Merge pull request #68 from matrix-org/rav/build_docs_improvements

Author: jmartinesp

README.md

@@ -20,23 +20,21 @@ Usage :
 
 ## Testing locally
 As the package vendors a pre-built binary of the SDK, all local development is done via the SDK's repo instead of this one.
-You can use the build script to generate the AAR file for testing. Be sure to have checkout the matrix-rust-sdk first.
-
-Usage:
+You can use the build script to generate the AAR file for testing. Be sure to have checked out the matrix-rust-sdk first.
 
+To build the main crate (eg, for Element-X):
 ```
-./scripts/build.sh -p matrix-rust-sdk-path -m sdk -t aarch64-linux-android
+./scripts/build.sh -p <matrix-rust-sdk-path> -m sdk -l
 ```
 
-To build just the crypto crate, use this instead:
-
+To build just the crypto crate (eg, for Element Android classic), use this instead:
 ```
-./scripts/build.sh -p matrix-rust-sdk-path -m crypto -t aarch64-linux-android
+./scripts/build.sh -p matrix-rust-sdk-path -m crypto -l
 ```
 
 Other useful flags:
 
-- `-o OUTPUT_DIR`: Writes the output AAR file to the dir `OUTPUT_DIR`.
+- `-o OUTPUT_DIR`: Moves the generated AAR file to the dir `OUTPUT_DIR`.
 - `-r`: Produces a release build instead of a development one.
 
 ## Prerequisites
@@ -45,11 +43,7 @@ Other useful flags:
 * the Rust toolchain
 * cargo-ndk `cargo install cargo-ndk`
 * protoc `brew install protobuf` or downloading [here](https://github.com/protocolbuffers/protobuf/releases)
-* android targets (e.g. `rustup target add \
-  aarch64-linux-android \
-  armv7-linux-androideabi \
-  x86_64-linux-android \
-  i686-linux-android`)
+* android targets (e.g. `rustup target add aarch64-linux-android armv7-linux-androideabi x86_64-linux-android i686-linux-android`)
 
 
 ## License

scripts/build.sh

@@ -8,7 +8,8 @@ helpFunction() {
   echo -e "\t-o Optional output path with the expected name of the aar file"
   echo -e "\t-r Flag to build in release mode"
   echo -e "\t-m Option to select the gradle module to build. Default is sdk"
-  echo -e "\t-t Option to to select an android target to build against. Default will build for all targets."
+  echo -e "\t-t Select a target architecture to build for. Default will build for all known Android targets."
+  echo -e "\t-l Build for the local architecture. Incompatible with '-t'."
   exit 1
 }
 
@@ -20,14 +21,16 @@ scripts_dir=$(
 is_release='false'
 gradle_module='sdk'
 only_target=''
+local_target=''
 output=''
 
-while getopts ':rp:m:t:o:' 'opt'; do
+while getopts ':rp:m:t:lo:' 'opt'; do
   case ${opt} in
   'r') is_release='true' ;;
   'p') sdk_path="$OPTARG" ;;
   'm') gradle_module="$OPTARG" ;;
   't') only_target="$OPTARG" ;;
+  'l') local_target='true' ;;
   'o') output="$OPTARG" ;;
   ?) helpFunction ;;
   esac
@@ -38,6 +41,17 @@ if [ -z "$sdk_path" ]; then
   helpFunction
 fi
 
+if [ -n "$local_target" ]; then
+    if [ -n "$only_target" ]; then
+        echo "Cannot specifiy both '-l' and '-t'." >&2
+        exit 1
+    fi
+
+    only_target="$(uname -m)-linux-android"
+    # On ARM MacOS, `uname -m` returns arm64, but the toolchain is called aarch64
+    only_target="${only_target/arm64/aarch64}"
+fi
+
 if [ -z "$only_target" ]; then
   echo "no target provided, build for all targets"
   target_command=()
@@ -53,7 +67,7 @@ fi
 
 if [ "$gradle_module" = "crypto" ]; then
   ## NDK is needed for https://crates.io/crates/olm-sys
-  if [ -z "$ANDROID_NDK" ]; then
+  if [ -z "$ANDROID_NDK" && -z "$ANDROID_HOME" ]; then
     echo "please set the ANDROID_NDK environment variable to your Android NDK installation"
     exit 1
   fi
@@ -80,9 +94,10 @@ shift $((OPTIND - 1))
 
 moveFunction() {
   if [ -z "$output" ]; then
-    echo "No output path provided, keep the generated path"
+    echo -e "\nSUCCESS: Output AAR file is '$1'"
   else
     mv "$1" "$output"
+    echo -e "\nSUCCESS: Output AAR file is '$output'"
   fi
 }