From ea6edf6efef538e60fe02edeee6f5f4bea4868a7 Mon Sep 17 00:00:00 2001
From: jmug <u.g.a.mariano@gmail.com>
Date: Sun, 2 Feb 2025 00:09:58 -0800
Subject: [PATCH] Assembler finished.

Signed-off-by: jmug <u.g.a.mariano@gmail.com>
---
 hw2/bin/simulator.ml    | 112 ++++++++++++++++++++++++++++++++++++++--
 hw2/test/gradedtests.ml |   2 +-
 2 files changed, 110 insertions(+), 4 deletions(-)

diff --git a/hw2/bin/simulator.ml b/hw2/bin/simulator.ml
index 53d419a..7d5d06d 100644
--- a/hw2/bin/simulator.ml
+++ b/hw2/bin/simulator.ml
@@ -406,9 +406,115 @@ exception Redefined_sym of lbl
 
    HINT: List.fold_left and List.fold_right are your friends.
 *)
-let is_size (is : ins list) : quad = failwith "is_size not implemented"
-let ds_size (ds : data list) : quad = failwith "ds_size not implemented"
-let assemble (p : prog) : exec = failwith "assemble unimplemented"
+
+exception UnexpectedData
+exception UnexpectedText
+
+let is_size (is : ins list) : quad = 8L *. (Int64.of_int @@ List.length is)
+;;
+
+let elem_is_size (e : elem) : quad = match e with
+| { asm = Text il; _ } -> is_size il
+| _ -> raise UnexpectedData
+;;
+
+let ds_size (ds : data list) : quad =
+  let d_size d acc = match d with
+  | Asciz s -> acc +. 1L +. (Int64.of_int @@ String.length s)
+  | Quad _ -> acc +. 8L
+  in
+  List.fold_right d_size ds 0L
+;;
+
+let elem_ds_size (e : elem) : quad = match e with
+| { asm = Data dl; _ } -> ds_size dl
+| _ -> raise UnexpectedText
+;;
+
+let elem_size (e : elem) : quad = match e with
+| { asm = Data dl; _ } -> ds_size dl
+| { asm = Text il; _ } -> is_size il
+;;
+
+type symbol_table = (lbl * quad) list
+
+let build_symbol_table (p : prog) : symbol_table =
+  let accum_elem ((addr, tbl) as acc) ({ lbl = l; _ } as e) =
+    let curr = List.assoc_opt l tbl in
+    let new_addr = addr +. (elem_size e) in
+    let new_sym_tbl = (l, addr) :: tbl in
+    match curr with
+    | Some _ -> raise (Redefined_sym l)
+    | None -> (new_addr, new_sym_tbl)
+  in
+  let (_, sym_tbl) = List.fold_left accum_elem (mem_bot, []) p in
+  sym_tbl
+;;
+
+let patch_imm (i : imm) (t : symbol_table) : imm = match i with
+| Lbl l ->
+    let addr_opt = List.assoc_opt l t in
+    (match addr_opt with
+    | Some addr -> Lit addr
+    | None -> raise (Undefined_sym l))
+| _ -> i
+;;
+
+let patch_data (t : symbol_table) (d : data)  : data = match d with
+  | Quad i -> Quad (patch_imm i t)
+  | _ -> d
+;;
+
+let patch_ins (t : symbol_table) ((op, operands) as i : ins)  : ins =
+  let patch_operand o = match o with
+  | Imm im -> Imm (patch_imm im t)
+  | Ind1 im -> Ind1 (patch_imm im t)
+  | Ind3 (im, r) -> Ind3 (patch_imm im t, r)
+  | _ -> o
+  in
+  let new_operands = List.map patch_operand operands in
+  (op, new_operands)
+;;
+
+let emit_elem (t :symbol_table) ({ asm = a; _ } : elem) : sbyte list = match a with
+| Text il -> List.fold_right (fun ins acc -> (sbytes_of_ins ins) @ acc) (List.map (patch_ins t) il) []
+| Data dl -> List.fold_right (fun d acc -> (sbytes_of_data d) @ acc) (List.map (patch_data t) dl) [] 
+;;
+
+let assemble (p : prog) : exec =
+  let txts =
+    let append_if_text e acc = match e with
+    | { asm = Text _; _ } -> e :: acc
+    | _ -> acc
+    in
+    List.fold_right append_if_text p []
+  in
+  let txts_size = List.fold_left (fun acc e -> acc +. (elem_is_size e)) 0L txts in
+  let dtas =
+    let append_if_data e acc = match e with
+    | { asm = Data _; _ } -> e :: acc
+    | _ -> acc
+    in
+    List.fold_right append_if_data p []
+  in
+  let dtas_size = List.fold_left (fun acc e -> acc +. (elem_ds_size e)) 0L dtas in
+  let ordered_prog = txts @ dtas in
+  let sym_tbl = build_symbol_table ordered_prog in
+  let entry = match (List.assoc_opt "main" sym_tbl) with
+    | Some q -> q
+    | None -> raise (Undefined_sym "main")
+  in
+  let ee = emit_elem sym_tbl in
+  let d_seg = List.fold_right (fun d acc -> (ee d) @ acc) dtas [] in
+  let t_seg = List.fold_right (fun t acc -> (ee t) @ acc) txts [] in
+  {
+    entry = entry;
+    text_pos = mem_bot;
+    data_pos = mem_bot +. txts_size;
+    text_seg = t_seg;
+    data_seg = d_seg;
+  }
+;;
 
 (* Convert an object file into an executable machine state.
    - allocate the mem array
diff --git a/hw2/test/gradedtests.ml b/hw2/test/gradedtests.ml
index 6b29ab6..1db9232 100644
--- a/hw2/test/gradedtests.ml
+++ b/hw2/test/gradedtests.ml
@@ -558,7 +558,7 @@ let ins_writeback_tests =
       99L)
     ]
 
-    let load_chunk_size_tests= 
+let load_chunk_size_tests= 
       let inss = [
         (Movq, [~$42; ~%Rax]);
     (Movq, [~$43; ~%Rbx]);