embed-resource

embed-resource is a Cargo build-script library that handles the compilation and inclusion of Windows resources — icons, version info, and application manifests defined in .rc files — into your Rust executables. Called from build.rs, it detects the available resource compiler (MSVC’s rc.exe or the GNU windres toolchain) and links the compiled resources into the final binary.

It is designed to be as resilient as possible across toolchains and cross-compilation setups, with per-binary resource selection, optional versus required manifest handling, and preprocessor macro support.

What You Get

• compile and compile_for build-script functions to compile and link .rc resource files
• Automatic detection of the MSVC (rc.exe) versus GNU (windres) resource toolchain
• manifest_optional() / manifest_required() handling to control failure behavior for manifests
• Preprocessor macro passing and per-binary resource targeting via IntoIterator arguments

Common Use Cases

• Embedding an application icon and version metadata into a Windows executable
• Bundling a Windows manifest for elevation, DPI awareness, or Common Controls
• Selecting different resource files for multiple binaries in one workspace

Under The Hood

Architecture - The crate is a build-time helper whose public API lives in src/lib.rs, delegating the actual compilation to platform modules: windows_msvc.rs drives Microsoft’s rc.exe, windows_not_msvc.rs drives the GNU windres/llvm-rc path, and non_windows.rs provides no-op stubs so cross-platform build scripts compile unconditionally. compile/compile_for return a result object whose manifest_optional/manifest_required methods decide whether a missing or failed manifest is fatal, after which linker cargo:rustc-link directives are emitted. A small main.rs provides a standalone helper binary.

Tech Stack - Pure Rust, edition 2021, MSRV 1.76. It shells out to the host’s native resource compiler rather than bundling one, keeping the dependency footprint minimal, and integrates with Cargo’s build-script protocol to communicate object/link paths back to the build.

Code Quality - With 205+ commits from 29 contributors over nearly a decade and 22 releases, the project is battle-tested across MSVC, MinGW, and cross-compilation scenarios; CI runs on both AppVeyor and GitHub Actions with dedicated MSVC test scripts. The codebase carefully isolates each toolchain into its own module and documents the many toolchain edge cases it guards against.

API Design - The API is compact and forgiving: a single compile call covers the common case, compile_for handles per-binary targeting, and arguments accept anything implementing IntoIterator<AsRef<OsStr>> so callers can pass slices, Vecs, or Options interchangeably. The explicit manifest_optional/manifest_required split makes failure semantics clear at the call site.