dtc: import latest upstream dtc

This updates scripts/dtc to commit 317a5d9 "dtc: zero out new label
objects" from git://git.jdl.com/software/dtc.git.

This adds features such as:
* /bits/ syntax for cell data.
* Math expressions within cell data.
* The ability to delete properties or nodes.
* Support for #line directives in the input file, which allows the use of
  cpp on *.dts.
* -i command-line option (/include/ path)
* -W/-E command-line options for error/warning control.
* Removal of spew to STDOUT containing the filename being compiled.
* Many additions to the libfdt API.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Jon Loeliger <jdl@jdl.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>

scripts/dtc/libfdt/fdt.c

@@ -74,7 +74,7 @@ int fdt_check_header(const void *fdt)
 	return 0;
 }
 
-const void *fdt_offset_ptr(const void *fdt, int offset, int len)
+const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
 {
 	const char *p;
 
@@ -90,42 +90,53 @@ const void *fdt_offset_ptr(const void *fdt, int offset, int len)
 	return p;
 }
 
-uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset)
+uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset)
 {
 	const uint32_t *tagp, *lenp;
 	uint32_t tag;
+	int offset = startoffset;
 	const char *p;
 
-	if (offset % FDT_TAGSIZE)
-		return -1;
-
+	*nextoffset = -FDT_ERR_TRUNCATED;
 	tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
-	if (! tagp)
+	if (!tagp)
 		return FDT_END; /* premature end */
 	tag = fdt32_to_cpu(*tagp);
 	offset += FDT_TAGSIZE;
 
+	*nextoffset = -FDT_ERR_BADSTRUCTURE;
 	switch (tag) {
 	case FDT_BEGIN_NODE:
 		/* skip name */
 		do {
 			p = fdt_offset_ptr(fdt, offset++, 1);
 		} while (p && (*p != '\0'));
-		if (! p)
-			return FDT_END;
+		if (!p)
+			return FDT_END; /* premature end */
 		break;
+
 	case FDT_PROP:
 		lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
-		if (! lenp)
-			return FDT_END;
-		/* skip name offset, length and value */
-		offset += 2*FDT_TAGSIZE + fdt32_to_cpu(*lenp);
+		if (!lenp)
+			return FDT_END; /* premature end */
+		/* skip-name offset, length and value */
+		offset += sizeof(struct fdt_property) - FDT_TAGSIZE
+			+ fdt32_to_cpu(*lenp);
 		break;
+
+	case FDT_END:
+	case FDT_END_NODE:
+	case FDT_NOP:
+		break;
+
+	default:
+		return FDT_END;
 	}
 
-	if (nextoffset)
-		*nextoffset = FDT_TAGALIGN(offset);
+	if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset))
+		return FDT_END; /* premature end */
 
+	*nextoffset = FDT_TAGALIGN(offset);
 	return tag;
 }
 
@@ -138,6 +149,15 @@ int _fdt_check_node_offset(const void *fdt, int offset)
 	return offset;
 }
 
+int _fdt_check_prop_offset(const void *fdt, int offset)
+{
+	if ((offset < 0) || (offset % FDT_TAGSIZE)
+	    || (fdt_next_tag(fdt, offset, &offset) != FDT_PROP))
+		return -FDT_ERR_BADOFFSET;
+
+	return offset;
+}
+
 int fdt_next_node(const void *fdt, int offset, int *depth)
 {
 	int nextoffset = 0;
@@ -162,15 +182,16 @@ int fdt_next_node(const void *fdt, int offset, int *depth)
 			break;
 
 		case FDT_END_NODE:
-			if (depth)
-				(*depth)--;
+			if (depth && ((--(*depth)) < 0))
+				return nextoffset;
 			break;
 
 		case FDT_END:
-			return -FDT_ERR_NOTFOUND;
-
-		default:
-			return -FDT_ERR_BADSTRUCTURE;
+			if ((nextoffset >= 0)
+			    || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth))
+				return -FDT_ERR_NOTFOUND;
+			else
+				return nextoffset;
 		}
 	} while (tag != FDT_BEGIN_NODE);