Remove read_memory_string

read_memory_string is redundant and only called in a couple of spots.
This patch removes it in favor of target_read_string.

gdb/ChangeLog
2020-06-15  Tom Tromey  <tromey@adacore.com>

	* corefile.c (read_memory_string): Remove.
	* ada-valprint.c (ada_value_print_ptr): Update.
	* ada-lang.h (ada_tag_name): Change return type.
	* ada-lang.c (type_from_tag): Update.
	(ada_tag_name_from_tsd): Change return type.  Use
	target_read_string.
	(ada_tag_name): Likewise.
	* gdbcore.h (read_memory_string): Don't declare.

gdb/ChangeLog

@@ -1,3 +1,14 @@
+2020-06-15  Tom Tromey  <tromey@adacore.com>
+
+	* corefile.c (read_memory_string): Remove.
+	* ada-valprint.c (ada_value_print_ptr): Update.
+	* ada-lang.h (ada_tag_name): Change return type.
+	* ada-lang.c (type_from_tag): Update.
+	(ada_tag_name_from_tsd): Change return type.  Use
+	target_read_string.
+	(ada_tag_name): Likewise.
+	* gdbcore.h (read_memory_string): Don't declare.
+
 2020-06-14  Hannes Domani  <ssbssa@yahoo.de>
 
 	* symtab.c (rbreak_command): Ignore Windows drive colon.

gdb/ada-lang.c

@@ -6567,10 +6567,10 @@ value_tag_from_contents_and_address (struct type *type,
 static struct type *
 type_from_tag (struct value *tag)
 {
-  const char *type_name = ada_tag_name (tag);
+  gdb::unique_xmalloc_ptr<char> type_name = ada_tag_name (tag);
 
   if (type_name != NULL)
-    return ada_find_any_type (ada_encode (type_name));
+    return ada_find_any_type (ada_encode (type_name.get ()));
   return NULL;
 }
 
@@ -6718,37 +6718,42 @@ ada_get_tsd_from_tag (struct value *tag)
 /* Given the TSD of a tag (type-specific data), return a string
    containing the name of the associated type.
 
-   The returned value is good until the next call.  May return NULL
-   if we are unable to determine the tag name.  */
+   May return NULL if we are unable to determine the tag name.  */
 
-static char *
+static gdb::unique_xmalloc_ptr<char>
 ada_tag_name_from_tsd (struct value *tsd)
 {
-  static char name[1024];
   char *p;
   struct value *val;
 
   val = ada_value_struct_elt (tsd, "expanded_name", 1);
   if (val == NULL)
     return NULL;
-  read_memory_string (value_as_address (val), name, sizeof (name) - 1);
-  for (p = name; *p != '\0'; p += 1)
-    if (isalpha (*p))
-      *p = tolower (*p);
-  return name;
+  gdb::unique_xmalloc_ptr<char> buffer;
+  int err;
+  if (target_read_string (value_as_address (val), &buffer, INT_MAX, &err) == 0
+      || err != 0)
+    return nullptr;
+
+  for (p = buffer.get (); *p != '\0'; ++p)
+    {
+      if (isalpha (*p))
+	*p = tolower (*p);
+    }
+
+  return buffer;
 }
 
 /* The type name of the dynamic type denoted by the 'tag value TAG, as
    a C string.
 
    Return NULL if the TAG is not an Ada tag, or if we were unable to
-   determine the name of that tag.  The result is good until the next
-   call.  */
+   determine the name of that tag.  */
 
-const char *
+gdb::unique_xmalloc_ptr<char>
 ada_tag_name (struct value *tag)
 {
-  char *name = NULL;
+  gdb::unique_xmalloc_ptr<char> name;
 
   if (!ada_is_tag_type (value_type (tag)))
     return NULL;
@@ -12104,9 +12109,11 @@ ada_exception_message_1 (void)
   if (e_msg_len <= 0)
     return NULL;
 
-  gdb::unique_xmalloc_ptr<char> e_msg ((char *) xmalloc (e_msg_len + 1));
-  read_memory_string (value_address (e_msg_val), e_msg.get (), e_msg_len + 1);
-  e_msg.get ()[e_msg_len] = '\0';
+  gdb::unique_xmalloc_ptr<char> e_msg;
+  int err;
+  if (target_read_string (value_address (e_msg_val), &e_msg, INT_MAX, &err) == 0
+      || err != 0)
+    return nullptr;
 
   return e_msg;
 }

gdb/ada-lang.h

@@ -260,7 +260,7 @@ extern int ada_is_tagged_type (struct type *, int);
 
 extern int ada_is_tag_type (struct type *);
 
-extern const char *ada_tag_name (struct value *);
+extern gdb::unique_xmalloc_ptr<char> ada_tag_name (struct value *);
 
 extern struct value *ada_tag_value_at_base_address (struct value *obj);
 

gdb/ada-valprint.c

@@ -754,10 +754,10 @@ ada_value_print_ptr (struct value *val,
   struct type *type = ada_check_typedef (value_type (val));
   if (ada_is_tag_type (type))
     {
-      const char *name = ada_tag_name (val);
+      gdb::unique_xmalloc_ptr<char> name = ada_tag_name (val);
 
       if (name != NULL)
-	fprintf_filtered (stream, " (%s)", name);
+	fprintf_filtered (stream, " (%s)", name.get ());
     }
 }
 

gdb/corefile.c

@@ -328,33 +328,6 @@ read_code_unsigned_integer (CORE_ADDR memaddr, int len,
   return extract_unsigned_integer (buf, len, byte_order);
 }
 
-void
-read_memory_string (CORE_ADDR memaddr, char *buffer, int max_len)
-{
-  char *cp;
-  int i;
-  int cnt;
-
-  cp = buffer;
-  while (1)
-    {
-      if (cp - buffer >= max_len)
-	{
-	  buffer[max_len - 1] = '\0';
-	  break;
-	}
-      cnt = max_len - (cp - buffer);
-      if (cnt > 8)
-	cnt = 8;
-      read_memory (memaddr + (int) (cp - buffer), (gdb_byte *) cp, cnt);
-      for (i = 0; i < cnt && *cp; i++, cp++)
-	;			/* null body */
-
-      if (i < cnt && !*cp)
-	break;
-    }
-}
-
 CORE_ADDR
 read_memory_typed_address (CORE_ADDR addr, struct type *type)
 {

gdb/gdbcore.h

@@ -87,12 +87,6 @@ extern ULONGEST read_code_unsigned_integer (CORE_ADDR memaddr,
 					    int len,
 					    enum bfd_endian byte_order);
 
-/* Read a null-terminated string from the debuggee's memory, given
-   address, a buffer into which to place the string, and the maximum
-   available space.  */
-
-extern void read_memory_string (CORE_ADDR, char *, int);
-
 /* Read the pointer of type TYPE at ADDR, and return the address it
    represents.  */