[PATCH 1/4] testcase - pointer to member function

[PATCH 1/4] testcase - pointer to member function

[Yao Qi]

Hi,
The new test cases expose some problem in GDB on handling member
pointers, and there are two fails shown below on current GDB trunk.

  print (diamond.*diamond_pfunc_ptr) (20)^M
  Non-pointer-to-member value used in pointer-to-member construct^M
  FAIL: gdb.cp/member-ptr.exp: print (diamond.*diamond_pfunc_ptr)(20)

  ptype (a.*pmf)(3)^M
  type = int (A * const, int)^M
  FAIL: gdb.cp/member-ptr.exp: ptype (a.*pmf)(3)

The following patches will fix them.

gdb/testsuite:

2012-11-22  Daniel Jacobowitz  <dan@codesourcery.com>

	* gdb.cp/member-ptr.cc (class Diamond): Add func_ptr.
	(func): New function.
	(main): Initialize diamond.func_ptr and add diamond_pfunc_ptr.
	* gdb.cp/member-ptr.exp: Add new tests for ptype and for
	pointers to members with pointer-to-function type.
---
 gdb/testsuite/gdb.cp/member-ptr.cc  |   17 +++++++++++++++++
 gdb/testsuite/gdb.cp/member-ptr.exp |   28 ++++++++++++++++++++++++++++
 2 files changed, 45 insertions(+), 0 deletions(-)

diff --git a/gdb/testsuite/gdb.cp/member-ptr.cc b/gdb/testsuite/gdb.cp/member-ptr.cc
index 17f022c..6cb87ef 100644
--- a/gdb/testsuite/gdb.cp/member-ptr.cc
+++ b/gdb/testsuite/gdb.cp/member-ptr.cc
@@ -137,6 +137,7 @@ class Diamond : public Padding, public Left, public Right
 {
 public:
   virtual int vget_base ();
+  int (*func_ptr) (int);
 };
 
 int Diamond::vget_base ()
@@ -144,6 +145,12 @@ int Diamond::vget_base ()
   return this->Left::x + 2000;
 }
 
+int
+func (int x)
+{
+  return 19 + x;
+}
+
 int main ()
 {
   A a;
@@ -161,6 +168,7 @@ int main ()
   int (Diamond::*right_vpmf) ();
   int (Base::*base_vpmf) ();
   int Diamond::*diamond_pmi;
+  int (* Diamond::*diamond_pfunc_ptr) (int);
 
   PMI null_pmi;
   PMF null_pmf;
@@ -178,6 +186,7 @@ int main ()
 
   diamond.Left::x = 77;
   diamond.Right::x = 88;
+  diamond.func_ptr = func;
 
   /* Some valid pointer to members from a base class.  */
   left_pmf = (int (Diamond::*) ()) (int (Left::*) ()) (&Base::get_x);
@@ -192,11 +201,19 @@ int main ()
   /* A pointer to data member from a base class.  */
   diamond_pmi = (int Diamond::*) (int Left::*) &Base::x;
 
+  /* A pointer to data member, where the member is itself a pointer to
+     a function.  */
+  diamond_pfunc_ptr = (int (* Diamond::*) (int)) &Diamond::func_ptr;
+
   null_pmi = NULL;
   null_pmf = NULL;
 
   pmi = NULL; /* Breakpoint 1 here.  */
 
+  // Invalid (uses diamond_pfunc_ptr as a function):
+  // diamond.*diamond_pfunc_ptr (20);
+  (diamond.*diamond_pfunc_ptr) (20);
+
   k = (a.*pmf)(3);
 
   pmi = &A::jj;
diff --git a/gdb/testsuite/gdb.cp/member-ptr.exp b/gdb/testsuite/gdb.cp/member-ptr.exp
index f569ca9..ae2b8b4 100644
--- a/gdb/testsuite/gdb.cp/member-ptr.exp
+++ b/gdb/testsuite/gdb.cp/member-ptr.exp
@@ -376,6 +376,33 @@ gdb_test_multiple "print ((int) pmi) == ((char *) &a.j - (char *) & a)" $name {
     }
 }
 
