From a6e65bacaf86ae80e7f9e1be8e6631bb78a2229e Mon Sep 17 00:00:00 2001
From: Lukas Krickl <lukas@krickl.dev>
Date: Wed, 27 Dec 2023 18:08:28 +0100
Subject: [PATCH] Fixed preproc recursive replacement in a better way

---
 src/test.c |  8 +++++---
 src/ulas.c | 18 +++++++++++-------
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/src/test.c b/src/test.c
index 66091a2..1238ab6 100644
--- a/src/test.c
+++ b/src/test.c
@@ -87,6 +87,7 @@ void test_strbuf(void) {
     assert(ulas_preproc(dst, src) == (expect_ret));                            \
     fclose(src);                                                               \
     fclose(dst);                                                               \
+    puts(dstbuf);                                                              \
     assert(strcmp(dstbuf, (expect_dst)) == 0);                                 \
   }
 
@@ -104,9 +105,10 @@ void test_preproc(void) {
   assert_preproc("", -1, "  #define\n");
   assert_preproc("this is a 123 for defs", 0,
                  "  #define test 123\nthis is a test for defs");
-  // define used inside define 
-  assert_preproc("this is a 123 for defs", 0,
-                 "  #define ftest 123\n#define test ftest\nthis is a test for defs");
+  // define used inside define
+  assert_preproc(
+      "this is a 123 for defs", 0,
+      "  #define ftest 123\n#define test ftest\nthis is a test for defs");
 
   // undefined
   assert_preproc("123\ntest", 0,
diff --git a/src/ulas.c b/src/ulas.c
index da38d98..c850bdf 100644
--- a/src/ulas.c
+++ b/src/ulas.c
@@ -707,23 +707,27 @@ char *ulas_preprocexpand(struct ulas_preproc *pp, const char *raw_line,
 
   int read = 0;
   int first_tok = 1;
+  int skip_next_tok = 0;
 
   // go through all tokens, see if a define matches the token,
   // if so expand it
   // only expand macros if they match toks[0] though!
   // otherwise memcpy the read bytes 1:1 into the new string
   while ((read = ulas_tok(&pp->tok, &praw_line, *n))) {
+    struct ulas_ppdef *def =
+        ulas_preprocgetdef(pp, pp->tok.buf, pp->tok.maxlen);
+    ;
+
     // if it is the first token, and it begins with a # do not process at all!
-    // only apply this to certain preproc types such as #undefine, #ifdef and #ifndef 
-    if (first_tok && pp->tok.buf[0] == ULAS_TOK_PREPROC_BEGIN && strcmp(ULAS_PPSTR_DEF, pp->tok.buf) != 0) {
-      ulas_strensr(&pp->line, (*n) + 1);
-      strncat(pp->line.buf, raw_line, *n);
-      break;
+    // if the first token is a # preproc directive skip the second token at all
+    // times
+    if ((first_tok && pp->tok.buf[0] == ULAS_TOK_PREPROC_BEGIN) ||
+        skip_next_tok) {
+      def = NULL;
+      skip_next_tok = !skip_next_tok;
     }
     first_tok = 0;
 
-    struct ulas_ppdef *def =
-        ulas_preprocgetdef(pp, pp->tok.buf, pp->tok.maxlen);
     if (def) {
       // if so... expand now and leave
       switch (def->type) {
-- 
2.30.2