From: Pedro Alves <palves@redhat.com>
Date: Thu, 14 Feb 2013 12:43:46 +0000 (+0000)
Subject: Fix ptype bug actually exercised in userdef.exp
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=4819b3f897686ee8a2d51f6ba1c9c4e7c3a22597;p=binutils-gdb.git

Fix ptype bug actually exercised in userdef.exp

I happened to notice a bug with ptype &Ref, and found out userdef.exp
actually exercises the bug.  With:

class Container
{
public:
  Member m;

  Member& operator* ();
};

Member& Container::operator* ()
{
  return this->m;
}

And 'c' is of type Container:

(gdb) p c
$1 = {m = {z = -9192}}
(gdb) p *c
$2 = (Member &) @0x7fffffffda20: {z = -9192}
(gdb) ptype *c
type = class Member {
  public:
    int z;
} &

(gdb) p &*c
$3 = (Member *) 0x7fffffffda20

(gdb) ptype &*c
type = class Member {
  public:
    int z;
} &*
(gdb)

Notice that last print (&*c) on says the type is a pointer - that's
how you get the address behind a reference.  But notice the last ptype
instead says the type of the same expression is a pointer _reference_.
This looks like a bug to me.

This patch fixes it.  The issue is that we're entering the VALUE_LVAL
(x) == lval_memory branch by mistake for references.  The fix is just
to swap the tests so references are checked first, like value_addr
also handles references first.

Tested on x86_64 Fedora 17.

2013-02-14  Pedro Alves  <palves@redhat.com>

	* eval.c (evaluate_subexp_for_address) <default_case_after_eval,
	EVAL_AVOID_SIDE_EFFECTS>: Swap and handle TYPE_CODE_REF before
	lval_memory.

2013-02-14  Pedro Alves  <palves@redhat.com>

	* gdb.cp/userdef.exp (ptype &*c): Don't expect an &.
---

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index ae09cc1e275..0a3f85de16e 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2013-02-14  Pedro Alves  <palves@redhat.com>
+
+	* eval.c (evaluate_subexp_for_address) <default_case_after_eval,
+	EVAL_AVOID_SIDE_EFFECTS>: Swap and handle TYPE_CODE_REF before
+	lval_memory.
+
 2013-02-14  Pedro Alves  <pedro@codesourcery.com>
 	    Hafiz Abid Qadeer  <abidh@codesourcery.com>
 
diff --git a/gdb/eval.c b/gdb/eval.c
index f4b39cbc2b0..d7f80e2d4f5 100644
--- a/gdb/eval.c
+++ b/gdb/eval.c
@@ -2929,12 +2929,12 @@ evaluate_subexp_for_address (struct expression *exp, int *pos,
 	{
 	  struct type *type = check_typedef (value_type (x));
 
-	  if (VALUE_LVAL (x) == lval_memory || value_must_coerce_to_target (x))
-	    return value_zero (lookup_pointer_type (value_type (x)),
-			       not_lval);
-	  else if (TYPE_CODE (type) == TYPE_CODE_REF)
+	  if (TYPE_CODE (type) == TYPE_CODE_REF)
 	    return value_zero (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
 			       not_lval);
+	  else if (VALUE_LVAL (x) == lval_memory || value_must_coerce_to_target (x))
+	    return value_zero (lookup_pointer_type (value_type (x)),
+			       not_lval);
 	  else
 	    error (_("Attempt to take address of "
 		     "value not located in memory."));
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 9a377259c04..c2affd18c3a 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2013-02-14  Pedro Alves  <palves@redhat.com>
+
+	* gdb.cp/userdef.exp (ptype &*c): Don't expect an &.
+
 2013-02-14  Pedro Alves  <pedro@codesourcery.com>
 	    Hafiz Abid Qadeer  <abidh@codesourcery.com>
 
diff --git a/gdb/testsuite/gdb.cp/userdef.exp b/gdb/testsuite/gdb.cp/userdef.exp
index 7c20b33b7fa..51a1bb5f67b 100644
--- a/gdb/testsuite/gdb.cp/userdef.exp
+++ b/gdb/testsuite/gdb.cp/userdef.exp
@@ -133,7 +133,7 @@ gdb_test "break A2::operator +" ".*Breakpoint $decimal at.*"
 gdb_test "print c" "\\\$\[0-9\]* = {m = {z = .*}}"
 gdb_test "print *c" "\\\$\[0-9\]* = \\(Member &\\) @$hex: {z = .*}"
 gdb_test "print &*c" "\\\$\[0-9\]* = \\(Member \\*\\) $hex"
-gdb_test "ptype &*c" "type = (struct|class) Member {(\[\r\n \]+public:)?\[\r\n \]+int z;\[\r\n\].*} &\\*"
+gdb_test "ptype &*c" "type = (struct|class) Member {(\[\r\n \]+public:)?\[\r\n \]+int z;\[\r\n\].*} \\*"
 
 gdb_test "print operator== (mem1, mem2)" " = false"
 gdb_test "print operator== (mem1, mem1)" " = true"