[Bug c++/28584] New: Cast to pointer from integer of different size [gcc 4.0.x and 4.1.x on x86_64]

[Bug c++/28584] New: Cast to pointer from integer of different size [gcc 4.0.x and 4.1.x on x86_64]

[denis dot charland at imi dot cnrc-nrc dot gc dot ca]

The following code does not generate any warning when
compiled with g++ 4.0.x and 4.1.x on a x86_64 platform:



/*
#include <cstdio>

int f(void);

int f(void)
{
   return (long) &std::printf;
}
*/

typedef unsigned long mysize_t;
void *mymmap(void *start, mysize_t length, int prot , int flags, int fd, int
offset);

//typedef unsigned long DWORD;
typedef unsigned int DWORD;

struct UDA {
  DWORD UserDirectAddr;
  DWORD TransAddr;
  DWORD Bytes;
};


void f(UDA *puda);

void f(UDA *puda)
{
   puda->UserDirectAddr = 
       (unsigned long) mymmap((void *) puda->TransAddr, 
                              puda->Bytes,
                              0, 0, 0, 0);
}



When compiled with g++ 3.4.6 on the same platform,
the following warning is issued:

g++ -c test.cpp

test.cpp: In function `void f(UDA*)':
test.cpp:30: warning: cast to pointer from integer of different size


-- 
           Summary: Cast to pointer from integer of different size [gcc
                    4.0.x  and 4.1.x on x86_64]
           Product: gcc
           Version: 4.0.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: denis dot charland at imi dot cnrc-nrc dot gc dot ca


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28584

[Bug c++/28584] Cast to pointer from integer of different size

[redi at gcc dot gnu dot org]

------- Comment #1 from redi at gcc dot gnu dot org  2009-12-08 20:32 -------
reduced:
void f() {
  unsigned short i = 0;
  void* p = (void*)i;
}
this warns in 32-bit or 64-bit mode using the C compiler, and is controlled by
this option that g++ doesn't support:

-Wno-int-to-pointer-cast (C and Objective-C only)
Suppress warnings from casts to pointer type of an integer of a different size.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28584

[Bug c++/28584] Cast to pointer from integer of different size

[manu at gcc dot gnu dot org]

------- Comment #2 from manu at gcc dot gnu dot org  2010-02-20 18:19 -------
Jason, do we want this?

It seems trivial:

Index: gcc/cp/typeck.c
===================================================================
--- gcc/cp/typeck.c     (revision 156923)
+++ gcc/cp/typeck.c     (working copy)
@@ -6260,10 +6260,20 @@ cp_build_c_cast (tree type, tree expr, t
       if (complain & tf_error)
         error ("invalid cast to function type %qT", type);
       return error_mark_node;
     }

+
+  if (TREE_CODE (type) == POINTER_TYPE
+      && TREE_CODE (TREE_TYPE (value)) == INTEGER_TYPE
+      && TYPE_PRECISION (type) != TYPE_PRECISION (TREE_TYPE (value))
+      /* Don't warn about converting any constant.  */
+      && !TREE_CONSTANT (value))
+    warning_at (loc,
+               OPT_Wint_to_pointer_cast, "cast to pointer from integer "
+               "of different size");
+
   /* A C-style cast can be a const_cast.  */
   result = build_const_cast_1 (type, value, /*complain=*/false,
                               &valid_p);
   if (valid_p)
     return result;


-- 

manu at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jason at redhat dot com,
                   |                            |manu at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28584

[Bug c++/28584] Cast to pointer from integer of different size

[jason at redhat dot com]

------- Comment #3 from jason at redhat dot com  2010-02-20 20:15 -------
Subject: Re:  Cast to pointer from integer of different size

On 02/20/2010 01:19 PM, manu at gcc dot gnu dot org wrote:
> Jason, do we want this?

Sure.

