[PATCH 0/6] Synchronize <sys/cdefs.h> with FreeBSD

[PATCH 0/6] Synchronize <sys/cdefs.h> with FreeBSD

[Sebastian Huber]

This patch synchronizes <sys/cdefs.h> with the latest FreeBSD main branch.

Alex Richardson (1):
  Expose clang's alignment builtins and use them for roundup2/rounddown2

Mark Johnston (2):
  cdefs: Make __nosanitizeaddress work for KASAN as well
  cdefs: Add a default definition for __nosanitizememory

Warner Losh (3):
  cdefs.h: remove intel_compiler support
  cdefs.h: Remove __GNUCLIKE___OFFSETOF, it's unused
  cdefs.h: Remove redundant #ifdefs

 newlib/libc/include/sys/cdefs.h | 67 +++++++++++++++++++--------------
 1 file changed, 39 insertions(+), 28 deletions(-)

-- 
2.35.3

[PATCH 1/6] cdefs.h: remove intel_compiler support

[Sebastian Huber]

From: Warner Losh <imp@FreeBSD.org>

The  age  of   the  intel  compiler  support  is  so   old  as  to  be
uninteresting. No recent recports of  intel compiler support have been
received.  Remove  all the  special  case  workarounds for  the  Intel
compiler. Should there be interest in supporting the compiler, contact
me and I'll work with people to make it happen, though I suspect these
instances are more likely to be in the way than to be helpful.

Reviewed by: cem, emaste, vangyzen, dim
Differential Revision: https://reviews.freebsd.org/D26817
---
 newlib/libc/include/sys/cdefs.h | 34 ++++++++++++---------------------
 1 file changed, 12 insertions(+), 22 deletions(-)

diff --git a/newlib/libc/include/sys/cdefs.h b/newlib/libc/include/sys/cdefs.h
index da7290921..e6a31bd51 100644
--- a/newlib/libc/include/sys/cdefs.h
+++ b/newlib/libc/include/sys/cdefs.h
@@ -101,9 +101,9 @@
  * having a compiler-agnostic source tree.
  */
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#if defined(__GNUC__)
 
-#if __GNUC__ >= 3 || defined(__INTEL_COMPILER)
+#if __GNUC__ >= 3
 #define	__GNUCLIKE_ASM 3
 #define	__GNUCLIKE_MATH_BUILTIN_CONSTANTS
 #else
@@ -113,15 +113,9 @@
 #define	__GNUCLIKE___OFFSETOF 1
 #define	__GNUCLIKE___SECTION 1
 
-#ifndef __INTEL_COMPILER
 #define	__GNUCLIKE_CTOR_SECTION_HANDLING 1
-#endif
 
 #define	__GNUCLIKE_BUILTIN_CONSTANT_P 1
-#if defined(__INTEL_COMPILER) && defined(__cplusplus) && \
-   __INTEL_COMPILER < 800
-#undef __GNUCLIKE_BUILTIN_CONSTANT_P
-#endif
 
 #if (__GNUC_MINOR__ > 95 || __GNUC__ >= 3)
 #define	__GNUCLIKE_BUILTIN_VARARGS 1
@@ -140,10 +134,8 @@
 #define	__compiler_membar()	__asm __volatile(" " : : : "memory")
 #endif
 
-#ifndef __INTEL_COMPILER
 #define	__GNUCLIKE_BUILTIN_NEXT_ARG 1
 #define	__GNUCLIKE_MATH_BUILTIN_RELOPS
-#endif
 
