simple gc

.clang-format

@@ -0,0 +1,66 @@
+# Generated from CLion C/C++ Code Style settings
+BasedOnStyle: LLVM
+AccessModifierOffset: -4
+AlignAfterOpenBracket: Align
+AlignConsecutiveAssignments: None
+AlignOperands: Align
+AllowAllArgumentsOnNextLine: false
+AllowAllConstructorInitializersOnNextLine: false
+AllowAllParametersOfDeclarationOnNextLine: false
+AllowShortBlocksOnASingleLine: Always
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: All
+AllowShortIfStatementsOnASingleLine: Always
+AllowShortLambdasOnASingleLine: All
+AllowShortLoopsOnASingleLine: true
+AlwaysBreakAfterReturnType: None
+AlwaysBreakTemplateDeclarations: Yes
+BreakBeforeBraces: Custom
+BraceWrapping:
+  AfterCaseLabel: false
+  AfterClass: false
+  AfterControlStatement: Never
+  AfterEnum: false
+  AfterFunction: false
+  AfterNamespace: false
+  AfterUnion: false
+  BeforeCatch: false
+  BeforeElse: false
+  IndentBraces: false
+  SplitEmptyFunction: false
+  SplitEmptyRecord: true
+BreakBeforeBinaryOperators: None
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializers: BeforeColon
+BreakInheritanceList: BeforeColon
+ColumnLimit: 0
+CompactNamespaces: false
+ContinuationIndentWidth: 8
+IndentCaseLabels: true
+IndentPPDirectives: None
+IndentWidth: 4
+KeepEmptyLinesAtTheStartOfBlocks: true
+MaxEmptyLinesToKeep: 2
+NamespaceIndentation: All
+ObjCSpaceAfterProperty: false
+ObjCSpaceBeforeProtocolList: true
+PointerAlignment: Right
+ReflowComments: false
+SpaceAfterCStyleCast: true
+SpaceAfterLogicalNot: false
+SpaceAfterTemplateKeyword: false
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeCpp11BracedList: false
+SpaceBeforeCtorInitializerColon: true
+SpaceBeforeInheritanceColon: true
+SpaceBeforeParens: ControlStatements
+SpaceBeforeRangeBasedForLoopColon: false
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 0
+SpacesInAngles: false
+SpacesInCStyleCastParentheses: false
+SpacesInContainerLiterals: false
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+TabWidth: 4
+UseTab: Never

.idea/codeStyles/Project.xml

@@ -0,0 +1,7 @@
+<component name="ProjectCodeStyleConfiguration">
+  <code_scheme name="Project" version="173">
+    <clangFormatSettings>
+      <option name="ENABLED" value="true" />
+    </clangFormatSettings>
+  </code_scheme>
+</component>

.idea/codeStyles/codeStyleConfig.xml

@@ -0,0 +1,5 @@
+<component name="ProjectCodeStyleConfiguration">
+  <state>
+    <option name="USE_PER_PROJECT_SETTINGS" value="true" />
+  </state>
+</component>

src/vm/includes/Cell.h

@@ -5,8 +5,8 @@
 #ifndef PSIL_CELL_H
 #define PSIL_CELL_H
 
-#include <cstdint>
 #include <cassert>
+#include <cstdint>
 
 enum class CellType {
     INT,
@@ -19,6 +19,8 @@ struct Cell {
     virtual ~Cell() = 0;
 
     CellType _type;
+
+    bool live = false;
 };
 
 struct IntCell : public Cell {
@@ -60,7 +62,6 @@ struct CommandCell : public IntCell {
         assert((_val > 0 && static_cast<CommandNum>(_val) <= CommandNum::END));
         return static_cast<CommandNum>(_val);
     }
-
 };
 
 struct ConsCell : public Cell {

src/vm/includes/VM.h

@@ -5,9 +5,10 @@
 #ifndef PSIL_VM_H
 #define PSIL_VM_H
 
-#include <vector>
-#include<utility>
 #include <iostream>
+#include <list>
+#include <utility>
+#include <vector>
 
 #include "Cell.h"
 
@@ -57,8 +58,10 @@ public:
         return what;
     }
 
+    uint64_t cellCount() const;
+
 private:
-    std::vector<Cell *> _cells;
+    std::list<Cell *> _cells;
     ConsCell *_s = nullptr;
     ConsCell *_e = nullptr;
     ConsCell *_c = nullptr;
@@ -67,6 +70,8 @@ private:
 
     std::istream &_instream;
     std::ostream &_outstream;
+
+    void gc();
 };
 
 

src/vm/src/VM.cpp

@@ -2,10 +2,11 @@
 // Created by Stepan Usatiuk on 22.12.2023.
 //
 
-#include "../includes/VM.h"
+#include "VM.h"
 
