README.md

@@ -117,4 +117,6 @@ Supported instructions so far:
 * jump
 * if
 * @ (label creation)
+* print
+* println
 * end

src/compiler.c

@@ -50,7 +50,7 @@ char* processValueString(GroundArg arg) {
     }
     if (arg.type == VALUE) {
         if (arg.value.value.type != INT) {
-            printf("Only int is supported right now");
+            printf("Only int is supported right now\n");
             exit(1);
         }
         char* buf = malloc(sizeof(char) * 64);
@@ -63,6 +63,59 @@ char* processValueString(GroundArg arg) {
 char* compileGroundProgram(GroundProgram* program) {
     Estr start = CREATE_ESTR("global _start\nsection .text\n_start:\n");
     Estr data = CREATE_ESTR("section .bss\n");
+    Estr helpers = CREATE_ESTR("");
+
+    APPEND_ESTR(helpers, "\n; Helper: Print integer in rax\n");
+    APPEND_ESTR(helpers, "print_int:\n");
+    APPEND_ESTR(helpers, "  push rbp\n");
+    APPEND_ESTR(helpers, "  mov rbp, rsp\n");
+    APPEND_ESTR(helpers, "  sub rsp, 32          ; Allocate buffer on stack\n");
+    APPEND_ESTR(helpers, "  mov rdi, rsp         ; RDI = buffer pointer\n");
+    APPEND_ESTR(helpers, "  add rdi, 31          ; Point to end of buffer\n");
+    APPEND_ESTR(helpers, "  mov byte [rdi], 0    ; Null terminator\n");
+    APPEND_ESTR(helpers, "  dec rdi\n");
+    APPEND_ESTR(helpers, "  mov rbx, 10          ; Divisor\n");
+    APPEND_ESTR(helpers, "  test rax, rax\n");
+    APPEND_ESTR(helpers, "  jns .positive\n");
+    APPEND_ESTR(helpers, "  neg rax              ; Make positive\n");
+    APPEND_ESTR(helpers, "  push rax\n");
+    APPEND_ESTR(helpers, "  mov byte [rdi], '-'\n");
+    APPEND_ESTR(helpers, "  dec rdi\n");
+    APPEND_ESTR(helpers, "  pop rax\n");
+    APPEND_ESTR(helpers, ".positive:\n");
+    APPEND_ESTR(helpers, "  xor rcx, rcx         ; Digit counter\n");
+    APPEND_ESTR(helpers, ".convert_loop:\n");
+    APPEND_ESTR(helpers, "  xor rdx, rdx\n");
+    APPEND_ESTR(helpers, "  div rbx              ; rax = rax/10, rdx = remainder\n");
+    APPEND_ESTR(helpers, "  add dl, '0'          ; Convert to ASCII\n");
+    APPEND_ESTR(helpers, "  mov [rdi], dl\n");
+    APPEND_ESTR(helpers, "  dec rdi\n");
+    APPEND_ESTR(helpers, "  inc rcx\n");
+    APPEND_ESTR(helpers, "  test rax, rax\n");
+    APPEND_ESTR(helpers, "  jnz .convert_loop\n");
+    APPEND_ESTR(helpers, "  inc rdi              ; Point back to first digit\n");
+    APPEND_ESTR(helpers, "  ; Now print the string\n");
+    APPEND_ESTR(helpers, "  mov rax, 1           ; sys_write\n");
+    APPEND_ESTR(helpers, "  mov rsi, rdi         ; Buffer\n");
+    APPEND_ESTR(helpers, "  mov rdx, rcx         ; Length\n");
+    APPEND_ESTR(helpers, "  mov rdi, 1           ; stdout\n");
+    APPEND_ESTR(helpers, "  syscall\n");
+    APPEND_ESTR(helpers, "  mov rsp, rbp\n");
+    APPEND_ESTR(helpers, "  pop rbp\n");
+    APPEND_ESTR(helpers, "  ret\n");
+
+    APPEND_ESTR(helpers, "\n; Helper: Print string at address in rax, length in rbx\n");
+    APPEND_ESTR(helpers, "print_string:\n");
+    APPEND_ESTR(helpers, "  push rax\n");
+    APPEND_ESTR(helpers, "  push rbx\n");
+    APPEND_ESTR(helpers, "  mov rdi, 1           ; stdout\n");
+    APPEND_ESTR(helpers, "  mov rsi, rax         ; String address\n");
+    APPEND_ESTR(helpers, "  mov rdx, rbx         ; Length\n");
+    APPEND_ESTR(helpers, "  mov rax, 1           ; sys_write\n");
+    APPEND_ESTR(helpers, "  syscall\n");
+    APPEND_ESTR(helpers, "  pop rbx\n");
+    APPEND_ESTR(helpers, "  pop rax\n");
+    APPEND_ESTR(helpers, "  ret\n");
 
