GH-43688: [C++] Prevent Snappy from disabling RTTI when bundled (#43706)

### Rationale for this change Snappy's CMakeLists.txt unconditionally disables RTTI. This is incompatible with some other options, such as activating UBSAN for a fuzzing build: google/snappy#189 ### What changes are included in this PR? Add `-frtti` at the end of compiler options when compiling a bundled Snappy build. ### Are these changes tested? On CI; also manually checked that this allows enabling Snappy on OSS-Fuzz builds. ### Are there any user-facing changes? No. * GitHub Issue: #43688 Lead-authored-by: Antoine Pitrou <[email protected]> Co-authored-by: Antoine Pitrou <[email protected]> Co-authored-by: Sutou Kouhei <[email protected]> Co-authored-by: Sutou Kouhei <[email protected]> Signed-off-by: Sutou Kouhei <[email protected]>
apache · Aug 16, 2024 · a970fd7 · a970fd7
1 parent a50ad42
commit a970fd7
Showing 1 changed file with 15 additions and 7 deletions.
diff --git a/cpp/cmake_modules/ThirdpartyToolchain.cmake b/cpp/cmake_modules/ThirdpartyToolchain.cmake
@@ -1355,16 +1355,24 @@ macro(build_snappy)
       "-DCMAKE_INSTALL_PREFIX=${SNAPPY_PREFIX}")
   # Snappy unconditionally enables -Werror when building with clang this can lead
   # to build failures by way of new compiler warnings. This adds a flag to disable
-  # Werror to the very end of the invocation to override the snappy internal setting.
+  # -Werror to the very end of the invocation to override the snappy internal setting.
+  set(SNAPPY_ADDITIONAL_CXX_FLAGS "")
   if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-    foreach(CONFIG DEBUG MINSIZEREL RELEASE RELWITHDEBINFO)
-      list(APPEND
-           SNAPPY_CMAKE_ARGS
-           "-DCMAKE_CXX_FLAGS_${UPPERCASE_BUILD_TYPE}=${EP_CXX_FLAGS_${CONFIG}} -Wno-error"
-      )
-    endforeach()
+    string(APPEND SNAPPY_ADDITIONAL_CXX_FLAGS " -Wno-error")
+  endif()
+  # Snappy unconditionally disables RTTI, which is incompatible with some other
+  # build settings (https://github.com/apache/arrow/issues/43688).
+  if(NOT MSVC)
+    string(APPEND SNAPPY_ADDITIONAL_CXX_FLAGS " -frtti")
   endif()
 
+  foreach(CONFIG DEBUG MINSIZEREL RELEASE RELWITHDEBINFO)
+    list(APPEND
+         SNAPPY_CMAKE_ARGS
+         "-DCMAKE_CXX_FLAGS_${CONFIG}=${EP_CXX_FLAGS_${CONFIG}} ${SNAPPY_ADDITIONAL_CXX_FLAGS}"
+    )
+  endforeach()
+
   if(APPLE AND CMAKE_HOST_SYSTEM_VERSION VERSION_LESS 20)
     # On macOS 10.13 we need to explicitly add <functional> to avoid a missing include error
     # This can be removed once CRAN no longer checks on macOS 10.13