tanishiking

Why

WebAssembly interacts with the external environment through imported and exported functions. If it's a simple function that takes an integer and returns an integer, there is no problem.

However, when trying to use complex data types (such as strings or arrays), the limitation of WebAssembly 1.0 having only 4 types (i32, i64, f32, f64) becomes an issue.

To represent strings or user-defined types, we have to represent it using these 4 types, and there are no predefined rules on how to represent them in linear memory. The consumers of these modules need to understand how these data structures are laid out in linear memory and implement glue code accordingly.

tanishiking

Why WASI?

To communicate with the systems provided by the operating system, you need to call system calls. However, WebAssembly is designed as a complete sandbox, and Wasm modules cannot directly access OS system calls.

To call system calls from Wasm, you need to import functions that have access to system calls from the host environment.

#[link(wasm_import_module = "syscall")]
extern "C" {
    fn write(pointer: i32, length: i32);

tanishiking

/**
  * The `String` class represents character strings. All string literals in Kotlin programs, such as `"abc"`, are
  * implemented as instances of this class.
  */
 public class String internal @WasmPrimitiveConstructor constructor(
     private var leftIfInSum: String?,
     @kotlin.internal.IntrinsicConstEvaluation
     public override val length: Int,
     private var _chars: WasmCharArray,

tanishiking

https://github.com/tanishiking/scala-wasm

• Basic mathematics
• class
• object (load module / store module)
• static function call
• virtual call
• interface call
• loop
• if/switch

tanishiking

The future of semanticDB, TASTy, and the overlap that they have #73

---

ckipp01

on Aug 22 Maintainer So I don't have a specific point to bring up for this topic, but lately on Discord there have been multiple different places where conversations about the usage of SemanticDB and TASTY are discussed. We currently have an ecosystem that heavily relies on semanticDB for tooling, but also TASTy is starting to be used in various places. There are also other tools/formats like SCIP that are using semanticDB to produce SCIP.

Especially to outsiders this web gets pretty confusing. Why do we need both? Can't X work for both use-cases, etc. I think it may be a good idea to have a session where we discuss the pros and cons of both and potentially look at solutions in tooling that only require using one these to avoid the situation where we have tools relying on both semanticDB and TASTy.

tanishiking

Scala Sprees Madrid 2023 | scalameta/metals

Welcome to scalameta/metals!

Documents

• CONTRIBUTING document is available here
  • Contributing to Metals | Metals, important parts are
    • https://scalameta.org/metals/docs/contributors/getting-started/#manual-tests
    • https://scalameta.org/metals/docs/contributors/getting-started/#workspace-logs
• https://scalameta.org/metals/docs/contributors/getting-started/#json-rpc-trace

tanishiking

WIP in https://github.com/tanishiking/scala-native/commits/fileline-stacktrace

As described in Programmatic access to the call stack in C++ - Eli Bendersky's website We can constrcut backtrace using libunwind in the following way

#include <libunwind.h>
#include <stdio.h>

// Call this function to get a backtrace.

tanishiking

#include <libunwind.h>
#include <stdio.h>

// Call this function to get a backtrace.
void backtrace() {
  unw_cursor_t cursor;
  unw_context_t context;

  // Initialize cursor to current frame for local unwinding.
  unw_getcontext(&context);

tanishiking

--- before	2023-04-20 14:27:08
+++ after	2023-04-20 14:28:58
@@ -5,33 +5,33 @@
   ret unit
 }
 var @"M4MainG4type" : {{ptr, int, int, ptr}, int, int, {ptr}, [ptr x 4]} = structvalue {structvalue {@"M15java.lang.ClassG4type" : ptr, int 639, int -1, const structvalue {@"M16java.lang.StringG4type" : ptr, const structvalue {@"M35scala.scalanative.runtime.CharArrayG4type" : ptr, int 4, int 0, arrayvalue char {char 77, char 97, char 105, char 110}}, int 0, int 4, int 2390489}}, int 8, int 639, structvalue {const arrayvalue long {long -1}}, arrayvalue ptr {@"M16java.lang.ObjectD12scala_$eq$eqL16java.lang.ObjectzEO" : ptr, @"M16java.lang.ObjectD8toStringL16java.lang.StringEO" : ptr, @"M16java.lang.ObjectD8hashCodeiEO" : ptr, @"M16java.lang.ObjectD6equalsL16java.lang.ObjectzEO" : ptr}}
-didopt def @"M5Main$D10$anonfun$1L28scala.scalanative.unsafe.PtriEPT5Main$" : (@"T5Main$", @"T28scala.scalanative.unsafe.Ptr") => int {
-%3000000(%1 : @"T5Main$", %2 : @"T28scala.scalanative.unsafe.Ptr"):
-  %3000004 = ine[@"T5Main$"] 

tanishiking

package dotty.tools.dotc
package transform

import ast.{TreeTypeMap, tpd}
import config.Printers.tailrec
import core.*
import Contexts.*, Flags.*, Symbols.*
import Constants.Constant
import NameKinds.{TailLabelName, TailLocalName, TailTempName}
import StdNames.nme