adjust TOTAL_MEMORY at runtime, to take into account last minute changes to Module.TOTAL_MEMORY

2 files changed, 16 insertions, 1 deletions

diff --git a/src/jsifier.js b/src/jsifier.js
index 2d0aadd7..58dc4653 100644
--- a/src/jsifier.js
+++ b/src/jsifier.js
@@ -1810,7 +1810,7 @@ function JSify(data, functionsOnly, givenFunctions) {
         print('staticSealed = true; // seal the static portion of memory\n');
         print('STACK_MAX = STACK_BASE + ' + TOTAL_STACK + ';\n');
         print('DYNAMIC_BASE = DYNAMICTOP = Runtime.alignMemory(STACK_MAX);\n');
-        print('assert(DYNAMIC_BASE < TOTAL_MEMORY); // Stack must fit in TOTAL_MEMORY; allocations from here on may enlarge TOTAL_MEMORY\n');
+        print('assert(DYNAMIC_BASE < TOTAL_MEMORY, "TOTAL_MEMORY not big enough for stack");\n');
       }
 
       if (asmLibraryFunctions.length > 0) {
diff --git a/src/preamble.js b/src/preamble.js
index 832ec2c3..f9fccdf6 100644
--- a/src/preamble.js
+++ b/src/preamble.js
@@ -866,6 +866,21 @@ var TOTAL_STACK = Module['TOTAL_STACK'] || {{{ TOTAL_STACK }}};
 var TOTAL_MEMORY = Module['TOTAL_MEMORY'] || {{{ TOTAL_MEMORY }}};
 var FAST_MEMORY = Module['FAST_MEMORY'] || {{{ FAST_MEMORY }}};
 
+#if ASM_JS
+var totalMemory = 4096;
+while (totalMemory < TOTAL_MEMORY || totalMemory < 2*TOTAL_STACK) {
+  if (totalMemory < 16*1024*1024) {
+    totalMemory *= 2;
+  } else {
+    totalMemory += 16*1024*1024
+  }
+}
+if (totalMemory !== TOTAL_MEMORY) {
+  Module.printErr('increasing TOTAL_MEMORY to ' + totalMemory + ' to be more reasonable');
+  TOTAL_MEMORY = totalMemory;
+}
+#endif
+
 // Initialize the runtime's memory
 #if USE_TYPED_ARRAYS
 // check for full engine support (use string 'subarray' to avoid closure compiler confusion)