Build fails with LTO: ODR and lto-type-mismatch issues.

[eli-schwartz]

What version of gRPC and what language are you using?

1.51.0 via the python bindings.

What operating system (Linux, Windows,...) and version?

Gentoo Linux (rolling release)

What runtime / compiler are you using (e.g. python version or version of gcc)

gcc (Gentoo 13.2.1_p20240210 p14) 13.2.1 20240210

What did you do?

I tried to build the python grpcio module with LTO.

Add the following to *FLAGS: -flto=4 -Werror=odr -Werror=lto-type-mismatch -Werror=strict-aliasing

Note the -Werror=* flags are used to help detect cases where the compiler tries to optimize by assuming UB cannot exist in the source code -- if it does exist, ordinarily the code would be miscompiled, and this says to make the miscompilation a fatal error.

Run: emerge -1 dev-python/grpcio

What did you expect to see?

A successful compilation.

What did you see instead?

2024-03-20 23:23:18,978 root INFO x86_64-pc-linux-gnu-g++ -shared -Wl,-O1 -Wl,--as-needed -flto=4 -Werror=odr -Werror=lto-type-mismatch -Werror=strict-aliasing -Wl,--defsym=__gentoo_check_ldflags__=0 -march=native -fstack-protector-all -O2 -pipe -fdiagnostics-color=always -frecord-gcc-switches -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=3 -fstack-clash-protection -flto=4 -Werror=odr -Werror=lto-type-mismatch -Werror=strict-aliasing -Wformat -Werror=format-security -Werror=implicit-function-declaration -Werror=implicit-int -Werror=int-conversion -Werror=incompatible-pointer-types -DNDEBUG /var/tmp/portage/dev-python/grpcio-1.51.0-r1/work/grpcio-1.51.0-python3_11/build/temp.linux-x86_64-cpython-311/src/core/ext/filters/census/grpc_context.o [...] /var/tmp/portage/dev-python/grpcio-1.51.0-r1/work/grpcio-1.51.0-python3_11/build/temp.linux-x86_64-cpython-311/third_party/upb/upb/upb.o -L/usr/lib64 -lrt -lm -lssl -lcrypto -lz -lcares -o /var/tmp/portage/dev-python/grpcio-1.51.0-r1/work/grpcio-1.51.0-python3_11/build/lib.linux-x86_64-cpython-311/grpc/_cython/cygrpc.cpython-311-x86_64-linux-gnu.so -lpthread -static-libgcc
src/core/lib/iomgr/ev_epoll1_linux.cc:146:8: error: type ‘struct grpc_fd’ violates the C++ One Definition Rule [-Werror=odr]
  146 | struct grpc_fd {
      |        ^
src/core/lib/iomgr/ev_poll_posix.cc:77:8: note: a different type is defined in another translation unit
   77 | struct grpc_fd {
      |        ^
src/core/lib/iomgr/ev_epoll1_linux.cc:149:58: note: the first difference of corresponding definitions is field ‘read_closure’
  149 |   grpc_core::ManualConstructor<grpc_core::LockfreeEvent> read_closure;
      |                                                          ^
src/core/lib/iomgr/ev_poll_posix.cc:84:11: note: a field with different name is defined in another translation unit
   84 |   gpr_atm refst;
      |           ^
src/core/lib/iomgr/ev_epoll1_linux.cc:140:8: error: type ‘struct grpc_fork_fd_list’ violates the C++ One Definition Rule [-Werror=odr]
  140 | struct grpc_fork_fd_list {
      |        ^
src/core/lib/iomgr/ev_poll_posix.cc:67:8: note: a different type is defined in another translation unit
   67 | struct grpc_fork_fd_list {
      |        ^
src/core/lib/iomgr/ev_epoll1_linux.cc:142:12: note: the first difference of corresponding definitions is field ‘next’
  142 |   grpc_fd* next;
      |            ^
src/core/lib/iomgr/ev_poll_posix.cc:71:26: note: a field with different name is defined in another translation unit
   71 |   grpc_cached_wakeup_fd* cached_wakeup_fd;
      |                          ^
src/core/lib/iomgr/ev_epoll1_linux.cc:235:8: error: type ‘struct grpc_pollset_set’ violates the C++ One Definition Rule [-Werror=odr]
  235 | struct grpc_pollset_set {
      |        ^
src/core/lib/iomgr/ev_poll_posix.cc:244:8: note: a different type is defined in another translation unit
  244 | struct grpc_pollset_set {
      |        ^
src/core/lib/iomgr/ev_epoll1_linux.cc:236:8: note: the first difference of corresponding definitions is field ‘unused’
  236 |   char unused;
      |        ^
src/core/lib/iomgr/ev_poll_posix.cc:245:10: note: a field with different name is defined in another translation unit
  245 |   gpr_mu mu;
      |          ^
src/core/lib/iomgr/ev_epoll1_linux.cc:182:8: error: type ‘struct grpc_pollset_worker’ violates the C++ One Definition Rule [-Werror=odr]
  182 | struct grpc_pollset_worker {
      |        ^
src/core/lib/iomgr/ev_poll_posix.cc:188:8: note: a different type is defined in another translation unit
  188 | struct grpc_pollset_worker {
      |        ^
src/core/lib/iomgr/ev_epoll1_linux.cc:183:14: note: the first difference of corresponding definitions is field ‘state’
  183 |   kick_state state;
      |              ^
src/core/lib/iomgr/ev_poll_posix.cc:189:26: note: a field with different name is defined in another translation unit
  189 |   grpc_cached_wakeup_fd* wakeup_fd;
