feat: support function params + stack based compiler!

example.rx

@@ -1,15 +1,18 @@
 extern putchar
 
-fn main() {
+fn hello() {
     local h = 72
     local e = 69
     local l = 76
     local o = 79
-    local nl = 10
     putchar(h)
     putchar(e)
     putchar(l)
     putchar(l)
     putchar(o)
-    putchar(nl)
+}
+
+fn main() {
+    hello()
+    putchar(10)
 }

include/ast.hpp

@@ -126,8 +126,8 @@ class FnDeclNode : public Node
 {
 public:
     // TODO: support parameters
-    FnDeclNode(const StringView& name, CompoundNode* body)
-        : m_name(name), m_body(body) {}
+    FnDeclNode(const StringView& name, CompoundNode* body, View<StringView> params)
+        : m_name(name), m_body(body), m_params(params) {}
     ~FnDeclNode() override {
         delete m_body;
     }
@@ -136,9 +136,11 @@ public:
 public:
     const StringView& name() const { return m_name; }
     const CompoundNode* body() const { return m_body; }
+    const View<StringView>& params() const { return m_params; }
 private:
     StringView m_name;
     CompoundNode* m_body;
+    View<StringView> m_params;
 };
 
 class FnCallNode : public Node
@@ -236,7 +238,13 @@ public:
         m_lexer->NextExpect(TokenType::Id);
         StringView name = m_lexer->token().string;
         m_lexer->NextExpect('(');
-        // TODO: parse parameters
+        Builder<StringView> params;
+        // TODO: support multiple params
+        if (m_lexer->seek_token()->token != ')')
+        {
+            m_lexer->NextExpect(TokenType::Id);
+            params.Push(m_lexer->token().string);
+        }
         m_lexer->NextExpect(')');
         m_lexer->NextExpect('{');
         auto compound = new CompoundNode();
@@ -245,7 +253,7 @@ public:
             compound->addNode(ParseStatement());
         }
         m_lexer->NextExpect('}');
-        return new FnDeclNode(name, compound);
+        return new FnDeclNode(name, compound, params.view());
     }
 
     FnCallNode* ParseFnCall(const StringView& name)
@@ -253,7 +261,12 @@ public:
         // m_lexer->NextExpect(TokenType::Id);
         // char* name = strdup(m_lexer->token().string);
         m_lexer->NextExpect('(');
-        Node* arg = ParseExpression();
+        Node* arg = nullptr;
+        // TODO: support multiple arguments
+        if (m_lexer->seek_token()->token != ')')
+        {
+            arg = ParseExpression();
+        }
         m_lexer->NextExpect(')');
         return new FnCallNode(name, arg);
     }

include/codegen.hpp

@@ -53,98 +53,98 @@ private:
     Builder<StackSlot> m_slots;
 };
 
-struct ConstSlot
-{
-    long value;
-    StringView addr;
-};
+// struct ConstSlot
+// {
+//     long value;
+//     StringView addr;
+// };
 
-class ConstAllocator : public Allocator<ConstSlot>
-{
-public:
-    ConstAllocator() = default;
-    ~ConstAllocator() override = default;
-public:
-    const ConstSlot& Allocate(const StringView& addr)
-    {
-        m_slots.Push(ConstSlot { 0, addr });
-        return m_slots.data[m_slots.size - 1];
-    }
+// class ConstAllocator : public Allocator<ConstSlot>
+// {
+// public:
+//     ConstAllocator() = default;
+//     ~ConstAllocator() override = default;
+// public:
+//     const ConstSlot& Allocate(const StringView& addr)
+//     {
+//         m_slots.Push(ConstSlot { 0, addr });
+//         return m_slots.data[m_slots.size - 1];
+//     }
 
