diff mbox series

c++: directives-only preprocessing and include translation [PR 99050]

Message ID 17dabded-a9ec-514b-5eea-bf09b47e1f16@acm.org
State New
Headers show
Series c++: directives-only preprocessing and include translation [PR 99050] | expand

Commit Message

Nathan Sidwell Feb. 16, 2021, 8:26 p.m. UTC 
We make	sure files end in \n by	placing	one at the limit of the	buffer 
(just past the end of what is read).  We need to do the	same for buffers 
generated via include-translation.  Fortunately	they have space.

	libcpp/
         * files.c (_cpp_stack_file): Make buffers end in unread \n.
         gcc/testsuite/
         * g++.dg/modules/pr99050_a.H: New.
         * g++.dg/modules/pr99050_b.C: New.
diff mbox series

Patch

diff --git c/gcc/testsuite/g++.dg/modules/pr99050_a.H w/gcc/testsuite/g++.dg/modules/pr99050_a.H
new file mode 100644
index 00000000000..137e37f567f
--- /dev/null
+++ w/gcc/testsuite/g++.dg/modules/pr99050_a.H
@@ -0,0 +1,4 @@ 
+// PR c++/99050 ICE with directives only
+// { dg-additional-options -fmodule-header }
+// { dg-module-cmi {} }
+void f ();
diff --git c/gcc/testsuite/g++.dg/modules/pr99050_b.C w/gcc/testsuite/g++.dg/modules/pr99050_b.C
new file mode 100644
index 00000000000..439e216eb16
--- /dev/null
+++ w/gcc/testsuite/g++.dg/modules/pr99050_b.C
@@ -0,0 +1,7 @@ 
+// { dg-do preprocess }
+// { dg-additional-options {-fdirectives-only -fmodules-ts} }
+#include "pr99050_a.H"
+
+int main () {}
+
+// { dg-final { scan-file pr99050_b.i {import  "[^\n]*99050_a.H" \[\[__translated\]\];\n} }  }
diff --git c/libcpp/files.c w/libcpp/files.c
index 5ea3f8e1bf3..3a35f7c9743 100644
--- c/libcpp/files.c
+++ w/libcpp/files.c
@@ -918,13 +918,17 @@  _cpp_stack_file (cpp_reader *pfile, _cpp_file *file, include_type type,
 	 because we don't usually need that location (we're popping an
 	 include file).  However in this case we do want to do the
 	 increment.  So push a writable buffer of two newlines to acheive
-	 that.  */
-      static uchar newlines[] = "\n\n";
+	 that.  (We also need an extra newline, so this looks like a regular
+	 file, which we do that to to make sure we don't fall off the end in the
+	 middle of a line.  */
+      static uchar newlines[] = "\n\n\n";
       cpp_push_buffer (pfile, newlines, 2, true);
 
+      size_t len = strlen (buf);
+      buf[len] = '\n'; /* See above  */
       cpp_buffer *buffer
 	= cpp_push_buffer (pfile, reinterpret_cast<unsigned char *> (buf),
-			   strlen (buf), true);
+			   len, true);
       buffer->to_free = buffer->buf;
 
       file->header_unit = +1;