      |                          ^
src/core/lib/iomgr/ev_epoll1_linux.cc:210:8: error: type ‘struct grpc_pollset’ violates the C++ One Definition Rule [-Werror=odr]
  210 | struct grpc_pollset {
      |        ^
src/core/lib/iomgr/ev_poll_posix.cc:196:8: note: a different type is defined in another translation unit
  196 | struct grpc_pollset {
      |        ^
src/core/lib/iomgr/ev_epoll1_linux.cc:212:25: note: the first difference of corresponding definitions is field ‘neighborhood’
  212 |   pollset_neighborhood* neighborhood;
      |                         ^
src/core/lib/iomgr/ev_poll_posix.cc:198:23: note: a field with different name is defined in another translation unit
  198 |   grpc_pollset_worker root_worker;
      |                       ^
./src/core/tsi/ssl/session_cache/ssl_session_cache.h:49: error: type ‘struct SslSessionLRUCache’ violates the C++ One Definition Rule [-Werror=odr]
   49 | class SslSessionLRUCache
      | 
./src/core/tsi/ssl/session_cache/ssl_session_cache.h:49: note: a type with the same name but different base type is defined in another translation unit
   49 | class SslSessionLRUCache
      | 
./src/core/lib/gprpp/cpp_impl_of.h:27: note: type name ‘grpc_core::CppImplOf<tsi::SslSessionLRUCache, tsi::tsi_ssl_session_cache>’ should match type name ‘grpc_core::CppImplOf<tsi::SslSessionLRUCache, tsi_ssl_session_cache>’
   27 | class CppImplOf {
      | 
src/core/ext/upb-generated/xds/type/v3/typed_struct.upb.h:25:28: error: type of ‘xds_type_v3_TypedStruct_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   25 | extern const upb_MiniTable xds_type_v3_TypedStruct_msginit;
      |                            ^
src/core/ext/upb-generated/xds/type/v3/typed_struct.upb.c:26:21: note: ‘xds_type_v3_TypedStruct_msginit’ was previously declared here
   26 | const upb_MiniTable xds_type_v3_TypedStruct_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/lookup/v1/rls_config.upb.h:49:28: error: type of ‘grpc_lookup_v1_RouteLookupClusterSpecifier_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   49 | extern const upb_MiniTable grpc_lookup_v1_RouteLookupClusterSpecifier_msginit;
      |                            ^
src/core/ext/upb-generated/src/proto/grpc/lookup/v1/rls_config.upb.c:147:21: note: ‘grpc_lookup_v1_RouteLookupClusterSpecifier_msginit’ was previously declared here
  147 | const upb_MiniTable grpc_lookup_v1_RouteLookupClusterSpecifier_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/gcp/transport_security_common.upb.h:28: error: type of ‘grpc_gcp_RpcProtocolVersions_Version_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   28 | extern const upb_MiniTable grpc_gcp_RpcProtocolVersions_Version_msginit;
      | 
src/core/ext/upb-generated/src/proto/grpc/gcp/transport_security_common.upb.c:36:21: note: ‘grpc_gcp_RpcProtocolVersions_Version_msginit’ was previously declared here
   36 | const upb_MiniTable grpc_gcp_RpcProtocolVersions_Version_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/gcp/handshaker.upb.h:58: error: type of ‘grpc_gcp_HandshakerResp_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   58 | extern const upb_MiniTable grpc_gcp_HandshakerResp_msginit;
      | 
src/core/ext/upb-generated/src/proto/grpc/gcp/handshaker.upb.c:209:21: note: ‘grpc_gcp_HandshakerResp_msginit’ was previously declared here
  209 | const upb_MiniTable grpc_gcp_HandshakerResp_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/gcp/handshaker.upb.h:55: error: type of ‘grpc_gcp_HandshakerReq_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   55 | extern const upb_MiniTable grpc_gcp_HandshakerReq_msginit;
      | 
src/core/ext/upb-generated/src/proto/grpc/gcp/handshaker.upb.c:157:21: note: ‘grpc_gcp_HandshakerReq_msginit’ was previously declared here
  157 | const upb_MiniTable grpc_gcp_HandshakerReq_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/gcp/handshaker.upb.h:54: error: type of ‘grpc_gcp_NextHandshakeMessageReq_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   54 | extern const upb_MiniTable grpc_gcp_NextHandshakeMessageReq_msginit;
      | 
src/core/ext/upb-generated/src/proto/grpc/gcp/handshaker.upb.c:139:21: note: ‘grpc_gcp_NextHandshakeMessageReq_msginit’ was previously declared here
  139 | const upb_MiniTable grpc_gcp_NextHandshakeMessageReq_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/gcp/handshaker.upb.h:52: error: type of ‘grpc_gcp_StartServerHandshakeReq_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   52 | extern const upb_MiniTable grpc_gcp_StartServerHandshakeReq_msginit;
      | 
src/core/ext/upb-generated/src/proto/grpc/gcp/handshaker.upb.c:114:21: note: ‘grpc_gcp_StartServerHandshakeReq_msginit’ was previously declared here
