Support Linux ARM

[kaaax0815]

Related tursodatabase/libsql-js#169 and cross-rs/cross#1646

I am using libsql-js in a larger open source project which I want to make available for older systems that use Armv7 like Raspberry Pis.

I am trying trying to add arm support but something does not support it yet

$ cross build -p libsql --features encryption --target arm-unknown-linux-gnueabihf
...
warning: libsql-ffi@0.9.2: CC_var_name=CC_arm_unknown_linux_gnueabihf

error: failed to run custom build command for `libsql-ffi v0.9.2 (/Users/berndstorath/Documents/X_Projekte/libsql/libsql-ffi)`

Caused by:
  process didn't exit successfully: `/target/debug/build/libsql-ffi-b172bf69f5b8099f/build-script-build` (exit status: 101)
  --- stdout
  cargo:rerun-if-changed=bundled/src/sqlite3.c
  cargo:rerun-if-changed=/target/arm-unknown-linux-gnueabihf/debug/build/libsql-ffi-f30780d0f93b66bc/out/sqlite3mc/libsqlite3mc_static.a
  cargo:lib_dir=/target/arm-unknown-linux-gnueabihf/debug/build/libsql-ffi-f30780d0f93b66bc/out
  cargo:warning=CC_var_name=CC_arm_unknown_linux_gnueabihf

  --- stderr
  [libsql-ffi/build.rs:435:9] format!("{BUNDLED_DIR}/SQLite3MultipleCiphers") = "bundled/SQLite3MultipleCiphers"
  thread 'main' panicked at libsql-ffi/build.rs:485:13:
  Unsupported cross target arm-unknown-linux-gnueabihf-gcc
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
warning: build failed, waiting for other jobs to finish...

[kaaax0815]

After adding arm to the system_processor at libsql-ffi/build.rs:485:13 I get theses logs

warning: libsql-ffi@0.9.2: CC_var_name=CC_arm_unknown_linux_gnueabihf

error: failed to run custom build command for `libsql-ffi v0.9.2 (/Users/berndstorath/Documents/X_Projekte/libsql/libsql-ffi)`

Caused by:
  process didn't exit successfully: `/target/debug/build/libsql-ffi-b172bf69f5b8099f/build-script-build` (exit status: 101)
  --- stdout
  cargo:rerun-if-changed=bundled/src/sqlite3.c
  cargo:rerun-if-changed=/target/arm-unknown-linux-gnueabihf/debug/build/libsql-ffi-f30780d0f93b66bc/out/sqlite3mc/libsqlite3mc_static.a
  cargo:lib_dir=/target/arm-unknown-linux-gnueabihf/debug/build/libsql-ffi-f30780d0f93b66bc/out
  cargo:warning=CC_var_name=CC_arm_unknown_linux_gnueabihf
  Running `cmake` with options: -DCMAKE_TOOLCHAIN_FILE=toolchain.cmake -DCMAKE_BUILD_TYPE=Release -DSQLITE3MC_STATIC=ON -DCODEC_TYPE=AES256 -DSQLITE3MC_BUILD_SHELL=OFF -DSQLITE_SHELL_IS_UTF8=OFF -DSQLITE_USER_AUTHENTICATION=OFF -DSQLITE_SECURE_DELETE=OFF -DSQLITE_ENABLE_COLUMN_METADATA=ON -DSQLITE_USE_URI=ON -DCMAKE_POSITION_INDEPENDENT_CODE=ON
  -- The C compiler identification is GNU 8.5.0
  -- The CXX compiler identification is GNU 8.5.0
  -- Detecting C compiler ABI info
  -- Detecting C compiler ABI info - done
  -- Check for working C compiler: /x-tools/arm-unknown-linux-gnueabihf/bin/arm-unknown-linux-gnueabihf-gcc - skipped
  -- Detecting C compile features
  -- Detecting C compile features - done
  -- Detecting CXX compiler ABI info
  -- Detecting CXX compiler ABI info - done
  -- Check for working CXX compiler: /x-tools/arm-unknown-linux-gnueabihf/bin/arm-unknown-linux-gnueabihf-g++ - skipped
  -- Detecting CXX compile features
  -- Detecting CXX compile features - done
  -- Configuring done
  -- Generating done
  -- Build files have been written to: /target/arm-unknown-linux-gnueabihf/debug/build/libsql-ffi-f30780d0f93b66bc/out/sqlite3mc
  [ 50%] Building C object CMakeFiles/sqlite3mc_static.dir/src/sqlite3mc.c.o

  --- stderr
  [libsql-ffi/build.rs:435:9] format!("{BUNDLED_DIR}/SQLite3MultipleCiphers") = "bundled/SQLite3MultipleCiphers"
  Will build sqlite3mc_static as STATIC
  arm-unknown-linux-gnueabihf-gcc: error: unrecognized command line option '-msse4.2'
  arm-unknown-linux-gnueabihf-gcc: error: unrecognized command line option '-maes'; did you mean '-mapcs'?
  make[2]: *** [CMakeFiles/sqlite3mc_static.dir/build.make:76: CMakeFiles/sqlite3mc_static.dir/src/sqlite3mc.c.o] Error 1
  make[1]: *** [CMakeFiles/Makefile2:83: CMakeFiles/sqlite3mc_static.dir/all] Error 2
  make: *** [Makefile:136: all] Error 2
  thread 'main' panicked at libsql-ffi/build.rs:543:9:
  Failed to run make
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
warning: build failed, waiting for other jobs to finish...

[kaaax0815]

Got it working here https://github.com/kaaax0815/libsql/tree/feat-arm