bad line numbers support

6 files changed, 35 insertions, 8 deletions

diff --git a/chibicc.h b/chibicc.h
index 01f4264..522c214 100644
--- a/chibicc.h
+++ b/chibicc.h
@@ -464,6 +464,7 @@ void hashmap_test(void);
 
 extern bool opt_fpic;
 extern bool opt_fcommon;
+extern bool opt_line_numbers;
 extern char *base_file;
 
 //
diff --git a/codegen.c b/codegen.c
index 5111c76..7acd2c9 100644
--- a/codegen.c
+++ b/codegen.c
@@ -60,6 +60,11 @@ static int count(void) {
   return i++;
 }
 
+static void emit_line(struct Token *tok) {
+  if (opt_line_numbers && tok && tok->line_no && tok->filename)
+    println("#line %d \"%s\"", tok->line_no, tok->filename);
+}
+
 static int RETURN_TMP;
 
 void print_label(char *label) {
@@ -305,8 +310,7 @@ static void gen_addr(Node *node, int to_tmp) {
 
 // Generate code for a given node.
 static void gen_expr(Node *node, int to_tmp) {
-  // println("  .loc %d %d", node->tok->file->file_no, node->tok->line_no);
-
+  emit_line(node->tok);
   switch (node->kind) {
   case ND_NULL_EXPR:
     return;
@@ -560,6 +564,7 @@ static void gen_expr(Node *node, int to_tmp) {
 }
 
 static void gen_stmt(Node *node) {
+  emit_line(node->tok);
   switch (node->kind) {
   case ND_IF: {
     int cond = count(), condfalse = count(), c = count();
@@ -838,6 +843,8 @@ static void emit_text(Obj *prog) {
     if (!fn->is_function || !fn->is_definition)
       continue;
 
+    emit_line(fn->body->tok);
+
     // No code is emitted for "static inline" functions
     // if no one is referencing them.
     if (!fn->is_live)
diff --git a/main.c b/main.c
index db9f31c..36c16e9 100644
--- a/main.c
+++ b/main.c
@@ -9,6 +9,7 @@ char *base_file;
 StringArray include_paths;
 bool opt_fcommon = false;
 bool opt_fpic;
+bool opt_line_numbers;
 
 static FILE *open_file(char *path) {
   if (!path || strcmp(path, "-") == 0)
@@ -64,8 +65,14 @@ static void cc1(char *base_file) {
 }
 
 int main(int argc, char **argv) {
-  assert(argc == 2);
-  base_file = argv[1];
-  cc1(argv[1]);
+  for (int i = 1; i < argc; i++) {
+    if (!strcmp(argv[i], "--line-numbers")) {
+      opt_line_numbers = 1;
+    } else {
+      assert(!base_file);
+      base_file = argv[1];
+    }
+  }
+  cc1(base_file);
   return 0;
 }
diff --git a/preprocess.c b/preprocess.c
index abc095f..e3a3455 100644
--- a/preprocess.c
+++ b/preprocess.c
@@ -24,6 +24,10 @@
 
 #include "chibicc.h"
 
+static char *CURR_FILE;
+static unsigned long LINE_SUB,
+                     LINE_ADD;
+
 typedef struct MacroParam MacroParam;
 struct MacroParam {
   MacroParam *next;
@@ -807,6 +811,9 @@ static void read_line_marker(Token **rest, Token *tok) {
   if (tok->kind != TK_STR)
     error_tok(tok, "filename expected");
   start->file->display_name = tok->str;
+  CURR_FILE = tok->str;
+  LINE_SUB = tok->line_no;
+  LINE_ADD = tok->val;
 }
 
 // Visit all tokens in `tok` while evaluating preprocessing
@@ -823,7 +830,9 @@ static Token *preprocess2(Token *tok) {
     // Pass through if it is not a "#".
     if (!is_hash(tok)) {
       tok->line_delta = tok->file->line_delta;
-      tok->filename = tok->file->display_name;
+      tok->line_no -= LINE_SUB;
+      tok->line_no += LINE_ADD;
+      tok->filename = CURR_FILE ? CURR_FILE : tok->file->display_name;
       cur = cur->next = tok;
       tok = tok->next;
       continue;
diff --git a/tests/should_not_build.c b/tests/should_not_build.c
new file mode 100644
index 0000000..6a7d2d0
--- /dev/null
+++ b/tests/should_not_build.c
@@ -0,0 +1,3 @@
+int main() {
+  return foo();
+}
diff --git a/tokenize.c b/tokenize.c
index 5c49c02..4cfb1bd 100644
--- a/tokenize.c
+++ b/tokenize.c
@@ -64,14 +64,14 @@ void error_at(char *loc, char *fmt, ...) {
 void error_tok(Token *tok, char *fmt, ...) {
   va_list ap;
   va_start(ap, fmt);
-  verror_at(tok->file->name, tok->file->contents, tok->line_no, tok->loc, fmt, ap);
+  verror_at(tok->filename, tok->file->contents, tok->line_no, tok->loc, fmt, ap);
   exit(1);
 }
 
 void warn_tok(Token *tok, char *fmt, ...) {
   va_list ap;
   va_start(ap, fmt);
-  verror_at(tok->file->name, tok->file->contents, tok->line_no, tok->loc, fmt, ap);
+  verror_at(tok->filename, tok->file->contents, tok->line_no, tok->loc, fmt, ap);
   va_end(ap);
 }