3 files changed, 19 insertions, 6 deletions
diff --git a/Makefile b/Makefile
index 37142aa..4e173d8 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@ sonsi: main.o parser.o builtin.o model.o eval.o exc.o consts.o types.o gc.o
 	g++ -o sonsi $^ -pg -lgmp
 
 .cpp.o:
-	g++ $< -c -O2 -DGMP_SUPPORT -Wall
+	g++ $< -c -g -DGMP_SUPPORT -Wall -O2
 
 clean:
 	rm -f *.o
diff --git a/types.cpp b/types.cpp
index 6a24239..7eae0f6 100644
--- a/types.cpp
+++ b/types.cpp
@@ -389,16 +389,24 @@ VectReprCons::VectReprCons(VecObj *_ptr, EvalObj *_ori) :
 PromObj::PromObj(EvalObj *exp) : 
     EvalObj(CLS_SIM_OBJ | CLS_PROM_OBJ), 
     entry(new Pair(exp, empty_list)), mem(NULL) {
+        gc.attach(entry);
         entry->next = NULL;
     }
 
+PromObj::~PromObj() {
+    gc.expose(entry);
+    gc.expose(mem);
+}
+
 Pair *PromObj::get_entry() { return entry; }
 
 ReprCons *PromObj::get_repr_cons() { return new ReprStr("#<Promise>"); }
 
 EvalObj *PromObj::get_mem() { return mem; }
 
-void PromObj::feed_mem(EvalObj *res) { mem = res; }
+void PromObj::feed_mem(EvalObj *res) { 
+    gc.attach(mem = res);
+}
 
 
 string double_to_str(double val, bool force_sign = false) {
@@ -573,8 +581,10 @@ void CompNumObj::sub(NumObj *_r) {
 
 void CompNumObj::mul(NumObj *_r) {
     CompNumObj *r = static_cast<CompNumObj*>(_r);
-    A = A * C - B * D;
-    B = B * C + A * D;
+    double ra = A * C - B * D;
+    double rb = B * C + A * D;
+    A = ra;
+    B = rb;
 }
 
 void CompNumObj::div(NumObj *_r) {
@@ -583,8 +593,10 @@ void CompNumObj::div(NumObj *_r) {
     if (f == 0)
         throw NormalError(RUN_ERR_NUMERIC_OVERFLOW);
     f = 1 / f;
-    A = (A * C + B * D) * f,
-    B = (B * C - A * D) * f;
+    double ra = (A * C + B * D) * f;
+    double rb = (B * C - A * D) * f;
+    A = ra;
+    B = rb;
 }
 
 bool NumObj::lt(NumObj *_r) {
diff --git a/types.h b/types.h
index 5147e2d..1e1e8a7 100644
--- a/types.h
+++ b/types.h
@@ -320,6 +320,7 @@ class PromObj: public EvalObj {/*{{{*/
         EvalObj *mem;
     public:
         PromObj(EvalObj *exp);
+        ~PromObj();
         Pair *get_entry();
         EvalObj *get_mem();
         void feed_mem(EvalObj *res);