Export function table by default and add an option to import it

bin/asc.js

@@ -360,6 +360,7 @@ exports.main = function main(argv, options, callback) {
   assemblyscript.setNoAssert(compilerOptions, !!args.noAssert);
   assemblyscript.setNoMemory(compilerOptions, !!args.noMemory);
   assemblyscript.setImportMemory(compilerOptions, !!args.importMemory);
+  assemblyscript.setImportTable(compilerOptions, !!args.importTable);
   assemblyscript.setMemoryBase(compilerOptions, args.memoryBase >>> 0);
   assemblyscript.setSourceMap(compilerOptions, args.sourceMap != null);
 

bin/asc.json

@@ -107,6 +107,10 @@
     "desc": "Sets the start offset of compiler-generated static memory.",
     "type": "number"
   },
+  "importTable": {
+    "desc": "Imports the function table instance provided by the embedder.",
+    "type": "boolean"
+  },
   "noLib": {
     "desc": "Does not include the shipped standard library.",
     "type": "boolean"

src/compiler.ts

@@ -147,6 +147,8 @@ export class Options {
   noMemory: bool = false;
   /** If true, imports the memory provided by the embedder. */
   importMemory: bool = false;
+  /** If true, imports the function table provided by the embedder. */
+  importTable: bool = false;
   /** Static memory start offset. */
   memoryBase: u32 = 0;
   /** If true, generates information necessary for source maps. */
@@ -327,6 +329,13 @@ export class Compiler extends DiagnosticEmitter {
         entries[i] = functionTable[i].ref;
       }
       module.setFunctionTable(entries);
+      module.addTableExport("0", "table");
+    }
+
+    // import table if requested
+    if (options.importTable) {
+      module.addTableImport("0", "env", "table");
+      if (!functionTableSize) module.addTableExport("0", "table");
     }
 
     return module;

src/index.ts

@@ -110,6 +110,11 @@ export function setImportMemory(options: Options, importMemory: bool): void {
   options.importMemory = importMemory;
 }
 
+/** Sets the `importTable` option. */
+export function setImportTable(options: Options, importTable: bool): void {
+  options.importTable = importTable;
+}
+
 /** Sets the `sourceMap` option. */
 export function setSourceMap(options: Options, sourceMap: bool): void {
   options.sourceMap = sourceMap;

tests/compiler/function-expression.optimized.wat

@@ -13,6 +13,7 @@
  (memory $0 1)
  (data (i32.const 4) "\16\00\00\00f\00u\00n\00c\00t\00i\00o\00n\00-\00e\00x\00p\00r\00e\00s\00s\00i\00o\00n\00.\00t\00s")
  (export "memory" (memory $0))
+ (export "table" (table $0))
  (start $start)
  (func $start~anonymous|0 (; 1 ;) (type $ii) (param $0 i32) (result i32)
   (get_local $0)

tests/compiler/function-expression.untouched.wat

@@ -14,6 +14,7 @@
  (memory $0 1)
  (data (i32.const 4) "\16\00\00\00f\00u\00n\00c\00t\00i\00o\00n\00-\00e\00x\00p\00r\00e\00s\00s\00i\00o\00n\00.\00t\00s\00")
  (export "memory" (memory $0))
+ (export "table" (table $0))
  (start $start)
  (func $start~anonymous|0 (; 1 ;) (type $ii) (param $0 i32) (result i32)
   (return

tests/compiler/function-types.optimized.wat

@@ -15,6 +15,7 @@
  (memory $0 1)
  (data (i32.const 4) "\11\00\00\00f\00u\00n\00c\00t\00i\00o\00n\00-\00t\00y\00p\00e\00s\00.\00t\00s")
  (export "memory" (memory $0))
+ (export "table" (table $0))
  (start $start)
  (func $function-types/makeAdder<i32>~anonymous|0 (; 1 ;) (type $iii) (param $0 i32) (param $1 i32) (result i32)
   (i32.add

tests/compiler/function-types.untouched.wat

@@ -16,6 +16,7 @@
  (memory $0 1)
  (data (i32.const 4) "\11\00\00\00f\00u\00n\00c\00t\00i\00o\00n\00-\00t\00y\00p\00e\00s\00.\00t\00s\00")
  (export "memory" (memory $0))
+ (export "table" (table $0))
  (start $start)
  (func $function-types/makeAdder<i32>~anonymous|0 (; 1 ;) (type $iii) (param $0 i32) (param $1 i32) (result i32)
   (return