The “cargo rustc” command is a tool in the Rust programming language that allows developers to compile a Rust package and pass additional options directly to the Rust compiler (“rustc”). It provides flexibility and customization by enabling developers to specify compiler-specific flags and configurations.
Here are the key features and functionalities of “cargo rustc”:
- Compilation Control: “cargo rustc” gives developers granular control over the compilation process of a Rust package. It invokes the Rust compiler (“rustc”) to compile the package’s source code into executable binaries or libraries. By using “cargo rustc,” developers can override the default compilation behavior and provide additional compiler options to tailor the build process to specific requirements.
- Custom Compiler Flags: With “cargo rustc,” developers can pass extra options and flags directly to the underlying Rust compiler. These options can include optimization settings, target specifications, debug symbols, code generation flags, and other compiler-specific configurations. By specifying these options, developers can fine-tune the compilation process to optimize performance, control binary size, or meet specific platform requirements.
- Conditional Compilation: “cargo rustc” supports conditional compilation, allowing developers to specify different compiler options based on specific conditions. This feature is particularly useful when targeting different platforms or when certain code sections require specific compiler settings. By utilizing conditional compilation, developers can ensure that the appropriate compiler flags are applied only when needed.
- Build Overrides: “cargo rustc” allows developers to override the build scripts defined in the Rust package. Build scripts are scripts written in Rust that can be executed before or during the compilation process. By using “cargo rustc,” developers can provide their custom build script or specify modifications to the existing build script, enabling further customization and control over the build process.
- Target Platform Configuration: Developers can use “cargo rustc” to specify the target platform for compilation. This is particularly useful when cross-compiling Rust code for different architectures or operating systems. By passing the appropriate target specifications, developers can ensure that the code is compiled for the desired platform, enabling portability and compatibility.
Integration with Cargo: “cargo rustc” seamlessly integrates with the Cargo package manager, which is the standard build tool for Rust projects. It leverages the project’s existing configuration and dependency management provided by Cargo. This integration allows developers to combine the flexibility of “cargo rustc” with the convenience of Cargo’s package management capabilities.
Build Output and Artifact Management: Once the compilation process is complete, “cargo rustc” generates the output artifacts, such as executable binaries or libraries, based on the specified compilation options. The resulting artifacts are stored in the project’s target directory, organized according to the target platform and build configuration.
“cargo rustc” provides Rust developers with enhanced control and customization over the compilation process by allowing them to pass additional options and flags directly to the underlying Rust compiler. This flexibility enables developers to optimize performance, tailor the build process to specific requirements, and target different platforms or architectures. By integrating with Cargo, “cargo rustc” combines the benefits of custom compilation with the convenience of Cargo’s package management capabilities.
cargo rustc Command Examples
1. Build the package or packages defined by the Cargo.toml manifest file in the current working directory:
# cargo rustc
2. Build artifacts in release mode, with optimizations:
# cargo rustc --release
3. Compile with architecture-specific optimizations for the current CPU:
# cargo rustc --release -- -C target-cpu=native
4. Compile with speed optimization:
# cargo rustc -- -C opt-level [1|2|3]
5. Compile with [s]ize optimization (z also turns off loop vectorization):
# cargo rustc -- -C opt-level [s|z]
6. Check if your package uses unsafe code:
# cargo rustc --lib -- -D unsafe-code
7. Build a specific package:
# cargo rustc --package package
8. Build only the specified binary:
# cargo --bin name