Author Name: Jeremy Bennett (@jeremybennett)
Original Redmine Issue: 53 from https://www.veripool.org
Original Date: 2009-01-22
Original Assignee: Wilson Snyder (@wsnyder)

A couple of problems with @$fopen@ (taken from the OpenRISC 1000). I have the original Verilog:

integer fflash;
    initial fflash = $fopen("flash.log");

First problem is that Verilator only accepts the two argument version of @$fopen@ (which returns a file descriptor), rather than the single argument version, which returns a multi-channel descriptor. I tried patching this to

integer fflash;
    initial fflash = $fopen("flash.log","w");

Verilator now works fine, but I get defective C++. The code generated includes:

void Vorpsoc::_initial__TOP(Vorpsoc__Syms* __restrict vlSymsp) {
     VL_DEBUG_IF(cout<<"    Vorpsoc::_initial__TOP"<<endl; );
     Vorpsoc* __restrict vlTOPp VL_ATTR_UNUSED = vlSymsp->TOPp;
     // Variables
     VL_SIGW(__Vtemp1,71,0,3);
     // Body
     // INITIAL at rtl/verilog/mem_if/flash_top.v:330
     __Vtemp1[0] = 0x2e6c6f67;
     __Vtemp1[1] = 0x6c617368;
     __Vtemp1[2] = 0x66;
     VL_EXTENDS_QI(64,32, vlTOPp->v__DOT__flash_top__DOT__fflash) = VL_FOPEN_WI(3, __Vtemp1, 0x77);

This last line prompts the G++ error:

Vorpsoc.cpp:5399: error: lvalue required as left operand of assignment

As far as I can see @VL_EXTENDS_QI@ is an inline function, so should not appear on the LHS of an assignment.

It's not a killer (this is not an important part of the code), but any suggestions on a workaround welcome.

Original Verilog file attached

Thanks, Jeremy