Rename `wasm2asm` to `wasm2js`, emit ESM by default (#1642)

* Rename the `wasm2asm` tool to `wasm2js`

This commit performs a relatively simple rename of the `wasm2asm` tool to
`wasm2js`. The functionality of the tool doesn't change just yet but it's
intended that we'll start generating an ES module instead of just an `asm.js`
function soon.

* wasm2js: Support `*.wasm` input files

Previously `wasm2js` only supported `*.wast` files but to make it a bit easier
to use in tooling pipelines this commit adds support for reading in a `*.wasm`
file directly. Determining which parser to use depends on the input filename,
where the binary parser is used with `*.wasm` files and the wast parser is used
for all other files.

* wasm2js: Emit ESM imports/exports by default

This commit alters the default behavior of `wasm2js` to emit an ESM by default,
either importing items from the environment or exporting. Items like
initialization of memory are also handled here.

1 files changed, 15 insertions, 12 deletions

diff --git a/auto_update_tests.py b/auto_update_tests.py
index a291421d5..4693351b1 100755
--- a/auto_update_tests.py
+++ b/auto_update_tests.py
@@ -22,10 +22,10 @@ import sys
 from scripts.test.support import run_command, split_wast, node_test_glue, node_has_webassembly
 from scripts.test.shared import (
     ASM2WASM, MOZJS, NODEJS, WASM_OPT, WASM_AS, WASM_DIS,
-    WASM_CTOR_EVAL, WASM_MERGE, WASM_REDUCE, WASM2ASM, WASM_METADCE,
+    WASM_CTOR_EVAL, WASM_MERGE, WASM_REDUCE, WASM2JS, WASM_METADCE,
     WASM_EMSCRIPTEN_FINALIZE, BINARYEN_INSTALL_DIR, BINARYEN_JS,
     files_with_pattern, has_shell_timeout, options)
-from scripts.test.wasm2asm import tests, spec_tests, extra_wasm2asm_tests, assert_tests, wasm2asm_dir
+from scripts.test.wasm2js import tests, spec_tests, extra_wasm2js_tests, assert_tests, wasm2js_dir, wasm2js_blacklist
 
 
 def update_asm_js_tests():
@@ -339,25 +339,28 @@ def update_ctor_eval_tests():
         o.write(actual)
 
 
-def update_wasm2asm_tests():
-  print '\n[ checking wasm2asm ]\n'
-  for wasm in tests + spec_tests + extra_wasm2asm_tests:
+def update_wasm2js_tests():
+  print '\n[ checking wasm2js ]\n'
+  for wasm in tests + spec_tests + extra_wasm2js_tests:
     if not wasm.endswith('.wast'):
       continue
 
+    if os.path.basename(wasm) in wasm2js_blacklist:
+      continue
+
     asm = os.path.basename(wasm).replace('.wast', '.2asm.js')
-    expected_file = os.path.join(wasm2asm_dir, asm)
+    expected_file = os.path.join(wasm2js_dir, asm)
 
-    # we run wasm2asm on tests and spec tests only if the output
+    # we run wasm2js on tests and spec tests only if the output
     # exists - only some work so far. the tests in extra are in
-    # the test/wasm2asm dir and so are specific to wasm2asm, and
+    # the test/wasm2js dir and so are specific to wasm2js, and
     # we run all of those.
-    if wasm not in extra_wasm2asm_tests and not os.path.exists(expected_file):
+    if wasm not in extra_wasm2js_tests and not os.path.exists(expected_file):
       continue
 
     print '..', wasm
 
-    cmd = WASM2ASM + [os.path.join('test', wasm)]
+    cmd = WASM2JS + [os.path.join('test', wasm)]
     out = run_command(cmd)
     with open(expected_file, 'w') as o:
       o.write(out)
@@ -370,7 +373,7 @@ def update_wasm2asm_tests():
     asserts_expected_file = os.path.join('test', asserts)
     traps_expected_file = os.path.join('test', traps)
 
-    cmd = WASM2ASM + [os.path.join(wasm2asm_dir, wasm), '--allow-asserts']
+    cmd = WASM2JS + [os.path.join(wasm2js_dir, wasm), '--allow-asserts']
     out = run_command(cmd)
     with open(asserts_expected_file, 'w') as o:
       o.write(out)
@@ -423,7 +426,7 @@ def main():
   update_wasm_merge_tests()
   update_binaryen_js_tests()
   update_ctor_eval_tests()
-  update_wasm2asm_tests()
+  update_wasm2js_tests()
   update_metadce_tests()
   update_reduce_tests()