refactor(cust_raw): Update cargo metadata names and add crate docs for the build script.

Author: jorge-ortega

crates/cudnn-sys/build/main.rs

@@ -5,7 +5,7 @@ pub mod cudnn_sdk;
 
 fn main() {
     let sdk = cudnn_sdk::CudnnSdk::new().expect("Cannot create cuDNN SDK instance.");
-    let cuda_include_paths = env::var_os("DEP_CUDA_CUDA_INCLUDE")
+    let cuda_include_paths = env::var_os("DEP_CUDA_INCLUDES")
         .map(|s| env::split_paths(s.as_os_str()).collect::<Vec<_>>())
         .expect("Cannot find transitive metadata 'cuda_include' from cust_raw package.");
 

crates/cust_raw/build/main.rs

@@ -1,3 +1,29 @@
+//! # The build script for cust_raw
+//! The build script for the cust_raw generates bindings for libraries in the
+//! CUDA SDK. The build scripts searches for the CUDA SDK by reading the
+//! `CUDA_PATH`, `CUDA_ROOT`, or `CUDA_TOOLKIT_ROOT_DIR` environment variables
+//! in that order. If none of these variables are set to a vaild CUDA Toolkit
+//! SDK path, the build script will attempt to search for any SDK in the
+//! default installation locations for the current platform.
+//!
+//! ## Bindings
+//! You can control which bindings are generated by enabling features in your
+//! `Cargo.toml` file. By default, only the CUDA driver API is enabled.
+//!
+//! ## Cargo metadata
+//! The build script emits Cargo metadata that can be used by dependent crates
+//! in their build script. You can read this metadata via `DEP_CUDA_*`
+//! environment variables. The current list of metadata includes:
+//!
+//! - `DEP_CUDA_ROOT`: The root directory of the CUDA SDK installation used.
+//! - `DEP_CUDA_DRIVER_VERSION`: The version of the CUDA driver API found (e.g: `12080`).
+//! - `DEP_CUDA_DRIVER_VERSION_MAJOR`: The major version of the CUDA driver API found.
+//! - `DEP_CUDA_DRIVER_VERSION_MINOR`: The minor version of the CUDA driver API found.
+//! - `DEP_CUDA_RUNTIME_VERSION`: The version of the CUDA runtime API found.
+//! - `DEP_CUDA_INCLUDES`: The include directories for the CUDA SDK, separated by platform-specific path separator.
+//! - `DEP_CUDA_NVVM_INCLUDES`: The include directories for NVVM headers, separated by platform-specific path separator.
+//!
+
 use std::env;
 use std::fs;
 use std::path;
@@ -29,8 +55,8 @@ fn main() {
     let metadata_nvvm_include = env::join_paths(sdk.nvvm_include_paths())
         .map(|s| s.to_string_lossy().to_string())
         .expect("Failed to build metadata for nvvm_include.");
-    println!("cargo::metadata=cuda_include={}", metadata_cuda_include);
-    println!("cargo::metadata=nvvm_include={}", metadata_nvvm_include);
+    println!("cargo::metadata=includes={}", metadata_cuda_include);
+    println!("cargo::metadata=nvvm_includes={}", metadata_nvvm_include);
     // Re-run build script conditions.
     println!("cargo::rerun-if-changed=build");
     for e in sdk.related_cuda_envs() {

crates/optix-sys/build/main.rs

@@ -10,7 +10,7 @@ pub mod optix_sdk;
 // to a lib and link it in so that we have the initialization and C function logic.
 fn main() {
     let sdk = optix_sdk::OptiXSdk::new().expect("Cannot create OptiX SDK instance.");
-    let cuda_include_paths = env::var_os("DEP_CUDA_CUDA_INCLUDE")
+    let cuda_include_paths = env::var_os("DEP_CUDA_INCLUDES")
         .map(|s| env::split_paths(s.as_os_str()).collect::<Vec<_>>())
         .expect("Cannot find transitive metadata 'cuda_include' from cust_raw package.");