Target-Specific Code Generation in Rust

In software development, it's often necessary to tailor code execution based on the target environment or platform. This can involve optimizing for specific hardware architectures, enabling or disabling features, or adhering to platform-specific conventions. This challenge focuses on leveraging Rust's build system and conditional compilation to generate code that is specific to different target platforms.

Problem Description

Your task is to create a Rust program that can generate different output based on the target architecture it's compiled for. You will use Rust's conditional compilation features (specifically cfg attributes) to achieve this. The program should define a function that returns a string. This string should indicate the target operating system and architecture.

Key Requirements:

1. Conditional Compilation: Implement different logic based on the target OS and architecture.
2. Function Definition: Create a public function, let's call it get_target_info, that returns a String.
3. Output Format: The returned String should clearly state the detected operating system and architecture. For example: "Running on: [OS] ([Architecture])".
4. Support Common Targets: The solution should demonstrate how to handle at least two different operating systems (e.g., Linux and Windows) and at least two different architectures (e.g., x86_64 and aarch64).

Expected Behavior:

When compiled for a specific target (e.g., x86_64-unknown-linux-gnu), the get_target_info function should return a string reflecting that target. When compiled for another target (e.g., x86_64-pc-windows-msvc), it should return a string appropriate for that target.

Edge Cases:

• Consider how to handle cases where a specific combination of OS and architecture isn't explicitly defined, falling back to a more general detection if necessary (though for this challenge, explicit definitions for the required targets are sufficient).

Examples

Example 1:

Input: (Conceptual - this is determined at compile time)

• Target Triple: x86_64-unknown-linux-gnu

Output:

Running on: Linux (x86_64)

Explanation: The code was compiled for a Linux system with an x86_64 architecture.

Example 2:

Input: (Conceptual - this is determined at compile time)

• Target Triple: x86_64-pc-windows-msvc

Output:

Running on: Windows (x86_64)

Explanation: The code was compiled for a Windows system with an x86_64 architecture.

Example 3: (Demonstrating a different architecture)

Input: (Conceptual - this is determined at compile time)

• Target Triple: aarch64-unknown-linux-gnu

Output:

Running on: Linux (aarch64)

Explanation: The code was compiled for a Linux system with an ARM 64-bit (aarch64) architecture.

Constraints

• The primary mechanism for achieving target-specific behavior must be Rust's #[cfg] attribute.
• The get_target_info function must be public and available for use by other modules.
• You should use the target_os and target_arch configuration predicates.
• Performance is not a critical concern for this specific challenge, but the generated code should be idiomatic Rust.

Notes

• You can use cargo build --target <target-triple> to compile for specific targets. Common target triples include:
  • x86_64-unknown-linux-gnu
  • x86_64-pc-windows-msvc
  • aarch64-unknown-linux-gnu
  • x86_64-apple-darwin (macOS)
• To see available target triples on your system, you can use rustc --print target-list.
• Consider how you might structure your code within a module (e.g., src/lib.rs if you're creating a library).
• Think about how to define your get_target_info function to encapsulate the conditional logic effectively.