From fd8a1f74bf0c0e7ae0ba6bcfb8e7bf4f0e180bde Mon Sep 17 00:00:00 2001
From: janis <janis@nirgendwo.xyz>
Date: Tue, 4 Nov 2025 02:12:33 +0100
Subject: [PATCH] can actually call functions!!!!!!!!!!

---
 lang/src/codegen.asm | 67 +++++++++++++++++++++++++++++++++-----------
 1 file changed, 50 insertions(+), 17 deletions(-)

diff --git a/lang/src/codegen.asm b/lang/src/codegen.asm
index 4d6e4ec..1e258b1 100644
--- a/lang/src/codegen.asm
+++ b/lang/src/codegen.asm
@@ -376,7 +376,7 @@ codegen_allocate_stack_value:
     mov rsi, 0xF
     not rsi
     and rax, rsi                ; clear kind to make it a value
-    and rax, OPERAND_RBP_VALUE  ; Operand.kind = OPERAND_RBP_VALUE
+    or rax, OPERAND_RBP_VALUE  ; Operand.kind = OPERAND_RBP_VALUE
 
     pop rbp
     ret
@@ -995,11 +995,10 @@ codegen_call_expr:
     mov rbx, rdx                ; copy of *AstCallExpr
 
     ; initialize param_operands
-    mov rcx, [rbx + 16]         ; AstCallExpr.args_len
     lea rdi, [rsp + 24]         ; param_operands
     mov rsi, 16                 ; size_of::<Operand>
     mov rdx, 0                  ; drop = None
-    mov rcx, rbx                ; initial capacity
+    mov rcx, 16                 ; initial capacity
     call vec_init_with
 
     ; codegen callee
@@ -1011,16 +1010,16 @@ codegen_call_expr:
     mov [rsp + 72], rdx
 
     ; If callee is in a param-register, move to stack
-    cmp byte [rax], OPERAND_REGISTER
+    cmp al, OPERAND_REGISTER
     jne .arg_loop_init
     mov rdx, 0b00000011_00111100
-    movzx rcx, byte [rax + 1]   ; callee register
+    movzx rcx, byte [rsp + 64 + 1] ; callee register
     bt rdx, rcx
     jnc .arg_loop_init
 
     ; allocate stack slot
-    mov rdi, [rsp + 8]          ; &function_ctx
-    movzx rsi, word [rax + 2]     ; Operand.width
+    mov rdi, [rsp + 8]             ; &function_ctx
+    movzx rsi, word [rsp + 64 + 2] ; Operand.width
     call codegen_allocate_stack_value
     mov [rsp + 80], rax         ; new stack operand
     mov [rsp + 88], rdx
@@ -1060,11 +1059,11 @@ codegen_call_expr:
     ; if the operand is in a register, move it to the stack
     ; we know already that these are values
 
-    cmp byte [rax], OPERAND_REGISTER
+    cmp byte [rsp + 80], OPERAND_REGISTER
     jne .store_param
     ; allocate stack slot
     mov rdi, [rsp + 8]          ; &function_ctx
-    movzx rsi, word [rax + 2]     ; Operand.width
+    movzx rsi, word [rsp + 80 + 2]     ; Operand.width
     call codegen_allocate_stack_value
     mov [rsp + 96], rax         ; new stack operand
     mov [rsp + 104], rdx
@@ -1861,9 +1860,29 @@ codegen_expr:
     jmp .done
 
 .var_ref:
-    mov rax, [rax + 8]          ; AstNode.data
-    mov rax, [rax]              ; variable index
+    mov rbx, [rax + 8]          ; AstNode.data
+    mov rax, [rbx]              ; variable index
 
+    ; check if we're trying to get a reference to a function
+    mov rdi, [rsp]              ; ctx
+    mov rdi, [rdi]              ; ast
+    mov rsi, rax                ; variable index
+    call vec_get
+    cmp byte [rax], AST_FUNCTION
+    jne .var_ref_var
+
+    mov rax, [rax + 8]         ; *AstFunction
+    ; create label operand for function
+    mov rcx, [rel OPERAND_LABEL0]
+    movzx rdx, word [rax + 8]         ; AstFunction.name_len
+    shl rdx, 32
+    or rcx, rdx
+    mov rdx, [rax + 0]          ; AstFunction.name
+    mov rax, rcx
+    jmp .done
+
+.var_ref_var:
+    mov rax, [rbx]
     mov [rsp + 16], rax
     mov qword [rsp + 24], 0
     ; lookup variable in stack_vars
@@ -1903,6 +1922,9 @@ codegen_expr:
     je .ptv_register_place
     cmp al, OPERAND_RBP_PLACE
     je .ptv_rbp_place
+    cmp al, OPERAND_LABEL
+    je .done
+    jmp .panic
 
 .ptv_rbp_offset:
     mov byte [rsp + 16], OPERAND_RBP_PVALUE
@@ -2134,6 +2156,8 @@ section .rdata
     OPERAND_RBP_P dq 0x0008_0009, 0
     align 8
     OPERAND_ZERO dq 0x0001_000b, 0
+    align 8
+    OPERAND_LABEL0 dq 0x0008_000d, 0
 
 section .text
 
@@ -2278,8 +2302,7 @@ codegen_write_operand:
     mov rax, [rsp + 8]          ; op
     mov rdi, [rsp]              ; *text
     mov rsi, [rax + 8]          ; Operand.value
-    mov rdx, [rax + 4]          ; Operand.len
-    mov dx, dx                  ; low 16 bits
+    movzx rdx, word [rax + 4]   ; Operand.len
     call vec_extend
 
     mov byte [rsp + 16], ']'
@@ -2307,13 +2330,18 @@ codegen_write_operand:
     mov rax, [rsp + 8]          ; op
     mov rdi, [rsp]              ; *text
     mov rsi, [rax + 8]          ; op.value
-    mov rdx, [rax + 2]          ; op.len
-    mov dx, dx                  ; low 16 bits
+    movzx rdx, word [rax + 4]   ; Operand.len
     call vec_extend
     jmp .epilogue
 
 .label:
-    jmp .panic
+    ; write address name
+    mov rax, [rsp + 8]          ; op
+    mov rdi, [rsp]              ; *text
+    mov rsi, [rax + 8]          ; Operand.value
+    movzx rdx, word [rax + 4]   ; Operand.len
+    call vec_extend
+    jmp .epilogue
 
 .epilogue:
     add rsp, 40
@@ -2683,7 +2711,10 @@ codegen_move_dst_src:
     mov cx, word [rsi + 2]          ; dst.width
     mov bx, word [rdx + 2]          ; src.width
     cmp cx, bx
-    jne .panic                  ; mismatched widths
+    jb .panic                   ; dst.width < src.width
+    je .width_ok
+    mov qword [rsp + 24], 'movzx '
+.width_ok:
 
     ; ; if dst.width == 8 && src.kind == OPERAND_ADDRESS
     ; xor rbx, rbx
@@ -2799,5 +2830,7 @@ section .rdata
     CALL_ dq "call "
     CALL_LEN equ $ - CALL_
     NEWLINE db 10
+    align 8
+    MOVZX_ dq "movzx "