New AssemblyScript compiler introduced floats

[MaksymZavershynskyi]

When we compile AssemblyScript that does not use floats it gets compiled into WebAssembly that uses float operations. Float operations are not allowed for smart contracts, since they introduce non-determinism, see relevant: https://github.com/AssemblyScript/assemblyscript/issues/732

To reproduce:

• Start local node (you would need to install rust)

  git clone https://github.com/nearprotocol/nearcore/
  cd nearcore
  git checkout staging
  ./scripts/start_unittest.py --local

• Copy smart contracts: https://www.dropbox.com/sh/yd1gi0a83robwvc/AACGJhts5TBr6OlOtWcZrg0sa?dl=0 https://www.dropbox.com/sh/5m4thls6bd3nwhw/AADa3CakXizUxfpA_d9Vwieta?dl=0

• Do not rebuild them (since we have https://github.com/nearprotocol/near-runtime-ts/issues/85 and I cannot tell what AssemblyScript will be like at the moment of someone trying to reproduce this issue);

• Launch contracts:

  cd wasm-project-it8oemvbn
  near create_account studio-it8oemvbn --masterAccount=test.near --homeDir=/Users/zaver/Projects/nearcore/testdir
  near deploy --accountId=studio-it8oemvbn --homeDir=/Users/zaver/Projects/nearcore/testdir --wasmFile=./out/main.wasm
  cd ../wasm-project-kr22owu3d
  near create_account studio-kr22owu3d --masterAccount=test.near --homeDir=/Users/zaver/Projects/nearcore/testdir
  near deploy --accountId=studio-kr22owu3d --homeDir=/Users/zaver/Projects/nearcore/testdir --wasmFile=./out/main.wasm

  (Fix the path to nearcore)

• Call the contract:

  near call studio-it8oemvbn calculate "{}" --accountId=test.near --homeDir=/Users/zaver/Projects/nearcore/testdir

  Observe the error message:

  [studio-it8oemvbn]: Runtime error: wasm async call execution failed with error: PrepareError("Gas instrumentation failed.")
  Error:  Error: Transaction 5bGQZ6KSiMWft5Wd3CKzaDitye3gBQiZakzuqcfMnE5c failed. Runtime error: wasm async call execution failed with error: PrepareError("Gas instrumentation failed.")
  at Account.signAndSendTransaction (/usr/local/lib/node_modules/near-shell/node_modules/nearlib/lib/account.js:89:23)
  at processTicksAndRejections (internal/process/task_queues.js:89:5)
  at async Object.exports.scheduleFunctionCall (/usr/local/lib/node_modules/near-shell/index.js:110:34)
  at async exitOnError (/usr/local/lib/node_modules/near-shell/bin/near:8:5)

  Expected: to get no error message.

To see that it is float-related comment out https://github.com/nearprotocol/nearcore/blob/2cb653181143cfe4a0c8b2eac5a9e7701e88d1ea/runtime/near-vm-runner/src/prepare.rs#L59 and try again, it will succeed this time.

[MaxGraey]

That's strange. I can't see any f64/f32 in generated code for second example: https://webassembly.studio/?f=www28iehfj

[MaksymZavershynskyi]

I do not remember exactly which contract out of the two given generated floats.

[willemneal]

The version of the compiler is currently tied to near-shell, so the dependency"near-shell": "github:nearprotocol/near-shell" is the issue. Unlike the compiler near-shell is versioned and since it uses a lock file to determine which commit of the compiler to use it acts as a proxy for the version of the compiler. Not saying we shouldn't version the compiler, but just perhaps this is the reason for the breakage/instability.

[willemneal]

Also I can't download the zip file as dropbox says it's too large and I can't open the .ts file in the browser since dropbox thinks it a video file.

[MaksymZavershynskyi]

@willemneal Did you figure out how to download the dropbox file?