save locals to memory before executing any instruction which might trigger an exception if that instruction lies within an exception handler

src/compile.cpp

@@ -530,7 +530,7 @@ class Context {
 
   Context(MyThread* t, object method):
     thread(t),
-    zone(t->m->system, t->m->heap, 16 * 1024),
+    zone(t->m->system, t->m->heap, 64 * 1024),
     assembler(makeAssembler(t->m->system, t->m->heap, &zone, t->arch)),
     client(t),
     compiler(makeCompiler(t->m->system, assembler, &zone, &client)),
@@ -1860,6 +1860,24 @@ exceptionIndex(MyThread* t, object code, unsigned jsrIp, unsigned dstIp)
   abort(t);
 }
 
+bool
+inTryBlock(MyThread* t, object code, unsigned ip)
+{
+  object table = codeExceptionHandlerTable(t, code);
+  if (table) {
+    unsigned length = exceptionHandlerTableLength(t, table);
+    for (unsigned i = 0; i < length; ++i) {
+      ExceptionHandler* eh = exceptionHandlerTableBody(t, table, i);
+      if (ip >= exceptionHandlerStart(eh)
+          and ip < exceptionHandlerEnd(eh))
+      {
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
 void
 compile(MyThread* t, Frame* initialFrame, unsigned ip,
         int exceptionHandlerStart = -1);
@@ -1926,6 +1944,10 @@ compile(MyThread* t, Frame* initialFrame, unsigned ip,
       Compiler::Operand* index = frame->popInt();
       Compiler::Operand* array = frame->popObject();
 
+      if (inTryBlock(t, code, ip - 1)) {
+        c->saveLocals();
+      }
+
       if (CheckArrayBounds) {
         c->checkBounds(array, ArrayLength, index, reinterpret_cast<intptr_t>
                        (&singletonValue(t, aioobThunk(t), 0)));
@@ -1982,6 +2004,10 @@ compile(MyThread* t, Frame* initialFrame, unsigned ip,
       Compiler::Operand* index = frame->popInt();
       Compiler::Operand* array = frame->popObject();
 
+      if (inTryBlock(t, code, ip - 1)) {
+        c->saveLocals();
+      }
+
       if (CheckArrayBounds) {
         c->checkBounds(array, ArrayLength, index, reinterpret_cast<intptr_t>
                        (&singletonValue(t, aioobThunk(t), 0)));
@@ -2405,6 +2431,10 @@ compile(MyThread* t, Frame* initialFrame, unsigned ip,
         table = frame->append(classStaticTable(t, fieldClass(t, field)));
       } else {
         table = frame->popObject();
+
+        if (inTryBlock(t, code, ip - 3)) {
+          c->saveLocals();
+        }
       }
 
       switch (fieldCode(t, field)) {
@@ -3330,6 +3360,8 @@ compile(MyThread* t, Frame* initialFrame, unsigned ip,
         }
 
         staticTable = classStaticTable(t, fieldClass(t, field));      
+      } else if (inTryBlock(t, code, ip - 3)) {
+        c->saveLocals();
       }
 
       Compiler::Operand* value;
@@ -3968,7 +4000,7 @@ finish(MyThread* t, Context* context)
       strcmp
       (reinterpret_cast<const char*>
        (&byteArrayBody(t, className(t, methodClass(t, context->method)), 0)),
-       "Longs") == 0 and
+       "Arrays") == 0 and
       strcmp
       (reinterpret_cast<const char*>
        (&byteArrayBody(t, methodName(t, context->method), 0)),

src/compiler.cpp

@@ -2294,7 +2294,7 @@ clean(Context* c, Event* e, Stack* stack, Local* locals, Read* reads,
 
   for (Read* r = reads; r; r = r->eventNext) {
     nextRead(c, e, r->value);
-  }  
+  }
 }
 
 CodePromise*
@@ -2313,6 +2313,26 @@ codePromise(Context* c, Promise* offset)
 void
 append(Context* c, Event* e);
 
+void
+saveLocals(Context* c, Event* e)
+{
+  for (unsigned li = 0; li < c->localFootprint; ++li) {
+    Local* local = e->localsBefore + li;
+    if (local->value) {
+      if (DebugReads) {
+        fprintf(stderr, "local save read %p of footprint %d at %d of %d\n",
+                local->value, local->footprint,
+                ::frameIndex(c, li, local->footprint),
+                c->alignedFrameSize + c->parameterFootprint);
+      }
+
+      addRead(c, e, local->value, read
+              (c, footprintSizeInBytes(local->footprint), 1 << MemoryOperand,
+               0, ::frameIndex(c, li, local->footprint)));
+    }
+  }
+}
+
 class CallEvent: public Event {
  public:
   CallEvent(Context* c, Value* address, unsigned flags,
@@ -2422,21 +2442,7 @@ class CallEvent: public Event {
       frameIndex += s->footprint;
     }
 
-    for (unsigned li = 0; li < c->localFootprint; ++li) {
-      Local* local = localsBefore + li;
-      if (local->value) {
-        if (DebugReads) {
-          fprintf(stderr, "local save read %p of footprint %d at %d of %d\n",
-                  local->value, local->footprint,
-                  ::frameIndex(c, li, local->footprint),
-                  c->alignedFrameSize + c->parameterFootprint);
-        }
-
-        addRead(c, this, local->value, read
-                (c, footprintSizeInBytes(local->footprint), 1 << MemoryOperand,
-                 0, ::frameIndex(c, li, local->footprint)));
-      }
-    }
+    saveLocals(c, this);
   }
 
   virtual const char* name() {
@@ -3412,6 +3418,32 @@ appendBuddy(Context* c, Value* original, Value* buddy, unsigned size)
          BuddyEvent(c, original, buddy, size));
 }
 
+class SaveLocalsEvent: public Event {
+ public:
+  SaveLocalsEvent(Context* c):
+    Event(c)
+  {
+    saveLocals(c, this);
+  }
+
+  virtual const char* name() {
+    return "SaveLocalsEvent";
+  }
+
+  virtual void compile(Context* c) {
+    for (Read* r = reads; r; r = r->eventNext) {
+      nextRead(c, this, r->value);
+    }
+  }
+};
+
+void
+appendSaveLocals(Context* c)
+{
+  append(c, new (c->zone->allocate(sizeof(SaveLocalsEvent)))
+         SaveLocalsEvent(c));
+}
+
 class DummyEvent: public Event {
  public:
   DummyEvent(Context* c):
@@ -4482,6 +4514,10 @@ class MyCompiler: public Compiler {
     return c.locals[index].value;
   }
 
+  virtual void saveLocals() {
+    appendSaveLocals(&c);
+  }
+
   virtual void checkBounds(Operand* object, unsigned lengthOffset,
                            Operand* index, intptr_t handler)
   {

src/compiler.h

@@ -92,6 +92,7 @@ class Compiler {
   virtual void storeLocal(unsigned footprint, Operand* src,
                           unsigned index) = 0;
   virtual Operand* loadLocal(unsigned footprint, unsigned index) = 0;
+  virtual void saveLocals() = 0;
 
   virtual void checkBounds(Operand* object, unsigned lengthOffset,
                            Operand* index, intptr_t handler) = 0;