From c58df87c27e3689991e27ab64d09d6e55233705b Mon Sep 17 00:00:00 2001
From: Tracy Narine <76846523+tmnarine@users.noreply.github.com>
Date: Tue, 24 Mar 2026 14:30:15 -0400
Subject: [PATCH] Fix MacOs lexer compile error (#7314) (#7315)

---
 docs/CONTRIBUTORS |  1 +
 src/flexfix       | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/docs/CONTRIBUTORS b/docs/CONTRIBUTORS
index 1e1e2b3e5..ab4f4526b 100644
--- a/docs/CONTRIBUTORS
+++ b/docs/CONTRIBUTORS
@@ -256,6 +256,7 @@ Tom Manner
 Tomasz Gorochowik
 Topa Topino
 Toru Niina
+Tracy Narine
 Trung Nguyen
 Tudor Timi
 Tymoteusz Blazejczyk
diff --git a/src/flexfix b/src/flexfix
index 3a4479bdd..307ddee3d 100755
--- a/src/flexfix
+++ b/src/flexfix
@@ -14,6 +14,7 @@
 
 import re
 import sys
+import platform
 
 for line in sys.stdin:
     # Fix flex 2.6.1 warning
@@ -47,5 +48,14 @@ for line in sys.stdin:
     line = re.sub(r'(#line \d+ ".*)_pretmp', r'\1', line)
     # Fix 'register' storage class specifier is deprecated and incompatible with C++17
     line = re.sub(r'register ', '', line)
+    # Change int to size_t on LexerInput/LexerOutput when using macOS Tahoe
+    if platform.system() == "Darwin":
+        try:
+            osv = platform.mac_ver()[0] # Example "26.2"
+            if len(osv) > 2 and osv[2] == "." and int(osv[:2]) >= 26:
+                if "::LexerInput(" in line or "::LexerOutput(" in line:
+                    line = re.sub(r'int ', r'size_t ', line)
+        except IndexError as e:
+            print(f"Unexpected index error {e}")
 
     print(line, end='')