  114 | const upb_MiniTable grpc_gcp_StartServerHandshakeReq_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/gcp/handshaker.upb.h:51: error: type of ‘grpc_gcp_ServerHandshakeParameters_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   51 | extern const upb_MiniTable grpc_gcp_ServerHandshakeParameters_msginit;
      | 
src/core/ext/upb-generated/src/proto/grpc/gcp/handshaker.upb.c:91:21: note: ‘grpc_gcp_ServerHandshakeParameters_msginit’ was previously declared here
   91 | const upb_MiniTable grpc_gcp_ServerHandshakeParameters_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/gcp/handshaker.upb.h:50: error: type of ‘grpc_gcp_StartClientHandshakeReq_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   50 | extern const upb_MiniTable grpc_gcp_StartClientHandshakeReq_msginit;
      | 
src/core/ext/upb-generated/src/proto/grpc/gcp/handshaker.upb.c:76:21: note: ‘grpc_gcp_StartClientHandshakeReq_msginit’ was previously declared here
   76 | const upb_MiniTable grpc_gcp_StartClientHandshakeReq_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/gcp/handshaker.upb.h:48: error: type of ‘grpc_gcp_Identity_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   48 | extern const upb_MiniTable grpc_gcp_Identity_msginit;
      | 
src/core/ext/upb-generated/src/proto/grpc/gcp/handshaker.upb.c:38:21: note: ‘grpc_gcp_Identity_msginit’ was previously declared here
   38 | const upb_MiniTable grpc_gcp_Identity_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/gcp/handshaker.upb.h:60: error: type of ‘grpc_gcp_RpcProtocolVersions_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   60 | extern const upb_MiniTable grpc_gcp_RpcProtocolVersions_msginit;
      | 
src/core/ext/upb-generated/src/proto/grpc/gcp/transport_security_common.upb.c:25:21: note: ‘grpc_gcp_RpcProtocolVersions_msginit’ was previously declared here
   25 | const upb_MiniTable grpc_gcp_RpcProtocolVersions_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/gcp/altscontext.upb.h:27: error: type of ‘grpc_gcp_AltsContext_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   27 | extern const upb_MiniTable grpc_gcp_AltsContext_msginit;
      | 
src/core/ext/upb-generated/src/proto/grpc/gcp/altscontext.upb.c:31:21: note: ‘grpc_gcp_AltsContext_msginit’ was previously declared here
   31 | const upb_MiniTable grpc_gcp_AltsContext_msginit = {
      |                     ^
src/core/ext/upb-generated/google/protobuf/struct.upb.h:34:28: error: type of ‘google_protobuf_ListValue_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   34 | extern const upb_MiniTable google_protobuf_ListValue_msginit;
      |                            ^
src/core/ext/upb-generated/google/protobuf/struct.upb.c:72:21: note: ‘google_protobuf_ListValue_msginit’ was previously declared here
   72 | const upb_MiniTable google_protobuf_ListValue_msginit = {
      |                     ^
src/core/ext/upb-generated/google/protobuf/struct.upb.h:33:28: error: type of ‘google_protobuf_Value_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   33 | extern const upb_MiniTable google_protobuf_Value_msginit;
      |                            ^
src/core/ext/upb-generated/google/protobuf/struct.upb.c:58:21: note: ‘google_protobuf_Value_msginit’ was previously declared here
   58 | const upb_MiniTable google_protobuf_Value_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/service/status/v3/csds.upb.h:36:28: error: type of ‘envoy_service_status_v3_ClientConfig_GenericXdsConfig_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   36 | extern const upb_MiniTable envoy_service_status_v3_ClientConfig_GenericXdsConfig_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/service/status/v3/csds.upb.c:100:21: note: ‘envoy_service_status_v3_ClientConfig_GenericXdsConfig_msginit’ was previously declared here
  100 | const upb_MiniTable envoy_service_status_v3_ClientConfig_GenericXdsConfig_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/service/status/v3/csds.upb.h:35:28: error: type of ‘envoy_service_status_v3_ClientConfig_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   35 | extern const upb_MiniTable envoy_service_status_v3_ClientConfig_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/service/status/v3/csds.upb.c:76:21: note: ‘envoy_service_status_v3_ClientConfig_msginit’ was previously declared here
   76 | const upb_MiniTable envoy_service_status_v3_ClientConfig_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/service/load_stats/v3/lrs.upb.h:28:28: error: type of ‘envoy_service_load_stats_v3_LoadStatsResponse_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   28 | extern const upb_MiniTable envoy_service_load_stats_v3_LoadStatsResponse_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/service/load_stats/v3/lrs.upb.c:47:21: note: ‘envoy_service_load_stats_v3_LoadStatsResponse_msginit’ was previously declared here
