dtc: Address an assortment of portability problems

I've recently worked with a FreeBSD developer, getting dtc and libfdt
working on FreeBSD.  This showed up a number of portability problems
in the dtc package which this patch addresses.  Changes are as
follows:

	- the parent_offset and supernode_atdepth_offset testcases
used the glibc extension functions strchrnul() and strndupa().  Those
are removed, using slightly longer coding with standard C functions
instead.

	- some other testcases had a #define _GNU_SOURCE for no
particular reason.  This is removed.

	- run_tests.sh has bash specific constructs removed, and the
interpreter changed to /bin/sh.  This apparently now runs fine on
FreeBSD's /bin/sh, and I've also tested it with both ash and dash.

	- convert-dtsv0-lexer.l has some extra #includes added.  These
must have been included indirectly with Linux and glibc, but aren't on
FreeBSD.

	- the endian handling functions in libfdt_env.h, based on
endian.h and byteswap.h are replaced with some portable open-coded
versions.  Unfortunately, these result in fairly crappy code when
compiled, but as far as I can determine there doesn't seem to be any
POSIX, SUS or de facto standard way of determining endianness at
compile time, nor standard names for byteswapping functions.

	- some more endian handling, from testdata.h using the
problematic endian.h is simply removed, since it wasn't actually being
used anyway.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

convert-dtsv0-lexer.l

@@ -28,9 +28,14 @@ PATHCHAR	({PROPNODECHAR}|[/])
 LABEL		[a-zA-Z_][a-zA-Z0-9_]*
 
 %{
+#include <string.h>
+#include <stdlib.h>
 #include <stdarg.h>
+
+#include <errno.h>
 #include <assert.h>
 #include <fnmatch.h>
+
 #include "srcpos.h"
 
 static int v1_tagged; /* = 0 */

libfdt/libfdt_env.h

@@ -4,19 +4,20 @@
 #include <stddef.h>
 #include <stdint.h>
 #include <string.h>
-#include <endian.h>
-#include <byteswap.h>
 
-#if __BYTE_ORDER == __BIG_ENDIAN
-#define fdt32_to_cpu(x)		(x)
-#define cpu_to_fdt32(x)		(x)
-#define fdt64_to_cpu(x)		(x)
-#define cpu_to_fdt64(x)		(x)
-#else
-#define fdt32_to_cpu(x)		(bswap_32((x)))
-#define cpu_to_fdt32(x)		(bswap_32((x)))
-#define fdt64_to_cpu(x)		(bswap_64((x)))
-#define cpu_to_fdt64(x)		(bswap_64((x)))
-#endif
+#define _B(n)	((unsigned long long)((uint8_t *)&x)[n])
+static inline uint32_t fdt32_to_cpu(uint32_t x)
+{
+	return (_B(0) << 24) | (_B(1) << 16) | (_B(2) << 8) | _B(3);
+}
+#define cpu_to_fdt32(x) fdt32_to_cpu(x)
+
+static inline uint64_t fdt64_to_cpu(uint64_t x)
+{
+	return (_B(0) << 56) | (_B(1) << 48) | (_B(2) << 40) | (_B(3) << 32)
+		| (_B(4) << 24) | (_B(5) << 16) | (_B(6) << 8) | _B(7);
+}
+#define cpu_to_fdt64(x) fdt64_to_cpu(x)
+#undef _B
 
 #endif /* _LIBFDT_ENV_H */

tests/get_path.c

@@ -17,8 +17,6 @@
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  */
-#define _GNU_SOURCE
-
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>

tests/parent_offset.c

@@ -17,8 +17,6 @@
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  */
-#define _GNU_SOURCE
-
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
@@ -45,9 +43,12 @@ int path_parent_len(const char *path)
 void check_path(struct fdt_header *fdt, const char *path)
 {
 	char *parentpath;
-	int nodeoffset, parentoffset, parentpathoffset;
+	int nodeoffset, parentoffset, parentpathoffset, pathparentlen;
 