+# Check pointers to data members, which are themselves pointers to
+# functions.  These behave like data members, not like pointers to
+# member functions.
+
+gdb_test "ptype diamond_pfunc_ptr" \
+    "type = int \\(\\*Diamond::\\*\\)\\(int\\)"
+
+gdb_test "ptype diamond.*diamond_pfunc_ptr" \
+    "type = int \\(\\*\\)\\(int\\)"
+
+# This one is invalid; () binds more tightly than .*, so it tries to
+# call the member pointer as a normal pointer-to-function.
+
+gdb_test "print diamond.*diamond_pfunc_ptr (20)" \
+    "Invalid data type for function to be called."
+
+# With parentheses, it is valid.
+
+gdb_test "print (diamond.*diamond_pfunc_ptr) (20)" \
+    "$vhn = 39"
+
+# Make sure that we do not interpret this as either a member pointer
+# call or a member function call.
+
+gdb_test "print diamond.func_ptr (20)" \
+    "$vhn = 39"
+
 # ==========================
 # pointer to member function
 # ==========================
@@ -595,6 +622,7 @@ gdb_test_multiple "print (a.*pmf)(3)" $name {
 }
 
 gdb_test "ptype a.*pmf" "type = int \\(A \\*( const)?, int\\)"
+gdb_test "ptype (a.*pmf)(3)" "type = int"
 
 # Print out a pointer to data member which requires looking into
 # a base class.
-- 
1.7.7.6

[PATCH 0/4] Fix member pointer bugs

[Yao Qi]

Hello,
This patch set fixes GDB bugs on member pointers.  This patch was
written by Daniel, I took it, and split it to four patches to make
each one more readable.  Each one is quite self-explained, so I don't
put much words here.

Regression tested on x86_64-linux.  Is it OK?

[PATCH 2/4] factor code

[Yao Qi]

This is a code refactor to pave the way for the following patches.
Functionality of GDB is not affected.

gdb:

2012-11-22  Daniel Jacobowitz  <dan@codesourcery.com>
	    Yao Qi  <yao@codesourcery.com>

	* eval.c (evaluate_subexp_standard): Code factor.
---
 gdb/eval.c |   27 +++++++++++++--------------
 1 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/gdb/eval.c b/gdb/eval.c
index f655957..9957d02 100644
--- a/gdb/eval.c
+++ b/gdb/eval.c
@@ -1364,7 +1364,6 @@ evaluate_subexp_standard (struct type *expect_type,
 	alloca (sizeof (struct value *) * (nargs + 3));
       if (op == STRUCTOP_MEMBER || op == STRUCTOP_MPTR)
 	{
-	  nargs++;
 	  /* First, evaluate the structure into arg2.  */
 	  pc2 = (*pos)++;
 
@@ -1388,22 +1387,22 @@ evaluate_subexp_standard (struct type *expect_type,
 
 	  arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
 
-	  if (TYPE_CODE (check_typedef (value_type (arg1)))
-	      != TYPE_CODE_METHODPTR)
-	    error (_("Non-pointer-to-member value used in pointer-to-member "
-		     "construct"));
-
-	  if (noside == EVAL_AVOID_SIDE_EFFECTS)
+	  type = check_typedef (value_type (arg1));
+	  if (TYPE_CODE (type) == TYPE_CODE_METHODPTR)
 	    {
-	      struct type *method_type = check_typedef (value_type (arg1));
+	      if (noside == EVAL_AVOID_SIDE_EFFECTS)
+		arg1 = value_zero (type, not_lval);
+	      else
+		arg1 = cplus_method_ptr_to_value (&arg2, arg1);
 
