netchild's mega-patch to isolate compiler dependencies into a central

place.

This moves the dependency on GCC's and other compiler's features into
the central sys/cdefs.h file, while the individual source files can
then refer to #ifdef __COMPILER_FEATURE_FOO where they by now used to
refer to #if __GNUC__ > 3.1415 && __BARC__ <= 42.

By now, GCC and ICC (the Intel compiler) have been actively tested on
IA32 platforms by netchild.  Extension to other compilers is supposed
to be possible, of course.

Submitted by:	netchild
Reviewed by:	various developers on arch@, some time ago

13 files changed, 107 insertions, 69 deletions

diff --git a/sys/amd64/include/_types.h b/sys/amd64/include/_types.h
index 4a7b6e7..709cc16 100644
--- a/sys/amd64/include/_types.h
+++ b/sys/amd64/include/_types.h
@@ -39,6 +39,10 @@
 #ifndef _MACHINE__TYPES_H_
 #define	_MACHINE__TYPES_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 /*
  * Basic types upon which most other types are built.
  */
@@ -97,12 +101,13 @@ typedef	__uint64_t	__vm_size_t;
 /*
  * Unusual type definitions.
  */
-#if defined(__GNUC__)
+#ifdef __GNUCLIKE_BUILTIN_VARARGS
 typedef	__builtin_va_list	__va_list;	/* internally known to gcc */
 #elif defined(lint)
 typedef	char *			__va_list;	/* pretend */
 #endif
-#if defined __GNUC__ && !defined(__GNUC_VA_LIST) && !defined(__NO_GNUC_VA_LIST)
+#if defined(__GNUC_VA_LIST_COMPATIBILITY) && !defined(__GNUC_VA_LIST) \
+    && !defined(__NO_GNUC_VA_LIST)
 #define	__GNUC_VA_LIST
 typedef	__va_list	__gnuc_va_list;		/* compatibility w/GNU headers*/
 #endif
diff --git a/sys/amd64/include/atomic.h b/sys/amd64/include/atomic.h
index cbee271..eaf8068 100644
--- a/sys/amd64/include/atomic.h
+++ b/sys/amd64/include/atomic.h
@@ -28,6 +28,10 @@
 #ifndef _MACHINE_ATOMIC_H_
 #define _MACHINE_ATOMIC_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 /*
  * Various simple arithmetic on memory which is atomic in the presence
  * of interrupts and multiple processors.
@@ -76,7 +80,7 @@ void		atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
 
 #else /* !KLD_MODULE */
 
-#ifdef __GNUC__
+#if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
 
 /*
  * For userland, assume the SMP case and use lock prefixes so that
@@ -102,12 +106,12 @@ atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
 }							\
 struct __hack
 
-#else /* !__GNUC__ */
+#else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */
 
 #define ATOMIC_ASM(NAME, TYPE, OP, CONS, V)				\
 extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
 
-#endif /* __GNUC__ */
+#endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
 
 /*
  * Atomic compare and set, used by the mutex functions
@@ -117,7 +121,7 @@ extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
  * Returns 0 on failure, non-zero on success
  */
 
-#if defined(__GNUC__)
+#if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
 
 static __inline int
 atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
@@ -158,9 +162,9 @@ atomic_cmpset_long(volatile u_long *dst, u_long exp, u_long src)
 
 	return (res);
 }
-#endif /* defined(__GNUC__) */
+#endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
 
-#if defined(__GNUC__)
+#if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
 
 #define ATOMIC_STORE_LOAD(TYPE, LOP, SOP)		\
 static __inline u_##TYPE				\
@@ -189,7 +193,7 @@ atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
 }							\
 struct __hack
 
-#else /* !defined(__GNUC__) */
+#else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */
 
 extern int atomic_cmpset_int(volatile u_int *, u_int, u_int);
 extern int atomic_cmpset_long(volatile u_long *, u_long, u_long);
@@ -198,7 +202,7 @@ extern int atomic_cmpset_long(volatile u_long *, u_long, u_long);
 extern u_##TYPE atomic_load_acq_##TYPE(volatile u_##TYPE *p);		\
 extern void atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
 
-#endif /* defined(__GNUC__) */
+#endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
 
 #endif /* KLD_MODULE */
 
@@ -371,7 +375,7 @@ ATOMIC_PTR(subtract)
 
