Implement native esp-idf cmake build

Move `build.rs` contents to `build_pio.rs`
Add feature `native`
Add optional dependency `strum`

Cargo.toml

@@ -16,15 +16,21 @@ links = "esp_idf"
 default-target = "x86_64-unknown-linux-gnu"
 
 [features]
-default = ["std", "embedded-svc/std"]
+default = ["std", "embedded-svc/std", "native"]
 
 std = []
 
+# Use `platformio` to build the `esp-idf`
+platformio = []
+# Use native `esp-idf` tooling to build it
+native = ["strum"]
+
 [dependencies]
 mutex-trait = "0.2"
 embedded-svc = "0.8.3"
 paste = "1"
 
 [build-dependencies]
 embuild = "0.23"
-anyhow = "1"
+anyhow = {version = "1", features = ["backtrace"]}
+strum = { version = "0.21", optional = true, features = ["derive"] }

build.rs

@@ -1,136 +1,14 @@
-use std::convert::TryFrom;
-use std::{env, path::PathBuf};
+#[cfg(not(any(feature = "pio", feature = "native")))]
+compile_error!("One of the features `platformio` or `native` must be selected.");
 
-use anyhow::*;
+#[cfg(all(feature = "pio", feature = "native"))]
+compile_error!("The features `platformio` and `native` are mutually exclusive. Only one of them can be selected at a time.");
 
-use embuild::bindgen;
-use embuild::build;
-use embuild::cargo;
-use embuild::kconfig;
-use embuild::pio;
-use embuild::pio::project;
+#[cfg(any(feature = "platformio", feature = "native"))]
+#[cfg_attr(feature = "platformio", path = "build_pio.rs")]
+#[cfg_attr(feature = "native", path = "build_native.rs")]
+mod build_impl;
 
-fn main() -> Result<()> {
-    let pio_scons_vars = if let Some(pio_scons_vars) = project::SconsVariables::from_piofirst() {
-        println!("cargo:info=PIO->Cargo build detected: generating bindings only");
-
-        pio_scons_vars
-    } else {
-        let pio = pio::Pio::install_default()?;
-
-        let resolution = pio::Resolver::new(pio.clone())
-            .params(pio::ResolutionParams {
-                platform: Some("espressif32".into()),
-                frameworks: vec!["espidf".into()],
-                target: Some(env::var("TARGET")?),
-                ..Default::default()
-            })
-            .resolve(true)?;
-
-        let mut builder =
-            project::Builder::new(PathBuf::from(env::var("OUT_DIR")?).join("esp-idf"));
-
-        builder
-            .enable_scons_dump()
-            .enable_c_entry_points()
-            .options(build::env_options_iter("ESP_IDF_SYS_PIO_CONF")?)
-            .files(build::tracked_globs_iter(
-                PathBuf::from("."),
-                &["patches/**"],
-            )?)
-            .files(build::tracked_env_globs_iter("ESP_IDF_SYS_GLOB")?);
-
-        #[cfg(feature = "espidf_master")]
-        builder
-            .platform_package(
-                "framework-espidf",
-                "https://github.com/ivmarkov/esp-idf.git#master",
-            )
-            .platform_package_patch(
-                PathBuf::from("patches").join("master_missing_xtensa_atomics_fix.diff"),
-                PathBuf::from("framework-espidf"),
-            )
-            .platform_package_patch(
-                PathBuf::from("patches").join("ping_setsockopt_fix.diff"),
-                PathBuf::from("framework-espidf"),
-            );
-
-        #[cfg(feature = "espidf_master")]
-        env::set_var("IDF_MAINTAINER", "1");
-
-        #[cfg(not(feature = "espidf_master"))]
-        builder
-            .platform_package_patch(
-                PathBuf::from("patches").join("pthread_destructor_fix.diff"),
-                PathBuf::from("framework-espidf"),
-            )
-            .platform_package_patch(
-                PathBuf::from("patches").join("ping_setsockopt_fix.diff"),
-                PathBuf::from("framework-espidf"),
-            )
-            .platform_package_patch(
-                PathBuf::from("patches").join("missing_xtensa_atomics_fix.diff"),
-                PathBuf::from("framework-espidf"),
-            );
-
-        let project_path = builder.generate(&resolution)?;
-
-        pio.build(&project_path, env::var("PROFILE")? == "release")?;
-
-        let pio_scons_vars = project::SconsVariables::from_dump(&project_path)?;
-
-        build::LinkArgsBuilder::try_from(&pio_scons_vars)?
-            .build()
-            .propagate();
-
-        pio_scons_vars
-    };
-
-    // In case other SYS crates need to have access to the ESP-IDF C headers
-    build::CInclArgs::try_from(&pio_scons_vars)?.propagate();
-
-    let cfg_args = kconfig::CfgArgs::try_from(
-        pio_scons_vars
-            .project_dir
-            .join(if pio_scons_vars.release_build {
-                "sdkconfig.release"
-            } else {
-                "sdkconfig.debug"
-            })
-            .as_path(),
-    )?;
-
-    cfg_args.propagate("ESP_IDF");
-    cfg_args.output("ESP_IDF");
-
-    let mcu = pio_scons_vars.mcu.as_str();
-
-    // Output the exact ESP32 MCU, so that we and crates depending directly on us can branch using e.g. #[cfg(esp32xxx)]
-    println!("cargo:rustc-cfg={}", mcu);
-    println!("cargo:MCU={}", mcu);
-
-    let header = PathBuf::from("src")
-        .join("include")
-        .join(if mcu == "esp8266" {
-            "esp-8266-rtos-sdk"
-        } else {
-            "esp-idf"
-        })
-        .join("bindings.h");
-
-    cargo::track_file(&header);
-
-    bindgen::run(
-        bindgen::Factory::from_scons_vars(&pio_scons_vars)?
-            .builder()?
-            .ctypes_prefix("c_types")
-            .header(header.to_string_lossy())
-            .blacklist_function("strtold")
-            .blacklist_function("_strtold_r")
-            .clang_args(if mcu == "esp32c3" {
-                vec!["-target", "riscv32"]
-            } else {
-                vec![]
-            }),
-    )
-}
+fn main() -> anyhow::Result<()> {
+    build_impl::main()
+}