   47 | const upb_MiniTable envoy_service_load_stats_v3_LoadStatsResponse_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/service/load_stats/v3/lrs.upb.h:27:28: error: type of ‘envoy_service_load_stats_v3_LoadStatsRequest_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   27 | extern const upb_MiniTable envoy_service_load_stats_v3_LoadStatsRequest_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/service/load_stats/v3/lrs.upb.c:30:21: note: ‘envoy_service_load_stats_v3_LoadStatsRequest_msginit’ was previously declared here
   30 | const upb_MiniTable envoy_service_load_stats_v3_LoadStatsRequest_msginit = {
      |                     ^
src/core/ext/upb-generated/google/rpc/status.upb.h:25:28: error: type of ‘google_rpc_Status_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   25 | extern const upb_MiniTable google_rpc_Status_msginit;
      |                            ^
src/core/ext/upb-generated/google/rpc/status.upb.c:26:21: note: ‘google_rpc_Status_msginit’ was previously declared here
   26 | const upb_MiniTable google_rpc_Status_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/service/discovery/v3/discovery.upb.h:63:28: error: type of ‘envoy_service_discovery_v3_Resource_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   63 | extern const upb_MiniTable envoy_service_discovery_v3_Resource_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/service/discovery/v3/discovery.upb.c:237:21: note: ‘envoy_service_discovery_v3_Resource_msginit’ was previously declared here
  237 | const upb_MiniTable envoy_service_discovery_v3_Resource_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/service/discovery/v3/discovery.upb.h:55:28: error: type of ‘envoy_service_discovery_v3_DiscoveryResponse_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   55 | extern const upb_MiniTable envoy_service_discovery_v3_DiscoveryResponse_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/service/discovery/v3/discovery.upb.c:99:21: note: ‘envoy_service_discovery_v3_DiscoveryResponse_msginit’ was previously declared here
   99 | const upb_MiniTable envoy_service_discovery_v3_DiscoveryResponse_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/service/discovery/v3/discovery.upb.h:54:28: error: type of ‘envoy_service_discovery_v3_DiscoveryRequest_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   54 | extern const upb_MiniTable envoy_service_discovery_v3_DiscoveryRequest_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/service/discovery/v3/discovery.upb.c:79:21: note: ‘envoy_service_discovery_v3_DiscoveryRequest_msginit’ was previously declared here
   79 | const upb_MiniTable envoy_service_discovery_v3_DiscoveryRequest_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/extensions/transport_sockets/tls/v3/tls.upb.h:38:28: error: type of ‘envoy_extensions_transport_sockets_tls_v3_DownstreamTlsContext_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   38 | extern const upb_MiniTable envoy_extensions_transport_sockets_tls_v3_DownstreamTlsContext_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/extensions/transport_sockets/tls/v3/tls.upb.c:63:21: note: ‘envoy_extensions_transport_sockets_tls_v3_DownstreamTlsContext_msginit’ was previously declared here
   63 | const upb_MiniTable envoy_extensions_transport_sockets_tls_v3_DownstreamTlsContext_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/extensions/transport_sockets/tls/v3/tls.upb.h:37:28: error: type of ‘envoy_extensions_transport_sockets_tls_v3_UpstreamTlsContext_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   37 | extern const upb_MiniTable envoy_extensions_transport_sockets_tls_v3_UpstreamTlsContext_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/extensions/transport_sockets/tls/v3/tls.upb.c:37:21: note: ‘envoy_extensions_transport_sockets_tls_v3_UpstreamTlsContext_msginit’ was previously declared here
   37 | const upb_MiniTable envoy_extensions_transport_sockets_tls_v3_UpstreamTlsContext_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/extensions/load_balancing_policies/wrr_locality/v3/wrr_locality.upb.h:25:28: error: type of ‘envoy_extensions_load_balancing_policies_wrr_locality_v3_WrrLocality_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   25 | extern const upb_MiniTable envoy_extensions_load_balancing_policies_wrr_locality_v3_WrrLocality_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/extensions/load_balancing_policies/wrr_locality/v3/wrr_locality.upb.c:26:21: note: ‘envoy_extensions_load_balancing_policies_wrr_locality_v3_WrrLocality_msginit’ was previously declared here
   26 | const upb_MiniTable envoy_extensions_load_balancing_policies_wrr_locality_v3_WrrLocality_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/extensions/load_balancing_policies/ring_hash/v3/ring_hash.upb.h:25:28: error: type of ‘envoy_extensions_load_balancing_policies_ring_hash_v3_RingHash_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   25 | extern const upb_MiniTable envoy_extensions_load_balancing_policies_ring_hash_v3_RingHash_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/extensions/load_balancing_policies/ring_hash/v3/ring_hash.upb.c:32:21: note: ‘envoy_extensions_load_balancing_policies_ring_hash_v3_RingHash_msginit’ was previously declared here