-	      arg1 = value_zero (method_type, not_lval);
+	      /* Now, say which argument to start evaluating from.  */
+	      nargs++;
+	      tem = 2;
+	      argvec[1] = arg2;
 	    }
 	  else
-	    arg1 = cplus_method_ptr_to_value (&arg2, arg1);
-
-	  /* Now, say which argument to start evaluating from.  */
-	  tem = 2;
+	    error (_("Non-pointer-to-member value used in pointer-to-member "
+		     "construct"));
 	}
       else if (op == STRUCTOP_STRUCT || op == STRUCTOP_PTR)
 	{
@@ -1654,7 +1653,7 @@ evaluate_subexp_standard (struct type *expect_type,
 	}
       else if (op == STRUCTOP_MEMBER || op == STRUCTOP_MPTR)
 	{
-	  argvec[1] = arg2;
+	  /* Pointer to member.  argvec[1] is already set up.  */
 	  argvec[0] = arg1;
 	}
       else if (op == OP_VAR_VALUE || (op == OP_SCOPE && function != NULL))
-- 
1.7.7.6

[PATCH 3/4] Use TYPE_TARGET_TYPE.

[Yao Qi]

For TYPE_CODE_METHODPTR, we should use TYPE_TARGET_TYPE to get the
type of function.  This patch fixes this fail

  FAIL: gdb.cp/member-ptr.exp: ptype (a.*pmf)(3)

gdb:

2012-11-22  Daniel Jacobowitz  <dan@codesourcery.com>

	* eval.c (evaluate_subexp_standard): Use TYPE_TARGET_TYPE.
---
 gdb/eval.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/gdb/eval.c b/gdb/eval.c
index 9957d02..82ea81b 100644
--- a/gdb/eval.c
+++ b/gdb/eval.c
@@ -1391,7 +1391,7 @@ evaluate_subexp_standard (struct type *expect_type,
 	  if (TYPE_CODE (type) == TYPE_CODE_METHODPTR)
 	    {
 	      if (noside == EVAL_AVOID_SIDE_EFFECTS)
-		arg1 = value_zero (type, not_lval);
+		arg1 = value_zero (TYPE_TARGET_TYPE (type), not_lval);
 	      else
 		arg1 = cplus_method_ptr_to_value (&arg2, arg1);
 
-- 
1.7.7.6

[PATCH 4/4] Handle TYPE_CODE_MEMBERPTR

[Yao Qi]

This patch handles TYPE_CODE_MEMBERPTR and fixes this fail,

  FAIL: gdb.cp/member-ptr.exp: print (diamond.*diamond_pfunc_ptr) (20)

gdb:

2012-11-22  Daniel Jacobowitz  <dan@codesourcery.com>

	* eval.c (evaluate_subexp_standard): Handle
	TYPE_CODE_MEMBERPTR.
---
 gdb/eval.c |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/gdb/eval.c b/gdb/eval.c
index 82ea81b..3c8ec55 100644
--- a/gdb/eval.c
+++ b/gdb/eval.c
@@ -1400,6 +1400,19 @@ evaluate_subexp_standard (struct type *expect_type,
 	      tem = 2;
 	      argvec[1] = arg2;
 	    }
+	  else if (TYPE_CODE (type) == TYPE_CODE_MEMBERPTR)
+	    {
+	      /* Now, convert these values to an address.  */
+	      arg2 = value_cast (lookup_pointer_type (TYPE_DOMAIN_TYPE (type)),
+				 arg2);
+
+	      mem_offset = value_as_long (arg1);
+
+	      arg1 = value_from_pointer (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
+					 value_as_long (arg2) + mem_offset);
+	      arg1 = value_ind (arg1);
+	      tem = 1;
+	    }
 	  else
 	    error (_("Non-pointer-to-member value used in pointer-to-member "
 		     "construct"));
-- 
1.7.7.6

Re: [PATCH 4/4] Handle TYPE_CODE_MEMBERPTR

[Yao Qi]

On 11/22/2012 03:32 PM, Yao Qi wrote:
> +	      arg2 = value_cast (lookup_pointer_type (TYPE_DOMAIN_TYPE (type)),
> +				 arg2);
> +
> +	      mem_offset = value_as_long (arg1);
> +
> +	      arg1 = value_from_pointer (lookup_pointer_type (TYPE_TARGET_TYPE (type)),

These two lines are too long.  Fixed in the updated patch.