-    const ConstSlot& StoreValue(const StringView& addr, long value)
-    {
-        for (size_t i = 0; i < m_slots.size; ++i)
-        {
-            if (strcmp(m_slots.data[i].addr.c_str(), addr.c_str()) == 0)
-            {
-                m_slots.data[i].value = value;
-                return m_slots.data[i];
-            }
-        }
+//     const ConstSlot& StoreValue(const StringView& addr, long value)
+//     {
+//         for (size_t i = 0; i < m_slots.size; ++i)
+//         {
+//             if (strcmp(m_slots.data[i].addr.c_str(), addr.c_str()) == 0)
+//             {
+//                 m_slots.data[i].value = value;
+//                 return m_slots.data[i];
+//             }
+//         }
 
-        assert(0 && "could not resolve const under specified address");
-    }
+//         assert(0 && "could not resolve const under specified address");
+//     }
 
-    const ConstSlot& Resolve(const StringView& addr)
-    {
-        for (size_t i = 0; i < m_slots.size; ++i)
-        {
-            if (strcmp(m_slots.data[i].addr.c_str(), addr.c_str()) == 0)
-            {
-                return m_slots.data[i];
-            }
-        }
+//     const ConstSlot& Resolve(const StringView& addr)
+//     {
+//         for (size_t i = 0; i < m_slots.size; ++i)
+//         {
+//             if (strcmp(m_slots.data[i].addr.c_str(), addr.c_str()) == 0)
+//             {
+//                 return m_slots.data[i];
+//             }
+//         }
 
-        assert(0 && "could not resolve const under specified address");
-    }
-private:
-    Builder<ConstSlot> m_slots;
-};
+//         assert(0 && "could not resolve const under specified address");
+//     }
+// private:
+//     Builder<ConstSlot> m_slots;
+// };
 
-struct RegisterSlot
-{
-    const StringView& reg;
-    StringView addr;
-};
+// struct RegisterSlot
+// {
+//     const StringView& reg;
+//     StringView addr;
+// };
 
-class RegisterAllocator : public Allocator<RegisterSlot>
-{
-public:
-    RegisterAllocator()
-    {
-        m_regs.Push(std::move(StringView("eax")));
-        m_regs.Push(std::move(StringView("ecx")));
-    }
-    ~RegisterAllocator() override = default;
-public:
-    const RegisterSlot& Allocate(const StringView& addr)
-    {
-        assert(m_slots.size < m_regs.size && "no space available for allocating to register");
-        m_slots.Push(RegisterSlot { m_regs.data[m_slots.size], addr });
-        return m_slots.data[m_slots.size - 1];
-    }
+// class RegisterAllocator : public Allocator<RegisterSlot>
+// {
+// public:
+//     RegisterAllocator()
+//     {
+//         m_regs.Push(std::move(StringView("eax")));
+//         m_regs.Push(std::move(StringView("ecx")));
+//     }
+//     ~RegisterAllocator() override = default;
+// public:
+//     const RegisterSlot& Allocate(const StringView& addr)
+//     {
+//         assert(m_slots.size < m_regs.size && "no space available for allocating to register");
+//         m_slots.Push(RegisterSlot { m_regs.data[m_slots.size], addr });
+//         return m_slots.data[m_slots.size - 1];
+//     }
 
-    const RegisterSlot& Resolve(const StringView& addr)
-    {
-        for (size_t i = 0; i < m_slots.size; ++i)
-        {
-            if (strcmp(m_slots.data[i].addr.c_str(), addr.c_str()) == 0)
-            {
-                return m_slots.data[i];
-            }
-        }
+//     const RegisterSlot& Resolve(const StringView& addr)
+//     {
+//         for (size_t i = 0; i < m_slots.size; ++i)
+//         {
+//             if (strcmp(m_slots.data[i].addr.c_str(), addr.c_str()) == 0)
+//             {
+//                 return m_slots.data[i];
+//             }
+//         }
 
-        assert(0 && "could not resolve register for specified address");
-    }
+//         assert(0 && "could not resolve register for specified address");
+//     }
 
