FileSystem/Archives: fix narrowing and aggregate-init portability (AppleClang/libc++)#3076
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sprunk merged 2 commits intoJun 30, 2026
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…pleClang/libc++) The archive readers build their entry vectors with emplace_back() of an aggregate struct, which relies on parenthesised aggregate initialisation (P0960R3). AppleClang 15 / libc++ does not fully implement it, so the emplace_back calls fail to compile. Switch to push_back() with brace-initialisation, which works on every compiler. Brace-init is stricter about narrowing, so add explicit casts to the declared member types (UInt32/UInt64/uLong -> int/uint32_t). The stored values are unchanged: the previous paren-init converted to the same member types implicitly. push_back() returns void rather than a reference, so use fileEntries.back() instead of capturing the result. No behavioural change on platforms that already compiled. Files: DirArchive.cpp, SevenZipArchive.cpp, ZipArchive.cpp Ports the code fixes from ExaDev/RecoilEngine commits 0095a7e, bba6321 and bc0457c (CI/runner changes deliberately excluded).
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Static casts look fine. |
n-morales
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Jun 29, 2026
| const auto& fd = fileEntries.emplace_back( | ||
| i, //fp | ||
| SzArEx_GetFileSize(&db, i), // size | ||
| fileEntries.push_back(FileEntry{ |
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| fileEntries.push_back(FileEntry{ | |
| const auto& fd = fileEntries.emplace_back(FileEntry{ |
You could just do this
n-morales noted push_back + fileEntries.back() can collapse back into a single emplace_back. Passing a single brace-initialised FileEntry/Files object avoids the parenthesised-aggregate-init (P0960R3) path that AppleClang/libc++ rejects, while emplace_back's returned reference (C++17) restores the named fd binding and drops the extra back() lookup. Applied to the SevenZip and Zip readers, and to the Dir reader for consistency.
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What
Fix three small portability issues in the VFS archive readers that break compilation under AppleClang / libc++, while remaining correct on every compiler. They touch overlapping files, so they land as one PR.
The archive readers build their entry vectors with
emplace_back()of an aggregate struct (FileEntry/Files). That relies on parenthesised aggregate initialisation (P0960R3), which AppleClang 15 / libc++ does not fully implement, so theemplace_backcalls fail to compile.Changes
emplace_back(...)topush_back(T{...})brace-initialisation, which works on every compiler.UInt32/UInt64/uLong->int/uint32_t). Brace-init is stricter about narrowing than paren-init; the stored values are identical, since the old paren-init performed the same conversions implicitly.fileEntries.back()instead of capturing the call result:push_back()returnsvoid, not a reference to the inserted element.Files:
rts/System/FileSystem/Archives/DirArchive.cpprts/System/FileSystem/Archives/SevenZipArchive.cpprts/System/FileSystem/Archives/ZipArchive.cppNo behavioural change on platforms that already compiled.
Provenance
Ports the code fixes from ExaDev/RecoilEngine commits
0095a7e5c5,bba6321b05,bc0457cf7b. The CI/runner (macos-15) changes in those commits are deliberately excluded as fork-specific.Testing
mastermatches the base those commits applied against.FileEntry.fp/sizeareint,crc/modTimeareuint32_t;Filesis{string, string, int32_t, uint32_t}) — every cast is value-preserving.archivestarget build (gcc-16 and clang, arm64 macOS) is currently blocked by an unrelatedstreflop_cond.hsqrtferror under the macOS SDK that affects every translation unit in the target (including files untouched here); that is being addressed separately. The changes here introduce no compile errors of their own up to that point.Human verification of a full build on a fixed toolchain is still required before merge.
AI disclosure
These changes were extracted and ported with AI assistance (Claude Code). The diffs were reviewed by a human; the verification limitation above is stated honestly and has not been worked around.