svn commit: r263775 - head/contrib/gcclibs/libcpp

[Dimitry Andric]

Author: dim
Date: Wed Mar 26 19:57:50 2014
New Revision: 263775
URL: http://svnweb.freebsd.org/changeset/base/263775

Log:
  Avoid "cc1: warning: is shorter than expected" when using GNU cpp in
  combination with dtrace scripts, which have "#!/usr/sbin/dtrace -Cs"
  shebang lines.  This is because dtrace positions the file pointer after
  the shebang line, before passing the file to GNU cpp.
  
  To fix the warning, adjust the size downwards by the current position,
  after a bit of sanity checking.
  
  Suggested by:	avg
  MFC after:	1 week

Modified:
  head/contrib/gcclibs/libcpp/files.c

Modified: head/contrib/gcclibs/libcpp/files.c
==============================================================================
--- head/contrib/gcclibs/libcpp/files.c	Wed Mar 26 19:31:33 2014	(r263774)
+++ head/contrib/gcclibs/libcpp/files.c	Wed Mar 26 19:57:50 2014	(r263775)
@@ -546,6 +546,7 @@ static bool
 read_file_guts (cpp_reader *pfile, _cpp_file *file)
 {
   ssize_t size, total, count;
+  off_t offset;
   uchar *buf;
   bool regular;
 
@@ -573,6 +574,21 @@ read_file_guts (cpp_reader *pfile, _cpp_
 	}
 
       size = file->st.st_size;
+
+      if ((offset = lseek(file->fd, 0, SEEK_CUR)) < 0)
+	{
+	  cpp_error (pfile, CPP_DL_ERROR, "%s has no current position",
+	    file->path);
+	  return false;
+	}
+      else if (offset > INTTYPE_MAXIMUM (ssize_t) || (ssize_t)offset > size)
+	{
+	  cpp_error (pfile, CPP_DL_ERROR, "current position of %s is too large",
+	    file->path);
+	  return false;
+	}
+
+      size -= (ssize_t)offset;
     }
   else
     /* 8 kilobytes is a sensible starting size.  It ought to be bigger