From 951b6f9f45e77901959befdc2c3f6e91abf34ac0 Mon Sep 17 00:00:00 2001
From: Nidin Vinayakan <nidinthb@gmail.com>
Date: Thu, 21 Feb 2019 00:22:25 +0100
Subject: [PATCH] Add shared memory support to compiler (#494)

---
 cli/asc.js      | 1 +
 cli/asc.json    | 5 +++++
 src/compiler.ts | 7 +++++--
 src/index.ts    | 5 +++++
 4 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/cli/asc.js b/cli/asc.js
index 0bbe4abf..840bebbb 100644
--- a/cli/asc.js
+++ b/cli/asc.js
@@ -421,6 +421,7 @@ exports.main = function main(argv, options, callback) {
   assemblyscript.setTarget(compilerOptions, 0);
   assemblyscript.setNoAssert(compilerOptions, args.noAssert);
   assemblyscript.setImportMemory(compilerOptions, args.importMemory);
+  assemblyscript.setSharedMemory(compilerOptions, args.sharedMemory);
   assemblyscript.setImportTable(compilerOptions, args.importTable);
   assemblyscript.setMemoryBase(compilerOptions, args.memoryBase >>> 0);
   assemblyscript.setSourceMap(compilerOptions, args.sourceMap != null);
diff --git a/cli/asc.json b/cli/asc.json
index adbddf51..74f7734c 100644
--- a/cli/asc.json
+++ b/cli/asc.json
@@ -101,6 +101,11 @@
     "type": "b",
     "default": false
   },
+  "sharedMemory": {
+    "description": "Declare memory as shared by settings the max shared memory.",
+    "type": "i",
+    "default": 0
+  },
   "memoryBase": {
     "description": "Sets the start offset of compiler-generated static memory.",
     "type": "i",
diff --git a/src/compiler.ts b/src/compiler.ts
index 27c84db7..d95f7f05 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -186,6 +186,8 @@ export class Options {
   noAssert: bool = false;
   /** If true, imports the memory provided by the embedder. */
   importMemory: bool = false;
+  /** If greater than zero, declare memory as shared by setting max memory to sharedMemory. */
+  sharedMemory: i32 = 0;
   /** If true, imports the function table provided by the embedder. */
   importTable: bool = false;
   /** If true, generates information necessary for source maps. */
@@ -400,18 +402,19 @@ export class Compiler extends DiagnosticEmitter {
     }
 
     // set up memory
+    var isSharedMemory = options.hasFeature(Feature.THREADS) && options.sharedMemory > 0;
     module.setMemory(
       this.options.memoryBase /* is specified */ || this.memorySegments.length
         ? i64_low(i64_shr_u(i64_align(memoryOffset, 0x10000), i64_new(16, 0)))
         : 0,
-      Module.UNLIMITED_MEMORY,
+      isSharedMemory ? options.sharedMemory : Module.UNLIMITED_MEMORY,
       this.memorySegments,
       options.target,
       "memory"
     );
 
     // import memory if requested (default memory is named '0' by Binaryen)
-    if (options.importMemory) module.addMemoryImport("0", "env", "memory");
+    if (options.importMemory) module.addMemoryImport("0", "env", "memory", isSharedMemory);
 
     // set up function table
     var functionTable = this.functionTable;
diff --git a/src/index.ts b/src/index.ts
index c1d5e0a0..9de73751 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -97,6 +97,11 @@ export function setImportMemory(options: Options, importMemory: bool): void {
   options.importMemory = importMemory;
 }
 
+/** Sets the `sharedMemory` option. */
+export function setSharedMemory(options: Options, sharedMemory: i32): void {
+  options.sharedMemory = sharedMemory;
+}
+
 /** Sets the `importTable` option. */
 export function setImportTable(options: Options, importTable: bool): void {
   options.importTable = importTable;