Add ToUpperOrdinal and ToLowerOrdinal casing APIs by tarekgh · Pull Request #130140 · dotnet/runtime

tarekgh · 2026-07-02T20:52:07Z

Implements the ordinal casing APIs approved in #90999.

APIs

char.ToUpperOrdinal(char) / char.ToLowerOrdinal(char)
Rune.ToUpperOrdinal(Rune) / Rune.ToLowerOrdinal(Rune)
string.ToUpperOrdinal() / string.ToLowerOrdinal()
MemoryExtensions.ToUpperOrdinal(ReadOnlySpan<char>, Span<char>) / ToLowerOrdinal(ReadOnlySpan<char>, Span<char>)

Notes

Ordinal casing uses the same simple, one-to-one mapping as OrdinalIgnoreCase comparisons. Two strings are OrdinalIgnoreCase-equal iff their ToUpperOrdinal results are ordinally equal.
Reuses the existing ordinal upper-casing tables and adds a mirrored lower-casing path. Six characters (U+0130, U+03F4, U+1E9E, U+2126, U+212A, U+212B) stay unchanged under lower casing to remain consistent with OrdinalIgnoreCase.
string.ToUpperOrdinal() / string.ToLowerOrdinal() return the same instance when an all-ASCII string is already in the requested case, avoiding an allocation.

Tests under System.Globalization.Tests validate the mappings against OrdinalIgnoreCase across the entire BMP.

Implement ordinal (simple, one-to-one) casing on Char, Rune, String, and MemoryExtensions, matching the mappings used by OrdinalIgnoreCase comparisons. String.ToUpperOrdinal/ToLowerOrdinal return the same instance when an all-ASCII string is already in the requested case.

dotnet-policy-service · 2026-07-02T20:53:21Z

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Pull request overview

Adds new ordinal casing APIs across char, Rune, string, and span-based MemoryExtensions, implemented to match the StringComparison.OrdinalIgnoreCase folding behavior (one-to-one mapping, length-preserving), including a new ordinal lower-casing table path alongside the existing upper-casing tables.

Changes:

Introduces ToUpperOrdinal / ToLowerOrdinal APIs on char, Rune, string, and ReadOnlySpan<char> -> Span<char> transforms.
Implements ICU-backed ordinal lower-casing table initialization (native + managed), mirroring the existing upper-casing infrastructure and special-case handling.
Adds comprehensive System.Globalization.Tests coverage validating BMP-wide behavior and overload consistency.

Reviewed changes

Copilot reviewed 18 out of 18 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
src/native/libs/System.Globalization.Native/System.Globalization.Native.def	Exports the new native entrypoint for ordinal lower-casing page initialization.
src/native/libs/System.Globalization.Native/pal_common.c	Implements `GlobalizationNative_InitOrdinalLowerCasingPage` using ICU simple lower casing + special cases.
src/native/libs/System.Globalization.Native/pal_casing.h	Declares the new native PAL export for ordinal lower-casing page initialization.
src/native/libs/System.Globalization.Native/entrypoints.c	Registers the new entrypoint for DllImport resolution.
src/libraries/Common/src/Interop/Interop.Casing.cs	Adds managed `LibraryImport` for `GlobalizationNative_InitOrdinalLowerCasingPage`.
src/libraries/System.Private.CoreLib/src/System/Globalization/OrdinalCasing.Icu.cs	Adds a mirrored lower-casing table + lazy per-page initialization and span-based lower casing.
src/libraries/System.Private.CoreLib/src/System/Globalization/TextInfo.cs	Adds `TextInfo.ToLowerOrdinal(char)` routing based on globalization mode (Invariant / NLS / ICU).
src/libraries/System.Private.CoreLib/src/System/Globalization/Ordinal.cs	Adds span-based `Ordinal.ToLowerOrdinal` entrypoint consistent with existing `ToUpperOrdinal`.
src/libraries/System.Private.CoreLib/src/System/MemoryExtensions.Globalization.cs	Adds public span extension methods `ToUpperOrdinal` / `ToLowerOrdinal`.
src/libraries/System.Private.CoreLib/src/System/String.Manipulation.cs	Adds `string.ToUpperOrdinal()` / `string.ToLowerOrdinal()` with ASCII fast-path returning same instance when unchanged.
src/libraries/System.Private.CoreLib/src/System/Char.cs	Adds public `char.ToUpperOrdinal(char)` / `char.ToLowerOrdinal(char)`.
src/libraries/System.Private.CoreLib/src/System/Text/Rune.cs	Adds public `Rune.ToUpperOrdinal(Rune)` / `Rune.ToLowerOrdinal(Rune)` implementations.
src/libraries/System.Runtime/ref/System.Runtime.cs	Adds the new public APIs to the System.Runtime ref surface (`char`, `string`, `Rune`).
src/libraries/System.Memory/ref/System.Memory.cs	Adds the new public APIs to the System.Memory ref surface (`MemoryExtensions`).
src/libraries/System.Runtime/tests/System.Globalization.Tests/System/Globalization/OrdinalCasingTests.cs	New tests validating ordinal casing invariants and special-case behavior across the BMP and overloads.
src/libraries/System.Runtime/tests/System.Globalization.Tests/System.Globalization.Tests.csproj	Includes the new test file in the test project.
src/coreclr/vm/wasm/wasi/callhelpers-pinvoke.cpp	Adds the new native export for WASM/WASI callhelper pinvoke tables.
src/coreclr/vm/wasm/browser/callhelpers-pinvoke.cpp	Adds the new native export for WASM/browser callhelper pinvoke tables.

