[GCC12] argument value ... exceeds maximum object size

[iarspider]

GCC12 emits Walloc-size-larger-than compilation warnings in SimG4CMS 1, 2, 3, and in DQM 4:

.../external/gcc/12.2.1-59043c7bdcfa6002a8c9155ca1109454/bin/c++ -O2 -pthread -pipe -Werror=main -Werror=pointer-arith -Werror=overlength-strings -Wno-vla -Werror=overflow -std=c++17 -ftree-vectorize -Werror=array-bounds -Werror=format-contains-nul -Werror=type-limits -fvisibility-inlines-hidden -fno-math-errno --param vect-max-version-for-alias-checks=50 -Xassembler --compress-debug-sections -Wno-error=array-bounds -Warray-bounds -fuse-ld=bfd -msse3 -felide-constructors -fmessage-length=0 -Wall -Wno-non-template-friend -Wno-long-long -Wreturn-type -Wextra -Wpessimizing-move -Wclass-memaccess -Wno-cast-function-type -Wno-unused-but-set-parameter -Wno-ignored-qualifiers -Wno-deprecated-copy -Wno-unused-parameter -Wunused -Wparentheses -Wno-deprecated -Werror=return-type -Werror=missing-braces -Werror=unused-value -Werror=unused-label -Werror=address -Werror=format -Werror=sign-compare -Werror=write-strings -Werror=delete-non-virtual-dtor -Werror=strict-aliasing -Werror=narrowing -Werror=unused-but-set-variable -Werror=reorder -Werror=unused-variable -Werror=conversion-null -Werror=return-local-addr -Wnon-virtual-dtor -Werror=switch -fdiagnostics-show-option -Wno-unused-local-typedefs -Wno-attributes -Wno-psabi -Wno-error=unused-variable -ftls-model=global-dynamic -pthread -DBOOST_DISABLE_ASSERTS -flto -fipa-icf -flto-odr-type-merging -fno-fat-lto-objects -Wodr -shared -Wl,-E -Wl,-z,defs tmp/el8_amd64_gcc12/src/SimG4CMS/FP420/src/SimG4CMSFP420/FP420G4Hit.cc.o tmp/el8_amd64_gcc12/src/SimG4CMS/FP420/src/SimG4CMSFP420/FP420HitsObject.cc.o tmp/el8_amd64_gcc12/src/SimG4CMS/FP420/src/SimG4CMSFP420/FP420NumberingScheme.cc.o tmp/el8_amd64_gcc12/src/SimG4CMS/FP420/src/SimG4CMSFP420/FP420SD.cc.o -o tmp/el8_amd64_gcc12/src/SimG4CMS/FP420/src/SimG4CMSFP420/libSimG4CMSFP420.so -Wl,-E -Wl,--hash-style=gnu -L.../CMSSW_13_2_X_2023-05-29-1100/biglib/el8_amd64_gcc12 -L.../CMSSW_13_2_X_2023-05-29-1100/lib/el8_amd64_gcc12 -L.../CMSSW_13_2_X_2023-05-29-1100/external/el8_amd64_gcc12/lib -L.../CMSSW_13_2_X_2023-05-29-1100/static/el8_amd64_gcc12 -lSimG4CoreSensitiveDetector -lSimDataFormatsSimHitMaker -lSimG4CoreGeometry -lDetectorDescriptionCore -lDetectorDescriptionDDCMS -lSimDataFormatsTrackingHit -lSimG4CoreNotification -lDataFormatsGeometryVector -lFWCoreFramework -lSimDataFormatsCaloHit -lSimDataFormatsTrack -lSimDataFormatsVertex -lDataFormatsMath -lFWCoreCommon -lFWCoreServiceRegistry -lSimDataFormatsForward -lDataFormatsCommon -lFWCoreParameterSet -lFWCoreMessageLogger -lDataFormatsProvenance -lFWCorePluginManager -lFWCoreReflection -lFWCoreConcurrency -lFWCoreUtilities -lFWCoreVersion -lSimDataFormatsEncodedEventId -lDDAlign -lDDCond -lDDG4-static -lDDCore -lDDParsers -lPhysics -lHist -lMatrix -lGenVector -lMathMore -lTree -lNet -lGeom -lThread -lG4digits_hits -lG4error_propagation -lG4event -lG4geometry -lG4global -lG4graphics_reps -lG4intercoms -lG4interfaces -lG4materials -lG4parmodels -lG4particles -lG4persistency -lG4physicslists -lG4processes -lG4readout -lG4run -lG4tracking -lG4track -lG4analysis -lMathCore -lRIO -lCore -lboost_thread -lboost_date_time -lCLHEP -lHepMCfio -lHepMC -lpcre -lvecgeom -lbz2 -lexpat -lgsl -luuid -ltbb -lxerces-c -llzma -lz -lfmt -lcms-md5 -lopenblas -lcrypt -ldl -lrt -lstdc++fs -ltinyxml2
.../CMSSW_13_2_X_2023-05-29-1100/src/SimG4CMS/FP420/src/FP420NumberingScheme.cc: In member function 'getUnitID':
  .../CMSSW_13_2_X_2023-05-29-1100/src/SimG4CMS/FP420/src/FP420NumberingScheme.cc:58:40: warning: argument 1 value '18446744073709551615' exceeds maximum object size 9223372036854775807 [-Walloc-size-larger-than=]
    58 |     G4String* name = new G4String[level];
      |                                        ^
.../external/gcc/12.2.1-59043c7bdcfa6002a8c9155ca1109454/include/c++/12.2.1/new:128:26: note: in a call to allocation function 'operator new []' declared here
  128 | _GLIBCXX_NODISCARD void* operator new[](std::size_t) _GLIBCXX_THROW (std::bad_alloc)
      |                          ^

These could be false-positives though, as I don't think the lines in question will ever ask for 2^64-1 bytes of memory...

[cmsbuild]

A new Issue was created by @iarspider .

@Dr15Jones, @perrotta, @dpiparo, @rappoccio, @makortel, @smuzaffar can you please review it and eventually sign/assign? Thanks.

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[iarspider]

assign simulation,dqm

[cmsbuild]

New categories assigned: dqm,simulation

@mdhildreth,@tjavaid,@micsucmed,@nothingface0,@rvenditti,@emanueleusai,@syuvivida,@civanch,@pmandrik you have been requested to review this Pull request/Issue and eventually sign? Thanks

[makortel]

All the warnings seem to be related to C-arrays of G4String or std::string.

[iarspider]

I would imagine that level somehow gets set to -1, but the code that triggers warning is explicitly guarded by if level>0

[makortel]

On a quick look the pieces of code look like replacing the C-arrays with std::vectors would make them more clear and concise anyway, and I'd hope moving to std::vector would silence this warning as well.

[VinInn]

seems to be lto related

[civanch]

Yes it is LTO, which has a problem if there is a complex code with C-arrays of unclear size. We have observed similar crazy report on Geant4. When migration to std::vector is done the warning disappears and code become more readable. I suspect that LTO simply confused.

[VinInn]

and can be reproduced only if -1 is explicitly "converted in unsigned (something that lto may do)

[VinInn]

of course "we" are NOT the only one
https://stackoverflow.com/questions/73047957/gcc-with-lto-warning-argument-1-value-18-615-size-max-exceeds-maximum-ob

[civanch]

+1

it is likely a problem of LTO in gcc12 but code itself was more complicate than needed. Now no C arrays.