Fix: GetEnumConstantValue when value can't be within int64_t - #970
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Fix: GetEnumConstantValue when value can't be within int64_t#970Vipul-Cariappa wants to merge 1 commit into
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Vipul-Cariappa
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May 5, 2026
| return INTEROP_RETURN(Val.getExtValue()); | ||
| llvm::SmallString<40> StrVal; | ||
| Val.toString(StrVal); | ||
| return INTEROP_RETURN(std::stoul(StrVal.c_str())); |
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Do we need macro to check if sizeof(unsigned long) == sizeof(size_t) then call stoul, else if sizeof(unsigned long long) == sizeof(size_t), call stoull? For all the systems we are interested (64 bit), I believe sizeof(unsigned long) == sizeof(unsigned long long) == 64. Then we will also have to change the return type. What is the enum value is negative...!?
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what if int128_t https://godbolt.org/z/zv758P33a?
Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## main #970 +/- ##
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Coverage 87.63% 87.64%
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Files 23 23
Lines 6364 6368 +4
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+ Hits 5577 5581 +4
Misses 787 787
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Hi, just wanted to see if this can be rebased and landed. |
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clang-tidy review says "All clean, LGTM! 👍" |
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GetEnumConstantValue returns size_t and calls APSInt::getExtValue
unguarded, which asserts for enumerators above INT64_MAX ("Too many
bits for int64_t") and truncates 64-bit values wherever size_t is
32 bit (win32, wasm32). Round-tripping the large values through a
string and std::stoul (the compiler-research#970 approach) throws std::out_of_range
wherever unsigned long is 32 bit — LLP64 Windows and ILP32 — which is
what fails compiler-research#970's msvc and emscripten lanes, and was seen in ROOT's
Windows CI as an uncaught std::_Xout_of_range from
Cpp::GetEnumConstantValue taking the interpreter process down
(MetaClingTests test_GH_20925, enum value 1 << 63).
Return the 64-bit bit pattern as int64_t on all platforms instead:
getExtValue when the value is representable, the zero-extended pattern
as two's complement otherwise. No string round-trip, no throw, and the
width no longer depends on the platform's size_t.
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GetEnumConstantValue returns size_t and calls APSInt::getExtValue unguarded, which asserts above INT64_MAX. Round-tripping large values through std::stoul (compiler-research#970) throws where unsigned long is 32 bit (LLP64 Windows, wasm32), and a size_t return truncates there regardless. ROOT's Windows CI hit this as an uncaught out_of_range in MetaClingTests test_GH_20925. Return the 64-bit pattern as int64_t everywhere: getExtValue when representable, the zero-extended value as two's complement otherwise.
aaronj0
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Aug 27, 2026
GetEnumConstantValue returns size_t and calls APSInt::getExtValue unguarded, which asserts above INT64_MAX. Round-tripping large values through std::stoul (compiler-research#970) throws where unsigned long is 32 bit (LLP64 Windows, wasm32), and a size_t return truncates there regardless. ROOT's Windows CI hit this as an uncaught out_of_range in MetaClingTests test_GH_20925. Return the 64-bit pattern as int64_t everywhere: getExtValue when representable, the zero-extended value as two's complement otherwise.
aaronj0
added a commit
to aaronj0/CppInterOp
that referenced
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Aug 27, 2026
GetEnumConstantValue returns size_t and calls APSInt::getExtValue unguarded, which asserts above INT64_MAX. Round-tripping large values through std::stoul (compiler-research#970) throws where unsigned long is 32 bit (LLP64 Windows, wasm32), and a size_t return truncates there regardless. ROOT's Windows CI hit this as an uncaught out_of_range in MetaClingTests test_GH_20925. Return the 64-bit pattern as int64_t everywhere: getExtValue when representable, the zero-extended value as two's complement otherwise.
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