-    void Clear()
-    {
-        m_slots.size = 0;
-    }
-private:
-    Builder<RegisterSlot> m_slots;
-    Builder<StringView> m_regs;
-};
+//     void Clear()
+//     {
+//         m_slots.size = 0;
+//     }
+// private:
+//     Builder<RegisterSlot> m_slots;
+//     Builder<StringView> m_regs;
+// };
 
 class CodeGenerator
 {
@@ -164,7 +164,15 @@ private:
         int stackSize = 0;
         for (auto &op : ops)
         {
-            if (op->GetType() == IR::OpType::STORE) stackSize += 4;
+            switch (op->GetType())
+            {
+            case IR::OpType::STORE:
+            case IR::OpType::LOAD:
+            case IR::OpType::LOAD_CONST:
+            case IR::OpType::ADD:
+            case IR::OpType::CALL:
+                stackSize += 4;
+            }
         }
         return stackSize;
     }
@@ -194,12 +202,19 @@ private:
             printf("%s:\n", name.c_str());
             printf("push rbp\n");
             printf("mov rbp, rsp\n");
+            m_stack = new StackAllocator();
             int stackSize = GetStackSize(fn->ops());
             printf("sub rsp, %d\n", stackSize);
+            if (fn->params().size > 0)
+            {
+                auto param_slot = m_stack->Allocate(fn->params().data[0]);
+                printf("mov [rbp-%d], edi\n", param_slot.offset);
+            }
             for(auto &fOp : fn->ops())
             {
                 GenerateOp(fOp);
             }
+            m_stack = nullptr;
             printf("leave\nret\n");
         }
         break;
@@ -209,46 +224,50 @@ private:
             // TODO: support several arguments
             if (call->args().size == 1)
             {
-                auto reg_slot = m_registers.Resolve(GetTempAddr(call->args().data[0]));
-                printf("mov edi, %s\n", reg_slot.reg.c_str());
+                auto slot = m_stack->Resolve(GetTempAddr(call->args().data[0]));
+                printf("mov edi, [rbp-%d]\n", slot.offset);
             }
             printf("call %s\n", call->callee().c_str());
-            m_registers.Clear();
+            auto result_slot = m_stack->Allocate(GetTempAddr(call->result()));
+            printf("mov dword [rbp-%d], eax\n", result_slot.offset);
         }
         break;
         case IR::OpType::LOAD_CONST:
         {
             auto lc = reinterpret_cast<const IR::LoadConstOp *>(op);
             auto addr = GetTempAddr(lc->result());
-            m_consts.Allocate(addr);
-            m_consts.StoreValue(addr, lc->value());
+            auto slot = m_stack->Allocate(addr);
+            printf("mov dword [rbp-%d], %ld\n", slot.offset, lc->value());
         }
         break;
         case IR::OpType::STORE:
         {
             auto s = reinterpret_cast<const IR::StoreOp *>(op);
             printf("; DEBUG: resolving stack slot at %s\n", s->addr().c_str());
-            auto slot = m_stack.Allocate(s->addr());
-            auto value = m_consts.Resolve(GetTempAddr(s->src()));
-            printf("mov dword [rbp-%d], %ld\n", slot.offset, value.value);
+            auto slot = m_stack->Allocate(s->addr());
+            auto value_slot = m_stack->Resolve(GetTempAddr(s->src()));
+            printf("mov eax, [rbp-%d]\n", value_slot.offset);
+            printf("mov dword [rbp-%d], eax\n", slot.offset);
         }
         break;
         case IR::OpType::LOAD:
         {
             auto l = reinterpret_cast<const IR::LoadOp *>(op);
-            auto reg_slot = m_registers.Allocate(GetTempAddr(l->result()));
-            auto stack_slot = m_stack.Resolve(l->addr());
-            printf("mov %s, [rbp-%d]\n", reg_slot.reg.c_str(), stack_slot.offset);
+            auto value_slot = m_stack->Allocate(GetTempAddr(l->result()));
+            auto variable_slot = m_stack->Resolve(l->addr());
+            printf("mov eax, [rbp-%d]\n", variable_slot.offset);
+            printf("mov dword [rbp-%d], eax\n", value_slot.offset);
         }
         break;
         case IR::OpType::ADD:
         {
             auto expr = reinterpret_cast<const IR::AddOp *>(op);
-            auto lhs_slot = m_registers.Resolve(GetTempAddr(expr->lhs()));
-            auto rhs_slot = m_registers.Resolve(GetTempAddr(expr->rhs()));
-            printf("add %s, %s\n", lhs_slot.reg.c_str(), rhs_slot.reg.c_str());
-            m_registers.Clear();
-            m_registers.Allocate(GetTempAddr(expr->result()));
+            auto lhs_slot = m_stack->Resolve(GetTempAddr(expr->lhs()));
+            printf("mov eax, [rbp-%d]\n", lhs_slot.offset);
+            auto rhs_slot = m_stack->Resolve(GetTempAddr(expr->rhs()));
+            printf("add eax, [rbp-%d]\n", rhs_slot.offset);
+            auto result_slot = m_stack->Allocate(GetTempAddr(expr->result()));
+            printf("mov dword [rbp-%d], eax\n", result_slot.offset);
         }
         break;
         default: printf("; NOT HANDLED\n; %s\n", op->Format(0).c_str()); break;
@@ -268,7 +287,5 @@ public:
     }
 public:
     // TODO: handle sub-blocks
-    StackAllocator m_stack;
-    ConstAllocator m_consts;
-    RegisterAllocator m_registers;
-};
+    StackAllocator* m_stack = nullptr;
+};

