track if there is inline js, and if so do not mark as valid asm.js

3 files changed, 11 insertions, 4 deletions

diff --git a/emscripten.py b/emscripten.py
index 257527fe..e05037b0 100755
--- a/emscripten.py
+++ b/emscripten.py
@@ -287,6 +287,7 @@ def emscript(infile, settings, outfile, libraries=[], compiler_engine=None,
     exported_implemented_functions = set()
   for func_js, curr_forwarded_data in outputs:
     curr_forwarded_json = json.loads(curr_forwarded_data)
+    forwarded_json['Types']['hasInlineJS'] = forwarded_json['Types']['hasInlineJS'] or curr_forwarded_json['Types']['hasInlineJS']
     forwarded_json['Types']['preciseI64MathUsed'] = forwarded_json['Types']['preciseI64MathUsed'] or curr_forwarded_json['Types']['preciseI64MathUsed']
     for key, value in curr_forwarded_json['Functions']['blockAddresses'].iteritems():
       forwarded_json['Functions']['blockAddresses'][key] = value
@@ -543,7 +544,7 @@ function asmPrintFloat(x, y) {
 }
 // EMSCRIPTEN_START_ASM
 var asm = (function(global, env, buffer) {
-  'use asm';
+  %s
   var HEAP8 = new global.Int8Array(buffer);
   var HEAP16 = new global.Int16Array(buffer);
   var HEAP32 = new global.Int32Array(buffer);
@@ -552,7 +553,7 @@ var asm = (function(global, env, buffer) {
   var HEAPU32 = new global.Uint32Array(buffer);
   var HEAPF32 = new global.Float32Array(buffer);
   var HEAPF64 = new global.Float64Array(buffer);
-''' % (asm_setup,) + '\n' + asm_global_vars + '''
+''' % (asm_setup, "'use asm';" if not forwarded_json['Types']['hasInlineJS'] else "'almost asm, but inline js';") + '\n' + asm_global_vars + '''
   var __THREW__ = 0;
   var threwValue = 0;
   var setjmpId = 0;
diff --git a/src/intertyper.js b/src/intertyper.js
index ddb93d71..f9633549 100644
--- a/src/intertyper.js
+++ b/src/intertyper.js
@@ -708,7 +708,8 @@ function intertyper(data, sidePass, baseLineNums) {
     item.ident = eatLLVMIdent(tokensLeft);
     if (item.ident == 'asm') {
       if (ASM_JS) {
-        warnOnce('inline JS in asm.js mode can cause the code to no longer fall in the asm.js subset of JavaScript');
+        Types.hasInlineJS = true;
+        warnOnce('inline JavaScript (asm, EM_ASM) will cause the code to no longer fall in the asm.js subset of JavaScript, which can reduce performance');
       }
       assert(TARGET_LE32, 'inline js is only supported in le32');
       // Inline assembly is just JavaScript that we paste into the code
diff --git a/src/modules.js b/src/modules.js
index 373e60d9..1a931572 100644
--- a/src/modules.js
+++ b/src/modules.js
@@ -227,6 +227,8 @@ var Types = {
 
   needAnalysis: {}, // Types noticed during parsing, that need analysis
 
+  hasInlineJS: false, // whether the program has inline JS anywhere
+
   // Set to true if we actually use precise i64 math: If PRECISE_I64_MATH is set, and also such math is actually
   // needed (+,-,*,/,% - we do not need it for bitops), or PRECISE_I64_MATH is 2 (forced)
   preciseI64MathUsed: (PRECISE_I64_MATH == 2)
@@ -467,7 +469,10 @@ var PassManager = {
       }));
     } else if (phase == 'funcs') {
       print('\n//FORWARDED_DATA:' + JSON.stringify({
-        Types: { preciseI64MathUsed: Types.preciseI64MathUsed },
+        Types: {
+          hasInlineJS: Types.hasInlineJS,
+          preciseI64MathUsed: Types.preciseI64MathUsed
+        },
         Functions: {
           blockAddresses: Functions.blockAddresses,
           indexedFunctions: Functions.indexedFunctions,