[RFA] Patch for PR gdb/2477

Paul Pluzhnikov
2008-07-14T17:32:21Z

Greetings,

Attached patch fixes error in printing NULL pointers when "set print object on".
http://sourceware.org/cgi-bin/gnatsweb.pl?cmd=view&database=gdb&pr=2477
and adds a test case for it.

Ok to commit?

--
Paul Pluzhnikov

ChangeLog
2008-07-14 Paul Pluzhnikov <ppluzhnikov@google.com>

PR gdb/2477
* cp-abi.c (value_virtual_fn_field): Handle NULL pointers.

testsuite/ChangeLog
2008-07-14 Paul Pluzhnikov <ppluzhnikov@google.com>

* gdb.cp/class2.exp, gdb.cp/class2.cc: Test for PR2477.

Index: cp-abi.c
===================================================================
RCS file: /cvs/src/src/gdb/cp-abi.c,v
retrieving revision 1.21
diff -u -p -u -r1.21 cp-abi.c
--- cp-abi.c 1 Jan 2008 22:53:09 -0000 1.21
+++ cp-abi.c 14 Jul 2008 17:23:56 -0000
@@ -89,7 +89,8 @@ value_virtual_fn_field (struct value **a
struct type *
value_rtti_type (struct value *v, int *full, int *top, int *using_enc)
{
- if ((current_cp_abi.rtti_type) == NULL)
+ if ((current_cp_abi.rtti_type) == NULL
+ || VALUE_ADDRESS (v) == 0)
return NULL;
return (*current_cp_abi.rtti_type) (v, full, top, using_enc);
}
Index: testsuite/gdb.cp/class2.cc
===================================================================
RCS file: /cvs/src/src/gdb/testsuite/gdb.cp/class2.cc,v
retrieving revision 1.6
diff -u -p -u -r1.6 class2.cc
--- testsuite/gdb.cp/class2.cc 1 Jan 2008 22:53:19 -0000 1.6
+++ testsuite/gdb.cp/class2.cc 14 Jul 2008 17:23:56 -0000
@@ -41,6 +41,11 @@ B::~B()
b2 = 902;
}

+struct C : public B
+{
+ A *c1;
+};
+
// Stop the compiler from optimizing away data.
void refer (A *)
{
@@ -57,16 +62,19 @@ void refer (empty *)

int main (void)
{
- A alpha, *aap, *abp;
+ A alpha, *aap, *abp, *acp;
B beta, *bbp;
+ C gamma;
empty e;

alpha.a1 = 100;
beta.a1 = 200; beta.b1 = 201; beta.b2 = 202;
+ gamma.c1 = 0;

aap = &alpha; refer (aap);
abp = &beta; refer (abp);
bbp = &beta; refer (bbp);
+ acp = &gamma; refer (acp);
refer (&e);

return 0; // marker return 0
Index: testsuite/gdb.cp/class2.exp
===================================================================
RCS file: /cvs/src/src/gdb/testsuite/gdb.cp/class2.exp,v
retrieving revision 1.6
diff -u -p -u -r1.6 class2.exp
--- testsuite/gdb.cp/class2.exp 1 Jan 2008 22:53:19 -0000 1.6
+++ testsuite/gdb.cp/class2.exp 14 Jul 2008 17:23:56 -0000
@@ -117,3 +117,9 @@ gdb_test "print * (B *) abp" \
# Printing the value of an object containing no data fields:

gdb_test "p e" "= \{<No data fields>\}" "print object with no data fields"
+
+# Printing NULL pointers with "set print object on"
+
+gdb_test "set print object on" ""
+gdb_test "p acp" "= \\(C \\*\\) 0x\[a-f0-9\]+"
+gdb_test "p acp->c1" "\\(A \\*\\) 0x0"