2 files changed, 91 insertions, 0 deletions
diff --git a/cup/generator.c b/cup/generator.c
new file mode 100644
index 0000000..edb38ad
--- /dev/null
+++ b/cup/generator.c
@@ -0,0 +1,85 @@
+/**
+ * This file generates x86-64 assembly code in NASM format from the parsed AST.
+ */
+
+#include "generator.h"
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+
+// The evaluated expression is stored into `rax`
+void generate_expr_into_rax(Node *expr, FILE *out)
+{
+    if (expr->type == AST_LITERAL) {
+        // TODO: More literal types
+        assert(expr->literal.type.type == TYPE_INT);
+        fprintf(out, "    mov rax, %d\n", expr->literal.as_int);
+
+    } else if (expr->type == OP_NEG) {
+        generate_expr_into_rax(expr->unary_expr, out);
+        fprintf(out, "    neg rax\n");
+
+    } else if (expr->type == OP_NOT) {
+        generate_expr_into_rax(expr->unary_expr, out);
+        fprintf(out, "    cmp rax, 0\n");
+        fprintf(out, "    sete al\n");
+        fprintf(out, "    movzx rax, al\n");
+
+    } else if (expr->type == OP_BWINV) {
+        generate_expr_into_rax(expr->unary_expr, out);
+        fprintf(out, "    not rax\n");
+        
+    } else {
+        fprintf(stderr, "Unsupported expression type in generate_expr: %d\n", expr->type);
+        exit(1);
+    }
+}
+
+void generate_statement(Node *stmt, FILE *out)
+{
+    if (stmt->type == AST_RETURN) {
+        generate_expr_into_rax(stmt->unary_expr, out);
+        fprintf(out, "    ret\n");
+    } else {
+        fprintf(stderr, "Unsupported statement type in generate_statement: %s\n", node_type_to_str(stmt->type));
+        exit(1);
+    }
+}
+
+void generate_block(Node *block, FILE *out)
+{
+    assert(block->type == AST_BLOCK);
+    for (int i = 0; i < block->block.num_children; i++)
+        generate_statement(block->block.children[i], out);
+}
+
+void generate_function(Node *func, FILE *out)
+{
+    assert(func->type == AST_FUNC);
+    fprintf(out, "global %s\n", func->func.name);
+    fprintf(out, "%s:\n", func->func.name);
+    generate_block(func->func.body, out);
+}
+
+
+void generate_asm(Node *root, FILE *out)
+{
+    assert(root->type == AST_PROGRAM);
+    for (int i = 0; i < root->block.num_children; i++) {
+        if (root->block.children[i]->type == AST_FUNC) {
+            generate_function(root->block.children[i], out);
+        } else {
+            fprintf(stderr, "Unsupported node type in generate_asm: %s\n", node_type_to_str(root->block.children[i]->type));
+            exit(1);
+        }
+    }
+
+    // Call `main` from `_main` and return
+    fprintf(out, "global _main\n");
+    fprintf(out, "_main:\n");
+    fprintf(out, "    call main\n");
+    fprintf(out, "    ret\n");
+
+    // TODO: Add implementations of some primitives?
+}
+\ No newline at end of file
diff --git a/cup/generator.h b/cup/generator.h
new file mode 100644
index 0000000..602cf3a
--- /dev/null
+++ b/cup/generator.h
@@ -0,0 +1,6 @@
+#pragma once
+
+#include "ast.h"
+#include <stdio.h>
+
+void generate_asm(Node *root, FILE *out);
+\ No newline at end of file