 #undef ATOMIC_PTR
 
-#if defined(__GNUC__)
+#if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
 
 static __inline u_int
 atomic_readandclear_int(volatile u_int *addr)
@@ -403,12 +407,12 @@ atomic_readandclear_long(volatile u_long *addr)
 	return (result);
 }
 
-#else /* !defined(__GNUC__) */
+#else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */
 
 extern u_long	atomic_readandclear_long(volatile u_long *);
 extern u_int	atomic_readandclear_int(volatile u_int *);
 
-#endif /* defined(__GNUC__) */
+#endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
 
 #endif	/* !defined(WANT_FUNCTIONS) */
 #endif /* ! _MACHINE_ATOMIC_H_ */
diff --git a/sys/amd64/include/bus_amd64.h b/sys/amd64/include/bus_amd64.h
index 189816b..9e0bc45 100644
--- a/sys/amd64/include/bus_amd64.h
+++ b/sys/amd64/include/bus_amd64.h
@@ -74,6 +74,10 @@
 
 #include <machine/cpufunc.h>
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 /*
  * To remain compatible with NetBSD's interface, default to both memio and
  * pio when neither of them is defined.
@@ -284,7 +288,7 @@ bus_space_read_multi_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	movb (%2),%%al				\n\
@@ -313,7 +317,7 @@ bus_space_read_multi_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	movw (%2),%%ax				\n\
@@ -342,7 +346,7 @@ bus_space_read_multi_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	movl (%2),%%eax				\n\
@@ -391,7 +395,7 @@ bus_space_read_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	inb %w2,%%al				\n\
@@ -410,7 +414,7 @@ bus_space_read_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		bus_space_handle_t _port_ = bsh + offset;
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -433,7 +437,7 @@ bus_space_read_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	inw %w2,%%ax				\n\
@@ -452,7 +456,7 @@ bus_space_read_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		bus_space_handle_t _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -475,7 +479,7 @@ bus_space_read_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	inl %w2,%%eax				\n\
@@ -494,7 +498,7 @@ bus_space_read_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		bus_space_handle_t _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -623,7 +627,7 @@ bus_space_write_multi_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsb					\n\
@@ -652,7 +656,7 @@ bus_space_write_multi_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsw					\n\
@@ -681,7 +685,7 @@ bus_space_write_multi_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsl					\n\
@@ -731,7 +735,7 @@ bus_space_write_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsb					\n\
@@ -750,7 +754,7 @@ bus_space_write_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		bus_space_handle_t _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -773,7 +777,7 @@ bus_space_write_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsw					\n\
@@ -792,7 +796,7 @@ bus_space_write_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		bus_space_handle_t _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -815,7 +819,7 @@ bus_space_write_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsl					\n\
@@ -834,7 +838,7 @@ bus_space_write_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		bus_space_handle_t _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -1213,7 +1217,7 @@ static __inline void
 bus_space_barrier(bus_space_tag_t tag __unused, bus_space_handle_t bsh __unused,
 		  bus_size_t offset __unused, bus_size_t len __unused, int flags)
 {
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 	if (flags & BUS_SPACE_BARRIER_READ)
 		__asm __volatile("lock; addl $0,0(%%rsp)" : : : "memory");
 	else
diff --git a/sys/amd64/include/cpufunc.h b/sys/amd64/include/cpufunc.h
index e558858..4c596a0 100644
--- a/sys/amd64/include/cpufunc.h
+++ b/sys/amd64/include/cpufunc.h
@@ -39,6 +39,10 @@
 #ifndef _MACHINE_CPUFUNC_H_
 #define	_MACHINE_CPUFUNC_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 struct region_descriptor;
 
 #define readb(va)	(*(volatile u_int8_t *) (va))
@@ -51,7 +55,7 @@ struct region_descriptor;
 #define writel(va, d)	(*(volatile u_int32_t *) (va) = (d))
 #define writeq(va, d)	(*(volatile u_int64_t *) (va) = (d))
 
-#ifdef	__GNUC__
+#if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
 
 static __inline void
 breakpoint(void)
@@ -152,12 +156,12 @@ halt(void)
 	__asm __volatile("hlt");
 }
 
-#if __GNUC__ < 2
+#if !defined(__GNUCLIKE_BUILTIN_CONSTANT_P) || __GNUCLIKE_ASM < 3
 
 #define	inb(port)		inbv(port)
 #define	outb(port, data)	outbv(port, data)
 
