support for Runtime.addFunction in asm.js

4 files changed, 34 insertions, 5 deletions

diff --git a/src/modules.js b/src/modules.js
index 5b5f7947..7a769846 100644
--- a/src/modules.js
+++ b/src/modules.js
@@ -234,7 +234,7 @@ var Functions = {
   unimplementedFunctions: {}, // library etc. functions that we need to index, maps id to signature
 
   indexedFunctions: {},
-  nextIndex: 2, // Start at a non-0 (even, see below) value
+  nextIndex: (ASM_JS ? 2*RESERVED_FUNCTION_POINTERS : 0) + 2, // Start at a non-0 (even, see below) value
 
   blockAddresses: {}, // maps functions to a map of block labels to label ids
 
diff --git a/src/preamble.js b/src/preamble.js
index 17b74cd9..92305ca0 100644
--- a/src/preamble.js
+++ b/src/preamble.js
@@ -6,6 +6,15 @@
 
 {{RUNTIME}}
 
+#if ASM_JS
+#if RESERVED_FUNCTION_POINTERS
+function jsCall() {
+  var args = Array.prototype.slice.call(arguments);
+  return Runtime.functionPointers[args[0]].apply(null, args.slice(1));
+}
+#endif
+#endif
+
 #if BENCHMARK
 Module.realPrint = Module.print;
 Module.print = Module.printErr = function(){};
diff --git a/src/runtime.js b/src/runtime.js
index 2a26db28..5b9a8134 100644
--- a/src/runtime.js
+++ b/src/runtime.js
@@ -305,18 +305,35 @@ var Runtime = {
     }
   },
 
-  addFunction: function(func, sig) {
-    //assert(sig); // TODO: support asm
-    var table = FUNCTION_TABLE; // TODO: support asm
+#if ASM_JS
+  functionPointers: new Array(RESERVED_FUNCTION_POINTERS),
+#endif
+
+  addFunction: function(func) {
+#if ASM_JS
+    for (var i = 0; i < Runtime.functionPointers.length; i++) {
+      if (!Runtime.functionPointers[i]) {
+        Runtime.functionPointers[i] = func;
+        return 2 + 2*i;
+      }
+    }
+    throw 'Finished up all reserved function pointers. Use a higher value for RESERVED_FUNCTION_POINTERS.';
+#else
+    var table = FUNCTION_TABLE;
     var ret = table.length;
     table.push(func);
     table.push(0);
     return ret;
+#endif
   },
 
   removeFunction: function(index) {
-    var table = FUNCTION_TABLE; // TODO: support asm
+#if ASM_JS
+    Runtime.functionPointers[(index-2)/2] = null;
+#else
+    var table = FUNCTION_TABLE;
     table[index] = null;
+#endif
   },
 
   warnOnce: function(text) {
diff --git a/src/settings.js b/src/settings.js
index db24cca4..7cd0c02e 100644
--- a/src/settings.js
+++ b/src/settings.js
@@ -131,6 +131,9 @@ var CHECK_HEAP_ALIGN = 0; // Check heap accesses for alignment, but don't do as
 
 var SAFE_DYNCALLS = 0; // Show stack traces on missing function pointer/virtual method calls
 
+var RESERVED_FUNCTION_POINTERS = 0; // In asm.js mode, we cannot simply add function pointers to
+                                    // function tables, so we reserve some slots for them.
+
 var ASM_HEAP_LOG = 0; // Simple heap logging, like SAFE_HEAP_LOG but cheaper, and in asm.js
 
 var CORRUPTION_CHECK = 0; // When enabled, will emit a buffer area at the beginning and