-- 
Yao (齐尧)

gdb:

2012-11-22  Daniel Jacobowitz  <dan@codesourcery.com>

	* eval.c (evaluate_subexp_standard): Handle
	TYPE_CODE_MEMBERPTR.
---
 gdb/eval.c |   15 +++++++++++++++
 1 files changed, 15 insertions(+), 0 deletions(-)

diff --git a/gdb/eval.c b/gdb/eval.c
index 82ea81b..55582e0 100644
--- a/gdb/eval.c
+++ b/gdb/eval.c
@@ -1400,6 +1400,21 @@ evaluate_subexp_standard (struct type *expect_type,
 	      tem = 2;
 	      argvec[1] = arg2;
 	    }
+	  else if (TYPE_CODE (type) == TYPE_CODE_MEMBERPTR)
+	    {
+	      struct type *type_ptr
+		= lookup_pointer_type (TYPE_DOMAIN_TYPE (type));
+
+	      /* Now, convert these values to an address.  */
+	      arg2 = value_cast (type_ptr, arg2);
+
+	      mem_offset = value_as_long (arg1);
+
+	      arg1 = value_from_pointer (type_ptr,
+					 value_as_long (arg2) + mem_offset);
+	      arg1 = value_ind (arg1);
+	      tem = 1;
+	    }
 	  else
 	    error (_("Non-pointer-to-member value used in pointer-to-member "
 		     "construct"));
-- 
1.7.7.6

Re: [PATCH 1/4] testcase - pointer to member function

[Tom Tromey]

>>>>> "Yao" == Yao Qi <yao@codesourcery.com> writes:

Yao> 2012-11-22  Daniel Jacobowitz  <dan@codesourcery.com>
Yao> 	* gdb.cp/member-ptr.cc (class Diamond): Add func_ptr.
Yao> 	(func): New function.
Yao> 	(main): Initialize diamond.func_ptr and add diamond_pfunc_ptr.
Yao> 	* gdb.cp/member-ptr.exp: Add new tests for ptype and for
Yao> 	pointers to members with pointer-to-function type.

Ok.  Thanks for this series.

Tom

Re: [PATCH 3/4] Use TYPE_TARGET_TYPE.

[Tom Tromey]

>>>>> "Yao" == Yao Qi <yao@codesourcery.com> writes:

Yao> 2012-11-22  Daniel Jacobowitz  <dan@codesourcery.com>

Yao> 	* eval.c (evaluate_subexp_standard): Use TYPE_TARGET_TYPE.

Ok.

Tom

Re: [PATCH 4/4] Handle TYPE_CODE_MEMBERPTR

[Tom Tromey]

>>>>> "Yao" == Yao Qi <yao@codesourcery.com> writes:

Yao> 2012-11-22  Daniel Jacobowitz  <dan@codesourcery.com>

Yao> 	* eval.c (evaluate_subexp_standard): Handle
Yao> 	TYPE_CODE_MEMBERPTR.

Ok, thanks again.

Tom

[committed]: [PATCH 0/4] Fix member pointer bugs

[Yao Qi]

On 11/22/2012 03:32 PM, Yao Qi wrote:
> Hello,
> This patch set fixes GDB bugs on member pointers.  This patch was
> written by Daniel, I took it, and split it to four patches to make
> each one more readable.  Each one is quite self-explained, so I don't
> put much words here.
>
> Regression tested on x86_64-linux.  Is it OK?
>

Thanks for the review.  This whole series are checked in in one commit.

-- 
Yao (齐尧)

Re: [committed]: [PATCH 0/4] Fix member pointer bugs

[Tom Tromey]

>>>>> "Yao" == Yao Qi <yao@codesourcery.com> writes:

Yao> Thanks for the review.  This whole series are checked in in one commit.

Thanks.

I see one failure now:

FAIL: gdb.cp/member-ptr.exp: print (diamond.*diamond_pfunc_ptr) (20)

From gdb.log:

    print (diamond.*diamond_pfunc_ptr) (20)
    warning: can't find linker symbol for virtual table for `Diamond' value
    warning:   found `Diamond::vget_base()' instead
    Invalid data type for function to be called.