-#else /* __GNUC >= 2 */
+#else /* __GNUCLIKE_BUILTIN_CONSTANT_P  && __GNUCLIKE_ASM >= 3 */
 
 /*
  * The following complications are to get around gcc not having a
@@ -204,7 +208,7 @@ outbc(u_int port, u_char data)
 	__asm __volatile("outb %0,%1" : : "a" (data), "id" ((u_short)(port)));
 }
 
-#endif /* __GNUC <= 2 */
+#endif /* __GNUCLIKE_BUILTIN_CONSTANT_P */
 
 static __inline u_char
 inbv(u_int port)
@@ -696,7 +700,7 @@ intr_restore(register_t rflags)
 	write_rflags(rflags);
 }
 
-#else /* !__GNUC__ */
+#else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */
 
 int	breakpoint(void);
 u_int	bsfl(u_int mask);
@@ -761,7 +765,7 @@ void	wbinvd(void);
 void	write_rflags(u_int rf);
 void	wrmsr(u_int msr, u_int64_t newval);
 
-#endif	/* __GNUC__ */
+#endif	/* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
 
 void	reset_dbregs(void);
 
diff --git a/sys/amd64/include/critical.h b/sys/amd64/include/critical.h
index 0e02e1f..37ba264 100644
--- a/sys/amd64/include/critical.h
+++ b/sys/amd64/include/critical.h
@@ -46,7 +46,7 @@ __BEGIN_DECLS
  */
 void cpu_critical_fork_exit(void);
 
-#ifdef	__GNUC__
+#ifdef	__CC_SUPPORTS___INLINE
 
 /*
  *	cpu_critical_enter:
@@ -74,12 +74,12 @@ cpu_critical_exit(struct thread *td)
 	intr_restore(td->td_md.md_savecrit);
 }
 
-#else /* !__GNUC__ */
+#else /* !__CC_SUPPORTS___INLINE */
 
 void cpu_critical_enter(struct thread *td);
 void cpu_critical_exit(struct thread *td);
 
-#endif	/* __GNUC__ */
+#endif	/* __CC_SUPPORTS___INLINE */
 
 __END_DECLS
 
diff --git a/sys/amd64/include/endian.h b/sys/amd64/include/endian.h
index 459126b..6ed2118 100644
--- a/sys/amd64/include/endian.h
+++ b/sys/amd64/include/endian.h
@@ -63,7 +63,7 @@
 #define	BYTE_ORDER	_BYTE_ORDER
 #endif
 
-#ifdef __GNUC__
+#if defined(__GNUCLIKE_ASM) && defined(__GNUCLIKE_BUILTIN_CONSTANT_P)
 
 #define __word_swap_int_var(x) \
 __extension__ ({ register __uint32_t __X = (x); \
@@ -177,7 +177,7 @@ __bswap16(__uint16_t _x)
 #define	__ntohl(x)	__bswap32(x)
 #define	__ntohs(x)	__bswap16(x)
 
-#else /* !__GNUC__ */
+#else /* !(__GNUCLIKE_ASM && __GNUCLIKE_BUILTIN_CONSTANT_P) */
 
 /*
  * No optimizations are available for this compiler.  Fall back to
@@ -186,6 +186,6 @@ __bswap16(__uint16_t _x)
  */
 #define	_BYTEORDER_FUNC_DEFINED
 
-#endif /* __GNUC__ */
+#endif /* __GNUCLIKE_ASM && __GNUCLIKE_BUILTIN_CONSTANT_P */
 
 #endif /* !_MACHINE_ENDIAN_H_ */
diff --git a/sys/amd64/include/ieeefp.h b/sys/amd64/include/ieeefp.h
index 214f3b5..bfa80aa 100644
--- a/sys/amd64/include/ieeefp.h
+++ b/sys/amd64/include/ieeefp.h
@@ -42,6 +42,10 @@
 #ifndef _MACHINE_IEEEFP_H_
 #define _MACHINE_IEEEFP_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 /*
  * FP rounding modes
  */
@@ -117,7 +121,8 @@ typedef enum {
 #define	SSE_RND_OFF	13	/* rounding control offset */
 #define	SSE_FZ_OFF	15	/* flush to zero offset */
 
-#if defined(__GNUC__) && !defined(__cplusplus)
+#if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE__) \
+    && !defined(__cplusplus)
 
 #define	__fldenv(addr)	__asm __volatile("fldenv %0" : : "m" (*(addr)))
 #define	__fnstenv(addr)	__asm __volatile("fnstenv %0" : "=m" (*(addr)))
@@ -263,9 +268,10 @@ __fpsetsticky(fp_except_t _m)
 	return (_p);
 }
 