-	parentpath = strndupa(path, path_parent_len(path));
+	pathparentlen = path_parent_len(path);
+	parentpath = alloca(pathparentlen + 1);
+	strncpy(parentpath, path, pathparentlen);
+	parentpath[pathparentlen] = '\0';
 
 	verbose_printf("Path: \"%s\"\tParent: \"%s\"\n", path, parentpath);
 

tests/run_tests.sh

@@ -1,6 +1,6 @@
-#! /bin/bash
+#! /bin/sh
 
-. tests.sh
+. ./tests.sh
 
 export QUIET_TEST=1
 
@@ -15,19 +15,19 @@ tot_vg=0
 tot_strange=0
 
 base_run_test() {
-    tot_tests=$[tot_tests + 1]
+    tot_tests=$((tot_tests + 1))
     if VALGRIND="$VALGRIND" "$@"; then
-	tot_pass=$[tot_pass + 1]
+	tot_pass=$((tot_pass + 1))
     else
 	ret="$?"
 	if [ "$ret" == "1" ]; then
-	    tot_config=$[tot_config + 1]
+	    tot_config=$((tot_config + 1))
 	elif [ "$ret" == "2" ]; then
-	    tot_fail=$[tot_fail + 1]
+	    tot_fail=$((tot_fail + 1))
 	elif [ "$ret" == "$VGCODE" ]; then
-	    tot_vg=$[tot_vg + 1]
+	    tot_vg=$((tot_vg + 1))
 	else
-	    tot_strange=$[tot_strange + 1]
+	    tot_strange=$((tot_strange + 1))
 	fi
     fi
 }
@@ -52,7 +52,7 @@ wrap_test () {
 	else
 	    ret="$?"
 	    if [ "$ret" -gt 127 ]; then
-		signame=$(kill -l $[ret - 128])
+		signame=$(kill -l $((ret - 128)))
 		FAIL "Killed by SIG$signame"
 	    else
 		FAIL "Returned error code $ret"

tests/supernode_atdepth_offset.c

@@ -17,8 +17,6 @@
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  */
-#define _GNU_SOURCE
-
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
@@ -64,7 +62,7 @@ int path_prefix(const char *path, int depth)
 
 	p = path;
 	for (i = 0; i < depth; i++)
-		p = strchrnul(p+1, '/');
+		p = p+1 + strcspn(p+1, "/");
 
 	return p - path;
 }
@@ -74,10 +72,14 @@ void check_supernode_atdepth(struct fdt_header *fdt, const char *path,
 {
 	int pdepth = path_depth(path);
 	char *superpath;
-	int nodeoffset, supernodeoffset, superpathoffset;
+	int nodeoffset, supernodeoffset, superpathoffset, pathprefixlen;
 	int nodedepth;
 
-	superpath = strndupa(path, path_prefix(path, depth));
+	pathprefixlen = path_prefix(path, depth);
+	superpath = alloca(pathprefixlen + 1);
+	strncpy(superpath, path, pathprefixlen);
+	superpath[pathprefixlen] = '\0';
+
 	verbose_printf("Path %s (%d), depth %d, supernode is %s\n",
 		       path, pdepth, depth, superpath);
 

tests/testdata.h

@@ -1,14 +1,3 @@
-#include <endian.h>
-
-#if __BYTE_ORDER == __BIG_ENDIAN
-#define cell_to_fdt(x)	(x)
-#else
-/* We do this as a big hairy expression instead of using bswap_32()
- * because we need it to work in asm as well as C. */
-#define cell_to_fdt(x)	((((x) >> 24) & 0xff) | (((x) >> 8) & 0xff00) \
-			 | (((x) << 8) & 0xff0000) | (((x) << 24) & 0xff000000))
-#endif
-
 #ifdef __ASSEMBLY__
 #define ASM_CONST_LL(x)	(x)
 #else

tests/testutils.c

@@ -18,7 +18,7 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-#define _GNU_SOURCE /* for strsignal() */
+#define _GNU_SOURCE /* for strsignal() in glibc.  FreeBSD has it either way */
 
 #include <stdio.h>
 #include <stdlib.h>