Fix warnings during bootstrap on Linux systems

Most warnings are currently off for the boostrap phase, but once D27598
lands they will be enabled again.

tools/build/Makefile

@@ -174,6 +174,8 @@ CFLAGS.closefrom.c+=	-DSTDC_HEADERS -DHAVE_SYS_DIR_H -DHAVE_DIRENT_H \
 	-DHAVE_DIRFD -DHAVE_SYSCONF
 # Provide warnc/errc/getprogname/setprograme
 SRCS+=	err.c progname.c
+# Stub implementations of fflagstostr/strtofflags
+SRCS+=	fflags.c
 .endif
 # Provide the same arc4random implementation on Linux/macOS
 CFLAGS.arc4random.c+=	-I${SRCTOP}/sys/crypto/chacha20 -D__isthreaded=1

tools/build/cross-build/capsicum_stubs.c

@@ -42,19 +42,20 @@ __FBSDID("$FreeBSD$");
 #include <errno.h>
 
 int
-cap_ioctls_limit(int fd, const cap_ioctl_t *cmds, size_t ncmds)
+cap_ioctls_limit(int fd __unused, const cap_ioctl_t *cmds __unused,
+    size_t ncmds __unused)
 {
 	return 0; /* Just pretend that it succeeded */
 }
 
 int
-cap_fcntls_limit(int fd, uint32_t fcntlrights)
+cap_fcntls_limit(int fd __unused, uint32_t fcntlrights __unused)
 {
 	return 0; /* Just pretend that it succeeded */
 }
 
 int
-cap_rights_limit(int fd, const cap_rights_t *rights)
+cap_rights_limit(int fd __unused, const cap_rights_t *rights __unused)
 {
 	return 0; /* Just pretend that it succeeded */
 }

tools/build/cross-build/fake_sysctl.c

@@ -37,13 +37,15 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+#include <sys/sysctl.h>
+
 #include <err.h>
 #include <string.h>
 #include <sysexits.h>
 
 int
-__freebsd_sysctlbyname(
-    const char *name, void *oldp, size_t *oldlenp, void *newp, size_t newlen)
+__freebsd_sysctlbyname(const char *name, void *oldp, size_t *oldlenp,
+    const void *newp, size_t newlen)
 {
 	if (strcmp(name, "kern.vm_guest") == 0) {
 		if (!oldp || !oldlenp)

tools/build/cross-build/fflags.c

@@ -12,6 +12,9 @@
  * Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
  * ("CTSRD"), as part of the DARPA CRASH research programme.
  *
+ * This work was supported by Innovate UK project 105694, "Digital Security by
+ * Design (DSbD) Technology Platform Prototype".
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -32,11 +35,28 @@
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
- *
- * $FreeBSD$
  */
-#pragma once
-/* The Linux sysctl struct has a member called __unused */
-#undef __unused
-#include_next <sys/sysctl.h>
-#define __unused __attribute__((unused))
+
+#include <string.h>
+#include <unistd.h>
+
+char *
+fflagstostr(u_long flags __unused)
+{
+	return strdup("");
+}
+
+int
+strtofflags(char **stringp __unused, u_long *setp, u_long *clrp)
+{
+	/* On linux just ignore the file flags for now */
+	/*
+	 * XXX: this will prevent makefs from setting noschg on libc, etc.
+	 * so we should really find a way to support flags in disk images.
+	 */
+	if (setp)
+		*setp = 0;
+	if (clrp)
+		*clrp = 0;
+	return (0); /* success */
+}

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

@@ -53,7 +53,7 @@ const char *group_from_gid(gid_t gid, int noname);
 
 #ifdef __linux__
 static inline int
-setgroupent(int stayopen)
+setgroupent(int stayopen __unused)
 {
 	setgrent();
 	return (1);

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

@@ -52,7 +52,7 @@ const char *user_from_uid(uid_t uid, int noname);
 
 #ifdef __linux__
 static inline int
-setpassent(int stayopen)
+setpassent(int stayopen __unused)
 {
 	setpwent();
 	return (1);

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

@@ -59,15 +59,6 @@
 #define __IDSTRING(name, string)
 #endif
 
-#ifndef rounddown
-#define rounddown(x, y) (((x) / (y)) * (y))
-#define rounddown2(x, y) ((x) & (~((y)-1))) /* if y is power of two */
-#define roundup(x, y) ((((x) + ((y)-1)) / (y)) * (y)) /* to any y */
-#define roundup2(x, y) \
-	(((x) + ((y)-1)) & (~((y)-1))) /* if y is powers of two */
-#define powerof2(x) ((((x)-1) & (x)) == 0)
-#endif
-
 #ifndef __pure
 #define __pure __attribute__((__pure__))
 #endif
@@ -145,12 +136,6 @@
 #define __malloc_like __attribute__((__malloc__))
 #endif
 
