Fixed bugs on freeing chunks and stack-scanning

Co-authored-by: ValterMiari <ValterMiari@users.noreply.github.com>

.gitignore

@@ -6,4 +6,6 @@ src/Grammar
 /language
 .vscode/
 
+src/GC/lib/*.o
+src/GC/lib/*.so
 src/GC/tests/*.out

src/GC/Makefile

@@ -1,18 +1,17 @@
-mkfile_path = $(abspath $(lastword $(MAKEFILE_LIST)))
-current_dir = $(notdir $(patsubst %/,%,$(dir $(mkfile_path))))
 CC 			= clang++
-
+CWD			= $(shell pwd)
-PWD_V 		= /Users/valtermiari/Desktop/DV/Bachelors/code/language/src/GC/include
+LIB_INCL 	= -I$(CWD)/include
-LIB_INCL 	= -I/home/virre/dev/systemF/org/language/src/GC/include
+LIB_SO 		= -L$(CWD)/lib
-LIB_SO 		= -L/home/virre/dev/systemF/org/language/src/GC/lib
+LIB_LINK	= $(CWD)/lib
-LIB_LINK	= /home/virre/dev/systemF/org/language/src/GC/lib
-
 CFLAGS 		= -Wall -Wextra -v -g -std=gnu++20 -stdlib=libc++ -I
 VGFLAGS 	= --leak-check=full --show-leak-kinds=all
 STDFLAGS 	= -std=gnu++20 -stdlib=libc++
 WFLAGS 		= -Wall -Wextra
 DBGFLAGS 	= -g
 
+test_test:
+	echo "$(shell pwd)"
+
 heap:
 	$(CC) $(WFLAGS) $(STDFLAGS) $(LIB_INCL) lib/heap.cpp
 

src/GC/include/heap.hpp

@@ -44,6 +44,7 @@ namespace GC {
     size_t m_allocated_size;
     uintptr_t *m_stack_end = nullptr;
 
+    // maybe change to std::list
     std::vector<Chunk *> m_allocated_chunks;
     std::vector<Chunk *> m_freed_chunks;
 

src/GC/lib/heap.cpp

@@ -147,14 +147,14 @@ namespace GC {
     std::vector<Chunk *> filtered;
     size_t i = 0;
     filtered.push_back(heap->m_freed_chunks.at(i++));
-    //cout << filtered.back()->start << endl;
+    cout << filtered.back()->start << endl;
     for (; i < heap->m_freed_chunks.size(); i++) {
       auto prev = filtered.back();
-      cout << "Previous start:\t" << prev->start << endl;
-      cout << "Previous end:\t" << prev->start + prev->size << endl;
       auto next = heap->m_freed_chunks.at(i);
-      cout << "Next start:\t" << next->start << endl;
+      auto p_start = (uintptr_t)(prev->start);
-      if (next->start > (prev->start + prev->size)) {
+      auto p_size  = (uintptr_t)(prev->size);
+      auto n_start = (uintptr_t)(next->start);
+      if (n_start >= (p_start + p_size)) {
         filtered.push_back(next);
       }
     }
@@ -186,7 +186,6 @@ namespace GC {
 
     cout << "Stack end in collect:\t " << stack_end << endl;
     auto work_list = heap->m_allocated_chunks;
-    //print_worklist(work_list);
 
     if (flags & MARK) {
       mark(stack_start, stack_end, work_list);
@@ -229,33 +228,35 @@ namespace GC {
   void Heap::mark(uintptr_t *start, const uintptr_t *end, vector<Chunk*> worklist) {
     int counter = 0;
     // To find adresses thats in the worklist
-    for (; start > end; start--) { 
+    for (; start < end; start++) { 
       counter++;
       // all pointers must be aligned as double words
-      if (*start % 8 == 0) { 
 
-        for (auto it = worklist.begin(); it != worklist.end();) {
+      for (auto it = worklist.begin(); it != worklist.end();) {
-          Chunk *chunk = *it;
+        Chunk *chunk = *it;
-          uintptr_t c_start = reinterpret_cast<uintptr_t>(chunk->start);
+        if (chunk == nullptr) {
-          uintptr_t c_end = reinterpret_cast<uintptr_t>(chunk->start + chunk->size);
+          assert(false && "EPIC FAIL");
+        }
+        uintptr_t c_start = reinterpret_cast<uintptr_t>(chunk->start);
+        uintptr_t c_end = reinterpret_cast<uintptr_t>(chunk->start + chunk->size);
+        // Check if the stack pointer aligns with the chunk
+        if (c_start <= *start && *start < c_end) {
+        //if (c_start == *start) {
+          cout << "Start points to:\t" << hex << *start << endl;
+          cout << "Chunk start:\t\t" << hex << c_start << endl;
+          cout << "Chunk end:\t\t" << hex << c_end << "\n" << endl;           
         
-          // Check if the stack pointer aligns with the chunk
+          if (!chunk->marked) {
-          //if ((c_start <= *start && *start < c_end) && chunk != nullptr) {
+            chunk->marked = true;
-          if (c_start == *start) {
+            it = worklist.erase(it);
-            cout << "Start points to:\t" << hex << *start << endl;
+          }
-            cout << "Chunk start:\t\t" << hex << c_start << endl;
+          else {
-            cout << "Chunk end:\t\t" << hex << c_end << "\n" << endl;           
-
-            if (!chunk->marked) {
-              chunk->marked = true;
-              it = worklist.erase(it);
-            }
-            else 
-              ++it;
-            }
-          else
             ++it;
           }
+        }
+        else {
+          ++it;
+        }
       }
     }
     cout << "Counter: " << counter << endl;

src/GC/tests/h_test.cpp

@@ -63,26 +63,23 @@ void test_some_types() {
 }
 
 int main() {
+    //gc->init();
+    //gc->check_init();
     auto stack_start = reinterpret_cast<uintptr_t *>(__builtin_frame_address(0));
     std::cout << "Stack start from main:\t" << stack_start << std::endl;
-    // This is allocated outside of the scope of the GC, thus garbage
+    
-    for (int i = 0; i < 10; i++) {
+    // char *c = static_cast<char *>(gc->alloc(sizeof(char))); // 0x0      | 0x0
-        gc->alloc(sizeof(int));
+    // int *i = static_cast<int *>(gc->alloc(sizeof(int)));    // 0x1-0x4  | 0x4-0x8
+    // char *c2 = static_cast<char *>(gc->alloc(sizeof(char)));// 0x5      | 0x9-0x
+    // long *l = static_cast<long *>(gc->alloc(sizeof(long))); // 0x6-0xd  | 0x
+    
+    // This is allocated outside of the scope of the GC (if gc->init() isn't called), thus garbage
+    long *longs[21];
+    std::cout << "Pointer to ints:\t" << longs << std::endl;
+    for (int i = 0; i < 21; i++) {
+        longs[i] = static_cast<long *>(gc->alloc(sizeof(long)));
     }
-    /* int depth = 10;
+
-    Node* nodes[depth];
-    Node *last_node = static_cast<Node *>(gc->alloc(sizeof(Node)));
-    last_node->id = depth;
-    last_node->child = nullptr;
-    nodes[0] = last_node;
-    for (int i = 1; i < depth; i++) {
-        Node *node = static_cast<Node *>(gc->alloc(sizeof(Node)));
-        node->id = depth-i;
-        node->child = nodes[i-1];
-        nodes[i] = node;
-    } */
-    //test_chain(10, false);
-    //test_some_types();
     gc->collect(MARK | SWEEP | FREE); // free misses some chunks
     gc->print_contents();
     return 0;