From ce4d74460972aa2b3b668280550888feed5684f3 Mon Sep 17 00:00:00 2001
From: Rui Ueyama <ruiu@cs.stanford.edu>
Date: Mon, 20 Apr 2020 22:15:09 +0900
Subject: [PATCH] Emit .file and .loc assembler directives

With these directives, gdb can print out an error location when
a compiled program crashes.
---
 codegen.c | 4 ++++
 main.c    | 1 +
 2 files changed, 5 insertions(+)

diff --git a/codegen.c b/codegen.c
index a276240..055f8c7 100644
--- a/codegen.c
+++ b/codegen.c
@@ -88,6 +88,8 @@ static void store(Type *ty) {
 
 // Generate code for a given node.
 static void gen_expr(Node *node) {
+  println("  .loc 1 %d", node->tok->line_no);
+
   switch (node->kind) {
   case ND_NUM:
     println("  mov $%d, %%rax", node->val);
@@ -172,6 +174,8 @@ static void gen_expr(Node *node) {
 }
 
 static void gen_stmt(Node *node) {
+  println("  .loc 1 %d", node->tok->line_no);
+
   switch (node->kind) {
   case ND_IF: {
     int c = count();
diff --git a/main.c b/main.c
index 59e08ec..914b08f 100644
--- a/main.c
+++ b/main.c
@@ -55,6 +55,7 @@ int main(int argc, char **argv) {
 
   // Traverse the AST to emit assembly.
   FILE *out = open_file(opt_o);
+  fprintf(out, ".file 1 \"%s\"\n", input_path);
   codegen(prog, out);
   return 0;
 }