[PATCH 3/4] Allow display of negative offsets in print_address_symbolic()

[Kevin Buettner <kevinb@redhat.com>]

When examining addresses associated with blocks with non-contiguous
address ranges, it's not uncommon to see large positive offsets which,
for some address width, actually represent a smaller negative offset.
Here's an example taken from the test case:

    (gdb) x/i foo_cold
       0x40110d <foo+4294967277>:	push   %rbp

This commit causes cases like the above to be displayed like this (below)
instead:

    (gdb) x/i foo_cold
       0x40110d <foo-19>:	push   %rbp

gdb/ChangeLog:

	* printcmd.c (print_address_symbolic): Print negative offsets.
	(build_address_symbolic): Force signed arithmetic when computing
	offset.
---
 gdb/printcmd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/gdb/printcmd.c b/gdb/printcmd.c
index e00a9c671a..8ceddd633a 100644
--- a/gdb/printcmd.c
+++ b/gdb/printcmd.c
@@ -537,7 +537,7 @@ print_address_symbolic (struct gdbarch *gdbarch, CORE_ADDR addr,
     fputs_filtered ("<", stream);
   fputs_styled (name.c_str (), function_name_style.style (), stream);
   if (offset != 0)
-    fprintf_filtered (stream, "+%u", (unsigned int) offset);
+    fprintf_filtered (stream, "%+d", offset);
 
   /* Append source filename and line number if desired.  Give specific
      line # of this addr, if we have it; else line # of the nearest symbol.  */
@@ -666,7 +666,7 @@ build_address_symbolic (struct gdbarch *gdbarch,
       && name_location + max_symbolic_offset > name_location)
     return 1;
 
-  *offset = addr - name_location;
+  *offset = (LONGEST) addr - name_location;
 
   *name = name_temp;
 
-- 
2.21.0