From 817a38494c79233749d93f0cc545befafae3cde4 Mon Sep 17 00:00:00 2001
From: Cary R <cygcary@yahoo.com>
Date: Wed, 24 Jul 2013 19:39:17 -0700
Subject: [PATCH] vlog95: add support for zero argument functions and better
 named block detect

Add support for translating a zero argument function by adding a dummy
argument and improve the code that looks for a named block in a process.
---
 tgt-vlog95/expr.c  |  5 ++--
 tgt-vlog95/scope.c | 74 +++++++++++++++++++++++++++++++++++++++-------
 2 files changed, 67 insertions(+), 12 deletions(-)

diff --git a/tgt-vlog95/expr.c b/tgt-vlog95/expr.c
index f4a609533..89e83d674 100644
--- a/tgt-vlog95/expr.c
+++ b/tgt-vlog95/expr.c
@@ -933,9 +933,10 @@ static void emit_expr_func(ivl_scope_t scope, ivl_expr_t expr, unsigned wid)
 // HERE: For a user function should the argument width be used here.
 	    emit_expr(scope, ivl_expr_parm(expr, count), 0, 1, 0, 0);
 	    fprintf(vlog_out, ")");
-	/* User functions without arguments are not supported. */
+	/* User functions without arguments are not supported so a dummy
+	 * argument is added both here and in the definition. */
       } else if (ivl_expr_type(expr) == IVL_EX_UFUNC) {
-	    fprintf(vlog_out, "()");
+	    fprintf(vlog_out, "(1'bx)");
       }
 }
 
diff --git a/tgt-vlog95/scope.c b/tgt-vlog95/scope.c
index 56d45c9d4..9238a8431 100644
--- a/tgt-vlog95/scope.c
+++ b/tgt-vlog95/scope.c
@@ -564,10 +564,71 @@ static void emit_task_func_port_defs(ivl_scope_t scope)
       for (idx = start; idx < count; idx += 1) {
 	    ivl_signal_t port = ivl_scope_port(scope, idx);
 	    emit_port(port);
+      }
+	/* If the start and count are both 1 then this is a SystemVerilog
+	 * function that does not have an argument so add a dummy one. */
+      if ((start == 1) && (count == 1)) {
+	    fprintf(vlog_out, "%*cinput _vlog95_dummy;", indent, ' ');
+	    if (emit_file_line) fprintf(vlog_out, " /* no file/line */");
+	    fprintf(vlog_out, "\n");
       }
       if (count) fprintf(vlog_out, "\n");
 }
 
+/*
+ * Recursively look for the named block in the given statement.
+ */
+static int has_named_block(ivl_scope_t scope, ivl_statement_t stmt)
+{
+      unsigned idx, count;
+      int rtn = 0;
+      if (! stmt) return 0;
+      switch (ivl_statement_type(stmt)) {
+	  /* Block or fork items can contain a named block. */
+	case IVL_ST_BLOCK:
+	case IVL_ST_FORK:
+	case IVL_ST_FORK_JOIN_ANY:
+	case IVL_ST_FORK_JOIN_NONE:
+	    if (ivl_stmt_block_scope(stmt) == scope) return 1;
+	    count = ivl_stmt_block_count(stmt);
+	    for (idx = 0; (idx < count) && ! rtn ; idx += 1) {
+		  rtn |= has_named_block(scope,
+		                         ivl_stmt_block_stmt(stmt, idx));
+	    }
+	    break;
+	  /* Case items can contain a named block. */
+	case IVL_ST_CASE:
+	case IVL_ST_CASER:
+	case IVL_ST_CASEX:
+	case IVL_ST_CASEZ:
+	    count = ivl_stmt_case_count(stmt);
+	    for (idx = 0; (idx < count) && ! rtn; idx += 1) {
+		  rtn |= has_named_block(scope,
+		                         ivl_stmt_case_stmt(stmt, idx));
+	    }
+	    break;
+	  /* Either the true or false clause may have a named block. */
+	case IVL_ST_CONDIT:
+	    rtn = has_named_block(scope, ivl_stmt_cond_true(stmt));
+	    if (! rtn) {
+		  rtn = has_named_block(scope, ivl_stmt_cond_false(stmt));
+	    }
+	    break;
+	  /* The looping statements may have a named block. */
+	case IVL_ST_FOREVER:
+	case IVL_ST_REPEAT:
+	case IVL_ST_WHILE:
+	  /* The delay and wait statements may have a named block. */
+	case IVL_ST_DELAY:
+	case IVL_ST_DELAYX:
+	case IVL_ST_WAIT:
+	    rtn = has_named_block(scope, ivl_stmt_sub_stmt(stmt));
+	    break;
+	default: /* The rest cannot have a named block. */ ;
+      }
+      return rtn;
+}
+
 /*
  * Look at all the processes to see if we can find one with the expected
  * scope. If we don't find one then we can assume the block only has
@@ -575,14 +636,7 @@ static void emit_task_func_port_defs(ivl_scope_t scope)
  */
 static int no_stmts_in_process(ivl_process_t proc, ivl_scope_t scope)
 {
-      ivl_statement_t stmt = ivl_process_stmt(proc);
-      switch (ivl_statement_type(stmt)) {
-	case IVL_ST_BLOCK:
-	case IVL_ST_FORK:
-	    if (ivl_stmt_block_scope(stmt) == scope) return 1;
-	default: /* Do nothing. */ ;
-      }
-      return 0;
+      return has_named_block(scope, ivl_process_stmt(proc));
 }
 
 /*
@@ -985,9 +1039,9 @@ int emit_scope(ivl_scope_t scope, ivl_scope_t parent)
 	case IVL_SCT_FUNCTION:
 	    assert(indent != 0);
 	    fprintf(vlog_out, "\n%*cfunction", indent, ' ');
-	    if (ivl_scope_ports(scope) < 2) {
+	    if (ivl_scope_ports(scope) < 1) {
 		  fprintf(stderr, "%s:%u: vlog95 error: Function (%s) has "
-		                  "no arguments (or return value).\n",
+		                  "no return value.\n",
 		                  ivl_scope_file(scope),
 		                  ivl_scope_lineno(scope),
 		                  ivl_scope_tname(scope));