#607 Wildcard sensitivity list of block with delay segfaults

v0.9
closed-fixed
Cary R.
5
2008-12-29
2008-12-27
No

The following example code seems to cause a bus error during the compilation phase. The problem appears when the delay (#1;) statement is added to the second always block. This bug was found with the latest git version of Icarus Verilog.

module main;

reg a, b, reset;

always @*
a = b | reset;

always @*
begin
b = 1'b0;
#1;
b = a;
end

initial begin
`ifdef DUMP
$dumpfile( "slist4.vcd" );
$dumpvars( 0, main );
`endif
reset = 1'b1;
#10;
reset = 1'b0;
#10;
$finish;
end

endmodule

Error message:

Macintosh:verilog trevorw$ iverilog slist4.v
sh: line 1: 73318 Done /Users/trevorw/install/lib/ivl/ivlpp -L -F/var/folders/OS/OSQFAgk5Fx8Xc-2eoudmtk+++TI/-Tmp-//ivrlg24972373c -f/var/folders/OS/OSQFAgk5Fx8Xc-2eoudmtk+++TI/-Tmp-//ivrlg4972373c -p/var/folders/OS/OSQFAgk5Fx8Xc-2eoudmtk+++TI/-Tmp-//ivrli4972373c
73319 Bus error | /Users/trevorw/install/lib/ivl/ivl -C/var/folders/OS/OSQFAgk5Fx8Xc-2eoudmtk+++TI/-Tmp-//ivrlh4972373c -C/Users/trevorw/install/lib/ivl/vvp.conf -- -

Discussion

  • Cary R.

    Cary R. - 2008-12-27
    • milestone: 530321 --> v0.9
     
  • Cary R.

    Cary R. - 2008-12-27

    As is implied by your comments @(a) for the second block will function correctly. I'm guessing that the code that looks for wild card inputs is getting confused, but we will need to look into this more. I'm marking this as something we want to fixed for V0.9. I'm leaving this at priority five since it is trivial to work around this with an explicit sensitivity list.

     
  • Cary R.

    Cary R. - 2008-12-29
    • assigned_to: nobody --> caryr
     
  • Cary R.

    Cary R. - 2008-12-29

    I have verified that this is being caused by the empty (null) statement after the delay. I'm claiming this and a patch should be available soon.

     
  • Cary R.

    Cary R. - 2008-12-29

    I have submitted a patch that fixes this problem to the patch tracker. It adds code to ignore the empty statement created in the #1; statement.

     
  • Cary R.

    Cary R. - 2008-12-29
    • status: open --> closed-fixed
     

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