-#ifndef nitems
-// https://stackoverflow.com/questions/1598773/is-there-a-standard-function-in-c-that-would-return-the-length-of-an-array/1598827#1598827
-#define nitems(x) \
-	((sizeof(x) / sizeof(0 [x])) / ((size_t)(!(sizeof(x) % sizeof(0 [x])))))
-#endif
-
 #ifndef __min_size
 #if !defined(__cplusplus)
 #define __min_size(x) static(x)
@@ -181,15 +166,6 @@
 #define __printf0__ __printf__
 #endif
 
-/*
- * These should probably be in sys/types.h but mtree expects them to exist
- * without including <sys/types.h>
- */
-typedef unsigned char u_char;
-typedef unsigned short u_short;
-typedef unsigned int u_int;
-typedef unsigned long u_long;
-
 /* On MacOS __CONCAT is defined as x ## y, which won't expand macros */
 #undef __CONCAT
 #define __CONCAT1(x, y) x##y

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

@@ -12,6 +12,9 @@
  * Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
  * ("CTSRD"), as part of the DARPA CRASH research programme.
  *
+ * This work was supported by Innovate UK project 105694, "Digital Security by
+ * Design (DSbD) Technology Platform Prototype".
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -63,3 +66,26 @@
 #ifndef __PAST_END
 #define __PAST_END(array, offset) (((__typeof__(*(array)) *)(array))[offset])
 #endif
+
+#ifndef nitems
+// https://stackoverflow.com/questions/1598773/is-there-a-standard-function-in-c-that-would-return-the-length-of-an-array/1598827#1598827
+#define nitems(x) \
+	((sizeof(x) / sizeof(0 [x])) / ((size_t)(!(sizeof(x) % sizeof(0 [x])))))
+#endif
+
+#ifndef rounddown
+#define rounddown(x, y) (((x) / (y)) * (y))
+#endif
+#ifndef rounddown2
+#define rounddown2(x, y) ((x) & (~((y)-1))) /* if y is power of two */
+#endif
+#ifndef roundup
+#define roundup(x, y) ((((x) + ((y)-1)) / (y)) * (y)) /* to any y */
+#endif
+#ifndef roundup2
+#define roundup2(x, y) \
+	(((x) + ((y)-1)) & (~((y)-1))) /* if y is powers of two */
+#endif
+#ifndef powerof2
+#define powerof2(x) ((((x)-1) & (x)) == 0)
+#endif

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

@@ -40,7 +40,7 @@
 #include <getopt.h>
 
 static inline int
-check_utility_compat(const char *utility)
+check_utility_compat(const char *utility __unused)
 {
 	/*
 	 * The check_utility_compat() function returns zero if utility should

tools/build/cross-build/include/linux/limits.h

@@ -39,10 +39,6 @@
 #include_next <limits.h>
 #endif
 
-#ifdef __STRICT_ANSI__
-#warning __STRICT_ANSI__ defined
-#endif
-
 #if __has_include(<linux/limits.h>)
 #include <linux/limits.h>
 #endif

tools/build/cross-build/include/linux/unistd.h

@@ -62,26 +62,8 @@ issetugid(void)
 }
 #endif
 
-static inline char *
-fflagstostr(u_long flags)
-{
-	return strdup("");
-}
-
-static inline int
-strtofflags(char **stringp, u_long *setp, u_long *clrp)
-{
-	/* On linux just ignore the file flags for now */
-	/*
-	 * XXXAR: this will prevent makefs from setting noschg on libc, etc
-	 * so we should really build the version from libc
-	 */
-	if (setp)
-		*setp = 0;
-	if (clrp)
-		*clrp = 0;
-	return (0); /* success */
-}
+char	*fflagstostr(unsigned long flags);
+int	strtofflags(char **stringp, u_long *setp, u_long *clrp);
 
 /*
  * getentropy() was added in glibc 2.25. Declare it for !glibc and older

tools/build/mk/Makefile.boot

@@ -45,6 +45,11 @@ CFLAGS+=	-Werror=implicit-function-declaration -Werror=implicit-int \
 		-Werror=return-type -Wundef
 CFLAGS+=	-DHAVE_NBTOOL_CONFIG_H=1
 CFLAGS+=	-I${SRCTOP}/tools/build/cross-build/include/common
+# This is needed for code that compiles for pre-C11 C standards
+CWARNFLAGS+=	-Wno-typedef-redefinition
+# bsd.sys.mk explicitly turns on -Wsystem-headers, but that's extremely
+# noisy when building on Linux.
+CWARNFLAGS+=	-Wno-system-headers
 
 # b64_pton and b64_ntop is in libresolv on MacOS and Linux:
 # TODO: only needed for uuencode and uudecode
@@ -52,7 +57,7 @@ LDADD+=-lresolv
 
 .if ${.MAKE.OS} == "Linux"
 CFLAGS+=	-I${SRCTOP}/tools/build/cross-build/include/linux
-CFLAGS+=	-std=gnu99 -D_GNU_SOURCE=1
+CFLAGS+=	-D_GNU_SOURCE=1
 # Needed for sem_init, etc. on Linux (used by usr.bin/sort)
 LDADD+=	-pthread