Debian bug 464384: fix OFF_T_FORMAT mismatches on amd64

On AMD64 apparently, off_t is long but ELinks detected SIZEOF_OFF_T == 8
and defined OFF_T_FORMAT as "lld", which expects long long and so causes
GCC to warn about a mismatching format specifier.  Because --enable-debug
adds -Werror to $CFLAGS, this warning breaks the build.  When both
SIZEOF_LONG and SIZEOF_LONG_LONG are 8, ELinks cannot know which type
it should use.

To fix this, do not attempt to find a format specifier for off_t itself.
Instead cast all printed off_t values to a new typedef off_print_T that
is large enough, and replace OFF_T_FORMAT with OFF_PRINT_FORMAT which
is suitable for off_print_T altough not necessarily for off_t.  ELinks
already had a similar scheme with time_print_T and TIME_PRINT_FORMAT.

src/cache/cache.c

@@ -40,9 +40,11 @@ static void truncate_entry(struct cache_entry *cached, off_t offset, int final);
 
 #define dump_frag(frag, count) \
 do { \
-	DBG(" [%d] f=%p offset=%" OFF_T_FORMAT " length=%" OFF_T_FORMAT \
-	    " real_length=%" OFF_T_FORMAT, \
-	    count, frag, frag->offset, frag->length, frag->real_length); \
+	DBG(" [%d] f=%p offset=%" OFF_PRINT_FORMAT \
+	    " length=%" OFF_PRINT_FORMAT \
+	    " real_length=%" OFF_PRINT_FORMAT, \
+	    count, frag, (off_print_T) frag->offset, \
+	    (off_print_T) frag->length, (off_print_T) frag->real_length); \
 } while (0)
 
 #define dump_frags(entry, comment) \

src/cache/dialogs.c

@@ -82,10 +82,10 @@ get_cache_entry_info(struct listbox_item *item, struct terminal *term)
 		}
 	}
 
-	add_format_to_string(&msg, "\n%s: %" OFF_T_FORMAT, _("Size", term),
-	                     cached->length);
-	add_format_to_string(&msg, "\n%s: %" OFF_T_FORMAT, _("Loaded size", term),
-						cached->data_size);
+	add_format_to_string(&msg, "\n%s: %" OFF_PRINT_FORMAT, _("Size", term),
+			     (off_print_T) cached->length);
+	add_format_to_string(&msg, "\n%s: %" OFF_PRINT_FORMAT, _("Loaded size", term),
+			     (off_print_T) cached->data_size);
 	if (cached->content_type) {
 		add_format_to_string(&msg, "\n%s: %s", _("Content type", term),
 				     cached->content_type);

src/dialogs/document.c

@@ -152,8 +152,9 @@ document_info_dialog(struct session *ses)
 	if (cached) {
 		unsigned char *a;
 
-		add_format_to_string(&msg, "\n%s: %" OFF_T_FORMAT,
-				     _("Size", term), cached->length);
+		add_format_to_string(&msg, "\n%s: %" OFF_PRINT_FORMAT,
+				     _("Size", term),
+				     (off_print_T) cached->length);
 
 		if (cached->incomplete) {
 			add_format_to_string(&msg, " (%s)", _("incomplete", term));

src/osdep/types.h

@@ -146,12 +146,24 @@ typedef unsigned long long uint32_t;
  */
 typedef long longptr_T;
 
-/* Define internal off_t format macro for printing variables. */
-#if HAVE_OFF_T == 1 && SIZEOF_OFF_T == 8
-#define OFF_T_FORMAT "lld"
+/* To print off_t offset, ELinks does:
+ *
+ * printf("%" OFF_PRINT_FORMAT, (off_print_T) offset);
+ *
+ * The cast is necessary because it is not possible to guess
+ * a printf format for off_t itself based on what we have here.
+ * The off_t type might be either long or long long, and the format
+ * string must match even if both types have the same representation,
+ * because GCC warns about mismatches and --enable-debug adds -Werror
+ * to $CFLAGS.  */
+#if !HAVE_OFF_T || SIZEOF_OFF_T <= SIZEOF_LONG
+typedef long off_print_T;
+# define OFF_PRINT_FORMAT "ld"
+#elif HAVE_LONG_LONG && SIZEOF_OFF_T <= SIZEOF_LONG_LONG
+typedef long long off_print_T;
+# define OFF_PRINT_FORMAT "lld"
 #else
-/* For ELinks, off_t defaults to long. */
-#define OFF_T_FORMAT "ld"
+# error "cannot figure out how to print off_t values"
 #endif
 
 #endif

src/protocol/fsp/fsp.c

@@ -314,7 +314,8 @@ do_fsp(struct connection *conn)
 #endif
 
 		/* Send filesize */
-		fprintf(stderr, "%" OFF_T_FORMAT "\n", (off_t)(sb.st_size));
+		fprintf(stderr, "%" OFF_PRINT_FORMAT "\n",
+			(off_print_T) sb.st_size);
 		fclose(stderr);
 
 		while ((r = fsp_fread(buf, 1, READ_SIZE, file)) > 0)

src/protocol/ftp/ftp.c

@@ -1170,7 +1170,8 @@ display_dir_entry(struct cache_entry *cached, off_t *pos, int *tries,
 	add_to_string(&string, "   1 ftp      ftp ");
 
 	if (ftp_info->size != FTP_SIZE_UNKNOWN) {
-		add_format_to_string(&string, "%12" OFF_T_FORMAT " ", ftp_info->size);
+		add_format_to_string(&string, "%12" OFF_PRINT_FORMAT " ",
+				     (off_print_T) ftp_info->size);
 	} else {
 		add_to_string(&string, "           - ");
 	}

src/protocol/smb/smb2.c

@@ -349,7 +349,8 @@ do_smb(struct connection *conn)
 			smb_error(res);
 		}
 		/* filesize */
-		fprintf(stderr, "%" OFF_T_FORMAT, sb.st_size);
+		fprintf(stderr, "%" OFF_PRINT_FORMAT,
+			(off_print_T) sb.st_size);
 		fclose(stderr);
 
 		while ((r = smbc_read(file, buf, READ_SIZE)) > 0) {