   32 | const upb_MiniTable envoy_extensions_load_balancing_policies_ring_hash_v3_RingHash_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/extensions/filters/network/http_connection_manager/v3/http_connection_manager.upb.h:63:28: error: type of ‘envoy_extensions_filters_network_http_connection_manager_v3_HttpConnectionManager_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   63 | extern const upb_MiniTable envoy_extensions_filters_network_http_connection_manager_v3_HttpConnectionManager_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/extensions/filters/network/http_connection_manager/v3/http_connection_manager.upb.c:121:21: note: ‘envoy_extensions_filters_network_http_connection_manager_v3_HttpConnectionManager_msginit’ was previously declared here
  121 | const upb_MiniTable envoy_extensions_filters_network_http_connection_manager_v3_HttpConnectionManager_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/extensions/filters/http/router/v3/router.upb.h:25:28: error: type of ‘envoy_extensions_filters_http_router_v3_Router_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   25 | extern const upb_MiniTable envoy_extensions_filters_http_router_v3_Router_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/extensions/filters/http/router/v3/router.upb.c:35:21: note: ‘envoy_extensions_filters_http_router_v3_Router_msginit’ was previously declared here
   35 | const upb_MiniTable envoy_extensions_filters_http_router_v3_Router_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/extensions/filters/http/rbac/v3/rbac.upb.h:28:28: error: type of ‘envoy_extensions_filters_http_rbac_v3_RBACPerRoute_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   28 | extern const upb_MiniTable envoy_extensions_filters_http_rbac_v3_RBACPerRoute_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/extensions/filters/http/rbac/v3/rbac.upb.c:50:21: note: ‘envoy_extensions_filters_http_rbac_v3_RBACPerRoute_msginit’ was previously declared here
   50 | const upb_MiniTable envoy_extensions_filters_http_rbac_v3_RBACPerRoute_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/extensions/filters/http/rbac/v3/rbac.upb.h:27:28: error: type of ‘envoy_extensions_filters_http_rbac_v3_RBAC_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   27 | extern const upb_MiniTable envoy_extensions_filters_http_rbac_v3_RBAC_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/extensions/filters/http/rbac/v3/rbac.upb.c:36:21: note: ‘envoy_extensions_filters_http_rbac_v3_RBAC_msginit’ was previously declared here
   36 | const upb_MiniTable envoy_extensions_filters_http_rbac_v3_RBAC_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/extensions/filters/http/fault/v3/fault.upb.h:31:28: error: type of ‘envoy_extensions_filters_http_fault_v3_HTTPFault_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   31 | extern const upb_MiniTable envoy_extensions_filters_http_fault_v3_HTTPFault_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/extensions/filters/http/fault/v3/fault.upb.c:72:21: note: ‘envoy_extensions_filters_http_fault_v3_HTTPFault_msginit’ was previously declared here
   72 | const upb_MiniTable envoy_extensions_filters_http_fault_v3_HTTPFault_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/extensions/clusters/aggregate/v3/cluster.upb.h:25:28: error: type of ‘envoy_extensions_clusters_aggregate_v3_ClusterConfig_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   25 | extern const upb_MiniTable envoy_extensions_clusters_aggregate_v3_ClusterConfig_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/extensions/clusters/aggregate/v3/cluster.upb.c:22:21: note: ‘envoy_extensions_clusters_aggregate_v3_ClusterConfig_msginit’ was previously declared here
   22 | const upb_MiniTable envoy_extensions_clusters_aggregate_v3_ClusterConfig_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/config/route/v3/route_components.upb.h:187:28: error: type of ‘envoy_config_route_v3_FilterConfig_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
  187 | extern const upb_MiniTable envoy_config_route_v3_FilterConfig_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/config/route/v3/route_components.upb.c:1022:21: note: ‘envoy_config_route_v3_FilterConfig_msginit’ was previously declared here
 1022 | const upb_MiniTable envoy_config_route_v3_FilterConfig_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/config/route/v3/route.upb.h:27:28: error: type of ‘envoy_config_route_v3_RouteConfiguration_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   27 | extern const upb_MiniTable envoy_config_route_v3_RouteConfiguration_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/config/route/v3/route.upb.c:51:21: note: ‘envoy_config_route_v3_RouteConfiguration_msginit’ was previously declared here
