Support string literal strings in the vvp runtime.

This also advances support for string expressions in general.
Handle assignments to string variables in the code generator by
trying to calculate a string expression. This involves the new
string object thread details.

tgt-vvp/Makefile.in

@@ -49,7 +49,7 @@ CFLAGS = @WARNING_FLAGS@ @CFLAGS@
 LDFLAGS = @LDFLAGS@
 
 O = vvp.o draw_enum.o draw_mux.o draw_net_input.o draw_switch.o draw_ufunc.o draw_vpi.o \
-    eval_bool.o eval_expr.o eval_real.o modpath.o stmt_assign.o vector.o \
+    eval_bool.o eval_expr.o eval_real.o eval_string.o modpath.o stmt_assign.o vector.o \
     vvp_process.o vvp_scope.o
 
 all: dep vvp.tgt vvp.conf vvp-s.conf

tgt-vvp/eval_string.c

@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2012 Stephen Williams (steve@icarus.com)
+ *
+ *    This source code is free software; you can redistribute it
+ *    and/or modify it in source code form under the terms of the GNU
+ *    General Public License as published by the Free Software
+ *    Foundation; either version 2 of the License, or (at your option)
+ *    any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program; if not, write to the Free Software
+ *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+# include  "vvp_priv.h"
+# include  <assert.h>
+
+
+void draw_eval_string(ivl_expr_t expr)
+{
+      struct vector_info res;
+
+      switch (ivl_expr_type(expr)) {
+	  case IVL_EX_STRING:
+	    fprintf(vvp_out, "    %%pushi/str \"%s\";\n", ivl_expr_string(expr));
+	    break;
+
+	  default:
+	    switch (ivl_expr_value(expr)) {
+
+		case IVL_VT_BOOL:
+		case IVL_VT_LOGIC:
+		  res = draw_eval_expr(expr, 0);
+		  fprintf(vvp_out, "    %%pushv/str %u, %u; Cast BOOL/LOGIC to string\n",
+			  res.base, res.wid);
+		  if (res.base > 0)
+			clr_vector(res);
+		  break;
+
+		default:
+		  assert(0);
+		  break;
+	    }
+	    break;
+      }
+}

tgt-vvp/stmt_assign.c

@@ -733,7 +733,6 @@ static int show_stmt_assign_sig_real(ivl_statement_t net)
 
 static int show_stmt_assign_sig_string(ivl_statement_t net)
 {
-      struct vector_info res;
       ivl_lval_t lval = ivl_stmt_lval(net, 0);
       ivl_expr_t rval = ivl_stmt_rval(net);
       ivl_signal_t var;
@@ -742,20 +741,8 @@ static int show_stmt_assign_sig_string(ivl_statement_t net)
 
       var = ivl_lval_sig(lval);
 
-      switch (ivl_expr_value(rval)) {
-	  case IVL_VT_BOOL:
-	  case IVL_VT_LOGIC:
-	    res = draw_eval_expr(rval, 0);
-	    fprintf(vvp_out, "    %%pushv/str %u, %u;\n",
-		    res.base, res.wid);
+      draw_eval_string(rval);
       fprintf(vvp_out, "    %%store/str v%p_0;\n", var);
-	    if (res.base > 0)
-		  clr_vector(res);
-	    break;
-	  default:
-	    assert(0);
-	    break;
-      }
 
       return 0;
 }

tgt-vvp/vvp_priv.h

@@ -313,6 +313,12 @@ extern int draw_eval_real(ivl_expr_t ex);
  */
 extern int draw_eval_bool64(ivl_expr_t ex);
 
+/*
+ * The draw_eval_string functio evaluates the expression as a string,
+ * and pushes the string onto the string stack.
+ */
+extern void draw_eval_string(ivl_expr_t ex);
+
 extern int show_stmt_assign(ivl_statement_t net);
 extern void show_stmt_file_line(ivl_statement_t net, const char*desc);
 

