[Bug c++/35652] [4.2/4.3/4.4 Regression] offset warning should be given in the front-end

2009-03-27 Thread andreasmeier80 at gmx dot de 


--- Comment #15 from andreasmeier80 at gmx dot de  2009-03-27 07:16 ---
Approved here: http://gcc.gnu.org/ml/gcc-patches/2009-03/msg01079.html


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35652

[Bug c++/35652] [4.2/4.3/4.4 Regression] offset warning should be given in the front-end

2009-02-08 Thread manu at gcc dot gnu dot org 


--- Comment #14 from manu at gcc dot gnu dot org  2009-02-08 15:46 ---
Patch: http://gcc.gnu.org/ml/gcc-patches/2009-02/msg00285.html


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manu at gcc dot gnu dot org changed:

   What|Removed |Added

URL||http://gcc.gnu.org/ml/gcc-
   ||patches/2009-
   ||02/msg00285.html
   Keywords||patch
   Last reconfirmed|2008-03-21 12:49:51 |2009-02-08 15:46:08
   date||


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35652

[Bug c++/35652] [4.2/4.3/4.4 Regression] offset warning should be given in the front-end

2009-02-03 Thread bonzini at gnu dot org 


--- Comment #13 from bonzini at gnu dot org  2009-02-03 16:40 ---
I agree that the patch is correct *without* the -1, so... ping :)


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35652

[Bug c++/35652] [4.2/4.3/4.4 Regression] offset warning should be given in the front-end

2008-11-02 Thread rguenther at suse dot de 


--- Comment #9 from rguenther at suse dot de  2008-11-02 12:20 ---
Subject: Re:  [4.2/4.3/4.4 Regression] offset warning should
 be given in the front-end

On Sat, 1 Nov 2008, manu at gcc dot gnu dot org wrote:

 --- Comment #8 from manu at gcc dot gnu dot org  2008-11-01 17:44 ---
 This is my current patch and it works in this testcase. However, it also
 triggers on cases like: const char *p = str + sizeof(str)
 
 Perhaps I am doing this at the wrong place. Any suggestions?

Keep in mind that one-after the string is ok, so ...

 
 @@ -3322,10 +3323,36 @@ pointer_int_sum (enum tree_code resultco
 
/* Create the sum or difference.  */
if (resultcode == MINUS_EXPR)
  intop = fold_build1 (NEGATE_EXPR, sizetype, intop);
 
 +
 +  if (TREE_CODE (intop) == INTEGER_CST)
 +{
 +  tree offset_node;
 +  tree string_cst = string_constant (ptrop, offset_node);
 +
 +  if (string_cst != 0
 +  !(offset_node  TREE_CODE (offset_node) != INTEGER_CST))
 +   {
 + HOST_WIDE_INT max = TREE_STRING_LENGTH (string_cst) - 1;

... the -1 is wrong here.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35652

[Bug c++/35652] [4.2/4.3/4.4 Regression] offset warning should be given in the front-end

2008-11-02 Thread manu at gcc dot gnu dot org 


--- Comment #10 from manu at gcc dot gnu dot org  2008-11-02 12:53 ---
(In reply to comment #9)
  This is my current patch and it works in this testcase. However, it also
  triggers on cases like: const char *p = str + sizeof(str)
  
  Perhaps I am doing this at the wrong place. Any suggestions?
 
 Keep in mind that one-after the string is ok, so ...

Do you mean one after the null character? If you have str = abcd. Then
sizeof(str) is 5 and str + sizeof(str) points outside the string. (str[4] is
the null character).

  
  @@ -3322,10 +3323,36 @@ pointer_int_sum (enum tree_code resultco
  +   {
  + HOST_WIDE_INT max = TREE_STRING_LENGTH (string_cst) - 1;
 
 ... the -1 is wrong here.
 

TREE_STRING_LENGTH is the size of the character array, not the string. Are you
sure it is wrong?


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35652

[Bug c++/35652] [4.2/4.3/4.4 Regression] offset warning should be given in the front-end

2008-11-02 Thread rguenth at gcc dot gnu dot org 


--- Comment #11 from rguenth at gcc dot gnu dot org  2008-11-02 13:02 
---
I'm not sure.  Does TREE_STRING_LENGTH in the particular case include the
NULL character?  Does sizeof(str) include the NULL character?

In principle it is allowed to have a pointer point one after the last element
of an array.  That IMHO would include the NULL character, so for foo
pointing to foo + 4 would be ok.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35652

Re: [Bug c++/35652] [4.2/4.3/4.4 Regression] offset warning should be given in the front-end

2008-11-02 Thread Andrew Thomas Pinski 



Sent from my iPhone

On Nov 2, 2008, at 4:53 AM, manu at gcc dot gnu dot org [EMAIL PROTECTED] 
 wrote:





--- Comment #10 from manu at gcc dot gnu dot org  2008-11-02  
12:53 ---

(In reply to comment #9)
This is my current patch and it works in this testcase. However,  
it also

triggers on cases like: const char *p = str + sizeof(str)

Perhaps I am doing this at the wrong place. Any suggestions?


