From cd0b360575ca0aebf6fd6487764e633aa8e510a5 Mon Sep 17 00:00:00 2001
From: Martin Whitaker <icarus@martin-whitaker.me.uk>
Date: Tue, 20 Dec 2022 17:30:57 +0000
Subject: [PATCH] Support free-form `default_net_type directives.

---
 ivtest/ivltests/br_gh782f.v | 19 +++++++++++++++++++
 ivtest/regress-vlg.list     |  1 +
 lexor.lex                   | 27 ++++++++++++++++-----------
 3 files changed, 36 insertions(+), 11 deletions(-)
 create mode 100644 ivtest/ivltests/br_gh782f.v

diff --git a/ivtest/ivltests/br_gh782f.v b/ivtest/ivltests/br_gh782f.v
new file mode 100644
index 000000000..b33b10c2d
--- /dev/null
+++ b/ivtest/ivltests/br_gh782f.v
@@ -0,0 +1,19 @@
+// This is just a syntax test.
+
+/* comment */ `default_nettype /* comment */ // comment
+/* comment */ wire /* comment */ // comment
+module m1;
+endmodule
+
+/* comment */`default_nettype/*
+   comment */
+/* comment */tri0/*
+   comment */
+module m2;
+endmodule
+
+module test;
+
+initial $display("PASSED");
+
+endmodule
diff --git a/ivtest/regress-vlg.list b/ivtest/regress-vlg.list
index 57f4c21fa..ef165b190 100644
--- a/ivtest/regress-vlg.list
+++ b/ivtest/regress-vlg.list
@@ -352,6 +352,7 @@ br_gh732		normal			ivltests gold=br_gh732.gold
 br_gh782c		normal			ivltests
 br_gh782d		normal			ivltests
 br_gh782e		normal			ivltests
+br_gh782f		normal			ivltests
 br_gh788		normal,-gno-io-range-error,-Wno-anachronisms	ivltests gold=br_gh788.gold
 br_gh793		normal			ivltests
 br_ml20150315		normal			ivltests gold=br_ml_20150315.gold
diff --git a/lexor.lex b/lexor.lex
index cad2d6350..74e3ca983 100644
--- a/lexor.lex
+++ b/lexor.lex
@@ -152,6 +152,7 @@ void lex_in_package_scope(PPackage*pkg)
 %x PPUCDRIVE
 %x PPUCDRIVE_ERROR
 %x PPDEFAULT_NETTYPE
+%x PPDEFAULT_NETTYPE_ERROR
 %x PPBEGIN_KEYWORDS
 %x PPBEGIN_KEYWORDS_ERROR
 %s EDGES
@@ -785,16 +786,12 @@ TU [munpf]
       }
  }
 
-  /* Notice and handle the default_nettype directive. The lexor
-     detects the default_nettype keyword, and the second part of the
-     rule collects the rest of the line and processes it. We only need
-     to look for the first work, and interpret it. */
+  /* Notice and handle the `default_nettype directive. */
 
-`default_nettype{W}? { BEGIN(PPDEFAULT_NETTYPE); }
-<PPDEFAULT_NETTYPE>.* {
+`default_nettype { BEGIN(PPDEFAULT_NETTYPE); }
+
+<PPDEFAULT_NETTYPE>[a-zA-Z0-9_]+ {
       NetNet::Type net_type;
-      size_t wordlen = strcspn(yytext, " \t\f\r\n");
-      yytext[wordlen] = 0;
   /* Add support for other wire types and better error detection. */
       if (strcmp(yytext,"wire") == 0) {
 	    net_type = NetNet::WIRE;
@@ -832,11 +829,19 @@ TU [munpf]
 	    error_count += 1;
       }
       pform_set_default_nettype(net_type, yylloc.text, yylloc.first_line);
+      BEGIN(0);
   }
-<PPDEFAULT_NETTYPE>\n {
-      yylloc.first_line += 1;
-      BEGIN(0); }
 
+<PPDEFAULT_NETTYPE>"//" { comment_enter = PPDEFAULT_NETTYPE; BEGIN(LCOMMENT); }
+<PPDEFAULT_NETTYPE>"/*" { comment_enter = PPDEFAULT_NETTYPE; BEGIN(CCOMMENT); }
+<PPDEFAULT_NETTYPE>"\n" { yylloc.first_line += 1; }
+<PPDEFAULT_NETTYPE>{W}  { ; }
+<PPDEFAULT_NETTYPE>.    { BEGIN(PPDEFAULT_NETTYPE_ERROR); }
+
+  /* On error, try to recover by skipping to the end of the line. */
+<PPDEFAULT_NETTYPE_ERROR>[^\n]+ {
+      VLerror(yylloc, "error: Invalid `default_nettype directive.");
+      BEGIN(0); }
 
   /* These are directives that are not supported by me and should have
      been handled by an external preprocessor such as ivlpp. */