vvp/codes.h

@@ -148,6 +148,7 @@ extern bool of_PAD(vthread_t thr, vvp_code_t code);
 extern bool of_POW(vthread_t thr, vvp_code_t code);
 extern bool of_POW_S(vthread_t thr, vvp_code_t code);
 extern bool of_POW_WR(vthread_t thr, vvp_code_t code);
+extern bool of_PUSHI_STR(vthread_t thr, vvp_code_t code);
 extern bool of_PUSHV_STR(vthread_t thr, vvp_code_t code);
 extern bool of_RELEASE_NET(vthread_t thr, vvp_code_t code);
 extern bool of_RELEASE_REG(vthread_t thr, vvp_code_t code);
@@ -191,6 +192,7 @@ struct vvp_code_s {
 	    vvp_array_t array;
 	    class __vpiHandle*handle;
 	    struct __vpiScope*scope;
+	    const char*text;
       };
 
       union {

vvp/compile.cc

@@ -70,7 +70,9 @@ enum operand_e {
 	/* The operand is a second functor pointer */
       OA_FUNC_PTR2,
 	/* The operand is a VPI handle */
-      OA_VPI_PTR
+      OA_VPI_PTR,
+	/* String */
+      OA_STRING
 };
 
 struct opcode_table_s {
@@ -194,6 +196,7 @@ static const struct opcode_table_s opcode_table[] = {
       { "%pow",    of_POW,    3,  {OA_BIT1,     OA_BIT2,     OA_NUMBER} },
       { "%pow/s",  of_POW_S,  3,  {OA_BIT1,     OA_BIT2,     OA_NUMBER} },
       { "%pow/wr", of_POW_WR, 2,  {OA_BIT1,     OA_BIT2,     OA_NONE} },
+      { "%pushi/str",of_PUSHI_STR,1,{OA_STRING, OA_NONE,     OA_NONE} },
       { "%pushv/str", of_PUSHV_STR, 2, {OA_BIT1,OA_BIT2,     OA_NONE} },
       { "%release/net",of_RELEASE_NET,3,{OA_FUNC_PTR,OA_BIT1,OA_BIT2} },
       { "%release/reg",of_RELEASE_REG,3,{OA_FUNC_PTR,OA_BIT1,OA_BIT2} },
@@ -1669,6 +1672,15 @@ void compile_code(char*label, char*mnem, comp_operands_t opa)
 
 		  compile_vpi_lookup(&code->handle, opa->argv[idx].symb.text);
 		  break;
+
+		case OA_STRING:
+		  if (opa->argv[idx].ltype != L_STRING) {
+			yyerror("operand format");
+			break;
+		  }
+
+		  code->text = opa->argv[idx].text;
+		  break;
 	    }
       }
 

vvp/compile.h

@@ -388,7 +388,7 @@ extern void compile_named_event(char*label, char*type);
  */
 
 #define OPERAND_MAX 3
-enum ltype_e { L_NUMB, L_SYMB };
+enum ltype_e { L_NUMB, L_SYMB, L_STRING };
 
 struct comp_operands_s {
       unsigned argc;
@@ -397,6 +397,7 @@ struct comp_operands_s {
 	    union {
 		  unsigned long numb;
 		  struct symb_s symb;
+		  const char   *text;
 	    };
       } argv[OPERAND_MAX];
 };

vvp/opcodes.txt

@@ -750,6 +750,10 @@ replaces the left operand.
 This opcode raises <bit-l> (real) to the power of <bit-r> (real). The
 result replaces the left operand.
 
+* %pushi/str <text>
+
+Push a literal string to the string stack.
+
 * %pushv/str <src>, <wid>
 
 Convert a vector to a string and push the string to the string stack.

vvp/parse.y

@@ -899,6 +899,14 @@ operand
 	opa->argv[0].numb = $1;
 	$$ = opa;
       }
+  | T_STRING
+      { comp_operands_t opa = (comp_operands_t)
+		  calloc(1, sizeof(struct comp_operands_s));
+	opa->argc = 1;
+	opa->argv[0].ltype = L_STRING;
+	opa->argv[0].text = $1;
+	$$ = opa;
+      }
   ;
 
 

vvp/vthread.cc

@@ -4148,6 +4148,13 @@ bool of_POW_WR(vthread_t thr, vvp_code_t cp)
       return true;
 }
 
+bool of_PUSHI_STR(vthread_t thr, vvp_code_t cp)
+{
+      const char*text = cp->text;
+      thr->stack_str.push_back(string(text));
+      return true;
+}
+
 bool of_PUSHV_STR(vthread_t thr, vvp_code_t cp)
 {
       unsigned src = cp->bit_idx[0];