1 files changed, 75 insertions, 0 deletions
diff --git a/rts/js/stableptr.js b/rts/js/stableptr.js
new file mode 100644
index 0000000000..82fc2d336c
--- /dev/null
+++ b/rts/js/stableptr.js
@@ -0,0 +1,75 @@
+//#OPTIONS: CPP
+
+/*
+  Stable pointers are all allocated in the h$StablePtrData buffer and
+  can therefore be distinguished by offset
+
+  StablePtr# is treated as Word32# when it comes to writing and reading them
+ */
+
+ #ifdef GHCJS_TRACE_STABLEPTR
+ function h$logStablePtr(args) { h$log.apply(h$log,arguments); }
+ #define TRACE_STABLEPTR(args...) h$logStablePtr(args)
+ #else
+ #define TRACE_STABLEPTR(args...)
+ #endif
+
+var h$stablePtrData = [null];
+var h$stablePtrBuf  = h$newByteArray(8);
+var h$stablePtrN    = 1;
+var h$stablePtrFree = [];
+
+function h$makeStablePtr(v) {
+  TRACE_STABLEPTR("makeStablePtr")
+  if(!v) return 0;
+  var slot = h$stablePtrFree.pop();
+  if(slot === undefined) {
+    slot = h$stablePtrN++;
+  }
+  TRACE_STABLEPTR("  -> slot:" + slot)
+  h$stablePtrData[slot] = v;
+  return slot << 2;
+}
+
+var h$foreignExports = [];
+function h$foreignExport(f, packageName, moduleName, functionName, typeSig) {
+  h$foreignExports.push({ exported: f,
+                          package: packageName,
+                          mod:  moduleName,
+                          name: functionName,
+                          sig: typeSig
+                        });
+  // console.log("foreign export:", f, packageName, moduleName, functionName, typeSig);
+  h$makeStablePtr(f);
+  if(typeof exports === 'object') {
+    if(typeof exports[functionName] === 'undefined') {
+      exports[functionName] = f;
+    }
+  }
+}
+/*
+function h$foreignExportStablePtr(x) {
+  // h$makeStablePtr(x);
+}
+*/
+function h$deRefStablePtr(stable_o) {
+  var slot = stable_o >> 2;
+  return h$stablePtrData[slot];
+}
+
+function h$hs_free_stable_ptr(stable_d, stable_o) {
+  var slot = stable_o >> 2;
+  TRACE_STABLEPTR("hs_free_stable_ptr")
+  if(h$stablePtrData[slot] !== null) {
+    h$stablePtrData[slot] = null;
+    h$stablePtrFree.push(slot);
+  }
+}
+
+// not strictly stableptr, but we make it work only for stable pointers
+function h$addrToAny(addr_v, addr_o) {
+  TRACE_STABLEPTR("addrToAny")
+  TRACE_STABLEPTR(addr_v === h$stablePtrBuf)
+  var slot = addr_o >> 2;
+  return h$stablePtrData[slot];
+}