From df187c44065fbd36b151424abcaf15ddc2e24266 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fabian=20Ke=C3=9Fler-Schulz?= <fabian_kessler@gmx.de>
Date: Tue, 23 Sep 2025 20:25:25 +0200
Subject: [PATCH] Fix Windows compilation of Verilator with spaces in the path
 (#6477)

---
 CMakeLists.txt    |  7 ++++++-
 docs/CONTRIBUTORS |  2 +-
 src/bisonpre      | 39 ++++++++++++++++++++-------------------
 3 files changed, 27 insertions(+), 21 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 596401d29..0269ca85b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -49,8 +49,13 @@ if(WIN32)
     if(DEFINED ENV{WIN_FLEX_BISON})
         set(WIN_FLEX_BISON "$ENV{WIN_FLEX_BISON}")
     endif()
-    if(EXISTS ${WIN_FLEX_BISON})
+    if(IS_DIRECTORY ${WIN_FLEX_BISON})
         list(APPEND CMAKE_PREFIX_PATH ${WIN_FLEX_BISON})
+    else()
+        message(
+            FATAL_ERROR
+            "The path specified by WIN_FLEX_BISON environment variable is not an existing folder: ${WIN_FLEX_BISON}"
+        )
     endif()
     if(NOT WIN_FLEX_BISON)
         message(
diff --git a/docs/CONTRIBUTORS b/docs/CONTRIBUTORS
index 4a0851e62..3450e2e21 100644
--- a/docs/CONTRIBUTORS
+++ b/docs/CONTRIBUTORS
@@ -58,7 +58,7 @@ Eric Müller
 Eric Rippey
 Ethan Sifferman
 Eyck Jentzsch
-Fabian Keßler
+Fabian Keßler-Schulz
 Fan Shupei
 Felix Neumärker
 Felix Yan
diff --git a/src/bisonpre b/src/bisonpre
index 3830c972d..e14b8170b 100755
--- a/src/bisonpre
+++ b/src/bisonpre
@@ -23,25 +23,26 @@ def process():
     clean_input(Args.input, tmp_prefix() + ".y")
 
     # Run bison
-    command = (
-        Args.yacc  #
-        + (" -t" if Args.debug else "")  #
-        + (" -d" if Args.definitions else "")  #
-        + (" -k" if Args.token_table else "")  #
-        + (" -v" if Args.verbose else "")  #
-        + (" -Wcounterexamples" if Args.Wcounterexamples else "")  #
-        + (" --report=itemset --report=lookahead" if (Args.verbose and supports_report) else "")
-        # Useful but slow:
-        # (" -Wcounterexamples" if
-        # (Args.verbose and supports_counter_examples) else "")
-        #
-        # -p required for GLR parsers; they write to -p basename, not -o
-        + ((" -p " + Args.name_prefix) if Args.name_prefix else "") + " -b " + tmp_prefix()  #
-        + " -o " + tmp_prefix() + ".c"  #
-        + " " + tmp_prefix() + ".y")
+    prefix = tmp_prefix()
+    command = [
+        Args.yacc,
+        *(["-t"] if Args.debug else []),
+        *(["-d"] if Args.definitions else []),
+        *(["-k"] if Args.token_table else []),
+        *(["-v"] if Args.verbose else []),
+        *(["-Wcounterexamples"] if Args.Wcounterexamples else []),
+        *(["--report=itemset", "--report=lookahead"] if
+          (Args.verbose and supports_report) else []),
+        *(["-p", Args.name_prefix] if Args.name_prefix else []),
+        "-b",
+        prefix,
+        "-o",
+        f"{prefix}.c",
+        f"{prefix}.y",
+    ]
 
-    print("  " + command)
-    status = subprocess.call(command, shell=True)
+    print(f"Executing: {subprocess.list2cmdline(command)}", flush=True)
+    status = subprocess.call(command)
     if status != 0:
         unlink_outputs()
         sys.exit("bisonpre: %Error: " + Args.yacc + " version " + str(Bison_Version) +
@@ -87,7 +88,7 @@ def unlink_outputs():
 
 
 def bison_version_check():
-    with subprocess.Popen(Args.yacc + " --version", shell=True, stdout=subprocess.PIPE) as sp:
+    with subprocess.Popen([Args.yacc, "--version"], stdout=subprocess.PIPE) as sp:
         out = str(sp.stdout.read())
     match = re.search(r'([0-9]+\.[0-9]+)', out)
     if match: