Re: splitting up cpplib, revised

[Zack Weinberg <zack at rabi dot columbia dot edu>]

On Mon, 26 Oct 1998 11:08:40 -0500, Dave Brolley wrote:
>I have no problems with the intent and structure of this patch. I can't commen
>t on the VMS stuff and would like to see
>this reviewd by a VMS guru before approval.

Ok.  That would probably be Klaus Kempf, right?

In the meantime, here's another patch.  This one is pure bugfix: it
makes -include work properly when cpplib is linked into cc1.  The
problem was that cpp_start_read was processing the -included file
through to the token_buffer, but c-lex.c didn't expect anything to be
in the token_buffer until after cpp_get_token had been called for the
first time.

The change in init_parse fixed that, but then another bug appeared in
the nesting of #line directives.  The only way to cure that was to
pretend that -included files were pulled in by a chain of #include
directives.  In other words, if you compile x.c with -include a.h
-include b.h, it's as if the first line of x.c is #include "b.h" and
the first line of b.h is #include "a.h".  The `In file included
from...' listing on an error in a.h looks a bit weird, but that's
harmless.

This patch should be independent of the splitup patch except that the
hunk for cpplib.c is offset a bit.

zw

1998-10-26 22:42 -0500  Zack Weinberg  <zack@rabi.phys.columbia.edu>

	* c-lang.c: Declare extern char *yy_cur if USE_CPPLIB.
          (lang_init): Call check_newline always.
	* c-lex.c (init_parse) [USE_CPPLIB=1]: After calling
          cpp_start_read, set yy_cur and yy_lim to read from
          parse_in.token_buffer, so that we'll see the first #line
          directive.
	* cpplib.c (cpp_start_read): finclude the main input file
          before processing -include/-imacros.  Process -imacros and
          -include separately, and handle -include by stacking a
          buffer for the file in question as if it'd been #included.
	* toplev.c (documented_lang_options) Recognize -H when
          USE_CPPLIB is on.

============================================================
Index: c-lang.c
--- c-lang.c	1998/06/19 21:58:00	1.14
+++ c-lang.c	1998/10/27 03:30:38
@@ -28,6 +28,10 @@
 #include "toplev.h"
 #include "output.h"
 
+#if USE_CPPLIB
+extern char *yy_cur;
+#endif
+
 /* Each of the functions defined here
    is an alternative to a function in objc-actions.c.  */
    
@@ -47,12 +51,15 @@
 void
 lang_init ()
 {
-#if !USE_CPPLIB
   /* the beginning of the file is a new line; check for # */
   /* With luck, we discover the real source file's name from that
      and put it in input_filename.  */
+#if !USE_CPPLIB
   ungetc (check_newline (), finput);
-#endif
+#else
+  check_newline ();
+  yy_cur--;
+#endif 
 }
 
 void
============================================================
Index: c-lex.c
--- c-lex.c	1998/10/21 09:53:23	1.36
+++ c-lex.c	1998/10/27 03:30:39
@@ -194,12 +194,14 @@
   init_lex ();
 
 #if USE_CPPLIB
-  yy_cur = "\n";
-  yy_lim = yy_cur+1;
-
   parse_in.show_column = 1;
   if (! cpp_start_read (&parse_in, filename))
     abort ();
+
+  /* cpp_start_read always puts at least one line directive into the
+     token buffer.  We must arrange to read it out here. */
+  yy_cur = parse_in.token_buffer;
+  yy_lim = CPP_PWRITTEN (&parse_in);
 #endif
 
   return filename;
============================================================
Index: cpplib.c
--- cpplib.c	1998/10/17 20:26:10	1.39
+++ cpplib.c	1998/10/27 03:30:40
@@ -6142,18 +5421,27 @@
     trigraph_pcp (fp);
 #endif
 
-  /* Avoid a #line 0 if -include files are present. */
-  CPP_BUFFER (pfile)->lineno = 1;
+  /* Must call finclude() on the main input before processing
+     -include switches; otherwise the -included text winds up
+     after the main input. */
+  if (!finclude (pfile, f, fname, 0, NULL_PTR))
+    return 0;
   output_line_command (pfile, 0, same_file);
-  
-  /* Scan the -include and -imacros files before the main input. */
+  pfile->only_seen_white = 2;
 
+  /* The -imacros files can be scanned now, but the -include files
+     have to be pushed onto the include stack and processed later,
+     in the main loop calling cpp_get_token.  That means the -include
+     files have to be processed in reverse order of the pending list,
+     which means the pending list has to be reversed again, which
+     means the -imacros files have to be done separately and first. */
+  
   pfile->no_record_file++;
-  for (pend = opts->pending;  pend;  pend = pend->next)
+  for (pend = opts->pending; pend; pend = pend->next)
     {
       if (pend->cmd != NULL)
         {
-	  if (strcmp (pend->cmd, "-include") == 0)
+	  if (strcmp (pend->cmd, "-imacros") == 0)
 	    {
 	      int fd = open (pend->arg, O_RDONLY, 0666);
 	      if (fd < 0)
@@ -6163,13 +5451,19 @@
 	        }
 	      if (!cpp_push_buffer (pfile, NULL, 0))
 	        return 0;
+	      opts->no_output++;
 	      if (finclude (pfile, fd, pend->arg, 0, NULL_PTR))
-	        {
-		  output_line_command (pfile, 0, enter_file);
-		  cpp_scan_buffer (pfile);
-		}
+		cpp_scan_buffer (pfile);
+	      opts->no_output--;
 	    }
-	  else if (strcmp (pend->cmd, "-imacros") == 0)
+	}
+    }
+  opts->pending = nreverse_pending (opts->pending);
+  for (pend = opts->pending; pend; pend = pend->next)
+    {
+      if (pend->cmd != NULL)
+        {
+	  if (strcmp (pend->cmd, "-include") == 0)
 	    {
 	      int fd = open (pend->arg, O_RDONLY, 0666);
 	      if (fd < 0)
@@ -6177,12 +5471,10 @@
 	          cpp_perror_with_name (pfile, pend->arg);
 	          return 0;
 	        }
-	      opts->no_output++;
 	      if (!cpp_push_buffer (pfile, NULL, 0))
 	        return 0;
 	      if (finclude (pfile, fd, pend->arg, 0, NULL_PTR))
-		cpp_scan_buffer (pfile);
-	      opts->no_output--;
+	        output_line_command (pfile, 0, enter_file);
 	    }
 	}
     }
@@ -6197,19 +5489,6 @@
     }
   opts->pending = NULL;
 
-#if 0
-  /* Scan the input, processing macros and directives.  */
-
-  rescan (&outbuf, 0);
-
-  if (missing_newline)
-    fp->lineno--;
-
-  if (CPP_PEDANTIC (pfile) && missing_newline)
-    pedwarn ("file does not end in newline");
-
-#endif
-  finclude (pfile, f, fname, 0, NULL_PTR);
   return 1;
 }
 
============================================================
Index: toplev.c
--- toplev.c	1998/10/21 09:53:37	1.115
+++ toplev.c	1998/10/27 03:30:40
@@ -1045,6 +1045,7 @@
   { "-D", "" },
   { "-I", "" },
   { "-U", "" },
+  { "-H", "" },
   { "-idirafter", "" },
   { "-imacros", "" },
   { "-include", "" },