Internal err 274 on dynamic array (Was: tt #1533 - Bug in g++?)

[James F. Carter]

/*bug04.C -- Internal compiler error 274 on dynamic auto array

In obscure circumstances involving a dynamic array where one dimension is
a nontrivial expression (and none of the dimensions are const, not that 
it seems to matter), the compiler gets one of two fatal errors: internal
compiler error 274, or signal 11 (segment violation).  It fails on Sparc
(sparc-sun-solaris2.5) but not on egcs-2.91.66 19990314/Linux 
(i386-slackware-linux).  Seemingly trivial changes in the source code make
the error behavior change radically or disappear entirely.

gcc version:	2.95.2 19991024 (release)
System type:	sparc-sun-solaris2.5
Command line:	g++ bug04.C
Discovered by:	"Duane Nykamp" <nykamp@math.ucla.edu>
Submitted by:	"James F. Carter" <jimc@math.ucla.edu>
Submitted date:	2000-10-11

Output complained about:
bug04.C: In function `int main()':
bug04.C:50: Internal compiler error 274.
bug04.C:50: Please submit a full bug report.
bug04.C:50: See <URL: http://www.gnu.org/software/gcc/faq.html#bugreport > for instructions.

James F. Carter        Voice 310 825 2897	FAX 310 206 6673
UCLA-Mathnet;  6115 MSA; 405 Hilgard Ave.; Los Angeles, CA, USA  90095-1555
Internet: jimc@math.ucla.edu (finger for PGP key)
UUCP:...!{ucsd,ames,ncar,gatech,purdue,rutgers,decvax,uunet}!math.ucla.edu!jimc
*/

extern int write(int, const void*, unsigned int);

int main() {
  int fileid /* = creat(...) */;  
/*  With the following exit() in place, the error message is
	Internal compiler error 274.
    With exit() removed, the error is
	g++: Internal compiler error: program cc1plus got fatal signal 11
    Further testing retains exit() in the code. */
  if(fileid==-1) exit(1);

  int Nn=2;
  int Nbins = 4;
  double mean_sb[Nn][Nbins];
  double cov[Nn][Nn][2*Nbins];	/*With Nbins instead of 2*Nbins wherever 
				occurring, the error does not appear.*/

/*  With both of these statements in place, the error occurs.  If either is
    commented out, the error hides. */
  write(fileid, *mean_sb, Nn*Nbins*sizeof(double));
  write(fileid, **cov, Nn*Nn*(2*Nbins)*sizeof(double));	//error reported here
}