Attempts at fixing GC issues

src/backend/vm.nim

@@ -236,9 +236,9 @@ proc markRoots(self: var PeonVM): seq[ptr HeapObject] =
     for p in live:
         obj = cast[ptr HeapObject](p)
         if obj.mark():
+            result.add(obj)
             when debugGC:
                 echo &"DEBUG - GC: Marked object: {obj[]}"
-            result.add(obj)
     when debugGC:
         echo "DEBUG - GC: Mark phase complete"
 
@@ -380,7 +380,7 @@ proc getInf*(self: var PeonVM, positive: bool): uint64 =
 proc getNan*(self: var PeonVM): uint64 = self.cache[5]
 
 
-# Thanks to nim's *genius* idea of making x !> y a template
+# Thanks to nim's *genius* idea of making x > y a template
 # for y < x (which by itself is fine) together with the fact
 # that the order of evaluation of templates with the same
 # expression is fucking stupid (see https://nim-lang.org/docs/manual.html#order-of-evaluation
@@ -659,7 +659,7 @@ when debugVM:   # So nim shuts up
                 of "n", "next":
                     self.debugNext = true
                     break
-                of "continue":
+                of "c", "continue":
                     self.debugNext = false
                     break
                 of "s", "stack":

src/frontend/compiler.nim

@@ -490,7 +490,7 @@ proc fixJumps(self: Compiler, oldLen: int, modifiedAt: int) =
 proc resolve(self: Compiler, name: string): Name =
     ## Traverses all existing namespaces and returns
     ## the first object with the given name. Returns
-    ## nil when the name can't be found. Note that, 
+    ## nil when the name can't be found. Note that 
     ## when a declaration is first resolved, it is
     ## also compiled on-the-fly
     for obj in reversed(self.names):
@@ -516,20 +516,20 @@ proc resolve(self: Compiler, name: string): Name =
                 # C and D and module B imports module A, then B
                 # might not want to also have access to C's and D's
                 # names as they might clash with its own stuff)
+                continue
             result = obj
             break
     if not result.isNil() and not result.resolved:
         # There's no reason to compile a declaration
         # unless it is used at least once: this way
         # not only do we save space if a name is declared
-        # but never used, but it also makes it easier to
-        # implement generics. Yay!
+        # but never used, it also makes it easier to
+        # implement generics and lets us emit warnings for
+        # unused names once they go out of scope. Yay!
         result.resolved = true
         # Now we just dispatch to one of our functions to
         # compile the declaration
         case result.kind:
-            of NameKind.Var:
-                self.varDecl(VarDecl(result.node), result)
             of NameKind.CustomType:
                 self.typeDecl(TypeDecl(result.node), result)
             of NameKind.Function:
@@ -587,8 +587,6 @@ proc getStackPos(self: Compiler, name: Name): int =
             # we skip it and pretend it doesn't exist
             if variable.isPrivate or not variable.exported:
                 continue
-        elif not variable.resolved:
-            dec(result)
         elif name.ident == variable.ident:
             # After all of these checks, we can
             # finally check whether the name of 
@@ -1251,7 +1249,7 @@ proc declareName(self: Compiler, node: ASTNode, mutable: bool = false): Name =
                                 isPrivate: node.isPrivate,
                                 owner: self.currentModule,
                                 isConst: node.isConst,
-                                valueType: self.infer(node.value),
+                                valueType: nil,  # Done later
                                 isLet: node.isLet,
                                 line: node.token.line,
                                 belongsTo: self.currentFunction,
@@ -2244,6 +2242,12 @@ proc declaration(self: Compiler, node: Declaration) =
     case node.kind:
         of NodeKind.varDecl, NodeKind.funDecl, NodeKind.typeDecl:
             self.dispatchPragmas(node, self.declareName(node))
+            if node.kind == NodeKind.varDecl:
+                self.names[^1].resolved = true
+                # We compile this immediately because we
+                # need to keep the stack in the right state
+                # at runtime
+                self.varDecl(VarDecl(node), self.names[^1])
         else:
             self.statement(Statement(node))
 

tests/gc.pn

@@ -1,7 +1,7 @@
 import std;
 
 
-var x: uint64 = 100000'u64;
+var x: uint64 = 1000000'u64;
 var y = "just a test";
 print(y);
 print("Starting GC torture test");