Code simplification from Hadriels abandoned change.

Change-Id: If859ff904b254d3bc62d1d0dc5cf26cace11cae3
Reviewed-on: https://code.wireshark.org/review/4075
Reviewed-by: Anders Broman <a.broman58@gmail.com>

1 files changed, 29 insertions, 36 deletions

diff --git a/epan/proto.c b/epan/proto.c
index af1f531596..23b9c2de81 100644
--- a/epan/proto.c
+++ b/epan/proto.c
@@ -246,6 +246,10 @@ static void
 proto_tree_set_uint64(field_info *fi, guint64 value);
 static void
 proto_tree_set_uint64_tvb(field_info *fi, tvbuff_t *tvb, gint start, guint length, const guint encoding);
+static guint64
+proto_tvb_get_uint64_value(tvbuff_t *tvb, gint start, guint length, const guint encoding);
+static guint64
+proto_tvb_get_int64_value(tvbuff_t *tvb, gint start, guint length, const guint encoding);
 static void
 proto_tree_set_eui64(field_info *fi, const guint64 value);
 static void
@@ -2874,10 +2878,13 @@ proto_tree_set_uint64(field_info *fi, guint64 value)
  * gboolean as its last argument, with FALSE meaning "big-endian"
  * and TRUE meaning "little-endian", we treat any non-zero value of
  * "encoding" as meaning "little-endian".
+ *
+ * XXX: I don't know why this has to copy the tvb with tvb_memdup(),
+ * when the similar tvb_get_ntoh64() and such functions don't do that but
+ * instead just call fast_ensure_contiguous(). Is this just old code?
  */
-static void
-proto_tree_set_uint64_tvb(field_info *fi, tvbuff_t *tvb, gint start,
-			  guint length, const guint encoding)
+static inline guint64
+proto_tvb_get_uint64_value(tvbuff_t *tvb, gint start, guint length, const guint encoding)
 {
 	guint64 value = 0;
 	guint8* b = (guint8 *)tvb_memdup(wmem_packet_scope(), tvb, start, length);
@@ -2911,44 +2918,23 @@ proto_tree_set_uint64_tvb(field_info *fi, tvbuff_t *tvb, gint start,
 		}
 	}
 
-	proto_tree_set_uint64(fi, value);
+    return value;
 }
 
 static void
-proto_tree_set_int64_tvb(field_info *fi, tvbuff_t *tvb, gint start,
+proto_tree_set_uint64_tvb(field_info *fi, tvbuff_t *tvb, gint start,
 			  guint length, const guint encoding)
 {
-	guint64 value = 0;
-	guint8* b = (guint8 *)tvb_memdup(wmem_packet_scope(), tvb, start, length);
+	proto_tree_set_uint64(fi, proto_tvb_get_uint64_value(tvb, start, length, encoding));
+}
 
-	if (encoding) {
-		b += length;
-		switch (length) {
-			default: DISSECTOR_ASSERT_NOT_REACHED();
-			case 8: value <<= 8; value += *--b;
-			case 7: value <<= 8; value += *--b;
-			case 6: value <<= 8; value += *--b;
-			case 5: value <<= 8; value += *--b;
-			case 4: value <<= 8; value += *--b;
-			case 3: value <<= 8; value += *--b;
-			case 2: value <<= 8; value += *--b;
-			case 1: value <<= 8; value += *--b;
-				break;
-		}
-	} else {
-		switch (length) {
-			default: DISSECTOR_ASSERT_NOT_REACHED();
-			case 8: value <<= 8; value += *b++;
-			case 7: value <<= 8; value += *b++;
-			case 6: value <<= 8; value += *b++;
-			case 5: value <<= 8; value += *b++;
-			case 4: value <<= 8; value += *b++;
-			case 3: value <<= 8; value += *b++;
-			case 2: value <<= 8; value += *b++;
-			case 1: value <<= 8; value += *b++;
-				break;
-		}
-	}
+/* Note: this returns an unsigned int64, but with the appropriate bit(s) set to
+ * be cast-able as a gint64. This is weird, but what the code has always done.
+ */
+static inline guint64
+proto_tvb_get_int64_value(tvbuff_t *tvb, gint start, guint length, const guint encoding)
+{
+    guint64 value = proto_tvb_get_uint64_value(tvb, start, length, encoding);
 
 	switch(length)
 	{
@@ -2975,7 +2961,14 @@ proto_tree_set_int64_tvb(field_info *fi, tvbuff_t *tvb, gint start,
 			break;
 	}
 
-	proto_tree_set_uint64(fi, value);
+    return value;
+}
+
+static void
+proto_tree_set_int64_tvb(field_info *fi, tvbuff_t *tvb, gint start,
+			  guint length, const guint encoding)
+{
+	proto_tree_set_uint64(fi, proto_tvb_get_int64_value(tvb, start, length, encoding));
 }
 
 /* Add a FT_STRING, FT_STRINGZ, or FT_STRINGZPAD to a proto_tree. Creates