gdb: move displaced_step_dump_bytes into gdbsupport (and rename)

It was pointed out during review of another patch that the function
displaced_step_dump_bytes really isn't specific to displaced stepping,
and should really get a more generic name and move into gdbsupport/.

This commit does just that.  The function is renamed to
bytes_to_string and is moved into gdbsupport/common-utils.{cc,h}.  The
function implementation doesn't really change. Much...

... I have updated the function to take an array view, which makes it
slightly easier to call in a couple of places where we already have a
gdb::bytes_vector.  I've then added an inline wrapper to convert a raw
pointer and length into an array view, which is used in places where
we don't easily have a gdb::bytes_vector (or similar).

Updated all users of displaced_step_dump_bytes.

There should be no user visible changes after this commit.

Finally, I ended up having to add an include of gdb_assert.h into
array-view.h.  When I include array-view.h into common-utils.h I ran
into build problems because array-view.h calls gdb_assert.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

3 files changed, 35 insertions, 0 deletions

diff --git a/gdbsupport/array-view.h b/gdbsupport/array-view.h
index 3d8248b..d07c8bc 100644
--- a/gdbsupport/array-view.h
+++ b/gdbsupport/array-view.h
@@ -21,6 +21,7 @@
 #include "traits.h"
 #include <algorithm>
 #include <type_traits>
+#include "gdbsupport/gdb_assert.h"
 
 /* An array_view is an abstraction that provides a non-owning view
    over a sequence of contiguous objects.
diff --git a/gdbsupport/common-utils.cc b/gdbsupport/common-utils.cc
index e382fb2..4a96f2c 100644
--- a/gdbsupport/common-utils.cc
+++ b/gdbsupport/common-utils.cc
@@ -445,3 +445,21 @@ hex2bin (const char *hex)
 
   return bin;
 }
+
+/* See gdbsupport/common-utils.h.  */
+
+std::string
+bytes_to_string (gdb::array_view<const gdb_byte> bytes)
+{
+  std::string ret;
+
+  for (size_t i = 0; i < bytes.size (); i++)
+    {
+      if (i == 0)
+	ret += string_printf ("%02x", bytes[i]);
+      else
+	ret += string_printf (" %02x", bytes[i]);
+    }
+
+  return ret;
+}
diff --git a/gdbsupport/common-utils.h b/gdbsupport/common-utils.h
index 97dcb9f..4ceb44d 100644
--- a/gdbsupport/common-utils.h
+++ b/gdbsupport/common-utils.h
@@ -24,6 +24,7 @@
 #include <vector>
 #include "gdbsupport/byte-vector.h"
 #include "gdbsupport/gdb_unique_ptr.h"
+#include "gdbsupport/array-view.h"
 #include "poison.h"
 #include "gdb_string_view.h"
 
@@ -194,6 +195,21 @@ extern int hex2bin (const char *hex, gdb_byte *bin, int count);
 /* Like the above, but return a gdb::byte_vector.  */
 gdb::byte_vector hex2bin (const char *hex);
 
+/* Build a string containing the contents of BYTES.  Each byte is
+   represented as a 2 character hex string, with spaces separating each
+   individual byte.  */
+
+extern std::string bytes_to_string (gdb::array_view<const gdb_byte> bytes);
+
+/* See bytes_to_string above.  This takes a BUFFER pointer and LENGTH
+   rather than an array view.  */
+
+static inline std::string bytes_to_string (const gdb_byte *buffer,
+					   size_t length)
+{
+  return bytes_to_string ({buffer, length});
+}
+
 /* A fast hashing function.  This can be used to hash data in a fast way
    when the length is known.  If no fast hashing library is available, falls
    back to iterative_hash from libiberty.  START_VALUE can be set to