From eca8714de776b963f2edfbd9b51557966885f9ca Mon Sep 17 00:00:00 2001
From: Zachary Snow <zach@zachjs.com>
Date: Tue, 7 Mar 2023 23:52:43 -0500
Subject: [PATCH] skip start of block before looking for its end

---
 CHANGELOG.md                                    | 3 +++
 src/Language/SystemVerilog/Parser/Preprocess.hs | 5 ++++-
 test/lex/block_comment.sv                       | 7 +++++++
 test/lex/block_comment.v                        | 3 +++
 4 files changed, 17 insertions(+), 1 deletion(-)
 create mode 100644 test/lex/block_comment.sv
 create mode 100644 test/lex/block_comment.v

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 208b3ac..de6ac44 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,9 @@
   static prefixes, which could cause deep recursion and run out of memory on
   some designs
 * Fixed unneeded scoping of constant function calls used in type lookups
+* `/*/` is no longer interpreted as a self-closing block comment, e.g.,
+  `$display("a"/*/,"b"/* */);` previously printed "ab", but now prints "a"
+
 
 ### New Features
 
diff --git a/src/Language/SystemVerilog/Parser/Preprocess.hs b/src/Language/SystemVerilog/Parser/Preprocess.hs
index 0b0fb4e..d42eed0 100644
--- a/src/Language/SystemVerilog/Parser/Preprocess.hs
+++ b/src/Language/SystemVerilog/Parser/Preprocess.hs
@@ -545,7 +545,10 @@ preprocessInput = do
     macroStack <- getMacroStack
     case str of
         '/' : '/' : _ -> removeThrough "\n"
-        '/' : '*' : _ -> removeThrough "*/"
+        '/' : '*' : _ ->
+            -- prevent treating `/*/` as self-closing
+            takeChar >> takeChar >>
+            removeThrough "*/"
         '`' : '"' : _ -> handleBacktickString
         '"' : _ -> handleString
         '/' : '`' : '`' : '*' : _ ->
diff --git a/test/lex/block_comment.sv b/test/lex/block_comment.sv
new file mode 100644
index 0000000..16bf1ce
--- /dev/null
+++ b/test/lex/block_comment.sv
@@ -0,0 +1,7 @@
+module top;
+    /*test*/
+    /*/test*/
+    /*test/*/
+    /*/test/*/
+    initial $display("foo"/*/,"bar"/*/);
+endmodule
diff --git a/test/lex/block_comment.v b/test/lex/block_comment.v
new file mode 100644
index 0000000..61c19cf
--- /dev/null
+++ b/test/lex/block_comment.v
@@ -0,0 +1,3 @@
+module top;
+    initial $display("foo");
+endmodule