From 96e5ce447a6e5bf7302a5f905b1bb0a996c0502c Mon Sep 17 00:00:00 2001
From: lemon <lsof@mailbox.org>
Date: Fri, 9 Jan 2026 12:31:32 +0100
Subject: cpp: fix multiline comment in skipped preprocessor directive

---
 c/lex.c      | 18 ++++++++++++++++--
 test/07-pp.c |  2 +-
 test/07-pp.h |  3 ++-
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/c/lex.c b/c/lex.c
index e2d86c6..02e9f3d 100644
--- a/c/lex.c
+++ b/c/lex.c
@@ -722,8 +722,22 @@ static void
 ppskipline(struct lexer *lx)
 {
    while (lx->macstk) popmac(lx);
-   while (peek(lx, 0) != '\n' && !lx->eof)
-      next(lx);
+   for (int c; (c = peek(lx, 0)) != '\n' && !lx->eof; next(lx)) {
+      if (c == '/' && peek(lx, 1) == '*') { /* comment */
+         next(lx), next(lx);
+         bool done = 0;
+         while (!((c = peek(lx, 0)) == '*' && peek(lx, 1) == '/')) {
+            if (lx->eof) {
+               struct span span = {{ lx->idx, lx->chridx - lx->idx, lx->fileid }};
+               fatal(&span, "unterminated comment");
+            }
+            done = c == '\n';
+            next(lx);
+         }
+         next(lx);
+         if (done) return;
+      }
+   }
 }
 
 static bool
diff --git a/test/07-pp.c b/test/07-pp.c
index 47b9dbb..071b359 100644
--- a/test/07-pp.c
+++ b/test/07-pp.c
@@ -37,7 +37,7 @@ s
 #ifdef CMD_WORKING
 int
 main(V)
-#endif
+#endif // comment
 {
    int CATl(foo);
    ++foobar;
diff --git a/test/07-pp.h b/test/07-pp.h
index 63de6f5..c0725b5 100644
--- a/test/07-pp.h
+++ b/test/07-pp.h
@@ -9,7 +9,8 @@ void hi(int x) {
 }
 #if 1
 #endif
-#elifndef Ww
+#elifndef Ww /*
+             t'e   */
 #define Bar 7
 #define SQR_(x) ((x)*(x))
 #define SQR(y) SQR_(1+(y)-1)
-- 
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