[verilator] Use Verilator context in C/Python wrapper

pymtl3/passes/backends/verilog/import_/verilator_wrapper_c_template.py

@@ -47,6 +47,7 @@
 
     // Verilator model
     void * model;
+    VerilatedContext * context_ptr;
 
     // VCD state
     int _vcd_en;
@@ -64,7 +65,7 @@
   void destroy_model( V{component_name}_t *);
   void comb_eval( V{component_name}_t * );
   void seq_eval( V{component_name}_t * );
-  void assert_en( bool en );
+  void assert_en( V{component_name}_t *, bool );
 
   #if VLINETRACE
   void trace( V{component_name}_t *, char * );
@@ -75,16 +76,14 @@
 //------------------------------------------------------------------------
 // sc_time_stamp
 //------------------------------------------------------------------------
-// Must be defined so the simulator knows the current time. Called by
-// $time in Verilog. See:
-// http://www.veripool.org/projects/verilator/wiki/Faq
-
-vluint64_t g_main_time = 0;
+// This is now a lgeacy function required only so linking works on Cygwin
+// and MSVC++:
+// https://github.com/verilator/verilator/blob/master/examples/make_tracing_c/sim_main.cpp
 
 double sc_time_stamp()
 {{
 
-  return g_main_time;
+  return 0;
 
 }}
 
@@ -98,12 +97,16 @@
 
   V{component_name}_t  * m;
   V{vl_component_name} * model;
+  VerilatedContext     * context_ptr;
+
+  context_ptr = new VerilatedContext;
 
-  Verilated::randReset( {verilator_xinit_value} );
-  Verilated::randSeed( {verilator_xinit_seed} );
+  context_ptr->debug(0);
+  context_ptr->randReset( {verilator_xinit_value} );
+  context_ptr->randSeed( {verilator_xinit_seed} );
 
   m     = (V{component_name}_t *) malloc( sizeof(V{component_name}_t) );
-  model = new V{vl_component_name}();
+  model = new V{vl_component_name}(context_ptr);
 
   m->model = (void *) model;
 
@@ -114,7 +117,7 @@
   #if DUMP_VCD
   if ( strlen( vcd_filename ) != 0 ) {{
     m->_vcd_en = 1;
-    Verilated::traceEverOn( true );
+    context_ptr->traceEverOn( true );
     VerilatedVcdC * tfp = new VerilatedVcdC();
 
     model->trace( tfp, 99 );
@@ -159,6 +162,8 @@
 
   delete model;
 
+  free(m);
+
 }}
 
 //------------------------------------------------------------------------
@@ -259,9 +264,9 @@
 //------------------------------------------------------------------------
 // Enable or disable assertions controlled by --assert
 
-void assert_en( bool en ) {{
+void assert_en( V{component_name}_t * m, bool en ) {{
 
-  Verilated::assertOn(en);
+  m->context_ptr->assertOn(en);
 
 }}
 

pymtl3/passes/backends/verilog/import_/verilator_wrapper_py_template.py

@@ -80,18 +80,28 @@ def finalize( s ):
     assert s._finalization_count == 0,\
       'Imported component can only be finalized once!'
     s._finalization_count += 1
+
+    # Clean up python side FFI references
+    # del s._line_trace_str
+
     s._ffi_inst.destroy_model( s._ffi_m )
     s.ffi.dlclose( s._ffi_inst )
-    s.ffi = None
-    s._ffi_inst = None
+
+    del s._ffi_inst
+    del s.ffi
 
   def __del__( s ):
     if s._finalization_count == 0:
       s._finalization_count += 1
+
+      # Clean up python side FFI references
+      # del s._line_trace_str
+
       s._ffi_inst.destroy_model( s._ffi_m )
       s.ffi.dlclose( s._ffi_inst )
-      s.ffi = None
-      s._ffi_inst = None
+
+      del s._ffi_inst
+      del s.ffi
 
   def construct( s, *args, **kwargs ):
     # Set up the VCD file name
@@ -106,11 +116,15 @@ def construct( s, *args, **kwargs ):
     verilator_vcd_file = verilator_vcd_file.encode('ascii')
 
     # Construct the model
-    s._ffi_m = s._ffi_inst.create_model( s.ffi.new("char[]", verilator_vcd_file) )
+    # PP: we need to keep the new'ed object alive by assigning it to
+    # a variable. See more about this:
+    # https://cffi.readthedocs.io/en/stable/ref.html#ffi-new
+    ffi_vl_vcd_file = s.ffi.new("char[]", verilator_vcd_file)
+    s._ffi_m = s._ffi_inst.create_model( ffi_vl_vcd_file )
 
     # Buffer for line tracing
-    s._line_trace_str = s.ffi.new('char[512]')
-    s._convert_string = s.ffi.string
+    # s._line_trace_str = s.ffi.new('char[512]')
+    # s._convert_string = s.ffi.string
 
     # Use non-attribute varialbe to reduce CPython bytecode count
     _ffi_m = s._ffi_m
@@ -150,12 +164,13 @@ def assert_en( s, en ):
     # at this moment I'm not sure if the C API's are compatible between
     # PyPy and CPython).
     assert isinstance( en, bool )
-    s._ffi_inst.assert_en( en )
+    s._ffi_inst.assert_en( s._ffi_m, en )
 
   def line_trace( s ):
     if {external_trace}:
-      s._ffi_inst.trace( s._ffi_m, s._line_trace_str )
-      return s._convert_string( s._line_trace_str ).decode('ascii')
+      # s._ffi_inst.trace( s._ffi_m, s._line_trace_str )
+      # return s._convert_string( s._line_trace_str ).decode('ascii')
+      print('no implemented')
     else:
 {line_trace}