[src] Update code to honor the first rule of unsafe coding practices. #23835

rolfbjarne · 2025-09-17T15:05:24Z

Don't do this:

unsafe void UnreliableCode(ref int x)
{
    int* nativePointer = (int*)Unsafe.AsPointer(ref x);
    nativePointer[0] = 42;
}

The reason being is that the GC can move the 'ref int' argument (which doesn't
seem right at first glance, but objects can be moved by the GC, and the 'ref
int' argument can point to an int field inside an object), which would make
the pointer point to an invalid memory location.

The proper pattern is:

unsafe void ReliableCode(ref int x)
{
	fixed (int* ptr = &x) {
	    ptr[0] = 42;
	}
}

So update everything to use this pattern instead.

References:

https://github.com/dotnet/designs/blob/67ad92c511d8f6a2b8b500bd6f13f865b163e282/accepted/2025/memory-safety/unsafe-code-guidelines.md#1-untracked-managed-pointers-unsafeaspointer-and-friends

Don't do this: ```cs unsafe void UnreliableCode(ref int x) { int* nativePointer = (int*)Unsafe.AsPointer(ref x); nativePointer[0] = 42; } ``` The reason being is that the GC can move the 'ref int' argument (which doesn't seem right at first glance, but objects can be moved by the GC, and the 'ref int' argument can point to an integer field inside an object). The proper pattern is: ```cs unsafe void ReliableCode(ref int x) { fixed (int* ptr = &x) { ptr[0] = 42; } } ``` So update everything to use this pattern instead. References: * https://github.com/dotnet/designs/blob/67ad92c511d8f6a2b8b500bd6f13f865b163e282/accepted/2025/memory-safety/unsafe-code-guidelines.md#1-untracked-managed-pointers-unsafeaspointer-and-friends

vs-mobiletools-engineering-service2 · 2025-09-18T21:17:57Z

✅ API diff for current PR / commit

NET (empty diffs)

iOS: vsdrops gist ( No breaking changes )
tvOS: vsdrops gist ( No breaking changes )
MacCatalyst: vsdrops gist ( No breaking changes )
macOS: vsdrops gist ( No breaking changes )

✅ API diff vs stable

NET (empty diffs)

iOS: vsdrops gist ( No breaking changes )
tvOS: vsdrops gist ( No breaking changes )
MacCatalyst: vsdrops gist ( No breaking changes )
macOS: vsdrops gist ( No breaking changes )

ℹ️ Generator diff

Generator Diff: vsdrops (html) vsdrops (raw diff) gist (raw diff) - Please review changes)

Pipeline on Agent
Hash: 12e381c3a5012e6e04a9c7230271b4b24610bd62 [PR build]

vs-mobiletools-engineering-service2 · 2025-09-18T23:59:10Z

✅ [CI Build #12e381c] Build passed (Build macOS tests) ✅

Pipeline on Agent
Hash: 12e381c3a5012e6e04a9c7230271b4b24610bd62 [PR build]

vs-mobiletools-engineering-service2 · 2025-09-19T00:08:25Z

💻 [CI Build #12e381c] Tests on macOS X64 - Mac Sonoma (14) passed 💻

✅ All tests on macOS X64 - Mac Sonoma (14) passed.

Pipeline on Agent
Hash: 12e381c3a5012e6e04a9c7230271b4b24610bd62 [PR build]

vs-mobiletools-engineering-service2 · 2025-09-19T00:11:50Z

💻 [CI Build #12e381c] Tests on macOS M1 - Mac Monterey (12) passed 💻

✅ All tests on macOS M1 - Mac Monterey (12) passed.

Pipeline on Agent
Hash: 12e381c3a5012e6e04a9c7230271b4b24610bd62 [PR build]

vs-mobiletools-engineering-service2 · 2025-09-19T00:12:52Z

💻 [CI Build #12e381c] Tests on macOS arm64 - Mac Sequoia (15) passed 💻

✅ All tests on macOS arm64 - Mac Sequoia (15) passed.

Pipeline on Agent
Hash: 12e381c3a5012e6e04a9c7230271b4b24610bd62 [PR build]

vs-mobiletools-engineering-service2 · 2025-09-19T00:14:29Z

💻 [CI Build #12e381c] Tests on macOS M1 - Mac Ventura (13) passed 💻

✅ All tests on macOS M1 - Mac Ventura (13) passed.

