`tests/ui/debuginfo/debuginfo-type-name-layout-ice-94961-2.rs` Emits "values Of The Type `[u8; Usize::MAX]` Are Too Big For The Target Architecture" Differently

May 3, 2025 by ADMIN 161 views

**Debugging the `tests/ui/debuginfo/debuginfo-type-name-layout-ice-94961-2.rs` Test Failure**

Introduction

The tests/ui/debuginfo/debuginfo-type-name-layout-ice-94961-2.rs test is designed to verify the correctness of the debug information generated by the Rust compiler. However, this test has been failing with a cryptic error message on certain architectures. In this article, we will delve into the details of this issue and explore possible solutions.

The Error Message

The error message reported by the test is:

values of the type `[u8; usize::MAX]` are too big for the target architecture

This message suggests that the Rust compiler is unable to generate debug information for arrays of type [u8; usize::MAX] due to size constraints.

Understanding the Issue

To better understand the issue, let's analyze the test code. The test creates an array of type [u8; usize::MAX] and attempts to generate debug information for it. However, the Rust compiler is unable to generate debug information for this array due to its large size.

The Problem with `usize::MAX`

The issue lies in the use of usize::MAX as the size of the array. usize::MAX is the maximum value that can be represented by the usize type, which is an unsigned integer type. On 64-bit architectures, usize::MAX is equal to 2^64 - 1, which is a very large number.

The Solution

To fix this issue, we need to modify the test code to use a smaller size for the array. One possible solution is to use a fixed size for the array, such as 1024 or 2048. This will ensure that the array is small enough to be generated by the Rust compiler.

Modified Test Code

Here is the modified test code:

#[test]
fn debuginfo_type_name_layout() {
    let arr: [u8; 1024] = [0; 1024];
    // ...
}

Conclusion

In conclusion, the tests/ui/debuginfo/debuginfo-type-name-layout-ice-94961-2.rs test failure is due to the use of usize::MAX as the size of the array. To fix this issue, we need to modify the test code to use a smaller size for the array. By using a fixed size, we can ensure that the array is small enough to be generated by the Rust compiler.

Additional Information

For more information on this issue, please refer to the following resources:

Example Test Failure

Here is an example of the test failure:

2025-05-03T13:15:27.5986675Z failures:
2025-05-03T13:15:27.5986936Z 
2025-05-03T13:15:27.5987603Z ---- [ui] tests\ui\debug\debuginfo-type-name-layout-ice-94961-2.rs stdout ----
2025-05-03T13:15:27.5988107Z 
2025-05-03T13:15:27.6243506Z error: D:/a/rust/rust/tests/ui/debuginfo/debuginfo-type-name-layout-ice-94961-2.rs:?: unexpected ERROR: '?:?: ?:?: values of the type `[u8; usize::MAX]` are too big for the target architecture'
2025-05-03T13:15:27.6244751Z 
2025-05-03T13:15:27.6245568Z error: D:/a/rust/rust/tests/ui/debuginfo/debuginfo-type-name-layout-ice-94961-2.rs:1: expected ERROR not found: values of the type `[u8; usize::MAX]` are too big for the target architecture
2025-05-03T13:15:27.6246383Z 
2025-05-03T13:15:27.6246602Z error: 1 unexpected errors found, 1 expected errors not found
2025-05-03T13:15:27.6247012Z status: exit code: 1
2025-05-03T13:15:27.6262898Z command: PATH="D:\a\rust\rust\build\x86_64-pc-windows-msvc\stage2\bin;C:\Program Files (x86)\Windows Kits\10\bin\x64;C:\Program Files (x86)\Windows Kits\10\bin\10.0.26100.0\x64;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.43.34808\bin\HostX64\x64;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.43.34808\bin\HostX64\x64;D:\a\rust\rust\build\x86_64-pc-windows-msvc\stage0-bootstrap-tools\x86_64-pc-windows-msvc\release\deps;D:\a\rust\rust\build\x86_64-pc-windows-msvc\stage0\bin;C:\Program Files\Git\mingw64\bin;C:\Program Files\Git\usr\bin;C:\Users\runneradmin\bin;D:\a\rust\rust\ninja;D:\a\rust\rust\sccache;C:\Program Files\MongoDB\Server\7.0\bin;C:\vcpkg;C:\tools\zstd;C:\hostedtoolcache\windows\stack\3.5.1\x64;C:\cabal\bin;C:\ghcup\bin;C:\mingw64\bin;C:\Program Files\dotnet;C:\Program Files\MySQL\MySQL Server 8.0\bin;C:\Program Files\R\R-4.4.2\bin\x64;C:\SeleniumWebDrivers\GeckoDriver;C:\SeleniumWebDrivers\EdgeDriver;C:\SeleniumWebDrivers\ChromeDriver;C:\Program Files (x86)\sbt\bin;C:\Program Files (x86)\GitHub CLI;C:\Program Files\Git\usr\bin;C:\Program Files (x86)\pipx_bin;C:\npm\prefix;C:\hostedtoolcache\windowsgo\1.23.8\x64\bin;C:\hostedtoolcache\windows\Python\3.9.13\x64\Scripts;C:\hostedtoolcache\windows\Python\3.9.13\x64;C:\hostedtoolcache\windows\Ruby\3.3.8\x64\bin;C:\Program Files\OpenSSL\bin;C:\tools\kotlinc\bin;C:\hostedtoolcache\windows\Java_Temurin-Hotspot_jdk\17.0.15-6\x64\bin;C:\Program Files\ImageMagick-7.1.1-Q16-HDRI;C:\Program Files\Microsoft SDKs\Azure\CLI2\wbin;C:\ProgramData\kind;C:\ProgramData\Chocolatey\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0;C:\Windows\System32\OpenSSH;C:\Program Files\PowerShell\7;C:\Program Files\Microsoft\Web Platform Installer;C:\Program Files\Microsoft SQL Server\Client SDK\ODBC\170\Tools\Binn;C:\Program Files\Microsoft SQL Server\150\Tools\Binn;C:\Program Files\dotnet;C:\Program Files (x86)\Windows Kits\10\Windows Performance Toolkit;C:\Program Files (x86)\WiX Toolset v3.14\bin;C:\Program Files\Microsoft SQL Server\130\DTS\Binn;C:\Program Files\Microsoft SQL Server\140\DTS\Binn;C:\Program Files\Microsoft SQL Server\150\DTS\Binn;C:\Program Files\Microsoft SQL Server\160\DTS\Binn;C:\ProgramData\chocolatey\lib\pulumi\tools\Pulumi\bin;C:\Program Files\CMake\bin;C:\Strawberry\c\bin;C:\Strawberry\perl\site\bin;C:\Strawberry\perl\bin;C:\ProgramData\chocolatey\lib\maven\apache-maven-3.9.9\bin;C:\Program Files\Microsoft Service Fabric\bin\Fabric\Fabric.Code;C:\Program Files\Microsoft SDKs\Service Fabric\Tools\ServiceFabricLocalClusterManager;C:\Program Files\nodejs;C:\Program Files\Git\cmd;C:\Program Files\Git\mingw64\bin;C:\Program Files\Git\usr\bin;C:\Program Files\GitHub CLI;C:\tools\php;C:\Program Files (x86)\sbt\bin;C:\Program Files\Amazon\AWSCLIV2;C:\Program Files<br/>
**Q&A: Debugging the `tests/ui/debuginfo/debuginfo-type-name-layout-ice-94961-2.rs` Test Failure**
====================================================================================

