Add -idirafter option

main.c

@@ -21,7 +21,7 @@ static void usage(int status) {
 }
 
 static bool take_arg(char *arg) {
-  char *x[] = {"-o", "-I"};
+  char *x[] = {"-o", "-I", "-idirafter"};
 
   for (int i = 0; i < sizeof(x) / sizeof(*x); i++)
     if (!strcmp(arg, x[i]))
@@ -56,6 +56,8 @@ static void parse_args(int argc, char **argv) {
       if (!argv[++i])
         usage(1);
 
+  StringArray idirafter = {};
+
   for (int i = 1; i < argc; i++) {
     if (!strcmp(argv[i], "-###")) {
       opt_hash_hash_hash = true;
@@ -130,6 +132,11 @@ static void parse_args(int argc, char **argv) {
       continue;
     }
 
+    if (!strcmp(argv[i], "-idirafter")) {
+      strarray_push(&idirafter, argv[i++]);
+      continue;
+    }
+
     // These options are ignored for now.
     if (!strncmp(argv[i], "-O", 2) ||
         !strncmp(argv[i], "-W", 2) ||
@@ -151,6 +158,9 @@ static void parse_args(int argc, char **argv) {
     strarray_push(&input_paths, argv[i]);
   }
 
+  for (int i = 0; i < idirafter.len; i++)
+    strarray_push(&include_paths, idirafter.data[i]);
+
   if (input_paths.len == 0)
     error("no input files");
 }

test/driver.sh

@@ -161,4 +161,13 @@ check inline
 echo 'static inline void f2(); static inline void f1() { f2(); } static inline void f2() { f1(); } void foo() { f2(); }' | $chibicc -o- -S - | grep -q f2:
 check inline
 
+# -idirafter
+mkdir -p $tmp/dir1 $tmp/dir2
+echo foo > $tmp/dir1/idirafter
+echo bar > $tmp/dir2/idirafter
+echo "#include \"idirafter\"" | $chibicc -I$tmp/dir1 -I$tmp/dir2 -E - | grep -q foo
+check -idirafter
+echo "#include \"idirafter\"" | $chibicc -idirafter $tmp/dir1 -I$tmp/dir2 -E - | grep -q bar
+check -idirafter
+
 echo OK