Fix &str printing in Rust

[deliverable/binutils-gdb.git] / gdb / rust-lang.c

diff --git a/gdb/rust-lang.c b/gdb/rust-lang.c
index 9b64efad78f9a8e027db1df66b33b79f668eec9c..261ddb1a10970cea89881638646d131eb1f22f13 100644 (file)
--- a/gdb/rust-lang.c
+++ b/gdb/rust-lang.c
@@ -467,6 +467,21 @@ rust_printstr (struct ui_file *stream, struct type *type,
 
 \f
 
+/* Helper function to print a string slice.  */
+
+static void
+rust_val_print_str (struct ui_file *stream, struct value *val,
+                   const struct value_print_options *options)
+{
+  struct value *base = value_struct_elt (&val, NULL, "data_ptr", NULL,
+                                        "slice");
+  struct value *len = value_struct_elt (&val, NULL, "length", NULL, "slice");
+
+  val_print_string (TYPE_TARGET_TYPE (value_type (base)), "UTF-8",
+                   value_as_address (base), value_as_long (len), stream,
+                   options);
+}
+
 /* rust_print_type branch for structs and untagged unions.  */
 
 static void
@@ -477,6 +492,13 @@ val_print_struct (struct type *type, int embedded_offset,
 {
   int i;
   int first_field;
+
+  if (rust_slice_type_p (type) && strcmp (TYPE_NAME (type), "&str") == 0)
+    {
+      rust_val_print_str (stream, val, options);
+      return;
+    }
+
   bool is_tuple = rust_tuple_type_p (type);
   bool is_tuple_struct = !is_tuple && rust_tuple_struct_type_p (type);
   struct value_print_options opts;
@@ -1562,8 +1584,11 @@ rust_subscript (struct expression *exp, int *pos, enum noside noside,
          usize = language_lookup_primitive_type (exp->language_defn,
                                                  exp->gdbarch,
                                                  "usize");
-         slice = rust_slice_type ("&[*gdb*]", value_type (result),
-                                  usize);
+         const char *new_name = ((type != nullptr
+                                  && rust_slice_type_p (type))
+                                 ? TYPE_NAME (type) : "&[*gdb*]");
+
+         slice = rust_slice_type (new_name, value_type (result), usize);
 
          addrval = value_allocate_space_in_inferior (TYPE_LENGTH (slice));
          addr = value_as_long (addrval);