Added emscripten sbrk implementation

lib/emscripten/src/lib.rs

@@ -85,6 +85,8 @@ const GLOBAL_BASE: u32 = 1024;
 const STATIC_BASE: u32 = GLOBAL_BASE;
 
 pub struct EmscriptenData<'a> {
+    pub globals: &'a EmscriptenGlobalsData,
+
     pub malloc: Option<Func<'a, u32, u32>>,
     pub free: Option<Func<'a, u32>>,
     pub memalign: Option<Func<'a, (u32, u32), u32>>,
@@ -163,6 +165,7 @@ pub struct EmscriptenData<'a> {
 impl<'a> EmscriptenData<'a> {
     pub fn new(
         instance: &'a mut Instance,
+        globals: &'a EmscriptenGlobalsData,
         mapped_dirs: HashMap<String, PathBuf>,
     ) -> EmscriptenData<'a> {
         let malloc = instance.func("_malloc").or(instance.func("malloc")).ok();
@@ -237,6 +240,8 @@ impl<'a> EmscriptenData<'a> {
             .ok();
 
         EmscriptenData {
+            globals,
+
             malloc,
             free,
             memalign,
@@ -312,12 +317,13 @@ impl<'a> EmscriptenData<'a> {
 pub fn run_emscripten_instance(
     _module: &Module,
     instance: &mut Instance,
+    globals: &mut EmscriptenGlobals,
     path: &str,
     args: Vec<&str>,
     entrypoint: Option<String>,
     mapped_dirs: Vec<(String, PathBuf)>,
 ) -> CallResult<()> {
-    let mut data = EmscriptenData::new(instance, mapped_dirs.into_iter().collect());
+    let mut data = EmscriptenData::new(instance, &globals.data, mapped_dirs.into_iter().collect());
     let data_ptr = &mut data as *mut _ as *mut c_void;
     instance.context_mut().data = data_ptr;
 
@@ -766,6 +772,7 @@ pub fn generate_emscripten_env(globals: &mut EmscriptenGlobals) -> ImportObject
         "alignfault" => func!(crate::memory::alignfault),
         "ftfault" => func!(crate::memory::ftfault),
         "getTotalMemory" => func!(crate::memory::get_total_memory),
+        "_sbrk" => func!(crate::memory::sbrk),
         "___map_file" => func!(crate::memory::___map_file),
 
         // Exception

lib/emscripten/src/memory.rs

@@ -1,3 +1,4 @@
+use super::env::get_emscripten_data;
 use super::process::abort_with_message;
 use libc::{c_int, c_void, memcpy, size_t};
 use wasmer_runtime_core::{
@@ -65,6 +66,57 @@ pub fn _emscripten_resize_heap(ctx: &mut Ctx, requested_size: u32) -> u32 {
     }
 }
 
+// function _sbrk(increment) {
+//  increment = increment | 0;
+//  var oldDynamicTop = 0;
+//  var newDynamicTop = 0;
+//  var totalMemory = 0;
+//  totalMemory = _emscripten_get_heap_size() | 0;
+//  oldDynamicTop = HEAP32[DYNAMICTOP_PTR >> 2] | 0;
+//  newDynamicTop = oldDynamicTop + increment | 0;
+//  if ((increment | 0) > 0 & (newDynamicTop | 0) < (oldDynamicTop | 0) | (newDynamicTop | 0) < 0) {
+//   abortOnCannotGrowMemory(newDynamicTop | 0) | 0;
+//   ___setErrNo(12);
+//   return -1;
+//  }
+//  if ((newDynamicTop | 0) > (totalMemory | 0)) {
+//   if (_emscripten_resize_heap(newDynamicTop | 0) | 0) {} else {
+//    ___setErrNo(12);
+//    return -1;
+//   }
+//  }
+//  HEAP32[DYNAMICTOP_PTR >> 2] = newDynamicTop | 0;
+//  return oldDynamicTop | 0;
+// }
+
+/// emscripten: sbrk
+pub fn sbrk(ctx: &mut Ctx, increment: i32) -> i32 {
+    debug!("emscripten::sbrk");
+    // let old_dynamic_top = 0;
+    // let new_dynamic_top = 0;
+    let mut globals = get_emscripten_data(ctx).globals;
+    let dynamictop_ptr = (globals.dynamictop_ptr) as usize;
+    let old_dynamic_top = ctx.memory(0).view::<u32>()[dynamictop_ptr].get() as i32;
+    let new_dynamic_top: i32 = old_dynamic_top + increment;
+    let total_memory = _emscripten_get_heap_size(ctx) as i32;
+    debug!(
+        " => PTR {}, old: {}, new: {}, increment: {}, total: {}",
+        dynamictop_ptr, old_dynamic_top, new_dynamic_top, increment, total_memory
+    );
+    if increment > 0 && new_dynamic_top < old_dynamic_top || new_dynamic_top < 0 {
+        abort_on_cannot_grow_memory_old(ctx);
+        return -1;
+    }
+    if new_dynamic_top > total_memory {
+        let resized = _emscripten_resize_heap(ctx, new_dynamic_top as u32);
+        if resized == 0 {
+            return -1;
+        }
+    }
+    ctx.memory(0).view::<u32>()[dynamictop_ptr].set(new_dynamic_top as u32);
+    return old_dynamic_top as _;
+}
+
 /// emscripten: getTotalMemory
 pub fn get_total_memory(_ctx: &mut Ctx) -> u32 {
     debug!("emscripten::get_total_memory");