From b4967b3297d8583298cd72b8d40cb747b48d0e31 Mon Sep 17 00:00:00 2001
From: Daniel Hajjar <daniel.hajjar16@gmail.com>
Date: Tue, 30 Dec 2025 16:37:23 +0100
Subject: [PATCH] Add support for length attribute

---
 src/vhd2vl.l |  1 +
 src/vhd2vl.y | 18 +++++++++++++++++-
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/vhd2vl.l b/src/vhd2vl.l
index aaac366..55d2703 100644
--- a/src/vhd2vl.l
+++ b/src/vhd2vl.l
@@ -88,6 +88,7 @@ int scan_int(char *s);
 "in"                              { return IN; }
 "inout"                           { return INOUT; }
 "is"                              { return IS; }
+"length"                          { return LENGTH; }
 "library ".*\n                    { lineno++; }
 "loop"                            { return LOOP; }
 "map"                             { return MAP; }
diff --git a/src/vhd2vl.y b/src/vhd2vl.y
index 159c9b1..b32256e 100644
--- a/src/vhd2vl.y
+++ b/src/vhd2vl.y
@@ -889,7 +889,7 @@ slist *emit_io_list(slist *sl)
 %token <txt> FOR LOOP GENERATE
 %token <txt> AFTER AND OR NAND NOR XOR XNOR MOD RW_REM POW
 %token <txt> LASTVALUE EVENT POSEDGE NEGEDGE
-%token <txt> STRING NAME RANGE NULLV OPEN
+%token <txt> STRING NAME RANGE LENGTH NULLV OPEN
 %token <txt> CONVFUNC_1 CONVFUNC_2 BASED FLOAT LEFT
 %token <txt> SCIENTIFIC REAL
 %token <txt> ASSERT REPORT SEVERITY WARNING ERROR FAILURE NOTE
@@ -2465,6 +2465,22 @@ expr : signal {
        /* two argument type conversion e.g. to_unsigned(x, 3) */
        $$ = addnest($3);
       }
+     | NAME '\'' LENGTH {
+      /* lookup NAME and copy its length */
+      sglist *sg = NULL;
+        if ((sg=lookup(io_list,$1))==NULL) {
+          sg=lookup(sig_list,$1);
+        }
+        if(sg) {
+          expdata *e=xmalloc(sizeof(expdata));
+            e->op='t'; /* Terminal symbol */
+            e->sl=addval(NULL,sg->range->sizeval);
+            $$ = e;
+        } else {
+          fprintf(stderr,"ERROR (line %d): undefined length \"%s'length\".\n", lineno, $1);
+          YYABORT;
+        }
+      }
      | '(' expr ')' {
        $$ = addnest($2);
       }