Keep in mind that one-after the string is ok, so ...


Do you mean one after the null character? If you have str = abcd.  
Then
sizeof(str) is 5 and str + sizeof(str) points outside the string.  
(str[4] is

the null character).


That is still well defined. Taking the address of one element past the  
end of the array is well defined. Just you can not derefence it.

Thanks,
Andrew Pinski






@@ -3322,10 +3323,36 @@ pointer_int_sum (enum tree_code resultco
+   {
+ HOST_WIDE_INT max = TREE_STRING_LENGTH (string_cst) - 1;


... the -1 is wrong here.



TREE_STRING_LENGTH is the size of the character array, not the  
string. Are you

sure it is wrong?


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35652

[Bug c++/35652] [4.2/4.3/4.4 Regression] offset warning should be given in the front-end

2008-11-02 Thread pinskia at gmail dot com 


--- Comment #12 from pinskia at gmail dot com  2008-11-02 13:07 ---
Subject: Re:  [4.2/4.3/4.4 Regression] offset warning should be given in the
front-end



Sent from my iPhone

On Nov 2, 2008, at 4:53 AM, manu at gcc dot gnu dot org
[EMAIL PROTECTED] 
  wrote:



 --- Comment #10 from manu at gcc dot gnu dot org  2008-11-02  
 12:53 ---
 (In reply to comment #9)
 This is my current patch and it works in this testcase. However,  
 it also
 triggers on cases like: const char *p = str + sizeof(str)

 Perhaps I am doing this at the wrong place. Any suggestions?

 Keep in mind that one-after the string is ok, so ...

 Do you mean one after the null character? If you have str = abcd.  
 Then
 sizeof(str) is 5 and str + sizeof(str) points outside the string.  
 (str[4] is
 the null character).

That is still well defined. Taking the address of one element past the  
end of the array is well defined. Just you can not derefence it.
Thanks,
Andrew Pinski




 @@ -3322,10 +3323,36 @@ pointer_int_sum (enum tree_code resultco
 +   {
 + HOST_WIDE_INT max = TREE_STRING_LENGTH (string_cst) - 1;

 ... the -1 is wrong here.


 TREE_STRING_LENGTH is the size of the character array, not the  
 string. Are you
 sure it is wrong?


 -- 


 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35652



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35652

[Bug c++/35652] [4.2/4.3/4.4 Regression] offset warning should be given in the front-end

2008-11-01 Thread manu at gcc dot gnu dot org 


--- Comment #8 from manu at gcc dot gnu dot org  2008-11-01 17:44 ---
This is my current patch and it works in this testcase. However, it also
triggers on cases like: const char *p = str + sizeof(str)

Perhaps I am doing this at the wrong place. Any suggestions?


@@ -3322,10 +3323,36 @@ pointer_int_sum (enum tree_code resultco

   /* Create the sum or difference.  */
   if (resultcode == MINUS_EXPR)
 intop = fold_build1 (NEGATE_EXPR, sizetype, intop);

+
+  if (TREE_CODE (intop) == INTEGER_CST)
+{
+  tree offset_node;
+  tree string_cst = string_constant (ptrop, offset_node);
+
+  if (string_cst != 0
+  !(offset_node  TREE_CODE (offset_node) != INTEGER_CST))
+   {
+ HOST_WIDE_INT max = TREE_STRING_LENGTH (string_cst) - 1;
+ HOST_WIDE_INT offset;
+ if (offset_node == 0)
+   offset = 0;
+ else if (! host_integerp (offset_node, 0))
+   offset = -1;
+ else
+   offset = tree_low_cst (offset_node, 0);
+
+ offset = offset + tree_low_cst (intop, 0);
+ if (offset  0 || offset  max)
+   warning_at (location, 0,
+   offset %%ld% outside bounds of constant string,
+   tree_low_cst (intop, 0));
+   }
+}
+
   ret = fold_build2 (POINTER_PLUS_EXPR, result_type, ptrop, intop);

   fold_undefer_and_ignore_overflow_warnings ();

   return ret;


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35652

[Bug c++/35652] [4.2/4.3/4.4 Regression] offset warning should be given in the front-end

2008-10-30 Thread manu at gcc dot gnu dot org 


--- Comment #7 from manu at gcc dot gnu dot org  2008-10-30 22:44 ---
The location info seems to be fixed in mainline. Nonetheless, I agree
completely with Richard. This warning belongs in the front-end. Moreover we
fail to diagnose:

const char *s = 'x' + y;

in both C and C++. Also, this warning does not really requires -O2, so it
should work at -O0 too.


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manu at gcc dot gnu dot org changed:

   What|Removed |Added

 CC||manu at gcc dot gnu dot org
Summary|[4.2/4.3/4.4 Regression]|[4.2/4.3/4.4 Regression]
   |Location information|offset warning should be
   |incorrect on string bounds  |given in the front-end
   |warning |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35652