From 376f14b5933e91d08ade6a503fdd657a6e01a149 Mon Sep 17 00:00:00 2001
From: Max <tchristy001@outlook.com>
Date: Wed, 24 Nov 2021 12:16:23 -0600
Subject: [PATCH] add option to enable rtti, set default to current behavior

---
 CMakeLists.txt | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6eef485c..aefd35bc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -53,8 +53,10 @@ if(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
   add_definitions(-D_HAS_EXCEPTIONS=0)
 
   # Disable RTTI.
-  string(REGEX REPLACE "/GR" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /GR-")
+  if(NOT SNAPPY_ENABLE_RTTI)
+    string(REGEX REPLACE "/GR" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /GR-")
+  endif(SNAPPY_ENABLE_RTTI)
 else(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
   # Use -Wall for clang and gcc.
   if(NOT CMAKE_CXX_FLAGS MATCHES "-Wall")
@@ -78,8 +80,10 @@ else(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-exceptions")
 
   # Disable RTTI.
-  string(REGEX REPLACE "-frtti" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-rtti")
+  if(NOT SNAPPY_ENABLE_RTTI)
+    string(REGEX REPLACE "-frtti" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-rtti")
+  endif(SNAPPY_ENABLE_RTTI)
 endif(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
 
 # BUILD_SHARED_LIBS is a standard CMake variable, but we declare it here to make
@@ -98,6 +102,8 @@ option(SNAPPY_REQUIRE_AVX2 "Target processors with AVX2 support." OFF)
 
 option(SNAPPY_INSTALL "Install Snappy's header and library" ON)
 
+option(SNAPPY_ENABLE_RTTI "Enable RTTI for Snappy's library" OFF)
+
 include(TestBigEndian)
 test_big_endian(SNAPPY_IS_BIG_ENDIAN)