-#include <utility>
 #include <iostream>
+#include <set>
+#include <utility>
 
 void VM::run() {
     while (!_stop) step();
@@ -113,7 +114,7 @@ void VM::step() {
             _s = s;
 
             push(_s, ret);
-
+            gc();
             break;
         }
         case CommandCell::CommandNum::DUM: {
@@ -143,6 +144,7 @@ void VM::step() {
         }
         case CommandCell::CommandNum::STOP: {
             _stop = true;
+            gc();
             break;
         }
         case CommandCell::CommandNum::ADD: {
@@ -188,7 +190,46 @@ void VM::step() {
         default:
             assert(false);
     }
-
 }
 
 VM::VM(std::istream &instream, std::ostream &outstream) : _instream(instream), _outstream(outstream) {}
+
+void VM::gc() {
+    std::function<void(ConsCell *)> visit = [&](ConsCell *c) {
+        if (c == nullptr) return;
+        if (c->live) return;
+
+        c->live = true;
+
+        if (c->_car) {
+            if (c->_car->_type == CellType::CONS) visit(dynamic_cast<ConsCell *>(c->_car));
+            c->_car->live = true;
+        }
+        if (c->_cdr) {
+            if (c->_cdr->_type == CellType::CONS) visit(dynamic_cast<ConsCell *>(c->_cdr));
+            c->_cdr->live = true;
+        }
+    };
+    visit(_s);
+    visit(_e);
+    visit(_c);
+    visit(_d);
+
+    uint64_t freed = 0;
+
+    _cells.remove_if([&](Cell *l) {
+        bool ret = !l->live;
+        if (ret) {
+            freed += 1;
+            delete l;
+        } else {
+            l->live = false;
+        }
+        return ret;
+    });
+
+    std::cout << "GC Freed " << freed << std::endl;
+}
+uint64_t VM::cellCount() const {
+    return _cells.size();
+}

test/vm/VMTest.cpp

@@ -91,7 +91,6 @@ TEST(VMTest, SimpleFunction) {
     }
     ssout.flush();
     EXPECT_EQ(ssout.str(), "3");
-
 }
 
 TEST(VMTest, RecursiveFunction) {
@@ -171,7 +170,7 @@ TEST(VMTest, RecursiveFunction) {
         vm.push(fibcallfn, vm.makeCell<ConsCell>(vm.makeCell<IntCell>(1), vm.makeCell<IntCell>(1)));
         vm.push(fibcallfn, vm.makeCell<CommandCell>(CommandCell::CommandNum::LD));
         vm.push(fibcallfn, vm.makeCell<CommandCell>(CommandCell::CommandNum::CONS));
-        vm.push(fibcallfn, vm.makeCell<IntCell>(20));
+        vm.push(fibcallfn, vm.makeCell<IntCell>(10));
         vm.push(fibcallfn, vm.makeCell<CommandCell>(CommandCell::CommandNum::LDC));
         vm.push(fibcallfn, vm.makeCell<CommandCell>(CommandCell::CommandNum::NIL));
 
@@ -236,6 +235,5 @@ TEST(VMTest, RecursiveFunction) {
         vm.run();
     }
     ssout.flush();
-    EXPECT_EQ(ssout.str(), "2358 6765");
-
+    EXPECT_EQ(ssout.str(), "2358 55");
 }

test/vm/VMWithParserTest.cpp

@@ -1,7 +1,7 @@
 #include <gtest/gtest.h>
 
-#include "VM.h"
 #include "Parser.h"
+#include "VM.h"
 
 TEST(VMWithParserTest, BasicHello) {
     std::stringstream ssin;
@@ -50,9 +50,9 @@ TEST(VMWithParserTest, RecFunction) {
         VM vm(ssin, ssout);
         Parser parser(vm);
         parser.loadSecd(
-                "( DUM NIL LDF ( LD ( 1 . 1 ) SEL ( LD ( 1 . 1 ) LDC -1 ADD SEL ( NIL LD ( 1 . 1 ) LDC -1 ADD CONS LD ( 2 . 1 ) AP NIL LD ( 1 . 1 ) LDC -2 ADD CONS LD ( 2 . 1 ) AP ADD JOIN ) ( LDC 1 JOIN ) JOIN ) ( LDC 0 JOIN ) RET ) CONS LDF ( NIL LDC 20 CONS LD ( 1 . 1 ) AP RET ) RAP PUTNUM STOP )");
+                "( DUM NIL LDF ( LD ( 1 . 1 ) SEL ( LD ( 1 . 1 ) LDC -1 ADD SEL ( NIL LD ( 1 . 1 ) LDC -1 ADD CONS LD ( 2 . 1 ) AP NIL LD ( 1 . 1 ) LDC -2 ADD CONS LD ( 2 . 1 ) AP ADD JOIN ) ( LDC 1 JOIN ) JOIN ) ( LDC 0 JOIN ) RET ) CONS LDF ( NIL LDC 10 CONS LD ( 1 . 1 ) AP RET ) RAP PUTNUM STOP )");
         vm.run();
     }
     ssout.flush();
-    EXPECT_EQ(ssout.str(), "6765");
+    EXPECT_EQ(ssout.str(), "55");
 }