Fix size test build on gcc11

[lucylq]

Summary

size_test on gcc11 fails with

In static member function ‘static constexpr std::size_t std::char_traits<char>::length(const char_type*)’,
    inlined from ‘constexpr std::basic_string_view<_CharT, _Traits>::basic_string_view(const _CharT*) [with _CharT = char; _Traits = std::char_traits<char>]’ at /usr/include/c++/11/string_view:132:35,
    inlined from ‘executorch::runtime::Result<void*> executorch::runtime::deserialization::getTensorDataPtr(const executorch_flatbuffer::Tensor*, const executorch::runtime::Program*, size_t, executorch::runtime::HierarchicalAllocator*, const executorch::runtime::NamedDataMap*, executorch::runtime::Span<executorch::runtime::deserialization::NamedData>)’ at /data/users/lfq/binary-size/executorch/runtime/executor/tensor_parser_exec_aten.cpp:218:41:
/usr/include/c++/11/bits/char_traits.h:399:32: error: ‘long unsigned int __builtin_strlen(const char*)’ reading 1 or more bytes from a region of size 0 [-Werror=stringop-overread]
  399 |         return __builtin_strlen(__s);
      |                ~~~~~~~~~~~~~~~~^~~~~
In file included from /data/users/lfq/binary-size/executorch/../executorch/runtime/executor/tensor_parser.h:21,
                 from /data/users/lfq/binary-size/executorch/runtime/executor/tensor_parser_exec_aten.cpp:9:
/data/users/lfq/binary-size/executorch/cmake-out/schema/include/executorch/schema/program_generated.h: In function ‘executorch::runtime::Result<void*> executorch::runtime::deserialization::getTensorDataPtr(const executorch_flatbuffer::Tensor*, const executorch::runtime::Program*, size_t, executorch::runtime::HierarchicalAllocator*, const executorch::runtime::NamedDataMap*, executorch::runtime::Span<executorch::runtime::deserialization::NamedData>)’:
/data/users/lfq/binary-size/executorch/cmake-out/schema/include/executorch/schema/program_generated.h:568:8: note: at offset 5 into source object ‘executorch_flatbuffer::ExtraTensorInfo::<anonymous>’ of size 1
  568 | struct ExtraTensorInfo FLATBUFFERS_FINAL_CLASS : private ::flatbuffers::Table {

Test plan

Flatbuffer should be safe - add -Wno-stringop-overread to suppress the error.

size results after stripping

sh test/build_size_test.sh 

(executorch) [lfq@devvm11764.nha0 /data/users/lfq/binary-size/executorch (binary-size)]$ ls -la cmake-out/test/size_test_all_ops
-rwxr-xr-x 1 lfq users 1670416 Mar  4 22:37 cmake-out/test/size_test_all_ops

(executorch) [lfq@devvm11764.nha0 /data/users/lfq/binary-size/executorch (binary-size)]$ ls -la cmake-out/test/size_test
-rwxr-xr-x 1 lfq users 56240 Mar  4 22:38 cmake-out/test/size_test

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/executorch/17867

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❌ 1 Awaiting Approval, 1 New Failure, 3 Unrelated Failures

As of commit 31c6aa8 with merge base 75f5a76 ():

AWAITING APPROVAL - The following workflow needs approval before CI can run:

• Claude Code (gh)

NEW FAILURE - The following job has failed:

• pull / test-binary-size-linux / linux-job (gh)
  RuntimeError: Command docker exec -t 6c4e54fba80e7ea284b58c6a7115216f55fcf15f0543b5e2e37768488a3d3962 /exec failed with exit code 1

FLAKY - The following job failed but was likely due to flakiness present on trunk:

• pull / test-models-linux (resnet18, portable, linux.2xlarge) / linux-job (gh) (detected as infra flaky with no log or failing log classifier)

BROKEN TRUNK - The following jobs failed but was present on the merge base:

👉 Rebase onto the `viable/strict` branch to avoid these failures

• pull / unittest / macos / macos-job (gh) (trunk failure)
  AttributeError: '_OpNamespace' 'mkldnn' object has no attribute '_is_mkldnn_acl_supported'
• pull / unittest-editable / macos / macos-job (gh) (trunk failure)
  AttributeError: '_OpNamespace' 'mkldnn' object has no attribute '_is_mkldnn_acl_supported'

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[github-actions]

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[Copilot]

Pull request overview

This PR fixes a build failure in the size test when compiled with GCC 11. GCC 11 produces a false positive -Wstringop-overread warning in Flatbuffers-generated code (program_generated.h), which is promoted to an error by -Werror. The fix suppresses this specific warning via -Wno-stringop-overread.

Changes:

• Added -Wno-stringop-overread to COMMON_CXXFLAGS in the size test build script to suppress a false positive GCC 11 warning in Flatbuffers-generated code.

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[Copilot]

The existing -Wno-int-in-bool-context flag has a TODO comment (line 15) explaining why it's there and that it should eventually be removed. Consider adding a similar TODO comment for -Wno-stringop-overread to document that it's a workaround for a GCC 11 false positive in Flatbuffers-generated code, and can potentially be removed when GCC 11 is no longer a supported compiler.

Suggested change

	# TODO(#8357): Remove -Wno-int-in-bool-context
	# TODO(#8357): Remove -Wno-int-in-bool-context
	# TODO: Remove -Wno-stringop-overread once GCC 11 is no longer supported.
	# This flag works around a GCC 11 false positive in Flatbuffers-generated code.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

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[Copilot]

Consider adding a TODO comment for -Wno-stringop-overread, similar to the existing # TODO(#8357): Remove -Wno-int-in-bool-context on line 15, to track when this suppression can be removed (e.g., when the FlatBuffers version is updated or the GCC11 false positive is resolved). This helps prevent warning suppressions from accumulating without tracking.

Suggested change

	# FileDataLoader used in the size_test breaks baremetal builds with pread when missing.
	# FileDataLoader used in the size_test breaks baremetal builds with pread when missing.
	# TODO: Remove -Wno-stringop-overread once the GCC11 FlatBuffers false positive is resolved or FlatBuffers is updated.

[lucylq]

duplicate of #17905, sorry @kirklandsign 😅