[PATCH] gdbhooks.py: Fix UnicodeDecodeErrors when printing trees with corrupt codes

[Eugene Sharygin]

Hi,

This silences UnicodeDecodeError Python exceptions raised when trying to
print a tree with a corrupt (or uninitialized) code in Gdb:

    Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode 
byte 0xb8 in position 0: invalid start byte:

With this patch, TreePrinter would print such trees generically like
this (in the format it uses for null trees):

     <tree 0x7f8459c76500>

Eugene

2018-04-18  Eugene Sharygin  <e...@ispras.ru>

        * gdbhooks.py: Fix UnicodeDecodeErrors when printing trees with
          corrupt codes.
---
 gcc/gdbhooks.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/gcc/gdbhooks.py b/gcc/gdbhooks.py
index bbe7618e299..7b1a7be0002 100644
--- a/gcc/gdbhooks.py
+++ b/gcc/gdbhooks.py
@@ -229,7 +229,10 @@ class TreePrinter:
         val_code_name = val_tree_code_name[intptr(val_TREE_CODE)]
         #print(val_code_name.string())
 
-        result = '<%s 0x%x' % (val_code_name.string(), intptr(self.gdbval))
+        try:
+            result = '<%s 0x%x' % (val_code_name.string(), intptr(self.gdbval))
+        except:
+            return '<tree 0x%x>' % intptr(self.gdbval)
         if intptr(val_tclass) == tcc_declaration:
             tree_DECL_NAME = self.node.DECL_NAME()
             if tree_DECL_NAME.is_nonnull():
-- 
2.21.0