     VariableTable varTable = createVariableTable();
 
@@ -77,7 +130,7 @@ char* compileGroundProgram(GroundProgram* program) {
     }
 
     // Create data section
-    for (size_t i = 0; i < program->size; i++) {
+    for (size_t i = 0; i < varTable.count; i++) {
         if (strcmp(varTable.vars[i].name, "") == 0) {
             continue;
         }
@@ -386,6 +439,42 @@ char* compileGroundProgram(GroundProgram* program) {
                 APPEND_ESTR(start, "], rax\n");
                 break;
             }
+            case PRINT:
+            case PRINTLN: {
+                if (gi.args.length < 1) {
+                    runtimeError(TOO_FEW_ARGS, "Expecting 1 or more args", &gi, i);
+                }
+                
+                for (size_t j = 0; j < gi.args.length; j++) {
+                    if (gi.args.args[j].type != VALUE && gi.args.args[j].type != VALREF) {
+                        runtimeError(ARG_TYPE_MISMATCH, "Expecting a Value", &gi, i);
+                    }
+                    if (j > 0) {
+                        // Print space between arguments
+                        APPEND_ESTR(start, "  ; print space\n");
+                        APPEND_ESTR(start, "  mov rax, 1\n");
+                        APPEND_ESTR(start, "  mov rdi, 1\n");
+                        APPEND_ESTR(start, "  lea rsi, [rel space_char]\n");
+                        APPEND_ESTR(start, "  mov rdx, 1\n");
+                        APPEND_ESTR(start, "  syscall\n");
+                    }
+                    APPEND_ESTR(start, "  ; print int\n");
+                    APPEND_ESTR(start, "  mov rax, ");
+                    APPEND_ESTR(start, processValueString(gi.args.args[j]));
+                    APPEND_ESTR(start, "\n");
+                    APPEND_ESTR(start, "  call print_int\n");
+                }
+                
+                if (gi.type == PRINTLN) {
+                    APPEND_ESTR(start, "  ; print newline\n");
+                    APPEND_ESTR(start, "  mov rax, 1\n");
+                    APPEND_ESTR(start, "  mov rdi, 1\n");
+                    APPEND_ESTR(start, "  lea rsi, [rel newline_char]\n");
+                    APPEND_ESTR(start, "  mov rdx, 1\n");
+                    APPEND_ESTR(start, "  syscall\n");
+                }
+                break;
+            }
             case END: {
                 if (gi.args.length < 1) {
                     runtimeError(TOO_FEW_ARGS, "Expecting 1 arg for end instruction", &gi, i);
@@ -401,6 +490,10 @@ char* compileGroundProgram(GroundProgram* program) {
                 APPEND_ESTR(start, "  syscall\n");
                 break;
             }
+            case DROP: {
+                // Drop does nothing in ground->asm as we use the stack
+                break;
+            }
             default: {
                 printf("no\n");
                 exit(1);
@@ -411,6 +504,10 @@ char* compileGroundProgram(GroundProgram* program) {
     Estr complete = CREATE_ESTR("");
     APPEND_ESTR(complete, start.str);
     APPEND_ESTR(complete, "  ; End of program\n  mov rax, 60\n  mov rdi, 0\n  syscall\n");
+    APPEND_ESTR(complete, helpers.str);
+    APPEND_ESTR(complete, "\nsection .rodata\n");
+    APPEND_ESTR(complete, "newline_char: db 10\n");
+    APPEND_ESTR(complete, "space_char: db 32\n");
     APPEND_ESTR(complete, data.str)
 
     return complete.str;