Read environment variables from .cargo/config.toml's [env] section

Cargo.toml

@@ -9,3 +9,7 @@ members = [
     "ndk-sys",
     "cargo-apk",
 ]
+
+[patch.crates-io]
+# https://github.com/dvc94ch/cargo-subcommand/pull/12
+cargo-subcommand = { git = "https://github.com/dvc94ch/cargo-subcommand", rev = "55269e6" }

cargo-apk/CHANGELOG.md

@@ -5,6 +5,7 @@
 - Default `target_sdk_version` to `30` or lower (instead of the highest supported SDK version by the detected NDK toolchain)
   for more consistent interaction with Android backwards compatibility handling and its increasingly strict usage rules:
   https://developer.android.com/distribute/best-practices/develop/target-sdk
+- Read environment variables from `.cargo/config.toml`'s `[env]` section.
 
 # 0.8.2 (2021-11-22)
 

cargo-apk/src/apk.rs

@@ -1,15 +1,16 @@
 use crate::error::Error;
 use crate::manifest::Manifest;
-use cargo_subcommand::{Artifact, CrateType, Profile, Subcommand};
+use cargo_subcommand::{Artifact, CrateType, LocalizedConfig, Profile, Subcommand};
 use ndk_build::apk::{Apk, ApkConfig};
-use ndk_build::cargo::{cargo_ndk, VersionCode};
+use ndk_build::cargo::{cargo_ndk, Env, VersionCode};
 use ndk_build::dylibs::get_libs_search_paths;
 use ndk_build::error::NdkError;
 use ndk_build::manifest::MetaData;
 use ndk_build::ndk::Ndk;
 use ndk_build::target::Target;
 use std::path::PathBuf;
 use std::process::Command;
+use std::sync::Arc;
 
 pub struct ApkBuilder<'a> {
     cmd: &'a Subcommand,
@@ -19,9 +20,23 @@ pub struct ApkBuilder<'a> {
     build_targets: Vec<Target>,
 }
 
+struct ConfigEnv(Option<LocalizedConfig>);
+impl Env for ConfigEnv {
+    fn var(&self, key: &str) -> std::result::Result<std::borrow::Cow<'_, str>, std::env::VarError> {
+        match &self.0 {
+            Some(config) => config
+                .resolve_env(key)
+                // IO error is currently only returned when path canonicalization fails
+                .expect("Failed to resolve environment variable")
+                .ok_or(std::env::VarError::NotPresent),
+            None => std::env::var(key).map(|s| s.into()),
+        }
+    }
+}
+
 impl<'a> ApkBuilder<'a> {
     pub fn from_subcommand(cmd: &'a Subcommand) -> Result<Self, Error> {
-        let ndk = Ndk::from_env()?;
+        let ndk = Ndk::from_env(Arc::new(ConfigEnv(cmd.config().cloned())))?;
         let mut manifest = Manifest::parse_from_toml(cmd.manifest())?;
         let build_targets = if let Some(target) = cmd.target() {
             vec![Target::from_rust_triple(target)?]
@@ -224,7 +239,7 @@ impl<'a> ApkBuilder<'a> {
     }
 
     pub fn default(&self) -> Result<(), Error> {
-        let ndk = Ndk::from_env()?;
+        let ndk = Ndk::from_env(Arc::new(ConfigEnv(None)))?;
         for target in &self.build_targets {
             let mut cargo = cargo_ndk(&ndk, *target, self.min_sdk_version())?;
             cargo.args(self.cmd.args());

ndk-build/CHANGELOG.md

@@ -3,6 +3,7 @@
 - Default `target_sdk_version` to `30` or lower (instead of the highest supported SDK version by the detected NDK toolchain)
   for more consistent interaction with Android backwards compatibility handling and its increasingly strict usage rules:
   https://developer.android.com/distribute/best-practices/develop/target-sdk
+- **Breaking:** `Ndk` now requires a struct implementing `Env` to read environment variables from.
 
 # 0.4.3 (2021-11-22)
 

ndk-build/src/cargo.rs

@@ -3,6 +3,10 @@ use crate::ndk::Ndk;
 use crate::target::Target;
 use std::process::Command;
 
+pub trait Env {
+    fn var(&self, key: &str) -> std::result::Result<std::borrow::Cow<'_, str>, std::env::VarError>;
+}
+
 pub fn cargo_ndk(ndk: &Ndk, target: Target, sdk_version: u32) -> Result<Command, NdkError> {
     let triple = target.rust_triple();
     let mut cargo = Command::new("cargo");

ndk-build/src/ndk.rs

@@ -1,47 +1,51 @@
+use crate::cargo::Env;
 use crate::error::NdkError;
 use crate::target::Target;
 use std::collections::HashMap;
 use std::path::{Path, PathBuf};
 use std::process::Command;
+use std::sync::Arc;
 
