Found and fixed a memory leak in the rope strings

Also fixed a bit manipulation error in the GC.

repl/bucket_inspector.c

@@ -0,0 +1,82 @@
+#include "bucket_inspector.h"
+// #include <toy_string.h>
+
+#include <stdio.h>
+
+int inspect_bucket(Toy_Bucket** bucketHandle) {
+	int depth = 0;
+
+	//for each bucket
+	for (Toy_Bucket* iter = (*bucketHandle); iter != NULL; iter = iter->next) {
+		int occupied = 0;
+		int released = 0;
+		unsigned char* ptr = iter->data;
+
+
+		while ((ptr - iter->data < iter->count) && *((int*)ptr) != 0) { //for each partition
+			if ( ( *((int*)ptr) & 1) == 0) { //is this partition still in use?
+				occupied++;
+			}
+			else {
+				released++;
+			}
+
+			//jump distance:   ((*((int*)ptr) | 1) ^ 1) + 4
+			// printf(" jump %d, ", ((*((int*)ptr) | 1) ^ 1) + 4);
+			ptr += ((*((int*)ptr) | 1) ^ 1) + 4; //OR + XOR to remove the 'free' flag from the size
+		}
+
+		printf("Bucket link %d: count %u, %d occupied, %d released\n", depth, iter->count, occupied, released);
+
+		depth++;
+	}
+
+	printf("\n");
+
+	return depth;
+}
+
+/*
+int inspect_bucket_for_strings(Toy_Bucket** bucketHandle) {
+	int depth = 0;
+
+	//for each bucket
+	for (Toy_Bucket* iter = (*bucketHandle); iter != NULL; iter = iter->next) {
+		int occupied = 0;
+		int released = 0;
+		unsigned char* ptr = iter->data;
+
+
+		while ((ptr - iter->data < iter->count) && *((int*)ptr) != 0) { //for each partition
+			if ( ( *((int*)ptr) & 1) == 0) { //is this partition still in use?
+				occupied++;
+
+				//try to print as a string if possible
+				Toy_String* str = (void*)(ptr + 4);
+
+				if (str->info.type == TOY_STRING_LEAF && str->info.length < 255) {
+					printf("String Leaf (%d bytes, %d refCount): %.*s\n", *((int*)ptr), str->info.refCount, str->info.length, str->leaf.data);
+				}
+				else if (str->info.type == TOY_STRING_NODE) {
+					printf("String Node (%d bytes, %d refCount): ...\n", *((int*)ptr), str->info.refCount);
+				}
+			}
+			else {
+				released++;
+			}
+
+			//jump distance:   ((*((int*)ptr) | 1) ^ 1) + 4
+			// printf(" jump %d, ", ((*((int*)ptr) | 1) ^ 1) + 4);
+			ptr += ((*((int*)ptr) | 1) ^ 1) + 4; //OR + XOR to remove the 'free' flag from the size
+		}
+
+		printf("Bucket link %d: count %u, %d occupied, %d released\n", depth, iter->count, occupied, released);
+
+		depth++;
+	}
+
+	printf("\n");
+
+	return depth;
+}
+*/

repl/bucket_inspector.h

@@ -0,0 +1,6 @@
+#pragma once
+
+#include "toy_bucket.h"
+
+int inspect_bucket(Toy_Bucket** bucketHandle);
+// int inspect_bucket_for_strings(Toy_Bucket** bucketHandle);

repl/main.c

@@ -1,5 +1,6 @@
 #include "ast_inspector.h"
 #include "bytecode_inspector.h"
+#include "bucket_inspector.h"
 
 #include "toy_console_colors.h"
 
@@ -380,14 +381,26 @@ int repl(const char* filepath, bool verbose) {
 		//run
 		Toy_runVM(&vm);
 
