system=interix");				\
+	if (preprocessing_asm_p ())					\
+	  builtin_define_std ("LANGUAGE_ASSEMBLY");			\
+	else								\
+	  {								\
+	     builtin_define_std ("LANGUAGE_C");				\
+	     if (c_language == clk_cplusplus)				\
+	       builtin_define_std ("LANGUAGE_C_PLUS_PLUS");		\
+	     else if (c_language == clk_objective_c)			\
+	       builtin_define_std ("LANGUAGE_OBJECTIVE_C");		\
+	  } 								\
+    }									\
+  while (0)
 
 #undef CPP_SPEC
 /* Write out the correct language type definition for the header files.  
    Unless we have assembler language, write out the symbols for C.
    mieee is an Alpha specific variant.  Cross polination a bad idea.
    */
-#define CPP_SPEC "\
-%{!.S:	-D__LANGUAGE_C__ -D__LANGUAGE_C %{!ansi:-DLANGUAGE_C}}  \
-%{.S:	-D__LANGUAGE_ASSEMBLY__ -D__LANGUAGE_ASSEMBLY %{!ansi:-DLANGUAGE_ASSEMBLY}} \
-%{.cc:	-D__LANGUAGE_C_PLUS_PLUS__ -D__LANGUAGE_C_PLUS_PLUS -D__cplusplus} \
-%{.cxx:	-D__LANGUAGE_C_PLUS_PLUS__ -D__LANGUAGE_C_PLUS_PLUS -D__cplusplus} \
-%{.C:	-D__LANGUAGE_C_PLUS_PLUS__ -D__LANGUAGE_C_PLUS_PLUS -D__cplusplus} \
-%{.m:	-D__LANGUAGE_OBJECTIVE_C__ -D__LANGUAGE_OBJECTIVE_C} \
--remap \
-%{posix:-D_POSIX_SOURCE} \
+#define CPP_SPEC "-remap %{posix:-D_POSIX_SOURCE} \
 -isystem %$INTERIX_ROOT/usr/include"
 
 #define TARGET_VERSION fprintf (stderr, " (i386 Interix)");
diff --git a/gcc/config/i386/i386-interix3.h b/gcc/config/i386/i386-interix3.h
index 38c6c55290f6628dddbe233f143e5172d559efe1..aafe57fa24d987fc613b4ec53fbc13678e418e9d 100644
--- a/gcc/config/i386/i386-interix3.h
+++ b/gcc/config/i386/i386-interix3.h
@@ -20,12 +20,5 @@ the Free Software Foundation, 59 Temple Place - Suite 330,
 Boston, MA 02111-1307, USA.  */
 
 #undef CPP_SPEC
-#define CPP_SPEC "\
-%{!.S:	-D__LANGUAGE_C__ -D__LANGUAGE_C %{!ansi:-DLANGUAGE_C}}  \
-%{.S:	-D__LANGUAGE_ASSEMBLY__ -D__LANGUAGE_ASSEMBLY %{!ansi:-DLANGUAGE_ASSEMBLY}} \
-%{.cc:	-D__LANGUAGE_C_PLUS_PLUS__ -D__LANGUAGE_C_PLUS_PLUS -D__cplusplus} \
-%{.cxx:	-D__LANGUAGE_C_PLUS_PLUS__ -D__LANGUAGE_C_PLUS_PLUS -D__cplusplus} \
-%{.C:	-D__LANGUAGE_C_PLUS_PLUS__ -D__LANGUAGE_C_PLUS_PLUS -D__cplusplus} \
-%{.m:	-D__LANGUAGE_OBJECTIVE_C__ -D__LANGUAGE_OBJECTIVE_C} \
-%{posix:-D_POSIX_SOURCE}"
+#define CPP_SPEC "%{posix:-D_POSIX_SOURCE}"
 
diff --git a/gcc/config/i386/lynx-ng.h b/gcc/config/i386/lynx-ng.h
index 1ef22fb23dcdb2806625efe9a6078d5ab2698884..08fa60f430ca4300f8e46ff89990f0f279104908 100644
--- a/gcc/config/i386/lynx-ng.h
+++ b/gcc/config/i386/lynx-ng.h
@@ -20,9 +20,17 @@ Boston, MA 02111-1307, USA.  */
 
 #define TARGET_VERSION fprintf (stderr, " (80386, LYNX BSD syntax)"); 
 
-#undef CPP_PREDEFINES
-#define CPP_PREDEFINES "-Dunix -DI386 -DLynx -DIBITS32 \
-  -Asystem=unix -Asystem=lynx"
+#define TARGET_OS_CPP_BUILTINS()		\
+  do						\
+    {						\
+	builtin_define_std ("unix");		\
+	builtin_define_std ("I386");		\
+	builtin_define_std ("Lynx");		\
+	builtin_define_std ("IBITS32");		\
+	builtin_assert ("system=unix");		\
+	builtin_assert ("system=lynx");		\
+    }						\
+  while (0)
 
