[m-rev.] diff: fix more issues with character escapes

[Julien Fischer]

Fix more issues with character escapes.

Update a out-of-date link in some comments.

runtime/mercury_trace_base.c:
     Handle missing character escapes.

     Add an XXX; the comment here says that MR_trace_write_quoted_atom
     is supposed to be equivalent to term_io.quote_atom but it is currently
     not.

library/term_io.m:
     Update comments about keeping code in this modules in sync with some
     that was *previously* in compiler/mercury_to_mercury.

Julien.

diff --git a/library/term_io.m b/library/term_io.m
index f9fd75c..eeaef88 100644
--- a/library/term_io.m
+++ b/library/term_io.m
@@ -728,7 +728,7 @@ write_escaped_char(Char, !IO) :-
  write_escaped_char(Stream, Char, !State) :-
      % Note: the code of add_escaped_char and write_escaped_char
      % should be kept in sync. The code of both is similar to code in
-    % compiler/mercury_to_mercury.m; any changes here may require
+    % compiler/parse_tree_out_pragma.m; any changes here may require
      % similar changes there.
      ( if mercury_escape_special_char(Char, QuoteChar) then
          stream.put(Stream, ('\\'), !State),
@@ -773,8 +773,12 @@ string_is_escaped_char(Char::out, String::in) :-
      % Succeed if Char is a character which is allowed in Mercury string
      % and character literals.
      %
-    % Note: the code here is similar to code in compiler/mercury_to_mercury.m;
-    % any changes here may require similar changes there.
+    % Note: the code here is similar to code in the following spots:
+    %
+    %   - compiler/parse_tree_out_pragma.m.
+    %   - runtime/mercury_trace_base.c
+    %
+    % Any changes here may require similar changes there.
      %
  :- pred is_mercury_source_char(char::in) is semidet.

@@ -786,7 +790,7 @@ is_mercury_source_char(Char) :-

  %---------------------------------------------------------------------------%

-% Note: the code here is similar to code in compiler/mercury_to_mercury.m;
+% Note: the code here is similar to code in compiler/parse_tree_out_pragma.m;
  % any changes here may require similar changes there.

  quote_string(S, !IO) :-
@@ -817,7 +821,7 @@ escaped_string(String) =
  add_escaped_char(Char, Strings0) = Strings :-
      % Note: the code of add_escaped_char and write_escaped_char
      % should be kept in sync. The code of both is similar to code in
-    % compiler/mercury_to_mercury.m; any changes here may require
+    % compiler/parse_tree_out_pragma.m; any changes here may require
      % similar changes there.
      ( if mercury_escape_special_char(Char, QuoteChar) then
          Strings = [from_char_list(['\\', QuoteChar]) | Strings0]
diff --git a/runtime/mercury_trace_base.c b/runtime/mercury_trace_base.c
index 454574b..cbedf30 100644
--- a/runtime/mercury_trace_base.c
+++ b/runtime/mercury_trace_base.c
@@ -613,9 +613,12 @@ MR_trace_name_count_port_ensure_init()
      }
  }

-// The output of this is supposed to be equivalent to term_io__quote_atom
+// The output of this is supposed to be equivalent to term_io.quote_atom
  // except that it always uses quotes, even if not strictly necessary.
-
+//
+// XXX term_io does *not* escape codepoints >= 0x80 whereas this always
+// does - juliensf.
+//
  static void
  MR_trace_write_quoted_atom(FILE *fp, const char *atom)
  {
@@ -642,11 +645,23 @@ MR_trace_write_quoted_atom(FILE *fp, const char *atom)
              case '\b':
                  fputs("\\b", fp);
                  break;
+            case '\a':
+                fputs("\\a", fp);
+                break;
+            case '\r':
+                fputs("\\r", fp);
+                break;
+            case '\f':
+                fputs("\\f", fp);
+                break;
+            case '\v':
+                fputs("\\v", fp);
+                break;
              default:
-                // This assumes isalnum is the same as char__isalnum.
+                // This assumes isalnum is the same as char.isalnum.
                  // The line noise is the equivalent of
                  // is_mercury_punctuation_char in library/term_io.m
-                // and compiler/mercury_to_mercury.m; any changes here
+                // and compiler/parse_tree_out_pragma.m; any changes here
                  // may require similar changes there.

                  if (MR_isalnum(*c) ||
@@ -688,6 +703,18 @@ MR_trace_write_string(FILE *fp, const char *atom)
              case '\b':
                  fputs("\\b", fp);
                  break;
+            case '\a':
+                fputs("\\a", fp);
+                break;
+            case '\r':
+                fputs("\\b", fp);
+                break;
+            case '\f':
+                fputs("\\f", fp);
+                break;
+            case '\v':
+                fputs("\\v", fp);
+                break;
              default:
                  fputc(*c, fp);
                  break;