-#endif /* __GNUC__ && !__cplusplus */
+#endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE__ && !__cplusplus */
 
-#if !defined(__IEEEFP_NOINLINES__) && !defined(__cplusplus) && defined(__GNUC__)
+#if !defined(__IEEEFP_NOINLINES__) && !defined(__cplusplus) \
+    && defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE__)
 
 #define	fpgetround()	__fpgetround()
 #define	fpsetround(_m)	__fpsetround(_m)
@@ -279,7 +285,8 @@ __fpsetsticky(fp_except_t _m)
 /* Suppress prototypes in the MI header. */
 #define	_IEEEFP_INLINED_	1
 
-#else /* !__IEEEFP_NOINLINES__ && !__cplusplus && __GNUC__ */
+#else /* !__IEEEFP_NOINLINES__ && !__cplusplus && __GNUCLIKE_ASM
+         && __CC_SUPPORTS___INLINE__ */
 
 /* Augment the userland declarations */
 __BEGIN_DECLS
@@ -287,6 +294,7 @@ extern fp_prec_t fpgetprec(void);
 extern fp_prec_t fpsetprec(fp_prec_t);
 __END_DECLS
 
-#endif /* !__IEEEFP_NOINLINES__ && !__cplusplus && __GNUC__ */
+#endif /* !__IEEEFP_NOINLINES__ && !__cplusplus && __GNUCLIKE_ASM
+          && __CC_SUPPORTS___INLINE__ */
 
 #endif /* !_MACHINE_IEEEFP_H_ */
diff --git a/sys/amd64/include/in_cksum.h b/sys/amd64/include/in_cksum.h
index a899ef0..0992006 100644
--- a/sys/amd64/include/in_cksum.h
+++ b/sys/amd64/include/in_cksum.h
@@ -45,7 +45,7 @@
  * in the normal case (where there are no options and the header length is
  * therefore always exactly five 32-bit words.
  */
-#ifdef __GNUC__
+#ifdef __CC_SUPPORTS___INLINE
 
 static __inline void
 in_cksum_update(struct ip *ip)
diff --git a/sys/amd64/include/limits.h b/sys/amd64/include/limits.h
index 8e3bb11..35eea1f 100644
--- a/sys/amd64/include/limits.h
+++ b/sys/amd64/include/limits.h
@@ -33,7 +33,9 @@
 #ifndef _MACHINE_LIMITS_H_
 #define	_MACHINE_LIMITS_H_
 
-#if __GNUC__
+#include <sys/cdefs.h>
+
+#ifdef __CC_SUPPORTS_WARNING
 #warning "machine/limits.h is deprecated.  Include sys/limits.h instead."
 #endif
 
diff --git a/sys/amd64/include/pcpu.h b/sys/amd64/include/pcpu.h
index 0694c76..b9d4a61 100644
--- a/sys/amd64/include/pcpu.h
+++ b/sys/amd64/include/pcpu.h
@@ -29,6 +29,10 @@
 #ifndef _MACHINE_PCPU_H_
 #define _MACHINE_PCPU_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 #ifdef _KERNEL
 
 /*
@@ -55,7 +59,8 @@ extern struct pcpu *pcpup;
 #define PCPU_PTR(member)        (&pcpup->pc_ ## member)
 #define PCPU_SET(member,value)  (pcpup->pc_ ## member = (value))
  
-#elif defined(__GNUC__)
+#elif defined(__GNUCLIKE___TYPEOF) && defined(__GNUCLIKE___OFFSETOF) \
+    && defined(__GNUCLIKE_ASM)
 
 /*
  * Evaluates to the byte offset of the per-cpu variable name.
@@ -170,7 +175,7 @@ __curthread(void)
 #define	curthread (__curthread())
 
 #else
-#error gcc or lint is required to use this file
+#error this file needs to be ported to your compiler
 #endif
 
 #endif	/* _KERNEL */
diff --git a/sys/amd64/include/profile.h b/sys/amd64/include/profile.h
index ecd3426..93e8614 100644
--- a/sys/amd64/include/profile.h
+++ b/sys/amd64/include/profile.h
@@ -33,6 +33,10 @@
 #ifndef _MACHINE_PROFILE_H_
 #define	_MACHINE_PROFILE_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 #ifdef _KERNEL
 
