[Bug c++/17655] New: g++ getting SEGFAULT compilling the code with HUGE_VAL comparasions

[Bug c++/17655] New: g++ getting SEGFAULT compilling the code with HUGE_VAL comparasions

[programm at metrocom dot ru]

gcc crashes compiling the following code:

(cmdline is g++-3.4 test.cc)

extern "C" {
#include <math.h>
};

template<typename T> void GetFromString()
{
    if (HUGE_VAL) {};
    // The same result as above
    // if (10.0 == HUGE_VAL) {};
};

int main(char argc, char** argv)
{
  GetFromString<char>();
};

It reports:

test.cc: In function `void GetFromString() [with T = char]':
test.cc:14:   instantiated from here
test.cc:7: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.

g++ -v output:

Reading specs from /usr/local/lib/gcc/i686-pc-linux-gnu/3.4.2/specs
Configured with: ../gcc-3.4.2/configure --enable-version-specific-runtime-libs
Thread model: posix
gcc version 3.4.2

Preprocessored source is attached.

-- 
           Summary: g++ getting SEGFAULT compilling the code with HUGE_VAL
                    comparasions
           Product: gcc
           Version: 3.4.2
            Status: UNCONFIRMED
          Severity: critical
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: programm at metrocom dot ru
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17655

[Bug c++/17655] g++ getting SEGFAULT compilling the code with HUGE_VAL comparasions

[programm at metrocom dot ru]

------- Additional Comments From programm at metrocom dot ru  2004-09-24 15:42 -------
Created an attachment (id=7214)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=7214&action=view)
Source file


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17655

[Bug c++/17655] g++ getting SEGFAULT compilling the code with HUGE_VAL comparasions

[programm at metrocom dot ru]

------- Additional Comments From programm at metrocom dot ru  2004-09-24 15:41 -------
Created an attachment (id=7213)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=7213&action=view)
Preprocessed source

Preprocessed source

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17655

[Bug c++/17655] g++ getting SEGFAULT compilling the code with HUGE_VAL comparasions

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-09-24 15:50 -------
You cannot do this:
extern "C" {
#include <math.h>
};

But we should not seg fault because of that.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17655

[Bug c++/17655] g++ getting SEGFAULT compilling the code with HUGE_VAL comparasions

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-09-24 17:27 -------
It doesn't fail for me with a 3.4 branch snapshot from 20040820. 
Can someone reproduce this with a newer or different snapshot? 
 
W. 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17655

[Bug c++/17655] g++ getting SEGFAULT compilling the code with HUGE_VAL comparasions

[programm at metrocom dot ru]

------- Additional Comments From programm at metrocom dot ru  2004-09-24 18:08 -------
Why extern "C" { #include <math.h> }; construction is prohibited?

What error should I receive from compiler?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17655

[Bug c++/17655] g++ getting SEGFAULT compilling the code with HUGE_VAL comparasions

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-09-24 18:11 -------
Because you should never wrap a header with extern "C" as the header can include C++ code too.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17655

[Bug c++/17655] g++ getting SEGFAULT compilling the code with HUGE_VAL comparasions

[programm at metrocom dot ru]

------- Additional Comments From programm at metrocom dot ru  2004-09-24 18:13 -------
To bangerth@dealii.org:

Have you try to compile the preprocessed source, test1.cc?

It seems to me, the problem is releated to the expansion of
HUGE_VAL macro which can be system-dependent (for ex., I use 
linux 2.2 kernel on my system):
 
template<typename T> void GetFromString()
{
    if ((__extension__ ((union { unsigned char __c[8]; double __d; }) { __c: {
0, 0, 0, 0, 0, 0, 0xf0, 0x7f } }).__d)) {};
};

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17655

[Bug c++/17655] g++ getting SEGFAULT compilling the code with HUGE_VAL comparasions

[programm at metrocom dot ru]

------- Additional Comments From programm at metrocom dot ru  2004-09-24 18:23 -------
To pinskia@gcc.gnu.org:

1) I've removed 'extern "C"' in my test source, but the compiler gets 
   SEGFAULT again. I also have tried to replace 'extern "C"' by 'include <cmath>'
   construction.  Nothing changes. 
2) It seems to me, I not only can but I even must wrap C-library
   include files by 'extern "C"'. (?) 3-rd edition of Straustrup's book
   recommends it in 9.2.2 section.  Have I mistaken?  

