[PATCH] Fix cpp to match cpp.texi in respect to warnings

[Jakub Jelinek]

Hi!

cpp.texi sais about -Wcomment that it enables warning whenever
backslash-newline appears in a // comment, but in reality this warning is
issued unconditionally. Likewise, cpp.texi speaks about -Wwhite-space, but
the warning is unconditional too.
This patch changes cpp0 to match its documentation.
Bootstrapped on i386-redhat-linux, no regressions.
Ok to commit?

2001-04-10  Jakub Jelinek  <jakub@redhat.com>

	* cpplex.c (skip_escaped_lines): Only warn if -Wwhite-space.
	(_cpp_lex_token): Only warn if -Wcomment.
	(cpp_handle_option): Handle -Wwhite-space.
	* cpplib.h (struct cpp_options): Add warn_white_space.

	* gcc.dg/cpp/backslash.c: Compile with -Wwhite-space.
	* gcc.dg/cpp/backslash2.c: Likewise.

--- gcc/cpplex.c.jj	Fri Mar 30 11:44:42 2001
+++ gcc/cpplex.c	Tue Apr 10 18:33:34 2001
@@ -1,5 +1,5 @@
 /* CPP Library - lexical analysis.
-   Copyright (C) 2000 Free Software Foundation, Inc.
+   Copyright (C) 2000, 2001 Free Software Foundation, Inc.
    Contributed by Per Bothner, 1994-95.
    Based on CCCP program by Paul Rubin, June 1986
    Adapted to ANSI C, Richard Stallman, Jan 1987
@@ -245,7 +245,8 @@ skip_escaped_newlines (buffer, next)
 	      break;
 	    }
 
-	  if (space && !buffer->pfile->state.lexing_comment)
+	  if (CPP_OPTION (buffer->pfile, warn_white_space)
+	      && space && !buffer->pfile->state.lexing_comment)
 	    cpp_warning (buffer->pfile,
 			 "backslash and newline separated by space");
 
@@ -1017,7 +1018,7 @@ _cpp_lex_token (pfile, result)
 	    }
 
 	  /* Skip_line_comment updates buffer->read_ahead.  */
-	  if (skip_line_comment (pfile))
+	  if (skip_line_comment (pfile) && CPP_OPTION (pfile, warn_comments))
 	    cpp_warning_with_line (pfile, pfile->lexer_pos.line,
 				   pfile->lexer_pos.col,
 				   "multi-line comment");
--- gcc/cppinit.c.jj	Tue Apr 10 17:42:17 2001
+++ gcc/cppinit.c	Tue Apr 10 18:27:47 2001
@@ -1621,6 +1621,7 @@ cpp_handle_option (pfile, argc, argv)
 	    {
 	      CPP_OPTION (pfile, warn_trigraphs) = 1;
 	      CPP_OPTION (pfile, warn_comments) = 1;
+	      CPP_OPTION (pfile, warn_white_space) = 1;
 	    }
 	  else if (!strcmp (argv[i], "-Wtraditional"))
 	    CPP_OPTION (pfile, warn_traditional) = 1;
@@ -1632,6 +1633,8 @@ cpp_handle_option (pfile, argc, argv)
 	    CPP_OPTION (pfile, warn_comments) = 1;
 	  else if (!strcmp (argv[i], "-Wundef"))
 	    CPP_OPTION (pfile, warn_undef) = 1;
+	  else if (!strcmp (argv[i], "-Wwhite-space"))
+	    CPP_OPTION (pfile, warn_white_space) = 1;
 	  else if (!strcmp (argv[i], "-Wimport"))
 	    CPP_OPTION (pfile, warn_import) = 1;
 	  else if (!strcmp (argv[i], "-Werror"))
@@ -1648,6 +1651,8 @@ cpp_handle_option (pfile, argc, argv)
 	    CPP_OPTION (pfile, warn_comments) = 0;
 	  else if (!strcmp (argv[i], "-Wno-undef"))
 	    CPP_OPTION (pfile, warn_undef) = 0;
+	  else if (!strcmp (argv[i], "-Wno-white-space"))
+	    CPP_OPTION (pfile, warn_white_space) = 0;
 	  else if (!strcmp (argv[i], "-Wno-import"))
 	    CPP_OPTION (pfile, warn_import) = 0;
 	  else if (!strcmp (argv[i], "-Wno-error"))
--- gcc/cpplib.h.jj	Mon Mar 12 11:45:01 2001
+++ gcc/cpplib.h	Tue Apr 10 18:29:08 2001
@@ -316,6 +316,10 @@ struct cpp_options
   /* Nonzero means warn if slash-star appears in a comment.  */
   unsigned char warn_comments;
 
+  /* Nonzero means warn if white-space appears inappropriately (e.g.
+     between backslash and newline.  */
+  unsigned char warn_white_space;
+
   /* Nonzero means warn if there are any trigraphs.  */
   unsigned char warn_trigraphs;
 
--- gcc/testsuite/gcc.dg/cpp/backslash.c.jj	Tue Sep 12 05:42:30 2000
+++ gcc/testsuite/gcc.dg/cpp/backslash.c	Tue Apr 10 19:50:16 2001
@@ -1,4 +1,5 @@
 /* Test backslash newline with and without trailing spaces.  */
+/* { dg-options "-Wwhite-space" } */
 
 #define alpha(a, b, c) \
 	a, \
@@ -11,9 +12,9 @@
 	b, \ 	
 	c
 
-/* { dg-warning "separated by space" "space" { target *-*-* } 9 } */
-/* { dg-warning "separated by space" "tab" { target *-*-* } 10 } */
-/* { dg-warning "separated by space" "space and tab" { target *-*-* } 11 } */
+/* { dg-warning "separated by space" "space" { target *-*-* } 10 } */
+/* { dg-warning "separated by space" "tab" { target *-*-* } 11 } */
+/* { dg-warning "separated by space" "space and tab" { target *-*-* } 12 } */
 
 int x[] = {
    alpha(1, 2, 3),
--- gcc/testsuite/gcc.dg/cpp/backslash2.c.jj	Wed Dec  6 21:14:32 2000
+++ gcc/testsuite/gcc.dg/cpp/backslash2.c	Tue Apr 10 19:50:54 2001
@@ -1,14 +1,15 @@
 /* Copyright (C) 2000 Free Software Foundation, Inc.  */
 
 /* { dg-do preprocess } */
+/* { dg-options "-Wwhite-space" } */
 
 /* Test warnings for backslash-space-newline.
    Source: Neil Booth. 6 Dec 2000.  */
 
 foo \  
 bar
-/* { dg-warning "separated by space" "" { target *-*-* } 8 } */
+/* { dg-warning "separated by space" "" { target *-*-* } 9 } */
 
 /* foo \   
    bar */
-/* { dg-bogus "separated by space" "" { target *-*-* } 12 } */
+/* { dg-bogus "separated by space" "" { target *-*-* } 13 } */

	Jakub