Merge branch 'incoming'

5 files changed, 25 insertions, 30 deletions

diff --git a/src/library.js b/src/library.js
index d2d61867..798a6f58 100644
--- a/src/library.js
+++ b/src/library.js
@@ -2802,9 +2802,9 @@ LibraryManager.library = {
           });
         } else if (next == 's'.charCodeAt(0)) {
           // String.
-          var arg = getNextArg('i8*') || 0; // 0 holds '(null)'
+          var arg = getNextArg('i8*') || nullString;
           var argLength = String_len(arg);
-          if (precisionSet) argLength = Math.min(String_len(arg), precision);
+          if (precisionSet) argLength = Math.min(argLength, precision);
           if (!flagLeftAlign) {
             while (argLength < width--) {
               ret.push(' '.charCodeAt(0));
@@ -3578,7 +3578,9 @@ LibraryManager.library = {
     }
 
     if (!whole && !fraction) {
-      {{{ makeSetValue('endptr', 0, 'origin', '*') }}}
+      if (endptr) {
+        {{{ makeSetValue('endptr', 0, 'origin', '*') }}}
+      }
       return 0;
     }
 
diff --git a/src/library_browser.js b/src/library_browser.js
index bf235493..43732e5b 100644
--- a/src/library_browser.js
+++ b/src/library_browser.js
@@ -379,12 +379,6 @@ mergeInto(LibraryManager.library, {
   emscripten_set_main_loop: function(func, fps) {
     Module['noExitRuntime'] = true;
 
-#if PROFILE_MAIN_LOOP
-    Module['totalTime'] = 0;
-    Module['iterations'] = 0;
-    Module['maxTime'] = 0;
-#endif
-
     var jsFunc = FUNCTION_TABLE[func];
     Browser.mainLoop.runner = function() {
       if (Browser.mainLoop.queue.length > 0) {
@@ -414,18 +408,15 @@ mergeInto(LibraryManager.library, {
         return;
       }
 
-#if PROFILE_MAIN_LOOP
-      var start = performance.now();
-#endif
+      if (Module['preMainLoop']) {
+        Module['preMainLoop']();
+      }
 
       jsFunc();
 
-#if PROFILE_MAIN_LOOP
-      var time = performance.now() - start;
-      Module['totalTime'] += time;
-      Module['iterations']++;
-      Module['maxTime'] = Math.max(Module['maxTime'], time);
-#endif
+      if (Module['postMainLoop']) {
+        Module['postMainLoop']();
+      }
 
       if (Browser.mainLoop.shouldPause) {
         // catch pauses from the main loop itself
diff --git a/src/parseTools.js b/src/parseTools.js
index e37f3a99..80ba269b 100644
--- a/src/parseTools.js
+++ b/src/parseTools.js
@@ -1265,6 +1265,9 @@ function makePointer(slab, pos, allocator, type) {
     de = dedup(evaled);
     if (de.length === 1 && de[0] === 0) {
       slab = types.length;
+      if (USE_TYPED_ARRAYS == 2) {
+        types = ['i8']; //  if data is zeros, we don't need type info
+      }
     }
     // TODO: if not all zeros, at least filter out items with type === 0. requires cleverness to know how to skip at runtime though. also
     //       be careful of structure padding
diff --git a/src/preamble.js b/src/preamble.js
index a8f19d64..b3cfca85 100644
--- a/src/preamble.js
+++ b/src/preamble.js
@@ -24,6 +24,8 @@ var ACCEPTABLE_SAFE_HEAP_ERRORS = 0;
 function SAFE_HEAP_ACCESS(dest, type, store, ignore) {
   //if (dest === A_NUMBER) Module.print ([dest, type, store] + ' ' + new Error().stack); // Something like this may be useful, in debugging
 
+  assert(dest >= STACK_ROOT, 'segmentation fault: null pointer, or below normal memory');
+
 #if USE_TYPED_ARRAYS
   // When using typed arrays, reads over the top of TOTAL_MEMORY will fail silently, so we must
   // correct that by growing TOTAL_MEMORY as needed. Without typed arrays, memory is a normal
@@ -639,13 +641,6 @@ var FAST_MEMORY = Module['FAST_MEMORY'] || {{{ FAST_MEMORY }}};
   }
 #endif
 
-var base = intArrayFromString('(null)'); // So printing %s of NULL gives '(null)'
-                                         // Also this ensures we leave 0 as an invalid address, 'NULL'
-STATICTOP = base.length;
-for (var i = 0; i < base.length; i++) {
-  {{{ makeSetValue(0, 'i', 'base[i]', 'i8') }}}
-}
-
 Module['HEAP'] = HEAP;
 #if USE_TYPED_ARRAYS == 1
 Module['IHEAP'] = IHEAP;
@@ -664,7 +659,7 @@ Module['HEAPF32'] = HEAPF32;
 Module['HEAPF64'] = HEAPF64;
 #endif
 
-STACK_ROOT = STACKTOP = Runtime.alignMemory(STATICTOP);
+STACK_ROOT = STACKTOP = Runtime.alignMemory(1);
 STACK_MAX = STACK_ROOT + TOTAL_STACK;
 
 #if USE_TYPED_ARRAYS == 2
@@ -694,6 +689,8 @@ STACK_MAX = tempDoublePtr + 8;
 
 STATICTOP = alignMemoryPage(STACK_MAX);
 
+var nullString = allocate(intArrayFromString('(null)'), 'i8', ALLOC_STATIC);
+
 function callRuntimeCallbacks(callbacks) {
   while(callbacks.length > 0) {
     var callback = callbacks.shift();
@@ -723,9 +720,9 @@ function exitRuntime() {
 }
 
 function String_len(ptr) {
-  var i = 0;
-  while ({{{ makeGetValue('ptr', 'i', 'i8') }}}) i++; // Note: should be |!= 0|, technically. But this helps catch bugs with undefineds
-  return i;
+  var i = ptr;
+  while ({{{ makeGetValue('i++', '0', 'i8') }}}) {}; // Note: should be |!= 0|, technically. But this helps catch bugs with undefineds
+  return i - ptr - 1;
 }
 Module['String_len'] = String_len;
 
diff --git a/src/settings.js b/src/settings.js
index 9f63622d..fe532bda 100644
--- a/src/settings.js
+++ b/src/settings.js
@@ -104,7 +104,9 @@ var CATCH_EXIT_CODE = 0; // If set, causes exit() to throw an exception object w
                          // terminated with an error message.
 
 // Generated code debugging options
-var SAFE_HEAP = 0; // Check each write to the heap against a list of blocked addresses
+var SAFE_HEAP = 0; // Check each write to the heap, for example, this will give a clear
+                   // error on what would be segfaults in a native build (like deferencing
+                   // 0). See preamble.js for the actual checks performed.
                    // If equal to 2, done on a line-by-line basis according to
                    // SAFE_HEAP_LINES, checking only the specified lines.
                    // If equal to 3, checking all *but* the specified lines. Note