 #define	__GNUCLIKE_BUILTIN_MEMCPY 1
 
@@ -159,7 +151,7 @@
 
 #define	__CC_SUPPORTS_DYNAMIC_ARRAY_INIT 1
 
-#endif /* __GNUC__ || __INTEL_COMPILER */
+#endif /* __GNUC__ */
 
 /*
  * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
@@ -228,18 +220,18 @@
  * a feature that we cannot live without.
  */
 #define	__weak_symbol	__attribute__((__weak__))
-#if !__GNUC_PREREQ__(2, 5) && !defined(__INTEL_COMPILER)
+#if !__GNUC_PREREQ__(2, 5)
 #define	__dead2
 #define	__pure2
 #define	__unused
 #endif
-#if __GNUC__ == 2 && __GNUC_MINOR__ >= 5 && __GNUC_MINOR__ < 7 && !defined(__INTEL_COMPILER)
+#if __GNUC__ == 2 && __GNUC_MINOR__ >= 5 && __GNUC_MINOR__ < 7
 #define	__dead2		__attribute__((__noreturn__))
 #define	__pure2		__attribute__((__const__))
 #define	__unused
 /* XXX Find out what to do for __packed, __aligned and __section */
 #endif
-#if __GNUC_PREREQ__(2, 7) || defined(__INTEL_COMPILER)
+#if __GNUC_PREREQ__(2, 7)
 #define	__dead2		__attribute__((__noreturn__))
 #define	__pure2		__attribute__((__const__))
 #define	__unused	__attribute__((__unused__))
@@ -376,7 +368,7 @@
 #define	__pure
 #endif
 
-#if __GNUC_PREREQ__(3, 1) || (defined(__INTEL_COMPILER) && __INTEL_COMPILER >= 800)
+#if __GNUC_PREREQ__(3, 1)
 #define	__always_inline	__inline__ __attribute__((__always_inline__))
 #else
 #define	__always_inline
@@ -417,7 +409,7 @@
 #endif
 
 /* XXX: should use `#if __STDC_VERSION__ < 199901'. */
-#if !__GNUC_PREREQ__(2, 7) && !defined(__INTEL_COMPILER)
+#if !__GNUC_PREREQ__(2, 7)
 #define	__func__	NULL
 #endif
 
@@ -512,7 +504,7 @@
  * that are known to support the features properly (old versions of gcc-2
  * didn't permit keeping the keywords out of the application namespace).
  */
-#if !__GNUC_PREREQ__(2, 7) && !defined(__INTEL_COMPILER)
+#if !__GNUC_PREREQ__(2, 7)
 #define	__printflike(fmtarg, firstvararg)
 #define	__scanflike(fmtarg, firstvararg)
 #define	__format_arg(fmtarg)
@@ -532,18 +524,16 @@
 
 /* Compiler-dependent macros that rely on FreeBSD-specific extensions. */
 #if defined(__FreeBSD_cc_version) && __FreeBSD_cc_version >= 300001 && \
-    defined(__GNUC__) && !defined(__INTEL_COMPILER)
+    defined(__GNUC__)
 #define	__printf0like(fmtarg, firstvararg) \
 	    __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
 #else
 #define	__printf0like(fmtarg, firstvararg)
 #endif
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
-#ifndef __INTEL_COMPILER
+#if defined(__GNUC__)
 #define	__strong_reference(sym,aliassym)	\
 	extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)))
-#endif
 #ifdef __ELF__
 #ifdef __STDC__
 #define	__weak_reference(sym,alias)	\
@@ -587,7 +577,7 @@
 	__asm__(".stabs \"_/**/sym\",1,0,0,0")
 #endif	/* __STDC__ */
 #endif	/* __ELF__ */
-#endif	/* __GNUC__ || __INTEL_COMPILER */
+#endif	/* __GNUC__ */
 
 #ifndef	__FBSDID
 #define	__FBSDID(s)	struct __hack
-- 
2.35.3

Re: [PATCH 1/6] cdefs.h: remove intel_compiler support

[Corinna Vinschen]

On Jul 11 09:15, Sebastian Huber wrote:
> From: Warner Losh <imp@FreeBSD.org>
> 
> The  age  of   the  intel  compiler  support  is  so   old  as  to  be
> uninteresting. No recent recports of  intel compiler support have been
> received.  Remove  all the  special  case  workarounds for  the  Intel
> compiler. Should there be interest in supporting the compiler, contact
> me and I'll work with people to make it happen, though I suspect these
> instances are more likely to be in the way than to be helpful.

What about the Intel compiler support in newlib?  Not that I have seen any
evidence that somebody is actually using one...

Other than that, the patchset looks good to me.


Thanks,
Corinna

Re: [PATCH 1/6] cdefs.h: remove intel_compiler support

[Sebastian Huber]

On 11/07/2022 10:32, Corinna Vinschen wrote:
> On Jul 11 09:15, Sebastian Huber wrote:
>> From: Warner Losh<imp@FreeBSD.org>
>>
>> The  age  of   the  intel  compiler  support  is  so   old  as  to  be
>> uninteresting. No recent recports of  intel compiler support have been
>> received.  Remove  all the  special  case  workarounds for  the  Intel
>> compiler. Should there be interest in supporting the compiler, contact
>> me and I'll work with people to make it happen, though I suspect these
>> instances are more likely to be in the way than to be helpful.
> What about the Intel compiler support in newlib?  Not that I have seen any
> evidence that somebody is actually using one...