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tarekgh · 2026-07-02T21:27:35Z

CC @lewing to advise if we need to do anything more for WASM with this change?

CC @jkotas & @GrabYourPitchforks for awareness.

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Copilot reviewed 18 out of 18 changed files in this pull request and generated 1 comment.

… modes Invariant and NLS simple lowering could move characters such as the Kelvin, Ohm and Angstrom signs out of their ordinal upper-casing class, so ToLowerOrdinal stopped being consistent with OrdinalIgnoreCase in those modes. Keep the original character when its simple lower mapping would change its ordinal upper-casing form, and extend the invariant-mode test to cover ToLowerOrdinal across the BMP.

…ecutor Guard the MICRO SIGN and GREEK SMALL FINAL SIGMA fold cases so they only run under ICU and invariant casing, since NLS does not treat them as OrdinalIgnoreCase-equal. Gate OrdinalIgnoreCase_Equivalence_HoldsInInvariantMode on RemoteExecutor.IsSupported so it is skipped on wasm and android instead of throwing PlatformNotSupportedException.

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Upper-case the source and lowered spans once each instead of calling TextInfo.ToUpperOrdinal per non-ASCII character, which is expensive under NLS.

Only a fixed set of five BMP scalars (Greek capital theta symbol, Latin capital sharp S, Ohm, Kelvin and Angstrom signs) fall out of their ordinal upper-casing class under simple invariant or NLS lowering. Scan the source once with SearchValues and skip the pass entirely when none are present, instead of upper-casing the whole span on every lowering.

Fast-path the leading ASCII run of the ICU ToUpperOrdinal/ToLowerOrdinal span helpers with Ascii.ToUpper/ToLower, and replace the hand-rolled unsafe scan in the string ChangeCaseOrdinal fast path with a vectorized IndexOfAnyExcept over a SearchValues of the ASCII characters already in the requested case.

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- Move ordinal-casing SearchValues into SearchValuesStorage using hardcoded ASCII literals so they are created lazily only when ordinal casing is used - Use (uint) loop bounds in OrdinalCasing.Icu.cs to elide bounds checks - Use collection expressions for single-char destination spans in tests

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tarekgh · 2026-07-09T18:23:39Z

/ba-g failures are WASm timeout or unrelated failures.