 /* Provide required defaults for linker switches.  */
 
diff --git a/gcc/config/i386/lynx.h b/gcc/config/i386/lynx.h
index 00fc0ac741750989093ba71e5443a75d0523c350..7835f2713f276cbb1cab6f5446293d27fc52daa7 100644
--- a/gcc/config/i386/lynx.h
+++ b/gcc/config/i386/lynx.h
@@ -20,8 +20,16 @@ Boston, MA 02111-1307, USA.  */
 
 #define TARGET_VERSION fprintf (stderr, " (80386, LYNX BSD syntax)"); 
 
-#undef CPP_PREDEFINES
-#define CPP_PREDEFINES "-DI386 -DLynx -DIBITS32 -Asystem=unix -Asystem=lynx"
+#define TARGET_OS_CPP_BUILTINS()		\
+  do						\
+    {						\
+	builtin_define_std ("I386");		\
+	builtin_define_std ("Lynx");		\
+	builtin_define_std ("IBITS32");		\
+	builtin_assert ("system=unix");		\
+	builtin_assert ("system=lynx");		\
+    }						\
+  while (0)
 
 /* The prefix to add to user-visible assembler symbols.  */
 
diff --git a/gcc/config/i386/mingw32.h b/gcc/config/i386/mingw32.h
index c5b8701f89842f0e239f81cd3df38355da2098cc..6b367eba314de4ff8f87e0690d73ec6701d4f62d 100644
--- a/gcc/config/i386/mingw32.h
+++ b/gcc/config/i386/mingw32.h
@@ -32,13 +32,35 @@ Boston, MA 02111-1307, USA.  */
 
 #define TARGET_EXECUTABLE_SUFFIX ".exe"
 
-/* Please keep changes to CPP_PREDEFINES in sync with i386/crtdll. The
-   only difference between the two should be __MSVCRT__ needed to 
-   distinguish MSVC from CRTDLL runtime in mingw headers.  */
-#undef CPP_PREDEFINES
-#define CPP_PREDEFINES "-D_WIN32 -D__WIN32 -D__WIN32__ -DWIN32 \
-  -D__MINGW32__ -D__MSVCRT__ -DWINNT -D_X86_=1 \
-  -Asystem=winnt"
+/* See i386/crtdll.h for an altervative definition.  */
+#define EXTRA_OS_CPP_BUILTINS()					\
+  do								\
+    {								\
+      builtin_define ("__MSVCRT__");				\
+      builtin_define ("__MINGW32__");			   	\
+    }								\
+  while (0)
+
+#undef TARGET_OS_CPP_BUILTINS	/* From cygwin.h.  */
+#define TARGET_OS_CPP_BUILTINS()					\
+  do									\
+    {									\
+	builtin_define ("_WIN32");					\
+	builtin_define_std ("WIN32");					\
+	builtin_define_std ("WINNT");					\
+	builtin_define ("_X86_=1");					\
+	builtin_define ("__stdcall=__attribute__((__stdcall__))");	\
+	builtin_define ("__cdecl=__attribute__((__cdecl__))");		\
+	builtin_define ("__declspec(x)=__attribute__((x))");		\
+	if (!flag_iso)							\
+	  {								\
+	    builtin_define ("_stdcall=__attribute__((__stdcall__))");	\
+	    builtin_define ("_cdecl=__attribute__((__cdecl__))");	\
+	  }								\
+	EXTRA_OS_CPP_BUILTINS ();					\
+	builtin_assert ("system=winnt");				\
+    }									\
+  while (0)
 
 /* Specific a different directory for the standard include files.  */
 #undef STANDARD_INCLUDE_DIR
@@ -47,14 +69,7 @@ Boston, MA 02111-1307, USA.  */
 #define STANDARD_INCLUDE_COMPONENT "MINGW"
 
 #undef CPP_SPEC
-#define CPP_SPEC \
-  "%{posix:-D_POSIX_SOURCE} %{mthreads:-D_MT} \
-  -D__stdcall=__attribute__((__stdcall__)) \
-  -D__cdecl=__attribute__((__cdecl__)) \
-  %{!ansi:-D_stdcall=__attribute__((__stdcall__)) \
-    -D_cdecl=__attribute__((__cdecl__))} \
-  -D__declspec(x)=__attribute__((x))"
-
+#define CPP_SPEC "%{posix:-D_POSIX_SOURCE} %{mthreads:-D_MT}"
 
 /* For Windows applications, include more libraries, but always include
    kernel32.  */
diff --git a/gcc/config/i386/openbsd.h b/gcc/config/i386/openbsd.h
index 9b7ce3e4f00a39584ef2b14e0e3f65bc2058afa2..8f54026539b001a6a3c5188b529820eacaeced36 100644
--- a/gcc/config/i386/openbsd.h
+++ b/gcc/config/i386/openbsd.h
@@ -26,9 +26,16 @@ Boston, MA 02111-1307, USA.  */
 #define TARGET_SUBTARGET_DEFAULT \
   (MASK_80387 | MASK_IEEE_FP | MASK_FLOAT_RETURNS | MASK_NO_FANCY_MATH_387)
 