-#[derive(Clone, Debug, Eq, PartialEq)]
+#[derive(Clone)]
 pub struct Ndk {
     sdk_path: PathBuf,
     ndk_path: PathBuf,
     build_tools_version: String,
     build_tag: u32,
     platforms: Vec<u32>,
+    env: Arc<dyn Env>,
 }
 
 impl Ndk {
-    pub fn from_env() -> Result<Self, NdkError> {
+    pub fn from_env(env: Arc<dyn Env>) -> Result<Self, NdkError> {
         let sdk_path = {
-            let mut sdk_path = std::env::var("ANDROID_HOME").ok();
+            let mut sdk_path = env.var("ANDROID_HOME").ok();
             if sdk_path.is_some() {
                 println!(
                     "Warning: You use environment variable ANDROID_HOME that is deprecated. \
                  Please, remove it and use ANDROID_SDK_ROOT instead. Now ANDROID_HOME is used"
                 );
             }
             if sdk_path.is_none() {
-                sdk_path = std::env::var("ANDROID_SDK_ROOT").ok();
+                sdk_path = env.var("ANDROID_SDK_ROOT").ok();
             }
 
-            PathBuf::from(sdk_path.ok_or(NdkError::SdkNotFound)?)
+            PathBuf::from(sdk_path.ok_or(NdkError::SdkNotFound)?.as_ref())
         };
 
         let ndk_path = {
-            let ndk_path = std::env::var("ANDROID_NDK_ROOT")
+            let ndk_path = env
+                .var("ANDROID_NDK_ROOT")
                 .ok()
-                .or_else(|| std::env::var("ANDROID_NDK_PATH").ok())
-                .or_else(|| std::env::var("ANDROID_NDK_HOME").ok())
-                .or_else(|| std::env::var("NDK_HOME").ok());
+                .or_else(|| env.var("ANDROID_NDK_PATH").ok())
+                .or_else(|| env.var("ANDROID_NDK_HOME").ok())
+                .or_else(|| env.var("NDK_HOME").ok());
 
             // default ndk installation path
             if ndk_path.is_none() && sdk_path.join("ndk-bundle").exists() {
                 sdk_path.join("ndk-bundle")
             } else {
-                PathBuf::from(ndk_path.ok_or(NdkError::NdkNotFound)?)
+                PathBuf::from(ndk_path.ok_or(NdkError::NdkNotFound)?.as_ref())
             }
         };
 
@@ -116,6 +120,7 @@ impl Ndk {
             build_tools_version,
             build_tag,
             platforms,
+            env,
         })
     }
 
@@ -191,7 +196,7 @@ impl Ndk {
     }
 
     pub fn toolchain_dir(&self) -> Result<PathBuf, NdkError> {
-        let host_os = std::env::var("HOST").ok();
+        let host_os = self.env.var("HOST").ok();
         let host_contains = |s| host_os.as_ref().map(|h| h.contains(s)).unwrap_or(false);
 
         let arch = if host_contains("linux") {
@@ -208,7 +213,7 @@ impl Ndk {
             "windows"
         } else {
             return match host_os {
-                Some(host_os) => Err(NdkError::UnsupportedHost(host_os)),
+                Some(host_os) => Err(NdkError::UnsupportedHost(host_os.into())),
                 _ => Err(NdkError::UnsupportedTarget),
             };
         };
@@ -293,8 +298,10 @@ impl Ndk {
         if let Ok(keytool) = which::which(bin!("keytool")) {
             return Ok(Command::new(keytool));
         }
-        if let Ok(java) = std::env::var("JAVA_HOME") {
-            let keytool = PathBuf::from(java).join("bin").join(bin!("keytool"));
+        if let Ok(java) = self.env.var("JAVA_HOME") {
+            let keytool = PathBuf::from(java.as_ref())
+                .join("bin")
+                .join(bin!("keytool"));
             if keytool.exists() {
                 return Ok(Command::new(keytool));
             }
@@ -401,7 +408,16 @@ mod tests {
     #[test]
     #[ignore]
     fn test_detect() {
-        let ndk = Ndk::from_env().unwrap();
+        struct GlobalEnv;
+        impl Env for GlobalEnv {
+            fn var(
+                &self,
+                key: &str,
+            ) -> std::result::Result<std::borrow::Cow<'_, str>, std::env::VarError> {
+                std::env::var(key).map(|s| s.into())
+            }
+        }
+        let ndk = Ndk::from_env(Arc::new(GlobalEnv)).unwrap();
         assert_eq!(ndk.build_tools_version(), "29.0.2");
         assert_eq!(ndk.platforms(), &[29, 28]);
     }