   51 | const upb_MiniTable envoy_config_route_v3_RouteConfiguration_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/config/endpoint/v3/load_report.upb.h:37:28: error: type of ‘envoy_config_endpoint_v3_ClusterStats_DroppedRequests_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   37 | extern const upb_MiniTable envoy_config_endpoint_v3_ClusterStats_DroppedRequests_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/config/endpoint/v3/load_report.upb.c:105:21: note: ‘envoy_config_endpoint_v3_ClusterStats_DroppedRequests_msginit’ was previously declared here
  105 | const upb_MiniTable envoy_config_endpoint_v3_ClusterStats_DroppedRequests_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/service/load_stats/v3/lrs.upb.h:33:28: error: type of ‘envoy_config_endpoint_v3_ClusterStats_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   33 | extern const upb_MiniTable envoy_config_endpoint_v3_ClusterStats_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/config/endpoint/v3/load_report.upb.c:94:21: note: ‘envoy_config_endpoint_v3_ClusterStats_msginit’ was previously declared here
   94 | const upb_MiniTable envoy_config_endpoint_v3_ClusterStats_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/config/endpoint/v3/load_report.upb.h:35:28: error: type of ‘envoy_config_endpoint_v3_EndpointLoadMetricStats_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   35 | extern const upb_MiniTable envoy_config_endpoint_v3_EndpointLoadMetricStats_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/config/endpoint/v3/load_report.upb.c:73:21: note: ‘envoy_config_endpoint_v3_EndpointLoadMetricStats_msginit’ was previously declared here
   73 | const upb_MiniTable envoy_config_endpoint_v3_EndpointLoadMetricStats_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/config/endpoint/v3/load_report.upb.h:33:28: error: type of ‘envoy_config_endpoint_v3_UpstreamLocalityStats_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   33 | extern const upb_MiniTable envoy_config_endpoint_v3_UpstreamLocalityStats_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/config/endpoint/v3/load_report.upb.c:39:21: note: ‘envoy_config_endpoint_v3_UpstreamLocalityStats_msginit’ was previously declared here
   39 | const upb_MiniTable envoy_config_endpoint_v3_UpstreamLocalityStats_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/config/endpoint/v3/endpoint.upb.h:31:28: error: type of ‘envoy_config_endpoint_v3_ClusterLoadAssignment_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   31 | extern const upb_MiniTable envoy_config_endpoint_v3_ClusterLoadAssignment_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/config/endpoint/v3/endpoint.upb.c:35:21: note: ‘envoy_config_endpoint_v3_ClusterLoadAssignment_msginit’ was previously declared here
   35 | const upb_MiniTable envoy_config_endpoint_v3_ClusterLoadAssignment_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/config/cluster/v3/cluster.upb.h:74:28: error: type of ‘envoy_config_cluster_v3_Cluster_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   74 | extern const upb_MiniTable envoy_config_cluster_v3_Cluster_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/config/cluster/v3/cluster.upb.c:148:21: note: ‘envoy_config_cluster_v3_Cluster_msginit’ was previously declared here
  148 | const upb_MiniTable envoy_config_cluster_v3_Cluster_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/config/listener/v3/listener.upb.h:39:28: error: type of ‘envoy_config_listener_v3_Listener_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   39 | extern const upb_MiniTable envoy_config_listener_v3_Listener_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/config/listener/v3/listener.upb.c:121:21: note: ‘envoy_config_listener_v3_Listener_msginit’ was previously declared here
  121 | const upb_MiniTable envoy_config_listener_v3_Listener_msginit = {
      |                     ^
src/core/ext/upb-generated/google/protobuf/struct.upb.h:31:28: error: type of ‘google_protobuf_Struct_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   31 | extern const upb_MiniTable google_protobuf_Struct_msginit;
      |                            ^
src/core/ext/upb-generated/google/protobuf/struct.upb.c:23:21: note: ‘google_protobuf_Struct_msginit’ was previously declared here
   23 | const upb_MiniTable google_protobuf_Struct_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/service/status/v3/csds.upb.h:54:28: error: type of ‘envoy_config_core_v3_Node_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   54 | extern const upb_MiniTable envoy_config_core_v3_Node_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/config/core/v3/base.upb.c:99:21: note: ‘envoy_config_core_v3_Node_msginit’ was previously declared here