include/ir.hpp

@@ -74,7 +74,7 @@ private:
 class FnOp : public Op
 {
 public:
-    FnOp(StringView name, const CompoundNode* body);
+    FnOp(StringView name, const CompoundNode* body, const View<StringView>& params);
     ~FnOp() {}
 
     OP_TYPE(FN)
@@ -93,9 +93,11 @@ public:
 public:
     const StringView& name() const { return m_name; }
     const OpView& ops() const { return m_ops; }
+    const View<StringView>& params() const { return m_params; }
 private:
     StringView m_name;
     OpView m_ops;
+    View<StringView> m_params;
 };
 
 class LoadConstOp : public Op, public Valued
@@ -243,11 +245,14 @@ public:
     Reg ParseFnCall(const FnCallNode* fn)
     {
         // TODO: support multiple args
-        auto arg = ParseExpression(fn->arg());
         auto argRegs = RegBuilder();
-        argRegs.Push(arg);
+        if (fn->arg() != nullptr)
+        {
+            auto arg = ParseExpression(fn->arg());
+            argRegs.Push(arg);
+        }
         auto dst = AllocateRegister();
-        m_ops.Push(new CallOp(dst, fn->name(), RegView(argRegs.data, argRegs.size)));
+        m_ops.Push(new CallOp(dst, fn->name(), argRegs.view()));
         return dst;
     }
 
@@ -319,7 +324,7 @@ public:
         // Functions
         for (auto &fn : program->funcs())
         {
-            m_ops.Push(new FnOp(fn->name(), fn->body()));
+            m_ops.Push(new FnOp(fn->name(), fn->body(), fn->params()));
         }
 
         return OpView(m_ops.data, m_ops.size);

src/ir.cpp

@@ -1,7 +1,7 @@
 #include "ir.hpp"
 
-IR::FnOp::FnOp(StringView name, const CompoundNode* body)
-    : m_name(name)
+IR::FnOp::FnOp(StringView name, const CompoundNode* body, const View<StringView>& params)
+    : m_name(name), m_params(params)
 {
     IRBuilder ir(body);        // Now IRBuilder is complete → OK
     ir.ParseBlock(body);

src/main.cpp

@@ -49,12 +49,12 @@ int main(int argc, char** argv)
 
     auto ops = irBuilder.Build();
 
-    printf("; ------ IR ------\n");
-    for (size_t i = 0; i < ops.size; ++i)
-    {
-        printf("; %s\n", ops.data[i]->Format(0).c_str());
-    }
-    printf("; ------ IR ------\n");
+    // printf("; ------ IR ------\n");
+    // for (size_t i = 0; i < ops.size; ++i)
+    // {
+    //     printf("; %s\n", ops.data[i]->Format(0).c_str());
+    // }
+    // printf("; ------ IR ------\n");
 
     StackFasmX86_64Generator gen;