From cd2d4e92873a8133097326829b6ab2bbf4d21608 Mon Sep 17 00:00:00 2001
From: Martin Whitaker <icarus@martin-whitaker.me.uk>
Date: Sat, 3 Feb 2024 14:06:40 +0000
Subject: [PATCH] Improve error messages when multiple drivers are detected.

Distinguish between nets declared as uwires and variables.
---
 elab_net.cc                                  | 8 ++++++--
 ivtest/gold/br_gh1087a2-iverilog-stderr.gold | 2 +-
 ivtest/gold/br_gh1087b-iverilog-stderr.gold  | 2 +-
 ivtest/gold/uwire_fail.gold                  | 2 +-
 4 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/elab_net.cc b/elab_net.cc
index 991b38fc4..ab7a89642 100644
--- a/elab_net.cc
+++ b/elab_net.cc
@@ -876,8 +876,12 @@ NetNet* PEIdent::elaborate_lnet_common_(Design*des, NetScope*scope,
 	    long wcount = widx_flag ? 1 : sig->pin_count();
 	    for (long idx = 0; idx < wcount; idx += 1) {
 		  if (sig->test_and_set_part_driver(midx, lidx, widx + idx)) {
-			cerr << get_fileline() << ": error: Unresolved net/uwire "
-			     << sig->name() << " cannot have multiple drivers." << endl;
+			cerr << get_fileline() << ": error: ";
+			if (sig->coerced_to_uwire())
+			      cerr << "Variable '";
+			else
+			      cerr << "Unresolved wire '";
+			cerr << sig->name() << "' cannot have multiple drivers." << endl;
 			if (debug_elaborate) {
 			      cerr << get_fileline() << ":	: Overlap in "
 				   << "[" << midx << ":" << lidx << "] (canonical)"
diff --git a/ivtest/gold/br_gh1087a2-iverilog-stderr.gold b/ivtest/gold/br_gh1087a2-iverilog-stderr.gold
index 816d398aa..10c4437c8 100644
--- a/ivtest/gold/br_gh1087a2-iverilog-stderr.gold
+++ b/ivtest/gold/br_gh1087a2-iverilog-stderr.gold
@@ -1,2 +1,2 @@
-ivltests/br_gh1087a.v:6: error: Unresolved net/uwire r cannot have multiple drivers.
+ivltests/br_gh1087a.v:6: error: Unresolved wire 'r' cannot have multiple drivers.
 1 error(s) during elaboration.
diff --git a/ivtest/gold/br_gh1087b-iverilog-stderr.gold b/ivtest/gold/br_gh1087b-iverilog-stderr.gold
index 1d1843f32..6eb1286ea 100644
--- a/ivtest/gold/br_gh1087b-iverilog-stderr.gold
+++ b/ivtest/gold/br_gh1087b-iverilog-stderr.gold
@@ -1,2 +1,2 @@
-ivltests/br_gh1087b.v:6: error: Unresolved net/uwire b cannot have multiple drivers.
+ivltests/br_gh1087b.v:6: error: Unresolved wire 'b' cannot have multiple drivers.
 1 error(s) during elaboration.
diff --git a/ivtest/gold/uwire_fail.gold b/ivtest/gold/uwire_fail.gold
index 3d0474a9f..2dc9c032a 100644
--- a/ivtest/gold/uwire_fail.gold
+++ b/ivtest/gold/uwire_fail.gold
@@ -1,2 +1,2 @@
-./ivltests/uwire_fail.v:5: error: Unresolved net/uwire two cannot have multiple drivers.
+./ivltests/uwire_fail.v:5: error: Unresolved wire 'two' cannot have multiple drivers.
 1 error(s) during elaboration.