Is this expected?

Tom

Re: [committed]: [PATCH 0/4] Fix member pointer bugs

[Yao Qi]

On 11/28/2012 10:46 PM, Tom Tromey wrote:
> FAIL: gdb.cp/member-ptr.exp: print (diamond.*diamond_pfunc_ptr) (20)
>
>  From gdb.log:
>
>      print (diamond.*diamond_pfunc_ptr) (20)
>      warning: can't find linker symbol for virtual table for `Diamond' value
>      warning:   found `Diamond::vget_base()' instead
>      Invalid data type for function to be called.
>
> Is this expected?

No, I didn't see this warning before.  I'll have a look.

-- 
Yao (齐尧)

Re: [committed]: [PATCH 0/4] Fix member pointer bugs

[Tom Tromey]

>>>>> "Yao" == Yao Qi <yao@codesourcery.com> writes:

Yao> No, I didn't see this warning before.  I'll have a look.

This fixes it for me.  What do you think?  I mean aside from the line
break problem...

Tom

diff --git a/gdb/eval.c b/gdb/eval.c
index 55582e0..faad9e3 100644
--- a/gdb/eval.c
+++ b/gdb/eval.c
@@ -1410,7 +1410,7 @@ evaluate_subexp_standard (struct type *expect_type,
 
 	      mem_offset = value_as_long (arg1);
 
-	      arg1 = value_from_pointer (type_ptr,
+	      arg1 = value_from_pointer (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
 					 value_as_long (arg2) + mem_offset);
 	      arg1 = value_ind (arg1);
 	      tem = 1;

Re: [committed]: [PATCH 0/4] Fix member pointer bugs

[Yao Qi]

On 11/29/2012 12:37 AM, Tom Tromey wrote:
> index 55582e0..faad9e3 100644
> --- a/gdb/eval.c
> +++ b/gdb/eval.c
> @@ -1410,7 +1410,7 @@ evaluate_subexp_standard (struct type *expect_type,
>   
>   	      mem_offset = value_as_long (arg1);
>   
> -	      arg1 = value_from_pointer (type_ptr,
> +	      arg1 = value_from_pointer (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
>   					 value_as_long (arg2) + mem_offset);
>   	      arg1 = value_ind (arg1);
>   	      tem = 1;

TYPE_TARGET_TYPE (type) was used in my first post, but it was replaced
by TYPE_DOMAIN_TYPE (type) by mistake in my follow-up patch, which is
to shorten the line.  I didn't run regression test again after the change.
Thanks for pointing this out.

The patch below is the same to yours, but shorten the line by defining a
new local variable.  Regression tested on x86_64-linux.  Committed.

-- 
Yao (齐尧)

gdb:

2012-11-29  Yao Qi  <yao@codesourcery.com>
	    Tom Tromey  <tromey@redhat.com>

	* eval.c (evaluate_subexp_standard): Get the correct pointer
	type for TYPE_CODE_MEMBERPTR.
---
 gdb/eval.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/gdb/eval.c b/gdb/eval.c
index 55582e0..7d48d7e 100644
--- a/gdb/eval.c
+++ b/gdb/eval.c
@@ -1404,13 +1404,15 @@ evaluate_subexp_standard (struct type *expect_type,
 	    {
 	      struct type *type_ptr
 		= lookup_pointer_type (TYPE_DOMAIN_TYPE (type));
+	      struct type *target_type_ptr
+		= lookup_pointer_type (TYPE_TARGET_TYPE (type));
 
 	      /* Now, convert these values to an address.  */
 	      arg2 = value_cast (type_ptr, arg2);
 
 	      mem_offset = value_as_long (arg1);
 
-	      arg1 = value_from_pointer (type_ptr,
+	      arg1 = value_from_pointer (target_type_ptr,
 					 value_as_long (arg2) + mem_offset);
 	      arg1 = value_ind (arg1);
 	      tem = 1;
-- 
1.7.7.6