Fix dtrace tools bootstrap on non-FreeBSD after OpenZFS import

This required surprisingly few build system changes and only two changes to the
openZFS compat headers which have been upstreamed as
openzfs/zfs#10863

Reviewed By:	#zfs, freqlabs
Differential Revision: https://reviews.freebsd.org/D26193

cddl/lib/libspl/Makefile

@@ -14,13 +14,14 @@ SRCS = \
         list.c \
         mkdirp.c \
         page.c \
-        strlcat.c \
-        strlcpy.c \
         timestamp.c \
         zone.c \
         include/sys/list.h \
         include/sys/list_impl.h
 
+# These functions are not required when bootstrapping and the atomic code
+# will not compile when building on macOS.
+.if !defined(BOOTSTRAPPING)
 SRCS += \
         getexecname.c \
         gethostid.c \
@@ -38,6 +39,7 @@ SRCS += atomic.S
 .PATH: ${SRCTOP}/sys/contrib/openzfs/lib/libspl/asm-generic
 SRCS += atomic.c
 .endif
+.endif
 
 
 WARNS?=	2

tools/build/cross-build/include/common/string.h

@@ -37,6 +37,10 @@
  */
 #pragma once
 
+/* Avoid incompatible opensolaris redeclarations (without _FORTIFY_SOURCE). */
+#define HAVE_STRLCAT 1
+#define HAVE_STRLCPY 1
+
 #include_next <string.h>
 /*
  * FreeBSD string.h #includes strings.h and all libmd code depends on

tools/build/cross-build/include/common/sys/cdefs.h

@@ -276,3 +276,11 @@ typedef unsigned long u_long;
 #ifndef __DEQUALIFY
 #define __DEQUALIFY(type, var) ((type)(__uintptr_t)(const volatile void *)(var))
 #endif
+
+
+/* Expose all declarations when using FreeBSD headers */
+#define	__POSIX_VISIBLE		200809
+#define	__XSI_VISIBLE		700
+#define	__BSD_VISIBLE		1
+#define	__ISO_C_VISIBLE		2011
+#define	__EXT1_VISIBLE		1

tools/build/cross-build/include/linux/sys/stat.h

@@ -59,3 +59,6 @@
 #ifndef S_ISTXT
 #define S_ISTXT S_ISVTX
 #endif
+
+/* This include is needed for OpenZFS bootstrap */
+#include <sys/mount.h>

tools/build/cross-build/include/mac/sys/_types.h

@@ -43,3 +43,5 @@
  * __darwin_ct_rune_t exists.
  */
 typedef __darwin_ct_rune_t __ct_rune_t;
+/* Needed for opensolaris compat. */
+typedef	__int64_t	off64_t;

tools/build/mk/Makefile.boot

@@ -44,7 +44,6 @@ LIBELF:=${WORLDTMP}/legacy/usr/lib/libelf.a
 CFLAGS+=	-Werror=implicit-function-declaration -Werror=implicit-int \
 		-Werror=return-type -Wundef
 CFLAGS+=	-DHAVE_NBTOOL_CONFIG_H=1
-CFLAGS+=	-D__BSD_VISIBLE=1
 CFLAGS+=	-I${SRCTOP}/tools/build/cross-build/include/common
 
 # b64_pton and b64_ntop is in libresolv on MacOS and Linux: