libcpp: Fix up -fdirectives-only preprocessing of includes not ending with newline...

If a header doesn't end with a new-line, with -fdirectives-only we right now
preprocess it as
int i = 1;# 2 "pr100392.c" 2
i.e. the line directive isn't on the next line, which means we fail to parse
it when compiling.

GCC 10 and earlier libcpp/directives-only.c had for this:
  if (!pfile->state.skipping && cur != base)
    {
      /* If the file was not newline terminated, add rlimit, which is
         guaranteed to point to a newline, to the end of our range.  */
      if (cur[-1] != '\n')
        {
          cur++;
          CPP_INCREMENT_LINE (pfile, 0);
          lines++;
        }

      cb->print_lines (lines, base, cur - base);
    }
and we have the assertion
      /* Files always end in a newline or carriage return.  We rely on this for
         character peeking safety.  */
      gcc_assert (buffer->rlimit[0] == '\n' || buffer->rlimit[0] == '\r');
So, this patch just does readd the more less same thing, so that we emit
a newline after the inline even when it wasn't there before.

2021-05-12  Jakub Jelinek  <jakub@redhat.com>

	PR preprocessor/100392
	* lex.c (cpp_directive_only_process): If buffer doesn't end with '\n',
	add buffer->rlimit[0] character to the printed range and
	CPP_INCREMENT_LINE and increment line_count.

	* gcc.dg/cpp/pr100392.c: New test.
	* gcc.dg/cpp/pr100392.h: New file.

diff --git a/gcc/testsuite/gcc.dg/cpp/pr100392.c b/gcc/testsuite/gcc.dg/cpp/pr100392.c
new file mode 100644 (file)
index 0000000..670ad2b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/pr100392.c
@@ -0,0 +1,5 @@
+/* PR preprocessor/100392 */
+/* { dg-do compile } */
+/* { dg-options "-save-temps -fdirectives-only" } */
+
+#include "pr100392.h"

diff --git a/gcc/testsuite/gcc.dg/cpp/pr100392.h b/gcc/testsuite/gcc.dg/cpp/pr100392.h
new file mode 100644 (file)
index 0000000..340bc92
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/pr100392.h
@@ -0,0 +1,4 @@
+/* PR preprocessor/100392 */
+
+/* No newline after ; below.  */
+int i = 1;
\ No newline at end of file

diff --git a/libcpp/lex.c b/libcpp/lex.c
index 36cd2e3..6fd722a 100644 (file)
--- a/libcpp/lex.c
+++ b/libcpp/lex.c
@@ -4768,7 +4768,18 @@ cpp_directive_only_process (cpp_reader *pfile,
        }
 
       if (buffer->rlimit > base && !pfile->state.skipping)
-       cb (pfile, CPP_DO_print, data, line_count, base, buffer->rlimit - base);
+       {
+         const unsigned char *limit = buffer->rlimit;
+         /* If the file was not newline terminated, add rlimit, which is
+            guaranteed to point to a newline, to the end of our range.  */
+         if (limit[-1] != '\n')
+           {
+             limit++;
+             CPP_INCREMENT_LINE (pfile, 0);
+             line_count++;
+           }
+         cb (pfile, CPP_DO_print, data, line_count, base, limit - base);
+       }
 
       _cpp_pop_buffer (pfile);
     }