Add custom platform configuration (#65)

Cargo.toml

@@ -32,7 +32,7 @@ keywords = ["api-bindings", "wasm", "webassembly"]
 wamr-sys = { path = "crates/wamr-sys", version = "1.0.0" }
 
 [target.'cfg( target_os = "espidf" )'.dependencies]
-esp-idf-sys = { version = "0.35" }
+esp-idf-sys = { version = "0.35", optional = true }
 
 [[package.metadata.esp-idf-sys.extra_components]]
 bindings_header = "./crates/wamr-sys/wasm-micro-runtime/core/iwasm/include/wasm_export.h"
@@ -44,3 +44,4 @@ dump-call-stack = ["wamr-sys/dump-call-stack"]
 llvmjit = ["wamr-sys/llvmjit"]
 multi-module = ["wamr-sys/multi-module"]
 name-section = ["wamr-sys/name-section"]
+esp-idf = ["esp-idf-sys", "wamr-sys/esp-idf"]

crates/wamr-sys/Cargo.toml

@@ -37,3 +37,4 @@ llvmjit = []
 multi-module = []
 name-section = [ "custom-section" ]
 std = []
+esp-idf = []

crates/wamr-sys/build.rs

@@ -14,9 +14,21 @@ fn main() {
     let wamr_root = wamr_root.join("wasm-micro-runtime");
     assert!(wamr_root.exists());
 
-    let no_espidf = env::var("CARGO_CFG_TARGET_OS").unwrap() != "espidf";
+    println!("cargo:rerun-if-env-changed=WAMR_BUILD_PLATFORM");
+    println!("cargo:rerun-if-env-changed=WAMR_SHARED_PLATFORM_CONFIG");
+    println!("cargo:rerun-if-env-changed=CARGO_FEATURE_ESP_IDF");
+
+    let is_espidf = env::var("CARGO_FEATURE_ESP_IDF").is_ok()
+        && env::var("CARGO_CFG_TARGET_OS").unwrap() == "espidf";
+
+    if is_espidf
+        && (env::var("WAMR_BUILD_PLATFORM").is_ok()
+            || env::var("WAMR_SHARED_PLATFORM_CONFIG").is_ok())
+    {
+        panic!("ESP-IDF build cannot use custom platform build (WAMR_BUILD_PLATFORM) or shared platform config (WAMR_SHARED_PLATFORM_CONFIG)");
+    }
     // because the ESP-IDF build procedure differs from the regular one (build internally by esp-idf-sys),
-    if no_espidf {
+    else {
         let enable_custom_section = if cfg!(feature = "custom-section") {
             "1"
         } else {
@@ -63,6 +75,15 @@ fn main() {
             .define("WAMR_BUILD_CUSTOM_NAME_SECTION", enable_name_section)
             .define("WAMR_BUILD_LOAD_CUSTOM_SECTION", enable_custom_section);
 
+        if let Ok(platform_name) = env::var("WAMR_BUILD_PLATFORM") {
+            cfg.define("WAMR_BUILD_PLATFORM", &platform_name);
+        }
+
+        if let Ok(platform_config) = env::var("WAMR_SHARED_PLATFORM_CONFIG") {
+            cfg.define("SHARED_PLATFORM_CONFIG", &platform_config);
+            println!("cargo:rerun-if-changed={}", platform_config);
+        }
+
         // support STDIN/STDOUT/STDERR redirect.
         cfg = match env::var("WAMR_BH_VPRINTF") {
             Ok(bh_vprintf) => match bh_vprintf.len() {