   99 | const upb_MiniTable envoy_config_core_v3_Node_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/service/status/v3/csds.upb.h:53:28: error: type of ‘envoy_admin_v3_UpdateFailureState_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   53 | extern const upb_MiniTable envoy_admin_v3_UpdateFailureState_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/admin/v3/config_dump_shared.upb.c:31:21: note: ‘envoy_admin_v3_UpdateFailureState_msginit’ was previously declared here
   31 | const upb_MiniTable envoy_admin_v3_UpdateFailureState_msginit = {
      |                     ^
src/core/ext/upb-generated/google/rpc/status.upb.h:27:28: error: type of ‘google_protobuf_Any_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   27 | extern const upb_MiniTable google_protobuf_Any_msginit;
      |                            ^
src/core/ext/upb-generated/google/protobuf/any.upb.c:20:21: note: ‘google_protobuf_Any_msginit’ was previously declared here
   20 | const upb_MiniTable google_protobuf_Any_msginit = {
      |                     ^
src/core/ext/upb-generated/envoy/config/endpoint/v3/load_report.upb.h:43:28: error: type of ‘envoy_config_core_v3_Locality_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   43 | extern const upb_MiniTable envoy_config_core_v3_Locality_msginit;
      |                            ^
src/core/ext/upb-generated/envoy/config/core/v3/base.upb.c:35:21: note: ‘envoy_config_core_v3_Locality_msginit’ was previously declared here
   35 | const upb_MiniTable envoy_config_core_v3_Locality_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/lookup/v1/rls.upb.h:31:28: error: type of ‘grpc_lookup_v1_RouteLookupResponse_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   31 | extern const upb_MiniTable grpc_lookup_v1_RouteLookupResponse_msginit;
      |                            ^
src/core/ext/upb-generated/src/proto/grpc/lookup/v1/rls.upb.c:48:21: note: ‘grpc_lookup_v1_RouteLookupResponse_msginit’ was previously declared here
   48 | const upb_MiniTable grpc_lookup_v1_RouteLookupResponse_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/lookup/v1/rls.upb.h:29:28: error: type of ‘grpc_lookup_v1_RouteLookupRequest_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   29 | extern const upb_MiniTable grpc_lookup_v1_RouteLookupRequest_msginit;
      |                            ^
src/core/ext/upb-generated/src/proto/grpc/lookup/v1/rls.upb.c:26:21: note: ‘grpc_lookup_v1_RouteLookupRequest_msginit’ was previously declared here
   26 | const upb_MiniTable grpc_lookup_v1_RouteLookupRequest_msginit = {
      |                     ^
src/core/ext/upb-generated/xds/service/orca/v3/orca.upb.h:25:28: error: type of ‘xds_service_orca_v3_OrcaLoadReportRequest_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   25 | extern const upb_MiniTable xds_service_orca_v3_OrcaLoadReportRequest_msginit;
      |                            ^
src/core/ext/upb-generated/xds/service/orca/v3/orca.upb.c:27:21: note: ‘xds_service_orca_v3_OrcaLoadReportRequest_msginit’ was previously declared here
   27 | const upb_MiniTable xds_service_orca_v3_OrcaLoadReportRequest_msginit = {
      |                     ^
src/core/ext/upb-generated/xds/service/orca/v3/orca.upb.h:27:28: error: type of ‘google_protobuf_Duration_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   27 | extern const upb_MiniTable google_protobuf_Duration_msginit;
      |                            ^
src/core/ext/upb-generated/google/protobuf/duration.upb.c:20:21: note: ‘google_protobuf_Duration_msginit’ was previously declared here
   20 | const upb_MiniTable google_protobuf_Duration_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/lb/v1/load_balancer.upb.h:45:28: error: type of ‘grpc_lb_v1_LoadBalanceResponse_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   45 | extern const upb_MiniTable grpc_lb_v1_LoadBalanceResponse_msginit;
      |                            ^
src/core/ext/upb-generated/src/proto/grpc/lb/v1/load_balancer.upb.c:86:21: note: ‘grpc_lb_v1_LoadBalanceResponse_msginit’ was previously declared here
   86 | const upb_MiniTable grpc_lb_v1_LoadBalanceResponse_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/lb/v1/load_balancer.upb.h:43:28: error: type of ‘grpc_lb_v1_ClientStatsPerToken_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   43 | extern const upb_MiniTable grpc_lb_v1_ClientStatsPerToken_msginit;
      |                            ^
src/core/ext/upb-generated/src/proto/grpc/lb/v1/load_balancer.upb.c:48:21: note: ‘grpc_lb_v1_ClientStatsPerToken_msginit’ was previously declared here
