From 35b82d26e5b92ba0471f59f0073590de3550f00a Mon Sep 17 00:00:00 2001
From: Nathan Sidwell <nathan@acm.org>
Date: Tue, 10 Oct 2017 18:56:31 +0000
Subject: [PATCH] [PATCH] preprocessor stringizing raw strings

https://gcc.gnu.org/ml/gcc-patches/2017-10/msg00611.html
	libcpp/
	PR preprocessor/82506
	* macro.c (cpp_quote_string): Escape raw LFs.

	gcc/testsuite/
	PR preprocessor/82506
	* g++.dg/cpp/string-3.C: New.

From-SVN: r253605
---
 gcc/testsuite/ChangeLog             |  5 +++++
 gcc/testsuite/g++.dg/cpp/string-3.C |  9 +++++++++
 libcpp/ChangeLog                    |  5 +++++
 libcpp/macro.c                      | 14 +++++++++++---
 4 files changed, 30 insertions(+), 3 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp/string-3.C

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index c2e064c7ff7..0cc5e32bdff 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-10-10  Nathan Sidwell  <nathan@acm.org>
+
+	PR preprocessor/82506
+	* g++.dg/cpp/string-3.C: New.
+
 2017-10-10  Will Schmidt  <will_schmidt@vnet.ibm.com>
 
 	* gcc.target/powerpc/fold-vec-splat-16.c: New
diff --git a/gcc/testsuite/g++.dg/cpp/string-3.C b/gcc/testsuite/g++.dg/cpp/string-3.C
new file mode 100644
index 00000000000..92bd930dc26
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp/string-3.C
@@ -0,0 +1,9 @@
+// PR c++/82506
+// { dg-do preprocess { target c++11 } }
+
+#define STRINGIZE(A) #A
+
+BEGIN STRINGIZE(R"(
+)") END
+
+// { dg-final { scan-file string-3.ii "BEGIN \"R\\\"(\\n)\\\"\"\n END" } }
diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog
index 0621074b53b..f2c0d4d63fd 100644
--- a/libcpp/ChangeLog
+++ b/libcpp/ChangeLog
@@ -1,3 +1,8 @@
+2017-10-10  Nathan Sidwell  <nathan@acm.org>
+
+	PR preprocessor/82506
+	* macro.c (cpp_quote_string): Escape raw LFs.
+
 2017-09-15  Andrew Sutton  <andrew.n.sutton@gmail.com>
 	    Jakub Jelinek  <jakub@redhat.com>
 
diff --git a/libcpp/macro.c b/libcpp/macro.c
index de18c2210cf..fab1cb051dc 100644
--- a/libcpp/macro.c
+++ b/libcpp/macro.c
@@ -502,13 +502,21 @@ cpp_quote_string (uchar *dest, const uchar *src, unsigned int len)
     {
       uchar c = *src++;
 
-      if (c == '\\' || c == '"')
+      switch (c)
 	{
+	case '\n':
+	  /* Naked LF can appear in raw string literals  */
+	  c = 'n';
+	  /* FALLTHROUGH */
+
+	case '\\':
+	case '"':
 	  *dest++ = '\\';
+	  /* FALLTHROUGH */
+
+	default:
 	  *dest++ = c;
 	}
-      else
-	  *dest++ = c;
     }
 
   return dest;
-- 
2.30.2