[Bug c/40097] New: inconsistent printf handling

[Andrey dot Martchovsky at gmail dot com]

The following code results in a segmentation fault at Line 7.

1:#include 
2:int main(){
3:  const char *tmp = NULL;
4:  printf("%s \n",NULL);
5:  printf("%s\n",NULL);
6:  printf("%s \n",tmp);
7:  printf("%s\n",tmp);
8:  return 1;
9:}

I've traced the bug to the code optimization in

/usr/src/gcc-4.3/gcc-4.3.3/gcc/builtins.c
fold_builtin_printf()

the printf() is replaced with puts(), which has no null handling

The alternate solution would be to add a NULL check to puts() or putc() in
libc.

This inconsistency is a major setback when porting code from Windows to Linux
as MCVC++ compiles the above code correctly and GCC does not.


-- 
   Summary: inconsistent printf handling
   Product: gcc
   Version: 4.3.3
Status: UNCONFIRMED
  Severity: blocker
  Priority: P3
 Component: c
AssignedTo: unassigned at gcc dot gnu dot org
    ReportedBy: Andrey dot Martchovsky at gmail dot com
GCC target triplet: gcc (Ubuntu 4.3.3-5ubuntu4) 4.3.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40097

[Bug c/40097] inconsistent printf handling

[Andrey dot Martchovsky at gmail dot com]

--- Comment #2 from Andrey dot Martchovsky at gmail dot com  2009-05-11 
01:26 ---
(In reply to comment #1)
> Actually this code is undefined.  Using %s with a NULL pointer is undefined so
> GCC's behavior is correct.
> 

You are wrong, the GCC behavior is incorrect.
Please compile code and run before replying.


Lines 4 & 6 behave identically
Lines 5 & 7 do not

that


-- 

Andrey dot Martchovsky at gmail dot com changed:

   What|Removed |Added

 Status|RESOLVED|UNCONFIRMED
 Resolution|INVALID |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40097

[Bug c++/40098] New: 64bit constants

[Andrey dot Martchovsky at gmail dot com]

-- 
   Summary: 64bit constants
   Product: gcc
   Version: 4.3.3
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: Andrey dot Martchovsky at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40098

[Bug c++/40099] New: 64bit constants

[Andrey dot Martchovsky at gmail dot com]

The following code produces

and...@tiny:~/Documents/Thesis/TIA/pll$ gcc tst.c 
tst.c:2: warning: integer constant is too large for ‘long’ type
and...@tiny:~/Documents/Thesis/TIA/pll$ g++ tst.c 
tst.c:2: error: integer constant is too large for ‘long’ type


1:#include 
2:long long int tst = 80;
3:int main(){
4:  printf("sizeof(long long int)=%d\n",sizeof(long long int));
5:  printf("tst=%lld\n",tst);
6:  return 0;
7:}


-- 
   Summary: 64bit constants
   Product: gcc
   Version: 4.3.3
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
    ReportedBy: Andrey dot Martchovsky at gmail dot com
GCC target triplet: g++ (Ubuntu 4.3.3-5ubuntu4) 4.3.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40099

[Bug c++/40098] 64bit constants

[Andrey dot Martchovsky at gmail dot com]

--- Comment #1 from Andrey dot Martchovsky at gmail dot com  2009-05-11 
02:07 ---


*** This bug has been marked as a duplicate of 40099 ***


-- 

Andrey dot Martchovsky at gmail dot com changed:

   What|Removed |Added

 Status|UNCONFIRMED |RESOLVED
 Resolution||DUPLICATE


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40098

[Bug c++/40099] 64bit constants

[Andrey dot Martchovsky at gmail dot com]

--- Comment #1 from Andrey dot Martchovsky at gmail dot com  2009-05-11 
02:07 ---
*** Bug 40098 has been marked as a duplicate of this bug. ***


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40099

[Bug c++/40099] 64bit constants

[Andrey dot Martchovsky at gmail dot com]

--- Comment #3 from Andrey dot Martchovsky at gmail dot com  2009-05-11 
18:22 ---
(In reply to comment #2)
> Why is that a problem? C and C++ are different languages.  Compiling with g++
> means you are compiling the C code as C++ (see documentation).
> 

My problem is that the error for 64bit ints in C++ shows up only under the x86
implementation of g++,
compiling the same code under x86_64 does not result in any errors.

Btw, the documentation for C++ suggests to use either int64_t or long long, for
64bit integers, and with either, I cannot define a constant that is greater
than 2^31-1. Therefore this is a bug, as the compiler DOES recognize the
declared variable to be 64 bit wide, and DOES all the 64bit arithmetic properly
(add,sub,mul,div,mod,shift ...), but DOES NOT recognize the variable to be
64bits in the initial parsing.


-- 

Andrey dot Martchovsky at gmail dot com changed:

   What|Removed |Added

 Status|RESOLVED|UNCONFIRMED
 Resolution|INVALID |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40099

[Bug c++/40099] 64bit constants

[Andrey dot Martchovsky at gmail dot com]

--- Comment #5 from Andrey dot Martchovsky at gmail dot com  2009-05-11 
19:04 ---
(In reply to comment #4)
> For C++98 and C90, integer constants can only fit into the long type. You need
> to use LL if you want a 64bit integer constant.
> 

Thank you for clarifying this.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40099