The Intel compiler support was added through a <sys/cdefs.h> 
synchronization with FreeBSD in 2013 and 2015. The Intel compiler was 
probably never used together with Newlib.

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Re: [PATCH 1/6] cdefs.h: remove intel_compiler support

[Corinna Vinschen]

On Jul 11 11:10, Sebastian Huber wrote:
> On 11/07/2022 10:32, Corinna Vinschen wrote:
> > On Jul 11 09:15, Sebastian Huber wrote:
> > > From: Warner Losh<imp@FreeBSD.org>
> > > 
> > > The  age  of   the  intel  compiler  support  is  so   old  as  to  be
> > > uninteresting. No recent recports of  intel compiler support have been
> > > received.  Remove  all the  special  case  workarounds for  the  Intel
> > > compiler. Should there be interest in supporting the compiler, contact
> > > me and I'll work with people to make it happen, though I suspect these
> > > instances are more likely to be in the way than to be helpful.
> > What about the Intel compiler support in newlib?  Not that I have seen any
> > evidence that somebody is actually using one...
> 
> The Intel compiler support was added through a <sys/cdefs.h> synchronization
> with FreeBSD in 2013 and 2015. The Intel compiler was probably never used
> together with Newlib.

Ok, then please push.


Thx,
Corinna

[PATCH 2/6] Expose clang's alignment builtins and use them for roundup2/rounddown2

[Sebastian Huber]

From: Alex Richardson <arichardson@FreeBSD.org>

This makes roundup2/rounddown2 type- and const-preserving and allows
using it on pointer types without casting to uintptr_t first. Not
performing pointer-to-integer conversions also helps the compiler's
optimization passes and can therefore result in better code generation.
When using it with integer values there should be no change other than
the compiler checking that the alignment value is a valid power-of-two.

I originally implemented these builtins for CHERI a few years ago and
they have been very useful for CheriBSD. However, they are also useful
for non-CHERI code so I was able to upstream them for Clang 10.0.

Rationale from the clang documentation:
Clang provides builtins to support checking and adjusting alignment
of pointers and integers. These builtins can be used to avoid relying
on implementation-defined behavior of arithmetic on integers derived
from pointers. Additionally, these builtins retain type information
and, unlike bitwise arithmetic, they can perform semantic checking on
the alignment value.

There is also a feature request for GCC, so GCC may also support it in
the future: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98641

Reviewed By:	brooks, jhb, imp
Differential Revision: https://reviews.freebsd.org/D28332
---
 newlib/libc/include/sys/cdefs.h | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/newlib/libc/include/sys/cdefs.h b/newlib/libc/include/sys/cdefs.h
index e6a31bd51..7dff2c8d8 100644
--- a/newlib/libc/include/sys/cdefs.h
+++ b/newlib/libc/include/sys/cdefs.h
@@ -716,4 +716,23 @@
 #define	__guarded_by(x)		__lock_annotate(guarded_by(x))
 #define	__pt_guarded_by(x)	__lock_annotate(pt_guarded_by(x))
 
+/* Alignment builtins for better type checking and improved code generation. */
+/* Provide fallback versions for other compilers (GCC/Clang < 10): */
+#if !__has_builtin(__builtin_is_aligned)
+#define __builtin_is_aligned(x, align)	\
+	(((__uintptr_t)x & ((align) - 1)) == 0)
+#endif
+#if !__has_builtin(__builtin_align_up)
+#define __builtin_align_up(x, align)	\
+	((__typeof__(x))(((__uintptr_t)(x)+((align)-1))&(~((align)-1))))
+#endif
+#if !__has_builtin(__builtin_align_down)
+#define __builtin_align_down(x, align)	\
+	((__typeof__(x))((x)&(~((align)-1))))
+#endif
+
+#define __align_up(x, y) __builtin_align_up(x, y)
+#define __align_down(x, y) __builtin_align_down(x, y)
+#define __is_aligned(x, y) __builtin_is_aligned(x, y)
+
 #endif /* !_SYS_CDEFS_H_ */
-- 
2.35.3

[PATCH 3/6] cdefs.h: Remove __GNUCLIKE___OFFSETOF, it's unused

[Sebastian Huber]