+		int depthBeforeGC = 0;
+		int depthAfterGC = 0;
+
 		//print the debug info
 		if (verbose) {
 			debugStackPrint(vm.stack);
 			debugScopePrint(vm.scope, 0);
+
+			depthBeforeGC = inspect_bucket(&vm.memoryBucket);
 		}
 
 		//free the memory, and leave the VM ready for the next loop
 		Toy_resetVM(&vm, true, true);
+
+		if (verbose) {
+			depthAfterGC = inspect_bucket(&vm.memoryBucket);
+
+			printf("GC Report: %d -> %d\n", depthBeforeGC, depthAfterGC);
+		}
+
 		free(bytecode);
 
 		printf("%s> ", prompt); //shows the terminal prompt

scripts/hello_world.toy

@@ -1,5 +1,5 @@
 
-
+/*
 fn swap(a, b) {
 	return b, a;
 }
@@ -10,4 +10,10 @@ var c;
 var d;
 
 //BUG: still causes a segfault
-c, d = swap(a, b);
+c, d = swap(a, b);
+
+*/
+
+
+{ var str = "Hello"; var i = 0; while (i < 10_000) { str = str .. " World"; i++; } }
+

source/toy_bucket.c

@@ -88,7 +88,7 @@ TOY_API void Toy_collectBucketGarbage(Toy_Bucket** bucketHandle) {
 				gc = false;
 				break;
 			}
-			ptr += (*((int*)(ptr)) ^ 1) + 4; //XOR to remove the 'free' flag from the size
+			ptr += ((*((int*)ptr) | 1) ^ 1) + 4; //OR + XOR to remove the 'free' flag from the size
 		}
 
 		//free this link, if its been entirely released

source/toy_scope.c

@@ -193,6 +193,8 @@ void Toy_assignScope(Toy_Scope* scope, Toy_String* key, Toy_Value value) {
 		return;
 	}
 
+	Toy_freeValue(entryPtr->value);
+
 	entryPtr->value = value;
 }
 

source/toy_string.c

@@ -20,10 +20,18 @@ static void incrementRefCount(Toy_String* str) {
 static void decrementRefCount(Toy_String* str) {
 	str->info.refCount--;
 	if (str->info.type == TOY_STRING_NODE) {
+		//the parent of this node triggered a decrement across the whole tree
 		decrementRefCount(str->node.left);
 		decrementRefCount(str->node.right);
 	}
 	if (str->info.refCount == 0) {
+		if (str->info.type == TOY_STRING_NODE) {
+			//THIS node has triggered the decrement, so run this again
+			decrementRefCount(str->node.left);
+			decrementRefCount(str->node.right);
+		}
+
+		//mark this memory as unused
 		Toy_releaseBucketPartition((void*)str);
 	}
 }

source/toy_vm.c

@@ -210,7 +210,7 @@ static void processAssign(Toy_VM* vm) {
 	Toy_Value name = Toy_popStack(&vm->stack);
 
 	//assign it
-	Toy_assignScope(vm->scope, TOY_VALUE_AS_STRING(name), Toy_copyValue(&vm->memoryBucket, value)); //scope now owns the value, doesn't need to be freed
+	Toy_assignScope(vm->scope, TOY_VALUE_AS_STRING(name), Toy_copyValue(&vm->memoryBucket, value));
 
 	//in case of chaining, leave a copy on the stack
 	bool chainedAssignment = READ_BYTE(vm);
@@ -220,6 +220,7 @@ static void processAssign(Toy_VM* vm) {
 
 	//cleanup
 	Toy_freeValue(name);
+	Toy_freeValue(value);
 }
 
 static void processAssignCompound(Toy_VM* vm) {

tests/units/test_string.c

@@ -192,8 +192,8 @@ int test_string_concatenation(void) {
 
 		free(buffer);
 		Toy_freeString(result);
-		Toy_freeString(first);
+		// Toy_freeString(first); //these do NOT need to be freed manually
-		Toy_freeString(second);
+		// Toy_freeString(second);
 		Toy_freeBucket(&bucket);
 	}