Neme12 · 2026-07-10T18:06:39Z

Yay 🎉

@tarekgh

…tive (#130543) ## Summary Fixes the browser-wasm **CoreCLR** library test leg (`WasmTestOnChrome-CLR` → `System.Globalization.Extensions.Tests`), failing on `main` since 2026-07-09 with: ``` System.DllNotFoundException : Unable to load shared library 'libSystem.Globalization.Native' ... dynamic linking not enabled at Interop.Globalization.ToUnicode(...) at System.Globalization.IdnMapping.IcuTryGetUnicodeCore(...) ``` Tracked by #130479 (`blocking-clean-ci`). ## Root cause #130140 added `GlobalizationNative_InitOrdinalLowerCasingPage` to the generated `callhelpers-pinvoke.cpp` P/Invoke tables (browser + wasi) — correctly inserting the sorted entry and its `extern "C"` declaration — but did **not** update the hard-coded `EntryCount` in `s_PInvokeTables` (left at `33`, now `34` entries). `minipal_resolve_dllimport` (`src/native/minipal/entrypoints.h`) linearly scans `entries[0 .. count-1]`. With `count = 33` over the 34-entry table, the **last** entry — `GlobalizationNative_ToUnicode` — became unreachable, so its P/Invoke resolved to `NULL` and fell back to `dlopen` (unsupported for CoreCLR-wasm) → `DllNotFoundException`. This is why **only** `IdnMapping.GetUnicode`/`ToUnicode` tests failed while `GetAscii` (`ToAscii`, index 32, still in range) kept passing. The generator emits this count from the table length, so `34` is exactly what a regeneration produces; #130140 hand-edited the generated file without re-running it. ## Fix Bump the `libSystem.Globalization.Native` `EntryCount` from `33` → `34` in both: - `src/coreclr/vm/wasm/browser/callhelpers-pinvoke.cpp` - `src/coreclr/vm/wasm/wasi/callhelpers-pinvoke.cpp` All other module counts already match their tables (verified in both files). ## Regression window (bisected on `main`, definition 129) | Build | SHA | `LibraryTestsCoreCLR` | |---|---|---| | 1500867 (Jul 9 08:00) | `0f907bfa` (no #130140) | ✅ pass | | 1502091 (Jul 9 20:00) | `6c584914` (has #130140) | ❌ fail — same signature | Emscripten 5.0.6/LLVM23 (Jun 25) and -O3 (#130111, Jul 2) were ruled out — the leg stayed green with both for two weeks. ## Verification - Native reproduction against the real `minipal/entrypoints.h`: `ToUnicode` resolves `NULL` at count 33 and `FOUND` at count 34; `ToAscii` resolves at 33 (matches the observed pass/fail split). - The browser-wasm CoreCLR `WasmTestOnChrome-CLR` CI leg exercises this end-to-end. cc @tarekgh @pavelsavara @lewing > [!NOTE] > Root-cause investigation and this fix were produced with GitHub Copilot. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

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Comment thread ...s/System.Runtime/tests/System.Globalization.Tests/System/Globalization/OrdinalCasingTests.cs

Tarek Mahmoud Sayed added 2 commits July 2, 2026 14:40

Add param and returns XML docs to Rune.ToUpperOrdinal/ToLowerOrdinal

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Merge remote-tracking branch 'upstream/main' into ordinal-casing-apis

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Comment thread src/libraries/System.Private.CoreLib/src/System/Globalization/Ordinal.cs Outdated

Comment thread src/coreclr/vm/wasm/browser/callhelpers-pinvoke.cpp

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Tarek Mahmoud Sayed added 2 commits July 6, 2026 13:46

Avoid per-character ToUpperOrdinal in PreserveOrdinalLowerCasingClass

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Upper-case the source and lowered spans once each instead of calling TextInfo.ToUpperOrdinal per non-ASCII character, which is expensive under NLS.

Merge remote-tracking branch 'upstream/main' into ordinal-casing-apis

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build-analysis Bot mentioned this pull request Jul 7, 2026

[ci-scan] Test failure: System.Formats.Tar.Tests.TarFile_ExtractToDirectory_File_Tests.ExtractToDirectory_RejectsChainedSymlinkDirectoryTraversal_WithNestedFile #130177

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Comment thread src/libraries/System.Private.CoreLib/src/System/Globalization/OrdinalCasing.Icu.cs

Comment thread src/libraries/System.Private.CoreLib/src/System/String.Manipulation.cs Outdated

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Comment thread src/libraries/System.Private.CoreLib/src/System/String.Manipulation.cs Outdated

This was referenced Jul 8, 2026

Android WebSocket failure #121518

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Flaky timeout in CreateFileChangeToken_RootDeletedAndRecreated_TokenFiresWhenFileCreated #129691

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Remove unused using in String.Manipulation.cs

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tarekgh merged commit a991d27 into dotnet:main Jul 9, 2026
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tarekgh mentioned this pull request Jul 9, 2026

[API Proposal]: Add ToLowerOrdinal() & ToUpperOrdinal() #90999

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dotnet-maestro Bot mentioned this pull request Jul 10, 2026

[main] Source code updates from dotnet/runtime dotnet/dotnet#7617

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dotnet-milestone-bot Bot modified the milestones: 11.0.0, 11.0-preview7 Jul 10, 2026

lewing mentioned this pull request Jul 11, 2026

[wasm] Fix CoreCLR P/Invoke EntryCount for libSystem.Globalization.Native #130543

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tarekgh commented Jul 2, 2026

APIs

Notes

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