ast: Create AST visitor to traverse the tree

In the future we want to have the possibility of traverse the tree and
pretty print it or generate binary for other platform like LLVM or
transpile to C.

This solution also implements the gas assembly x86_64 Linux code
generation by using the visitor interface.

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

1 files changed, 4 insertions, 10 deletions

diff --git a/src/pipac.c b/src/pipac.c
index 6e6df9e..e56d8a1 100644
--- a/src/pipac.c
+++ b/src/pipac.c
@@ -21,21 +21,15 @@
 #include "lexer.h"
 #include "parser.h"
 #include "string_view.h"
+#include "gas_assembly_generator.h"
 
 void
 generate_gas_x86_64_linux(ast_function_t *func)
 {
-  if (!string_view_eq(func->name, string_view_from_str("main"))) {
-    fprintf(stderr, "[ERROR]: no main function has been defined!\n");
-    exit(EXIT_FAILURE);
-  }
+  gas_assembly_generator_t gen;
+  gas_assembly_generator_init(&gen, stdout);
 
-  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");
+  ast_visitor_visit(&gen, func);
 }
 
 void