   48 | const upb_MiniTable grpc_lb_v1_ClientStatsPerToken_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/lb/v1/load_balancer.upb.h:53:28: error: type of ‘google_protobuf_Timestamp_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   53 | extern const upb_MiniTable google_protobuf_Timestamp_msginit;
      |                            ^
src/core/ext/upb-generated/google/protobuf/timestamp.upb.c:20:21: note: ‘google_protobuf_Timestamp_msginit’ was previously declared here
   20 | const upb_MiniTable google_protobuf_Timestamp_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/lb/v1/load_balancer.upb.h:44:28: error: type of ‘grpc_lb_v1_ClientStats_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   44 | extern const upb_MiniTable grpc_lb_v1_ClientStats_msginit;
      |                            ^
src/core/ext/upb-generated/src/proto/grpc/lb/v1/load_balancer.upb.c:68:21: note: ‘grpc_lb_v1_ClientStats_msginit’ was previously declared here
   68 | const upb_MiniTable grpc_lb_v1_ClientStats_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/lb/v1/load_balancer.upb.h:42:28: error: type of ‘grpc_lb_v1_InitialLoadBalanceRequest_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   42 | extern const upb_MiniTable grpc_lb_v1_InitialLoadBalanceRequest_msginit;
      |                            ^
src/core/ext/upb-generated/src/proto/grpc/lb/v1/load_balancer.upb.c:37:21: note: ‘grpc_lb_v1_InitialLoadBalanceRequest_msginit’ was previously declared here
   37 | const upb_MiniTable grpc_lb_v1_InitialLoadBalanceRequest_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/lb/v1/load_balancer.upb.h:41:28: error: type of ‘grpc_lb_v1_LoadBalanceRequest_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   41 | extern const upb_MiniTable grpc_lb_v1_LoadBalanceRequest_msginit;
      |                            ^
src/core/ext/upb-generated/src/proto/grpc/lb/v1/load_balancer.upb.c:27:21: note: ‘grpc_lb_v1_LoadBalanceRequest_msginit’ was previously declared here
   27 | const upb_MiniTable grpc_lb_v1_LoadBalanceRequest_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/health/v1/health.upb.h:28:28: error: type of ‘grpc_health_v1_HealthCheckResponse_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   28 | extern const upb_MiniTable grpc_health_v1_HealthCheckResponse_msginit;
      |                            ^
src/core/ext/upb-generated/src/proto/grpc/health/v1/health.upb.c:29:21: note: ‘grpc_health_v1_HealthCheckResponse_msginit’ was previously declared here
   29 | const upb_MiniTable grpc_health_v1_HealthCheckResponse_msginit = {
      |                     ^
src/core/ext/upb-generated/src/proto/grpc/health/v1/health.upb.h:27:28: error: type of ‘grpc_health_v1_HealthCheckRequest_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   27 | extern const upb_MiniTable grpc_health_v1_HealthCheckRequest_msginit;
      |                            ^
src/core/ext/upb-generated/src/proto/grpc/health/v1/health.upb.c:19:21: note: ‘grpc_health_v1_HealthCheckRequest_msginit’ was previously declared here
   19 | const upb_MiniTable grpc_health_v1_HealthCheckRequest_msginit = {
      |                     ^
src/core/ext/upb-generated/xds/data/orca/v3/orca_load_report.upb.h:29:28: error: type of ‘xds_data_orca_v3_OrcaLoadReport_msginit’ does not match original declaration [-Werror=lto-type-mismatch]
   29 | extern const upb_MiniTable xds_data_orca_v3_OrcaLoadReport_msginit;
      |                            ^
src/core/ext/upb-generated/xds/data/orca/v3/orca_load_report.upb.c:29:21: note: ‘xds_data_orca_v3_OrcaLoadReport_msginit’ was previously declared here
   29 | const upb_MiniTable xds_data_orca_v3_OrcaLoadReport_msginit = {
      |                     ^
lto1: some warnings being treated as errors
lto-wrapper: fatal error: /usr/bin/x86_64-pc-linux-gnu-g++ returned 1 exit status
compilation terminated.

Full build log: build.log

Anything else we should know about your project / environment?

Gentoo is working to make all packages LTO-clean, since users may want to add -flto to their system *FLAGS. We want to make sure that all packages either support it correctly or don't use LTO since it may produce unpredictable bad behavior.

Hence we are testing by ensuring warnings that indicate issues are promoted to errors.

There is a tracking bug for grpcio: https://bugs.gentoo.org/856775

Note: I double checked the latest version of ev_poll_posix.cc / ev_epoll1_linux.cc from git master and verified it seems to still have the mismatched struct grpc_fd ODR issue.

[yashykt]

assigning to Richard from the python team for the initial triage.

[XuanWang-Amos]

@yashykt This seems a cut and dry case of multiple LTO related errors in Core, please let us know if you think otherwise.

[eli-schwartz]

(That's why I originally filed it against core. Core is being linked by the python bindings, and was discovered while building the python bindings, but is otherwise unrelated to python.)