[Bug middle-end/16567] New: Nested function and variable-sized structure ICE

[Bug middle-end/16567] New: Nested function and variable-sized structure ICE

[jsm28 at gcc dot gnu dot org]

The following GNU C testcase ICEs with every compiler version tested
from 2.6.3 to recent mainline.  With mainline 3.5.0 20040710 on
i686-pc-linux-gnu, the error is:

t.c: In function `nested':
t.c:12: internal compiler error: in make_decl_rtl, at varasm.c:758
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

With 3.4.1, the error is:

t.c: In function `nested':
t.c:12: internal compiler error: in expand_expr_real, at expr.c:6638
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

The proper fix may well involve getting rid of variable-sized structures
in GNU C, but I don't know whether the problem can be triggered with
equivalent testcases in other languages (all ICEs are in various middle-end
files).

#include <stddef.h>

extern int printf (const char *, ...);
extern void *memset (void *, int, size_t);

int bar (int (*)(), int, void *);

int
main(int argc, char **argv)
{
  struct s { int a; char b[argc]; };
  int nested (struct s x) { return x.a + sizeof(x); }
  struct s t;
  memset (&t, 0, sizeof(t));
  t.a = 123;
  printf("%d\n", bar (nested, argc, &t));
  return 0;
}

-- 
           Summary: Nested function and variable-sized structure ICE
           Product: gcc
           Version: 3.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jsm28 at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16567

[Bug middle-end/16567] Nested function and variable-sized structure ICE

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-07-15 15:10 -------
Confirmed indeed. I guess we should say "don't do evil things!" :-) 

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-07-15 15:10:46
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16567

[Bug middle-end/16567] Nested function and variable-sized structure ICE

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-07-15 15:17 -------
BTW, the code is definitely invalid (even leaving aside the matter of 
variable-sized structures). You declare 
  int bar (int (*)(), int, void *); 
and call it with 
  int nested (struct s x) { return x.a + sizeof(x); } 
  bar (nested, argc, &t); 
Note that &nested does not satisfy the signature that bar() expects 
as first argument. It seems, however, as if we never even get to 
the point where gcc would like to check for this, it ICEs before that. 
 
Here's something that should be closer to validity: 
--------------- 
void bar (void *); 
 
int main(int argc, char **argv) { 
  struct s { char b[argc]; }; 
  int nested (struct s x) { return 0; } 
  struct s t; 
  bar ((void*)&nested); 
  return 0; 
} 
---------------- 
 
g/x> /home/bangerth/bin/gcc-3.5*/bin/gcc -c x.c 
x.c: In function `nested': 
x.c:5: internal compiler error: in make_decl_rtl, at varasm.c:758 
Please submit a full bug report, 
with preprocessed source if appropriate. 
See <URL:http://gcc.gnu.org/bugs.html> for instructions. 
 
g/x> /home/bangerth/bin/gcc-2.95.3/bin/gcc -c x.c 
x.c: In function `nested': 
x.c:5: Internal compiler error in `fix_lexical_addr', at function.c:5622 
Please submit a full bug report. 
See <URL:http://www.gnu.org/software/gcc/bugs.html> for instructions. 
 
W. 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16567

[Bug middle-end/16567] Nested function and variable-sized structure ICE

[jsm at polyomino dot org dot uk]

------- Additional Comments From jsm at polyomino dot org dot uk  2004-07-15 15:25 -------
Subject: Re:  Nested function and variable-sized
 structure ICE

On Thu, 15 Jul 2004, bangerth at dealii dot org wrote:

> BTW, the code is definitely invalid (even leaving aside the matter of 
> variable-sized structures). You declare 
>   int bar (int (*)(), int, void *); 
> and call it with 
>   int nested (struct s x) { return x.a + sizeof(x); } 
>   bar (nested, argc, &t); 
> Note that &nested does not satisfy the signature that bar() expects 
> as first argument. It seems, however, as if we never even get to 
> the point where gcc would like to check for this, it ICEs before that. 

I deliberately declare bar's first argument with an old-style
non-prototype declaration precisely because a matching prototype can't be
written at that point - but &nested can match a simple "pointer to
function returning int"!  (The original two-file testcase
<http://gcc.gnu.org/ml/gcc/2004-07/msg00776.html> was intended to be a
valid illustration of how variable-sized arguments are part of the C ABI,
which had the unintended effect of showing the ABI to be completely
irrelevant for this code because all versions of GCC ICE on it.)



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16567

[Bug middle-end/16567] Nested function and variable-sized structure ICE

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-10-14 01:54 -------
This now works on the mainline.  If I get time I will apply the testcase (otherwise someone else can do 
that plus close the bug).

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16567

[Bug middle-end/16567] Nested function and variable-sized structure ICE

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-10-15 13:49 -------
Fixed: Search converges between 2004-07-16-trunk (#487) and 2004-07-17-trunk (#488).
Committed the testcase so closing.

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16567

[Bug middle-end/16567] Nested function and variable-sized structure ICE

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-10-15 13:49 -------
Subject: Bug 16567

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	pinskia@gcc.gnu.org	2004-10-15 13:49:21

Modified files:
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/gcc.c-torture/compile: nested-1.c 

Log message:
	2004-10-14  Andrew Pinski  <pinskia@physics.uc.edu>
	
	PR middle-end/16567
	* gcc.c-torture/compile/nested-1.c: New test.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.c-torture/compile/nested-1.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.4454&r2=1.4455



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16567

[Bug middle-end/16567] Nested function and variable-sized structure ICE

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.0.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16567