GCC maybe-uninitialized failure

[pprkut]

I'm trying to compile binaryen 118 with gcc 14.1.0 and run into this error

[ 30%] Building CXX object third_party/llvm-project/CMakeFiles/llvm_dwarf.dir/DWARFDebugAbbrev.cpp.o
cd /usr/src/sbo_tmp/binaryen-version_118/build/third_party/llvm-project && /usr/libexec/icecc/bin/c++  -I/usr/src/sbo_tmp/binaryen-version_118/src -I/usr/src/sbo_tmp/binaryen-version_118/third_party/llvm-project/include -I/usr/src/sbo_tmp/binaryen-version_118/build -O2 -fPIC -DBUILD_LLVM_DWARF -Wall -Werror -Wextra -Wno-unused-parameter -Wno-dangling-pointer -fno-omit-frame-pointer -fno-rtti -Wno-implicit-int-float-conversion -Wno-unknown-warning-option -Wswitch -Wimplicit-fallthrough -Wnon-virtual-dtor -fPIC -w -std=c++14 -D_GNU_SOURCE -D_DEBUG -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -O3 -DNDEBUG -UNDEBUG -std=c++17 -MD -MT third_party/llvm-project/CMakeFiles/llvm_dwarf.dir/DWARFDebugAbbrev.cpp.o -MF CMakeFiles/llvm_dwarf.dir/DWARFDebugAbbrev.cpp.o.d -o CMakeFiles/llvm_dwarf.dir/DWARFDebugAbbrev.cpp.o -c /usr/src/sbo_tmp/binaryen-version_118/third_party/llvm-project/DWARFDebugAbbrev.cpp
In file included from /usr/src/sbo_tmp/binaryen-version_118/src/parser/wast-parser.cpp:19:
/usr/src/sbo_tmp/binaryen-version_118/src/parser/wat-parser.h: In function ‘wasm::Result<std::vector<wasm::WATParser::ScriptEntry> > wasm::WATParser::{anonymous}::wast(wasm::WATParser::Lexer&)’:
/usr/src/sbo_tmp/binaryen-version_118/src/parser/wat-parser.h:37:8: error: ‘*(wasm::WATParser::InvokeAction*)((char*)&<unnamed> + offsetof(wasm::WATParser::value_type, wasm::WATParser::ScriptEntry::cmd.std::variant<std::variant<wasm::WATParser::QuotedModule, std::shared_ptr<wasm::Module> >, wasm::WATParser::Register, std::variant<wasm::WATParser::InvokeAction, wasm::WATParser::GetAction>, std::variant<wasm::WATParser::AssertReturn, wasm::WATParser::AssertAction, wasm::WATParser::AssertModule> >::<unnamed>.std::__detail::__variant::_Variant_base<std::variant<wasm::WATParser::QuotedModule, std::shared_ptr<wasm::Module> >, wasm::WATParser::Register, std::variant<wasm::WATParser::InvokeAction, wasm::WATParser::GetAction>, std::variant<wasm::WATParser::AssertReturn, wasm::WATParser::AssertAction, wasm::WATParser::AssertModule> >::<unnamed>.std::__detail::__variant::_Move_assign_base<false, std::variant<wasm::WATParser::QuotedModule, std::shared_ptr<wasm::Module> >, wasm::WATParser::Register, std::variant<wasm::WATParser::InvokeAction, wasm::WATParser::GetAction>, std::variant<wasm::WATParser::AssertReturn, wasm::WATParser::AssertAction, wasm::WATParser::AssertModule> >::<unnamed>.std::__detail::__variant::_Copy_assign_base<false, std::variant<wasm::WATParser::QuotedModule, std::shared_ptr<wasm::Module> >, wasm::WATParser::Register, std::variant<wasm::WATParser::InvokeAction, wasm::WATParser::GetAction>, std::variant<wasm::WATParser::AssertReturn, wasm::WATParser::AssertAction, wasm::WATParser::AssertModule> >::<unnamed>.std::__detail::__variant::_Move_ctor_base<false, std::variant<wasm::WATParser::QuotedModule, std::shared_ptr<wasm::Module> >, wasm::WATParser::Register, std::variant<wasm::WATParser::InvokeAction, wasm::WATParser::GetAction>, std::variant<wasm::WATParser::AssertReturn, wasm::WATParser::AssertAction, wasm::WATParser::AssertModule> >::<unnamed>.std::__detail::__variant::_Copy_ctor_base<false, std::variant<wasm::WATParser::QuotedModule, std::shared_ptr<wasm::Module> >, wasm::WATParser::Register, std::variant<wasm::WATParser::InvokeAction, wasm::WATParser::GetAction>, std::variant<wasm::WATParser::AssertReturn, wasm::WATParser::AssertAction, wasm::WATParser::AssertModule> >::<unnamed>.std::__detail::__variant::_Variant_storage<false, std::variant<wasm::WATParser::QuotedModule, std::shared_ptr<wasm::Module> >, wasm::WATParser::Register, std::variant<wasm::WATParser::InvokeAction, wasm::WATParser::GetAction>, std::variant<wasm::WATParser::AssertReturn, wasm::WATParser::AssertAction, wasm::WATParser::AssertModule> >::_M_u)).wasm::WATParser::InvokeAction::name’ may be used uninitialized [-Werror=maybe-uninitialized]
   37 | struct InvokeAction {
      |        ^~~~~~~~~~~~
/usr/src/sbo_tmp/binaryen-version_118/src/parser/wast-parser.cpp:411:21: note: ‘<anonymous>’ declared here
  411 |       cmds.push_back({WASTModule{std::move(wasm)}, line});
      |       ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
At global scope:
cc1plus: note: unrecognized command-line option ‘-Wno-unknown-warning-option’ may have been intended to silence earlier diagnostics
cc1plus: note: unrecognized command-line option ‘-Wno-implicit-int-float-conversion’ may have been intended to silence earlier diagnostics
cc1plus: all warnings being treated as errors
make[2]: *** [src/parser/CMakeFiles/parser.dir/build.make:188: src/parser/CMakeFiles/parser.dir/wast-parser.cpp.o] Error 1
make[2]: *** Waiting for unfinished jobs....

-Wno-maybe-uninitialized helps to work around it

[kripken]

@tlively you know that code best - any ideas?

[tlively]

Looks like another false positive we could work around with a pragma. Maybe we should just consider turning off this warning globally?

[kripken]

I think this warning is sometimes helpful, so I'd lean towards finding a reasonable workaround in the code, or using a pragma.