Pipeline on Agent
Hash: 12e381c3a5012e6e04a9c7230271b4b24610bd62 [PR build]

vs-mobiletools-engineering-service2 · 2025-09-19T00:14:59Z

💻 [CI Build #12e381c] Tests on macOS arm64 - Mac Tahoe (26) passed 💻

✅ All tests on macOS arm64 - Mac Tahoe (26) passed.

Pipeline on Agent
Hash: 12e381c3a5012e6e04a9c7230271b4b24610bd62 [PR build]

vs-mobiletools-engineering-service2 · 2025-09-19T06:02:47Z

🚀 [CI Build #12e381c] Test results 🚀

Test results

✅ All tests passed on VSTS: test results.

🎉 All 126 tests passed 🎉

Tests counts

✅ cecil: All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (iOS): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (MacCatalyst): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (macOS): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (Multiple platforms): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (tvOS): All 1 tests passed. Html Report (VSDrops) Download
✅ framework: All 2 tests passed. Html Report (VSDrops) Download
✅ fsharp: All 4 tests passed. Html Report (VSDrops) Download
✅ generator: All 5 tests passed. Html Report (VSDrops) Download
✅ interdependent-binding-projects: All 4 tests passed. Html Report (VSDrops) Download
✅ introspection: All 6 tests passed. Html Report (VSDrops) Download
✅ linker: All 44 tests passed. Html Report (VSDrops) Download
✅ monotouch (iOS): All 10 tests passed. Html Report (VSDrops) Download
✅ monotouch (MacCatalyst): All 15 tests passed. Html Report (VSDrops) Download
✅ monotouch (macOS): All 12 tests passed. Html Report (VSDrops) Download
✅ monotouch (tvOS): All 8 tests passed. [attempt 6] Html Report (VSDrops) Download
✅ msbuild: All 2 tests passed. Html Report (VSDrops) Download
✅ windows: All 3 tests passed. Html Report (VSDrops) Download
✅ xcframework: All 4 tests passed. Html Report (VSDrops) Download
✅ xtro: All 1 tests passed. Html Report (VSDrops) Download

Pipeline on Agent
Hash: 12e381c3a5012e6e04a9c7230271b4b24610bd62 [PR build]

rolfbjarne requested a review from dalexsoto as a code owner September 17, 2025 15:05

Auto-format source code

7fd50a6

This comment has been minimized.

Sign in to view

dalexsoto approved these changes Sep 17, 2025

View reviewed changes

This comment has been minimized.

Sign in to view

Base automatically changed from dev/rolf/xcode26.0-into-main to main September 19, 2025 01:03

dalexsoto enabled auto-merge (squash) September 19, 2025 01:48

This comment has been minimized.

Sign in to view

dalexsoto merged commit 6f3671d into main Sep 19, 2025
45 checks passed

dalexsoto deleted the dev/rolf/notaspointer branch September 19, 2025 06:03

[src] Update code to honor the first rule of unsafe coding practices. #23835

[src] Update code to honor the first rule of unsafe coding practices. #23835

Uh oh!

Conversation

rolfbjarne commented Sep 17, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

vs-mobiletools-engineering-service2 commented Sep 18, 2025

✅ API diff for current PR / commit

✅ API diff vs stable

ℹ️ Generator diff

Uh oh!

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

vs-mobiletools-engineering-service2 commented Sep 18, 2025

✅ [CI Build #12e381c] Build passed (Build macOS tests) ✅

Uh oh!

This comment has been minimized.

vs-mobiletools-engineering-service2 commented Sep 19, 2025

💻 [CI Build #12e381c] Tests on macOS X64 - Mac Sonoma (14) passed 💻

Uh oh!

vs-mobiletools-engineering-service2 commented Sep 19, 2025

💻 [CI Build #12e381c] Tests on macOS M1 - Mac Monterey (12) passed 💻

Uh oh!

vs-mobiletools-engineering-service2 commented Sep 19, 2025

💻 [CI Build #12e381c] Tests on macOS arm64 - Mac Sequoia (15) passed 💻

Uh oh!

vs-mobiletools-engineering-service2 commented Sep 19, 2025

💻 [CI Build #12e381c] Tests on macOS M1 - Mac Ventura (13) passed 💻

Uh oh!

vs-mobiletools-engineering-service2 commented Sep 19, 2025

💻 [CI Build #12e381c] Tests on macOS arm64 - Mac Tahoe (26) passed 💻

Uh oh!

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

vs-mobiletools-engineering-service2 commented Sep 19, 2025

🚀 [CI Build #12e381c] Test results 🚀

Test results

Tests counts

Uh oh!

Uh oh!

rolfbjarne commented Sep 17, 2025 •

edited

Loading