Jason


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28584

[Bug c++/28584] Cast to pointer from integer of different size

[manu at gcc dot gnu dot org]

------- Comment #4 from manu at gcc dot gnu dot org  2010-02-22 19:04 -------
Patch http://gcc.gnu.org/ml/gcc-patches/2010-02/msg00891.html


-- 

manu at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |manu at gcc dot gnu dot org
                   |dot org                     |
                URL|                            |http://gcc.gnu.org/ml/gcc-
                   |                            |patches/2010-
                   |                            |02/msg00891.html
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
           Keywords|                            |patch
   Last reconfirmed|0000-00-00 00:00:00         |2010-02-22 19:04:58
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28584

[Bug c++/28584] Cast to pointer from integer of different size

[manu at gcc dot gnu dot org]

------- Comment #5 from manu at gcc dot gnu dot org  2010-02-22 19:49 -------
Approved for GCC 4.6

http://gcc.gnu.org/ml/gcc-patches/2010-02/msg00893.html


-- 

manu at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
OtherBugsDependingO|                            |41998
              nThis|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28584

[Bug c++/28584] Cast to pointer from integer of different size

[manu at gcc dot gnu dot org]

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------- Comment #6 from manu at gcc dot gnu dot org  2010-04-09 07:50 -------
Subject: Bug 28584

Author: manu
Date: Fri Apr  9 07:49:41 2010
New Revision: 158150

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=158150
Log:
2010-04-09  Manuel López-Ibáñez  <manu@gcc.gnu.org>

        PR c++/28584
        * c.opt (Wint-to-pointer-cast): Available in C++.
        * doc/invoke.texi (Wint-to-pointer-cast): Available in C++.
cp/
        * typeck.c (cp_build_c_cast): Warn for casting integer to larger
        pointer type.
testsuite/
        * gcc.dg/Wint-to-pointer-cast-1.c: Move to...
        * c-c++-common/Wint-to-pointer-cast-1.c: ...  here.
        * gcc.dg/Wint-to-pointer-cast-2.c: Move to...   
        * c-c++-common/Wint-to-pointer-cast-2.c: ...  here.
        * gcc.dg/Wint-to-pointer-cast-3.c: Move to...   
        * c-c++-common/Wint-to-pointer-cast-3.c: ...  here. Update.
        * g++.old-deja/g++.mike/warn1.C: Add -Wno-int-to-pointer-cast.
        * g++.dg/other/increment1.C: Likewise.

Added:
    trunk/gcc/testsuite/c-c++-common/Wint-to-pointer-cast-1.c   (props changed)
      - copied unchanged from r158134,
trunk/gcc/testsuite/gcc.dg/Wint-to-pointer-cast-1.c
    trunk/gcc/testsuite/c-c++-common/Wint-to-pointer-cast-2.c   (props changed)
      - copied unchanged from r158134,
trunk/gcc/testsuite/gcc.dg/Wint-to-pointer-cast-2.c
    trunk/gcc/testsuite/c-c++-common/Wint-to-pointer-cast-3.c   (contents,
props changed)
      - copied, changed from r158134,
trunk/gcc/testsuite/gcc.dg/Wint-to-pointer-cast-3.c
Removed:
    trunk/gcc/testsuite/gcc.dg/Wint-to-pointer-cast-1.c
    trunk/gcc/testsuite/gcc.dg/Wint-to-pointer-cast-2.c
    trunk/gcc/testsuite/gcc.dg/Wint-to-pointer-cast-3.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/c.opt
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/typeck.c
    trunk/gcc/doc/invoke.texi
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/g++.dg/other/increment1.C
    trunk/gcc/testsuite/g++.old-deja/g++.mike/warn1.C

Propchange: trunk/gcc/testsuite/c-c++-common/Wint-to-pointer-cast-1.c
            ('svn:mergeinfo' added)

Propchange: trunk/gcc/testsuite/c-c++-common/Wint-to-pointer-cast-2.c
            ('svn:mergeinfo' added)

Propchange: trunk/gcc/testsuite/c-c++-common/Wint-to-pointer-cast-3.c
            ('svn:mergeinfo' added)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28584

[Bug c++/28584] Cast to pointer from integer of different size

[manu at gcc dot gnu dot org]

------- Comment #7 from manu at gcc dot gnu dot org  2010-04-09 07:53 -------
FIXED in GCC 4.6


-- 

manu at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28584