parser: Generate GAS 64-bit assembly for linux

Signed-off-by: Johnny Richard <johnny@johnnyrichard.com>

1 files changed, 19 insertions, 1 deletions

diff --git a/src/pipac.c b/src/pipac.c
index 29c21bd..993d56d 100644
--- a/src/pipac.c
+++ b/src/pipac.c
@@ -16,10 +16,28 @@
 */
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+
 #include "lexer.h"
 #include "parser.h"
 
 void
+generate_gas_x86_64_linux(ast_function_t *func)
+{
+  if (strcmp(func->name, "main") != 0) {
+    fprintf(stderr, "[ERROR]: no main function has been defined!\n");
+    exit(EXIT_FAILURE);
+  }
+
+  printf(".global _start\n");
+  printf(".text\n");
+  printf("_start:\n");
+  printf("  mov $1, %%al\n");
+  printf("  mov $%d, %%ebx\n", func->body.number);
+  printf("  int $0x80\n");
+}
+
+void
 print_usage()
 {
   fputs("pipac <filename.pipa>\n", stderr);
@@ -50,7 +68,7 @@ main(int argc, char **argv)
   parser_init(&parser, &lexer);
   ast_function_t func = parser_parse_function(&parser);
 
-  printf("function name='%s' and return type '%d' with value %d\n", func.name, func.return_type, func.body.number);
+  generate_gas_x86_64_linux(&func);
 
   return EXIT_SUCCESS;
 }