wasmer/spectests/README.md
2018-11-18 11:13:20 -08:00

5.3 KiB

This directory contains tests for the core WebAssembly semantics, as described in Semantics.md and specified by the spec interpreter.

This files should be a direct copy of the original WebAssembly spec tests.

Tests are written in the S-Expression script format defined by the interpreter.

Autogenerated Rust test cases

This files will serve as base for autogenerating Rust testcases when WASM_GENERATE_SPECTESTS=1 cargo build is executed (src/build_spectests.rs).

The result autogenerated spectests live in the src/spectests directory.

Testcases

Currently supported command assertions:

  • Module mostly implemented (it should support named modules (module $Xx)).
  • AssertReturn mostly implemented (it should support calls to named modules (invoke $Xx "call")).
  • AssertReturnCanonicalNan fully implemented
  • AssertReturnArithmeticNan fully implemented
  • AssertTrap fully implemented
  • AssertInvalid Fully implemented (it should not require to do validation separate from compilation)
  • AssertMalformed Fully implemented
  • AssertUninstantiable not implemented yet
  • AssertExhaustion not implemented yet
  • Register not implemented yet
  • PerformAction partially implemented, only function invokations for now

Covered spectests

This spectests are currently covered:

  • address.wast
  • align.wast
  • binary.wast
  • block.wast
  • br.wast
  • br_if.wast
  • br_table.wast
  • break-drop.wast
  • call.wast
  • call_indirect.wast
  • comments.wast
  • const.wast
  • conversions.wast
  • custom.wast
  • data.wast
  • elem.wast
  • endianness.wast
  • exports.wast
  • f32.wast
  • f32_bitwise.wast
  • f32_cmp.wast
  • f64.wast
  • f64_bitwise.wast
  • f64_cmp.wast
  • fac.wast
  • float_exprs.wast
  • float_literals.wast
  • float_memory.wast
  • float_misc.wast
  • forward.wast
  • func.wast
  • func_ptrs.wast
  • get_local.wast
  • globals.wast
  • i32.wast
  • i64.wast
  • if.wast
  • imports.wast
  • inline-module.wast
  • int_exprs.wast
  • int_literals.wast
  • labels.wast
  • left-to-right.wast
  • linking.wast
  • loop.wast
  • memory.wast
  • memory_grow.wast
  • memory_redundancy.wast
  • memory_trap.wast
  • names.wast
  • nop.wast
  • return.wast
  • select.wast
  • set_local.wast
  • skip-stack-guard-page.wast
  • stack.wast
  • start.wast
  • store_retval.wast
  • switch.wast
  • tee_local.wast
  • token.wast
  • traps.wast
  • type.wast
  • typecheck.wast
  • unreachable.wast
  • unreached-invalid.wast
  • unwind.wast
  • utf8-custom-section-id.wast
  • utf8-import-field.wast
  • utf8-import-module.wast
  • utf8-invalid-encoding.wast

Specific non-supported cases

There are some cases that we decided to skip for now to fasten the time to release:

  • SKIP_MUTABLE_GLOBALS: Right now the WASM parser can't validate a module with imported/exported mut globals. We decided to skip the tests until Cranelift and wasmparser can handle this (original spec proposal: https://github.com/WebAssembly/mutable-global). Spectests affected:

    • globals.wast
  • SKIP_CALL_INDIRECT_TYPE_MISMATCH: we implemented traps in a fast way. We haven't covered yet the type mismatch on call_indirect. Specs affected:

    • call_indirect.wast
  • SKIP_CALL_UNDEFINED_ELEMENT Tables are imported into every spec module, even for modules that don't expect it. We need to figure out a way to prevent import of objects that are not explicitly imported into the module.

Currently cranelift_wasm::ModuleEnvironment does not provide declare_table_import, etc. so there is no meaningful way of fixing this yet.

  • call_indirect.wast

  • SKIP_SHARED_TABLE [elem.wast] Currently sharing tables between instances/modules does not work. Below are some of the reasons it is hard to achieve.

    • Rust naturally prevents such because of the possibility of race conditions

    • ImportObject is just a wrapper, what we really care about is references to its content.

    • Instance::new contains a mutation points, the part where after getting the object (memory or table) we push values to it table[table_element_index] = func_addr

    • Instance has its own created memories and tables and references to them must outlive Instance::new()

    • Possible strategy

      // ImportObject should be passed by ref
      Instance::new<'a>(..., &ImportObject);
      
      // Add OwnedData to Instance struct
      struct OwnedData;
      
      // For parts where mutatation is really needed
      fn get_mut(&import) -> &mut ImportObject {
          unsafe { transmute::<&ImportObject, &mut ImportObject>(import) }
      }
      
    • elem.wast

  • SKIP_GLOBAL_VALUE_OFFSETS There is no support for using global values as offset into tables yet. I believe this is an issue from cranelift side as well, so we will have to wait for it to be supported.

    • elem.wast