From 4255c44a6a69a9b1a9928078e71fb583f2302f44 Mon Sep 17 00:00:00 2001
From: Aryadev Chavali <aryadev@aryadevchavali.com>
Date: Sat, 27 Apr 2024 17:43:24 +0530
Subject: [PATCH] Propagated change in prog_t into vm

main now does error reporting for read errors
---
 vm/main.c    | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
 vm/runtime.c | 14 +++++++-------
 vm/struct.c  |  8 ++++----
 vm/struct.h  |  4 ++--
 4 files changed, 60 insertions(+), 15 deletions(-)

diff --git a/vm/main.c b/vm/main.c
index 8b4d09c..31404cb 100644
--- a/vm/main.c
+++ b/vm/main.c
@@ -43,12 +43,57 @@ int main(int argc, char *argv[])
 #endif
 
   FILE *fp        = fopen(filename, "rb");
-  prog_t *program = prog_read_file(fp);
+  darr_t fp_bytes = darr_read_file(fp);
   fclose(fp);
 
+  prog_t program = {0};
+  size_t header_read =
+      prog_read_header(&program, fp_bytes.data, fp_bytes.available);
+
+  if (!header_read)
+  {
+    fprintf(stderr, "[ERROR]: Could not deserialise program header in `%s`\n",
+            filename);
+    return 1;
+  }
+  // Ensure that we MUST have something to read
+  else if (program.count == 0)
+    return 0;
+
+  // After reading header, we can allocate the buffer of instrutions
+  // exactly
+  program.instructions = calloc(program.count, sizeof(*program.instructions));
+  size_t bytes_read    = 0;
+  read_err_prog_t read_err =
+      prog_read_instructions(&program, &bytes_read, fp_bytes.data + header_read,
+                             fp_bytes.available - header_read);
+
+  if (bytes_read == 0)
+  {
+    fprintf(stderr, "[ERROR]:%s [%lu]:", filename, read_err.index);
+    switch (read_err.type)
+    {
+    case READ_ERR_INVALID_OPCODE:
+      fprintf(stderr, "INVALID_OPCODE");
+      break;
+    case READ_ERR_OPERAND_NO_FIT:
+      fprintf(stderr, "OPERAND_NO_FIT");
+      break;
+    case READ_ERR_EXPECTED_MORE:
+      fprintf(stderr, "EXPECTED_MORE");
+      break;
+    case READ_ERR_END:
+    default:
+      fprintf(stderr, "UNKNOWN");
+      break;
+    }
+    fprintf(stderr, "\n");
+    return 1;
+  }
+
 #if VERBOSE >= 1
   printf("\t[" TERM_GREEN "SETUP" TERM_RESET "]: Read %lu instructions\n",
-         program->count);
+         program.count);
 #endif
 
   size_t stack_size     = 256;
diff --git a/vm/runtime.c b/vm/runtime.c
index 553fa8e..3ad369c 100644
--- a/vm/runtime.c
+++ b/vm/runtime.c
@@ -66,10 +66,10 @@ static_assert(OP_PRINT_LONG - OP_PRINT_BYTE == 5,
 err_t vm_execute(vm_t *vm)
 {
   struct Program *prog = &vm->program;
-  prog_t *program_data = prog->data;
-  if (prog->ptr >= program_data->count)
+  prog_t program_data  = prog->data;
+  if (prog->ptr >= program_data.count)
     return ERR_END_OF_PROGRAM;
-  inst_t instruction = program_data->instructions[prog->ptr];
+  inst_t instruction = program_data.instructions[prog->ptr];
 
   if (UNSIGNED_OPCODE_IS_TYPE(instruction.opcode, OP_PUSH))
   {
@@ -244,10 +244,10 @@ err_t vm_execute(vm_t *vm)
 err_t vm_execute_all(vm_t *vm)
 {
   struct Program *program = &vm->program;
-  const size_t count      = program->data->count;
+  const size_t count      = program->data.count;
   err_t err               = ERR_OK;
   // Setup the initial address according to the program
-  program->ptr = program->data->start_address;
+  program->ptr = program->data.start_address;
 #if VERBOSE >= 1
   size_t cycles = 0;
 #endif
@@ -258,7 +258,7 @@ err_t vm_execute_all(vm_t *vm)
   size_t prev_cptr           = 0;
 #endif
   while (program->ptr < count &&
-         program->data->instructions[program->ptr].opcode != OP_HALT)
+         program->data.instructions[program->ptr].opcode != OP_HALT)
   {
 #if VERBOSE >= 2
     fprintf(stdout, "[vm_execute_all]: Trace(Cycle %lu)\n", cycles);
@@ -326,7 +326,7 @@ err_t vm_execute_all(vm_t *vm)
 
 err_t vm_jump(vm_t *vm, word_t w)
 {
-  if (w >= vm->program.data->count)
+  if (w >= vm->program.data.count)
     return ERR_INVALID_PROGRAM_ADDRESS;
   vm->program.ptr = w;
   return ERR_OK;
diff --git a/vm/struct.c b/vm/struct.c
index 89f67b7..2a49b39 100644
--- a/vm/struct.c
+++ b/vm/struct.c
@@ -22,7 +22,7 @@ void vm_load_stack(vm_t *vm, byte_t *bytes, size_t size)
   vm->stack.ptr  = 0;
 }
 
-void vm_load_program(vm_t *vm, prog_t *program)
+void vm_load_program(vm_t *vm, prog_t program)
 {
   vm->program.ptr  = 0;
   vm->program.data = program;
@@ -95,7 +95,7 @@ void vm_stop(vm_t *vm)
 #endif
 
   free(vm->registers.data);
-  free(vm->program.data);
+  free(vm->program.data.instructions);
   free(vm->stack.data);
   heap_stop(&vm->heap);
   free(vm->call_stack.address_pointers);
@@ -151,7 +151,7 @@ void vm_print_stack(vm_t *vm, FILE *fp)
 void vm_print_program(vm_t *vm, FILE *fp)
 {
   struct Program program = vm->program;
-  const size_t count     = program.data->count;
+  const size_t count     = program.data.count;
   fprintf(fp,
           "Program.max          = %lu\nProgram.ptr          = "
           "%lu\nProgram.instructions = [\n",
@@ -168,7 +168,7 @@ void vm_print_program(vm_t *vm, FILE *fp)
   for (size_t i = beg; i < end; ++i)
   {
     fprintf(fp, "\t%lu: ", i);
-    inst_print(program.data->instructions[i], fp);
+    inst_print(program.data.instructions[i], fp);
     if (i == program.ptr)
       fprintf(fp, " <---");
     fprintf(fp, "\n");
diff --git a/vm/struct.h b/vm/struct.h
index ac17260..f4bbd58 100644
--- a/vm/struct.h
+++ b/vm/struct.h
@@ -29,7 +29,7 @@ struct Stack
 
 struct Program
 {
-  prog_t *data;
+  prog_t data;
   word_t ptr;
 };
 
@@ -53,7 +53,7 @@ typedef struct
 void vm_load_stack(vm_t *, byte_t *, size_t);
 void vm_load_registers(vm_t *, registers_t);
 void vm_load_heap(vm_t *, heap_t);
-void vm_load_program(vm_t *, prog_t *);
+void vm_load_program(vm_t *, prog_t);
 void vm_load_call_stack(vm_t *, word_t *, size_t);
 void vm_stop(vm_t *);