cosmoV_throw() now resets the vm stack as well

also a minor GC bug in cosmoO_newError was fixed.

i'm going to try to phase out cosmoM_freezeGC & friends
since that would cause hell with this new
error handling solution. the only thing still using it is the GC.

src/cbaselib.c

@@ -948,16 +948,9 @@ int cosmoB_vnewindexBProto(CState *state, int nargs, CValue *args)
 // vm.collect()
 int cosmoB_vcollect(CState *state, int nargs, CValue *args)
 {
-    // first, unfreeze the state (we start frozen on entry to any C Function)
-    cosmoM_unfreezeGC(state);
-
     // now force a garbage collection
     cosmoM_collectGarbage(state);
 
-    // and re-freeze the state
-    cosmoM_freezeGC(state);
-
-    // the end!
     return 0;
 }
 

src/cobj.c

@@ -229,14 +229,13 @@ CObjCFunction *cosmoO_newCFunction(CState *state, CosmoCFunction func)
 
 CObjError *cosmoO_newError(CState *state, CValue err)
 {
+    CCallFrame *frames = cosmoM_xmalloc(state, sizeof(CCallFrame) * state->frameCount);
     CObjError *cerror = (CObjError *)cosmoO_allocateBase(state, sizeof(CObjError), COBJ_ERROR);
     cerror->err = err;
     cerror->frameCount = state->frameCount;
+    cerror->frames = frames;
     cerror->parserError = false;
 
-    // allocate the callframe
-    cerror->frames = cosmoM_xmalloc(state, sizeof(CCallFrame) * cerror->frameCount);
-
     // clone the call frame
     for (int i = 0; i < state->frameCount; i++)
         cerror->frames[i] = state->callFrame[i];
@@ -762,6 +761,8 @@ const char *cosmoO_typeStr(CObj *obj)
         return "<function>";
     case COBJ_CFUNCTION:
         return "<c function>";
+    case COBJ_ERROR:
+        return "<error>";
     case COBJ_METHOD:
         return "<method>";
     case COBJ_CLOSURE:

src/cparse.h

@@ -4,8 +4,7 @@
 #include "clex.h"
 #include "cosmo.h"
 
-// compiles source into CChunk, if NULL is returned, a syntaxical error has occurred and pushed onto
-// the stack
+// compiles source into CChunk
 CObjFunction *cosmoP_compileString(CState *state, const char *source, const char *module);
 
 #endif

src/cstate.c

@@ -10,6 +10,8 @@
 CPanic *cosmoV_newPanic(CState *state)
 {
     CPanic *panic = cosmoM_xmalloc(state, sizeof(CPanic));
+    panic->top = state->top;
+    panic->frameCount = state->frameCount;
     panic->prev = state->panic;
     state->panic = panic;
 
@@ -95,7 +97,6 @@ void cosmoV_freeState(CState *state)
 #ifdef GC_DEBUG
     printf("state %p is being free'd!\n", state);
 #endif
-    cosmoM_freezeGC(state);
 
     // frees all the objects
     CObj *objs = state->objects;

src/cstate.h

@@ -43,6 +43,8 @@ typedef struct ArrayCObj
 typedef struct CPanic
 {
     jmp_buf jmp;
+    StkPtr top;
+    int frameCount;
     struct CPanic *prev;
 } CPanic;
 

src/cvm.c

@@ -118,11 +118,14 @@ void cosmoV_throw(CState *state)
     StkPtr temp = cosmoV_getTop(state, 0);
     CObjError *error = cosmoO_newError(state, *temp);
 
-    // replace the value on the stack with the error
-    *temp = cosmoV_newRef((CObj *)cosmoO_newError(state, *temp));
+    CValue val = cosmoV_newRef((CObj *)cosmoO_newError(state, *temp));
     if (state->panic) {
+        state->top = state->panic->top;
+        state->frameCount = state->panic->frameCount;
+        cosmoV_pushValue(state, val);
         longjmp(state->panic->jmp, 1);
     } else {
+        cosmoV_pushValue(state, val);
         fprintf(stderr, "Unhandled panic! ");
         cosmoV_printError(state, error);
         exit(1);