-/* Run-time target specifications */
-#define CPP_PREDEFINES "-D__unix__ -D__OpenBSD__ \
- -Asystem=unix -Asystem=bsd -Asystem=OpenBSD"
+#define TARGET_OS_CPP_BUILTINS()		\
+  do						\
+    {						\
+	builtin_define ("__unix__");		\
+	builtin_define ("__OpenBSD__");		\
+	builtin_assert ("system=unix");		\
+	builtin_assert ("system=bsd");		\
+	builtin_assert ("system=OpenBSD");	\
+    }						\
+  while (0)
 
 /* Layout of source language data types.  */
 
diff --git a/gcc/config/i386/ptx4-i.h b/gcc/config/i386/ptx4-i.h
index d29bdade144b764933212e6e3cd84f0b5a6b74a6..a7d571067628baf9bdd9903a10bae3a2fa52baa6 100644
--- a/gcc/config/i386/ptx4-i.h
+++ b/gcc/config/i386/ptx4-i.h
@@ -33,11 +33,15 @@ Boston, MA 02111-1307, USA.  */
   (TYPE_MODE (TYPE) == BLKmode \
    || (VECTOR_MODE_P (TYPE_MODE (TYPE)) && int_size_in_bytes (TYPE) == 8))
 
-/* Define which macros to predefine.  _SEQUENT_ is our extension.  */
-/* This used to define X86, but james@bigtex.cactus.org says that
-   is supposed to be defined optionally by user programs--not by default.  */
-#define CPP_PREDEFINES \
-  "-Dunix -D_SEQUENT_ -Asystem=unix -Asystem=ptx4"
+#define TARGET_OS_CPP_BUILTINS()		\
+  do						\
+    {						\
+	builtin_define_std ("unix");		\
+	builtin_define ("_SEQUENT_");		\
+	builtin_assert ("system=unix");		\
+	builtin_assert ("system=ptx4");		\
+    }						\
+  while (0)
 
 #undef DBX_REGISTER_NUMBER
 #define DBX_REGISTER_NUMBER(n)  svr4_dbx_register_map[n]
diff --git a/gcc/config/i386/sysv3.h b/gcc/config/i386/sysv3.h
index 07dadb818ed25c1f676d13bd24d785f783a7c8db..67194f4acc57811bf0724a841d3f0de6420e031d 100644
--- a/gcc/config/i386/sysv3.h
+++ b/gcc/config/i386/sysv3.h
@@ -32,7 +32,13 @@ Boston, MA 02111-1307, USA.  */
 
 /* Specify predefined symbols in preprocessor.  */
 
-#define CPP_PREDEFINES "-Dunix -Asystem=svr3"
+#define TARGET_OS_CPP_BUILTINS()		\
+  do						\
+    {						\
+	builtin_define_std ("unix");		\
+	builtin_assert ("system=svr3");		\
+    }						\
+  while (0)
 
 #define CPP_SPEC "%{posix:-D_POSIX_SOURCE}"
 
diff --git a/gcc/config/i386/uwin.h b/gcc/config/i386/uwin.h
index b5865ac97871e0d9532fa6c1390146ba9f7086bd..121051064e4f7dd4ed567ced835fd8f38ec5ed07 100644
--- a/gcc/config/i386/uwin.h
+++ b/gcc/config/i386/uwin.h
@@ -30,16 +30,19 @@ Boston, MA 02111-1307, USA.  */
 #undef MD_STARTFILE_PREFIX
 #define MD_STARTFILE_PREFIX "/usr/gnu/lib/"
 
-#undef CPP_PREDEFINES
-#define CPP_PREDEFINES "-D_WIN32 -D__WIN32__ \
-  -D_UWIN -DWINNT  -D_X86_=1 -D__STDC__=1 \
-  -D__UWIN__ -D__MSVCRT__ \
-  -D_STD_INCLUDE_DIR=mingw32 \
-  -D__stdcall=__attribute__((__stdcall__)) \
-  _D_stdcall=__attribute__((__stdcall__)) \
-  -D__cdecl=__attribute__((__cdecl__)) \
-  -D__declspec(x)=__attribute__((x)) \
-  -Asystem=winnt"
+#undef MAYBE_UWIN_CPP_BUILTINS
+#define MAYBE_UWIN_CPP_BUILTINS()			\
+  do							\
+    {							\
+	builtin_define_std ("WINNT");			\
+	builtin_define ("_WIN32");			\
+	builtin_define ("__WIN32__");			\
+	builtin_define ("_UWIN");			\
+	builtin_define ("__UWIN__");			\
+	builtin_define ("__MSVCRT__");			\
+	builtin_define ("_STD_INCLUDE_DIR=mingw32");	\
+    }							\
+  while (0)
 
 #undef CPP_SPEC
 #define CPP_SPEC "-remap %{posix:-D_POSIX_SOURCE} \