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17655

[Bug c++/17655] [3.3/3.4 regression] ICE with using a C99 initializer in an if-condition

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-09-24 20:35 -------
In reply to comment #7: 
No I hadn't. I have now, and I can indeed reproduce the failure. Here's 
a smaller testcase: 
------------------------ 
template<typename T> void foo() { 
  if (((union { char __d; }) { 0 }).__d) {} 
} 
 
template void  foo<char>(); 
------------------------ 
This fails with gcc 3.2.3, 3.3.4, and 3.4.2, but not mainline or 2.95.3: 
 
g/x> /home/bangerth/bin/gcc-3.4-pre/bin/c++ -c x.ii  
x.ii: In function `void foo() [with T = char]': 
x.ii:5:   instantiated from here 
x.ii:2: internal compiler error: Segmentation fault 
Please submit a full bug report, 
with preprocessed source if appropriate. 
See <URL:http://gcc.gnu.org/bugs.html> for instructions. 
 
It is thus a regression, although one that is fixed on mainline already. 
Note that the exact same thing happens if I replace "union" with "struct". 
On the other hand, the bug goes away if I move the declaration of the 
union/struct to outside the if-clause; this indicates that it has something 
to do with the C99 initializer syntax used here. 
 
W. 
 
W. 

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
      Known to fail|                            |3.2.3 3.3.3 3.4.0
      Known to work|                            |2.95 4.0.0
   Last reconfirmed|0000-00-00 00:00:00         |2004-09-24 20:35:58
               date|                            |
            Summary|g++ getting SEGFAULT        |[3.3/3.4 regression] ICE
                   |compilling the code with    |with using a C99 initializer
                   |HUGE_VAL comparasions       |in an if-condition


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17655

[Bug c++/17655] [3.3/3.4 regression] ICE with using a C99 initializer in an if-condition

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-09-24 20:46 -------
Fixed on the mainline : Search converges between 2004-06-14-trunk (#466) and 2004-06-16-trunk 
(#467).

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |gdr at gcc dot gnu dot org
           Keywords|                            |ice-on-valid-code
   Target Milestone|---                         |3.4.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17655

[Bug c++/17655] [3.3/3.4 regression] ICE with using a C99 initializer in an if-condition

[programm at metrocom dot ru]

------- Additional Comments From programm at metrocom dot ru  2004-09-27 13:29 -------
(In reply to comment #10)
> Fixed on the mainline : Search converges between 2004-06-14-trunk (#466) and
2004-06-16-trunk 
> (#467).

Thanks a lot.  It really works for me.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17655

[Bug c++/17655] [3.3/3.4 regression] ICE with using a C99 initializer in an if-condition

[programm at metrocom dot ru]

------- Additional Comments From programm at metrocom dot ru  2004-09-27 13:30 -------
I've changed the bug status after compiling and testing latest g++
from cvs

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |WORKSFORME


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17655

[Bug c++/17655] [3.3/3.4 regression] ICE with using a C99 initializer in an if-condition

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-09-27 13:34 -------
No this is a regression that is still on a release branch.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
         Resolution|WORKSFORME                  |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17655

[Bug c++/17655] [3.3/3.4 regression] ICE with using a C99 initializer in an if-condition

[mmitchel at gcc dot gnu dot org]

------- Additional Comments From mmitchel at gcc dot gnu dot org  2004-11-01 00:46 -------
Postponed until GCC 3.4.4.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|3.4.3                       |3.4.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17655

[Bug c++/17655] [3.3/3.4 regression] ICE with using a C99 initializer in an if-condition

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|REOPENED                    |NEW


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17655

[Bug c++/17655] [3.3/3.4 regression] ICE with using a C99 initializer in an if-condition

[mmitchel at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|3.4.4                       |3.4.5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17655