 /*
@@ -53,7 +57,7 @@
 #define	MCOUNT_DECL(s)
 #define	MCOUNT_ENTER(s)
 #define	MCOUNT_EXIT(s)
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 #define	MCOUNT_OVERHEAD(label)						\
 	__asm __volatile("pushq %0; call __mcount; popq %%rcx"		\
 			 :						\
@@ -70,8 +74,8 @@
 #define	MEXITCOUNT_OVERHEAD()
 #define	MEXITCOUNT_OVERHEAD_GETLABEL()
 #else
-#error
-#endif /* __GNUC */
+#error this file needs to be ported to your compiler
+#endif /* __GNUCLIKE_ASM */
 #else /* !GUPROF */
 #define	MCOUNT_DECL(s)	u_long s;
 #ifdef SMP
@@ -108,7 +112,7 @@ void user(void);
 static void _mcount(uintfptr_t frompc, uintfptr_t selfpc) __used; \
 static void _mcount
 
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 #define	MCOUNT __asm("			\n\
 	.globl	.mcount			\n\
 	.type	.mcount @function	\n\
@@ -166,13 +170,13 @@ mcount()								\
 	_mcount(frompc, selfpc);					\
 }
 #endif
-#else /* !__GNUC__ */
+#else /* !__GNUCLIKE_ASM */
 #define	MCOUNT								\
 void									\
 mcount()								\
 {									\
 }
-#endif /* __GNUC__ */
+#endif /* __GNUCLIKE_ASM */
 
 typedef	u_long	uintfptr_t;
 
@@ -193,7 +197,7 @@ void	mcount(uintfptr_t frompc, uintfptr_t selfpc);
 #include <sys/cdefs.h>
 
 __BEGIN_DECLS
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 void	mcount(void) __asm(".mcount");
 #endif
 __END_DECLS
diff --git a/sys/amd64/include/stdarg.h b/sys/amd64/include/stdarg.h
index 60a204a..d3612d2 100644
--- a/sys/amd64/include/stdarg.h
+++ b/sys/amd64/include/stdarg.h
@@ -39,7 +39,7 @@
 typedef	__va_list	va_list;
 #endif
 
-#if defined(__GNUC__)
+#if defined(__GNUCLIKE_BUILTIN_STDARG)
 #define	va_start(ap, last) \
 	__builtin_stdarg_start((ap), (last))
 
@@ -67,6 +67,8 @@ typedef	__va_list	va_list;
 	(*(type *)((ap) += __va_size(type), (ap) - __va_size(type)))
 #define	va_end(ap)
 
+#else
+#error this file needs to be ported to your compiler
 #endif
 
 #endif /* !_MACHINE_STDARG_H_ */
diff --git a/sys/amd64/include/varargs.h b/sys/amd64/include/varargs.h
index 1a58a47..3b9f542 100644
--- a/sys/amd64/include/varargs.h
+++ b/sys/amd64/include/varargs.h
@@ -43,7 +43,11 @@
 #ifndef _MACHINE_VARARGS_H_
 #define	_MACHINE_VARARGS_H_
 
-#if defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3)
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
+#ifdef __GNUCLIKE_BUILTIN_VARARGS
 
 #include <sys/_types.h>
 
@@ -60,21 +64,17 @@ typedef int __builtin_va_alist_t __attribute__((__mode__(__word__)));
 #define	va_arg(ap, type)	__builtin_va_arg((ap), type)
 #define	va_end(ap)		__builtin_va_end(ap)
 
-#else	/* ! __GNUC__ post GCC 2.95 */
+#else	/* !__GNUCLIKE_BUILTIN_VARARGS */
 
 typedef char *va_list;
 
 #define	__va_size(type) \
 	(((sizeof(type) + sizeof(int) - 1) / sizeof(int)) * sizeof(int))
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_BUILTIN_VAALIST
 #define	va_alist	__builtin_va_alist
 #endif
-#if __GNUC__ > 1
 #define	va_dcl	int va_alist; ...
-#else
-#define	va_dcl	int va_alist; 
-#endif
 
 #define	va_start(ap) \
 	((ap) = (va_list)&va_alist)
@@ -84,6 +84,6 @@ typedef char *va_list;
 
 #define	va_end(ap)
 
-#endif /* __GNUC__ post GCC 2.95 */
+#endif /* __GNUCLIKE_BUILTIN_VARARGS */
 
 #endif /* !_MACHINE_VARARGS_H_ */