From: Warner Losh <imp@FreeBSD.org>

__GNUCLIKE___OFFSETOF is unreferenced in the tree, remove it as long
obsolete.

Sponsored by:		Netflix
---
 newlib/libc/include/sys/cdefs.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/newlib/libc/include/sys/cdefs.h b/newlib/libc/include/sys/cdefs.h
index 7dff2c8d8..6d179c2b4 100644
--- a/newlib/libc/include/sys/cdefs.h
+++ b/newlib/libc/include/sys/cdefs.h
@@ -110,7 +110,6 @@
 #define	__GNUCLIKE_ASM 2
 #endif
 #define	__GNUCLIKE___TYPEOF 1
-#define	__GNUCLIKE___OFFSETOF 1
 #define	__GNUCLIKE___SECTION 1
 
 #define	__GNUCLIKE_CTOR_SECTION_HANDLING 1
-- 
2.35.3

[PATCH 4/6] cdefs: Make __nosanitizeaddress work for KASAN as well

[Sebastian Huber]

From: Mark Johnston <markj@FreeBSD.org>

Add __nosanitizememory while I'm here.

Reviewed by:	andrew, kib
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D30126
---
 newlib/libc/include/sys/cdefs.h | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/newlib/libc/include/sys/cdefs.h b/newlib/libc/include/sys/cdefs.h
index 6d179c2b4..7eb6c0430 100644
--- a/newlib/libc/include/sys/cdefs.h
+++ b/newlib/libc/include/sys/cdefs.h
@@ -699,12 +699,18 @@
 #define	__no_lock_analysis	__lock_annotate(no_thread_safety_analysis)
 
 /*
- * Function or variable should not be sanitized, i.e. by AddressSanitizer.
+ * Function or variable should not be sanitized, e.g., by AddressSanitizer.
  * GCC has the nosanitize attribute, but as a function attribute only, and
  * warns on use as a variable attribute.
  */
 #if __has_attribute(no_sanitize) && defined(__clang__)
+#ifdef _KERNEL
+#define __nosanitizeaddress	__attribute__((no_sanitize("kernel-address")))
+#define __nosanitizememory	__attribute__((no_sanitize("kernel-memory")))
+#else
 #define __nosanitizeaddress	__attribute__((no_sanitize("address")))
+#define __nosanitizememory	__attribute__((no_sanitize("memory")))
+#endif
 #define __nosanitizethread	__attribute__((no_sanitize("thread")))
 #else
 #define __nosanitizeaddress
-- 
2.35.3

[PATCH 5/6] cdefs: Add a default definition for __nosanitizememory

[Sebastian Huber]

From: Mark Johnston <markj@FreeBSD.org>

MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
---
 newlib/libc/include/sys/cdefs.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/newlib/libc/include/sys/cdefs.h b/newlib/libc/include/sys/cdefs.h
index 7eb6c0430..b3508f3a9 100644
--- a/newlib/libc/include/sys/cdefs.h
+++ b/newlib/libc/include/sys/cdefs.h
@@ -714,6 +714,7 @@
 #define __nosanitizethread	__attribute__((no_sanitize("thread")))
 #else
 #define __nosanitizeaddress
+#define __nosanitizememory
 #define __nosanitizethread
 #endif
 
-- 
2.35.3

[PATCH 6/6] cdefs.h: Remove redundant #ifdefs

[Sebastian Huber]

From: Warner Losh <imp@FreeBSD.org>

Remove redunant #ifdef __GNUC__ inside an #if defined(__GNUC__)
block. They are nops.

Sponsored by:		Netflix
---
 newlib/libc/include/sys/cdefs.h | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/newlib/libc/include/sys/cdefs.h b/newlib/libc/include/sys/cdefs.h
index b3508f3a9..720e70092 100644
--- a/newlib/libc/include/sys/cdefs.h
+++ b/newlib/libc/include/sys/cdefs.h
@@ -122,16 +122,12 @@
 #define	__GNUCLIKE_BUILTIN_VAALIST 1
 #endif
 
-#if defined(__GNUC__)
 #define	__GNUC_VA_LIST_COMPATIBILITY 1
-#endif
 
 /*
  * Compiler memory barriers, specific to gcc and clang.
  */
-#if defined(__GNUC__)
 #define	__compiler_membar()	__asm __volatile(" " : : : "memory")
-#endif
 
 #define	__GNUCLIKE_BUILTIN_NEXT_ARG 1
 #define	__GNUCLIKE_MATH_BUILTIN_RELOPS
-- 
2.35.3