From: Jakub Jelinek <jakub@redhat.com>
Date: Thu, 20 May 2021 07:09:07 +0000 (+0200)
Subject: libcpp: Fix up -fdirectives-only handling of // comments on last line not terminated... 
X-Git-Tag: releases/gcc-11.2.0~312
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=3a2fa2e819d4714cecf5048eda2b7e52ba9e3cdd;p=thirdparty%2Fgcc.git

libcpp: Fix up -fdirectives-only handling of // comments on last line not terminated with newline [PR100646]

As can be seen on the testcases, before the -fdirectives-only preprocessing
rewrite the preprocessor would assume // comments are terminated by the
end of file even when newline wasn't there, but now we error out.
The following patch restores the previous behavior.

2021-05-20  Jakub Jelinek  <jakub@redhat.com>

	PR preprocessor/100646
	* lex.c (cpp_directive_only_process): Treat end of file as termination
	for !is_block comments.

	* gcc.dg/cpp/pr100646-1.c: New test.
	* gcc.dg/cpp/pr100646-2.c: New test.

(cherry picked from commit d15a2d261b24adcbfe5e663b15dde3df5d2b3486)
---

diff --git a/gcc/testsuite/gcc.dg/cpp/pr100646-1.c b/gcc/testsuite/gcc.dg/cpp/pr100646-1.c
new file mode 100644
index 000000000000..8f2caf40c3f0
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/pr100646-1.c
@@ -0,0 +1,5 @@
+/* PR preprocessor/100646 */
+/* { dg-do compile } */
+/* { dg-options "-fdirectives-only -save-temps -std=c17" } */
+int main () { return 0; }
+// Not newline terminated
\ No newline at end of file
diff --git a/gcc/testsuite/gcc.dg/cpp/pr100646-2.c b/gcc/testsuite/gcc.dg/cpp/pr100646-2.c
new file mode 100644
index 000000000000..a1deba10634b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/pr100646-2.c
@@ -0,0 +1,6 @@
+/* PR preprocessor/100646 */
+/* { dg-do compile } */
+/* { dg-options "-fdirectives-only -save-temps -std=c17" } */
+int main () { return 0; }
+/* { dg-warning "backslash-newline at end of file" "" { target *-*-* } .+1 } */
+// Not newline terminated\
\ No newline at end of file
diff --git a/libcpp/lex.c b/libcpp/lex.c
index 6c0ca8d2e2db..3791f388207b 100644
--- a/libcpp/lex.c
+++ b/libcpp/lex.c
@@ -4469,8 +4469,9 @@ cpp_directive_only_process (cpp_reader *pfile,
 			break;
 		      }
 		  }
-		cpp_error_with_line (pfile, CPP_DL_ERROR, sloc, 0,
-				     "unterminated comment");
+		if (pos < limit || is_block)
+		  cpp_error_with_line (pfile, CPP_DL_ERROR, sloc, 0,
+				       "unterminated comment");
 	      done_comment:
 		lwm = pos;
 		break;