Build fails with LTO due to ODR violations

[eli-schwartz]

I tried to build with the following *FLAGS to optimize the build: -flto=4 -Werror=odr -Werror=lto-type-mismatch -Werror=strict-aliasing

Link-Time Optimization is a massively global compiler optimization pass which is pretty handy for producing faster executables. It also has the interesting property that because the compiler does whole-program analysis using bytecode, it can save type information and perform error checks that it normally doesn’t have enough insight for. In particular, checking for ODR issues and checking function type signature mismatches.

Note that all 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.

I got this error:

    "x86_64-pc-linux-gnu-g++"    -o "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/quickbook" -Wl,--start-group "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/quickbook.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/actions.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/doc_info_actions.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/state.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/dependency_tracker.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/utils.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/files.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/native_text.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/stream.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/glob.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/path.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/include_paths.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/values.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/document_state.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/id_generation.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/id_xml.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/post_process.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/bb2html.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/boostbook_chunker.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/xml_parse.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/html_printer.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/tree.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/collector.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/template_stack.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/code_snippet.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/markups.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/syntax_highlight.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/grammar.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/main_grammar.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/block_element_grammar.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/phrase_element_grammar.o" "../bin.v2/tools/quickbook/src/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/doc_info_grammar.o" "../bin.v2/libs/program_options/build/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/visibility-hidden/libboost_program_options.a" "../bin.v2/libs/filesystem/build/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/visibility-hidden/libboost_filesystem.a" "../bin.v2/libs/atomic/build/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/visibility-hidden/libboost_atomic.a" "../bin.v2/libs/system/build/gcc-14.2/release/x86_64/cxxstd-0x-iso/link-static/pch-off/threading-multi/visibility-hidden/libboost_system.a"  -Wl,-Bstatic  -Wl,-Bdynamic -lrt -Wl,--end-group -m64 -pthread -std=c++0x -Wl,-O1 -Wl,--as-needed -Wl,-z,pack-relative-relocs -flto=4 -Werror=odr -Werror=lto-type-mismatch -Werror=strict-aliasing -Wl,--defsym=__gentoo_check_ldflags__=0

/var/tmp/portage/dev-libs/boost-1.88.0/work/boost_1_88_0-abi_x86_64.amd64/tools/quickbook/src/parsers.hpp:181:52: error: ‘operator()’ violates the C++ One Definition Rule [-Werror=odr]
  181 |         scoped_parser_gen<Impl, phoenix::tuple<> > operator()() const
      |                                                    ^
/var/tmp/portage/dev-libs/boost-1.88.0/work/boost_1_88_0-abi_x86_64.amd64/tools/quickbook/src/parsers.hpp:181:52: note: return value type mismatch
  181 |         scoped_parser_gen<Impl, phoenix::tuple<> > operator()() const
      |                                                    ^
/var/tmp/portage/dev-libs/boost-1.88.0/work/boost_1_88_0-abi_x86_64.amd64/tools/quickbook/src/parsers.hpp:152:57: note: type name ‘quickbook::scoped_parser_gen<quickbook::to_value_scoped_action, phoenix::tuple<phoenix::nil_t, phoenix::nil_t, phoenix::nil_t, phoenix::nil_t, phoenix::nil_t, phoenix::nil_t, phoenix::nil_t> >’ should match type name ‘quickbook::scoped_parser_gen<quickbook::to_value_scoped_action, phoenix::tuple<phoenix::nil_t, phoenix::nil_t, phoenix::nil_t, phoenix::nil_t> >’
  152 |     template <typename Impl, typename Arguments> struct scoped_parser_gen
      |                                                         ^
/var/tmp/portage/dev-libs/boost-1.88.0/work/boost_1_88_0-abi_x86_64.amd64/tools/quickbook/src/parsers.hpp:181:52: note: ‘operator()’ was previously declared here
  181 |         scoped_parser_gen<Impl, phoenix::tuple<> > operator()() const
      |                                                    ^
/var/tmp/portage/dev-libs/boost-1.88.0/work/boost_1_88_0-abi_x86_64.amd64/tools/quickbook/src/parsers.hpp:181:52: note: code may be misoptimized unless ‘-fno-strict-aliasing’ is used
lto1: some warnings being treated as errors
lto-wrapper: fatal error: x86_64-pc-linux-gnu-g++ returned 1 exit status
compilation terminated.
/usr/lib/gcc/x86_64-pc-linux-gnu/14/../../../../x86_64-pc-linux-gnu/bin/ld: error: lto-wrapper failed
collect2: error: ld returned 1 exit status

Originally reported downstream: https://bugs.gentoo.org/943975
Full build log: build.log

[pdimov]

Reported to Spirit: boostorg/spirit#800

[pdimov]

If you want to patch this locally, the fix is to change 3 to 6 here:

https://github.com/boostorg/spirit/blob/dcaded05c84db5ecea6485178f77e825df5352f1/include/boost/spirit/home/classic/phoenix/tuples.hpp#L21

[eli-schwartz]

Thanks for root cause'ing this. Looks like it's been around since 2010... boostorg/spirit@c595440