**Q: What is the `tests/ui/debuginfo/debuginfo-type-name-layout-ice-94961-2.rs` test?**
--------------------------------------------------------------------------------

A: The `tests/ui/debuginfo/debuginfo-type-name-layout-ice-94961-2.rs` test is a Rust test that verifies the correctness of the debug information generated by the Rust compiler.

**Q: What is the error message reported by the test?**
------------------------------------------------

A: The error message reported by the test is:

values of the type [u8; usize::MAX] are too big for the target architecture


**Q: What is the cause of the error message?**
------------------------------------------------

A: The cause of the error message is the use of `usize::MAX` as the size of the array in the test code. `usize::MAX` is the maximum value that can be represented by the `usize` type, which is an unsigned integer type. On 64-bit architectures, `usize::MAX` is equal to `2^64 - 1`, which is a very large number.

**Q: How can I fix the error message?**
-----------------------------------------

A: To fix the error message, you can modify the test code to use a smaller size for the array. One possible solution is to use a fixed size for the array, such as `1024` or `2048`. This will ensure that the array is small enough to be generated by the Rust compiler.

**Q: What are the implications of using `usize::MAX` as the size of the array?**
--------------------------------------------------------------------------------

A: Using `usize::MAX` as the size of the array can lead to a number of issues, including:

* The array may be too large to be generated by the Rust compiler.
* The array may not be properly aligned in memory, leading to issues with pointer arithmetic.
* The array may not be properly initialized, leading to issues with data corruption.

**Q: How can I avoid using `usize::MAX` as the size of the array?**
-------------------------------------------------------------------

A: To avoid using `usize::MAX` as the size of the array, you can use a fixed size for the array instead. This will ensure that the array is small enough to be generated by the Rust compiler and properly aligned in memory.

**Q: What are some best practices for debugging the `tests/ui/debuginfo/debuginfo-type-name-layout-ice-94961-2.rs` test?**
-----------------------------------------------------------------------------------------

A: Some best practices for debugging the `tests/ui/debuginfo/debuginfo-type-name-layout-ice-94961-2.rs` test include:

* Use a debugger to step through the test code and identify the source of the error.
* Use print statements or logging to output information about the test code and its execution.
* Use a code review tool to review the test code and identify potential issues.
* Use a testing framework to write and run tests for the test code.

**Q: Where can I find more information about the `tests/ui/debuginfo/debuginfo-type-name-layout-ice-94961-2.rs` test?**
-----------------------------------------------------------------------------------------

A: You can find more information about the `tests/ui/debuginfo/debug-type-name-layout-ice-94961-2.rs` test in the following resources:

* [Rust issue #140586](https://github.com/rust-lang/rust/pull/140586#issuecomment-2848494132)
* [Rust documentation on debug information](https://doc.rust-lang.org/book/ch15-06-debugging.html)

**Q: How can I contribute to the `tests/ui/debuginfo/debuginfo-type-name-layout-ice-94961-2.rs` test?**
-----------------------------------------------------------------------------------------

A: You can contribute to the `tests/ui/debuginfo/debuginfo-type-name-layout-ice-94961-2.rs` test by:

* Reporting issues or bugs with the test code.
* Submitting patches or pull requests to fix issues or improve the test code.
* Participating in discussions on the Rust issue tracker or mailing list to provide feedback and suggestions for the test code.