[PATCH] Fix cpp0 -MG bugs, add -MD, -MMD and -MG support to tradcpp0

[Jakub Jelinek <jakub at redhat dot com>]

Hi!

This patch adds -MD, -MMD and -MG support to tradcpp0 and while I was coding
it, I found two bugs in cppfiles (it would wrongly print dependencies of
missing </xyz> style headers by prepending first include path to them and if
*ptr->name == '\0', it would strcat to a freshly alloced area.
Ok to commit?

2001-01-04  Jakub Jelinek  <jakub@redhat.com>

	* tradcpp.c (deps_file, print_deps_missing_files): New variables.
	(main): Handle -MG, -MD, -MMD.  Bail out if -MG is given without -M
	or -MM.
	(do_include): Handle missing headers like cpp0.
	* cppfiles.c (_cpp_execute_include): Don't prefix absolute header
	paths with first include pathname.  Don't strcat to uninitialized
	string.

--- gcc/tradcpp.c.jj	Thu Jan  4 14:03:56 2001
+++ gcc/tradcpp.c	Thu Jan  4 14:09:00 2001
@@ -46,6 +46,16 @@ int put_out_comments = 0;
 
 int print_deps = 0;
 
+/* File name which deps are being written to.  This is 0 if deps are
+   being written to stdout.  */
+
+const char *deps_file = 0;
+
+/* Nonzero if missing .h files in -M output are assumed to be
+   generated files and not errors.  */
+
+int print_deps_missing_files = 0;
+       
 /* Nonzero means don't output line number information.  */
 
 int no_line_commands;
@@ -608,11 +618,32 @@ main (argc, argv)
 	break;
 
       case 'M':
-	if (!strcmp (argv[i], "-M"))
-	  print_deps = 2;
-	else if (!strcmp (argv[i], "-MM"))
-	  print_deps = 1;
-	inhibit_output = 1;
+	{
+	  char *p = NULL;
+
+	  if (!strncmp (argv[i], "-MD", 3)) {
+	    p = argv[i] + 3;
+	    print_deps = 2;
+	  } else if (!strncmp (argv[i], "-MMD", 4)) {
+	    p = argv[i] + 4;
+	    print_deps = 1;
+	  } else if (!strcmp (argv[i], "-M")) {
+	    print_deps = 2;
+	    inhibit_output = 1;
+	  } else if (!strcmp (argv[i], "-MM")) {
+	    print_deps = 1;
+	    inhibit_output = 1;
+	  } else if (!strcmp (argv[i], "-MG"))
+	    print_deps_missing_files = 1;
+	  if (p) {
+	    if (*p)
+	      deps_file = p;
+	    else if (i + 1 == argc)
+	      fatal ("Filename missing after %s option", argv[i]);
+	    else
+	      deps_file = argv[++i];
+	  }
+	}
 	break;
 
       case 'd':
@@ -716,6 +747,9 @@ main (argc, argv)
     }
   }
 
+  if (print_deps_missing_files && (!print_deps || !inhibit_output))
+    fatal ("-MG must be specified with one of -M or -MM");
+
   if (user_label_prefix == 0)
     user_label_prefix = USER_LABEL_PREFIX;
 
@@ -809,7 +843,6 @@ main (argc, argv)
     {
       char *spec = getenv ("DEPENDENCIES_OUTPUT");
       char *s;
-      char *output_file;
 
       if (spec == 0)
 	{
@@ -823,28 +856,33 @@ main (argc, argv)
       s = strchr (spec, ' ');
       if (s)
 	{
+	  char *out_file;
+
 	  deps_target = s + 1;
-	  output_file = (char *) xmalloc (s - spec + 1);
-	  memcpy (output_file, spec, s - spec);
-	  output_file[s - spec] = 0;
+	  out_file = (char *) xmalloc (s - spec + 1);
+	  memcpy (out_file, spec, s - spec);
+	  out_file[s - spec] = 0;
+	  deps_file = out_file;
 	}
       else
 	{
 	  deps_target = 0;
-	  output_file = spec;
+	  deps_file = spec;
 	}
-      
-      deps_stream = fopen (output_file, "a");
-      if (deps_stream == 0)
-	pfatal_with_name (output_file);
     }
-  /* If the -M option was used, output the deps to standard output.  */
-  else if (print_deps)
-    deps_stream = stdout;
 
   /* For -M, print the expected object file name
      as the target of this Make-rule.  */
   if (print_deps) {
+
+    if (deps_file) {
+      deps_stream = fopen (deps_file, "a");
+      if (deps_stream == 0)
+	pfatal_with_name (deps_file);
+    } else
+      /* If the -M option was used, output the deps to standard output.  */
+      deps_stream = stdout;
+
     deps_allocated_size = 200;
     deps_buffer = (char *) xmalloc (deps_allocated_size);
     deps_buffer[0] = 0;
@@ -2334,19 +2372,38 @@ get_filename:
   if (f < 0) {
     strncpy (fname, (const char *)fbeg, flen);
     fname[flen] = 0;
-    error_from_errno (fname);
+    if (print_deps_missing_files
+	&& print_deps > (system_header_p || (system_include_depth > 0))) {
 
-    /* For -M, add this file to the dependencies.  */
-    if (print_deps > (system_header_p || (system_include_depth > 0))) {
-      if (system_header_p)
-	warning ("nonexistent file <%.*s> omitted from dependency output",
-		 flen, fbeg);
+      /* If requested as a system header, assume it belongs in
+	 the first system header directory. */
+      if (first_bracket_include)
+	stackp = first_bracket_include;
       else
-	{
-	  deps_output ((const char *)fbeg, flen);
-	  deps_output (" ", 0);
-	}
-    }
+	stackp = include;
+
+      if (!system_header_p || *fbeg == '/' || !stackp->fname)
+	deps_output ((const char *)fbeg, flen);
+      else {
+	char *p;
+	int len = strlen(stackp->fname);
+
+	p = (char *) alloca (len + flen + 2);
+	memcpy (p, stackp->fname, len);
+	p[len++] = '/';
+	memcpy (p + len, fbeg, flen);
+	len += flen;
+	deps_output (p, len);
+      }
+      deps_output (" ", 0);
+
+    } else if (print_deps
+	       && print_deps <= (system_header_p
+				 || (system_include_depth > 0)))
+      warning ("No include path in which to find %.*s", flen, fbeg);
+    else
+      error_from_errno (fname);
+
   } else {
 
     /* Check to see if this include file is a once-only include file.
--- gcc/cppfiles.c.jj	Tue Dec 19 12:01:13 2000
+++ gcc/cppfiles.c	Thu Jan  4 14:04:52 2001
@@ -648,12 +648,14 @@ _cpp_execute_include (pfile, header, no_
   if (CPP_OPTION (pfile, print_deps_missing_files)
       && PRINT_THIS_DEP (pfile, angle_brackets))
     {
-      if (!angle_brackets)
+      if (!angle_brackets || *fname == '/')
 	deps_add_dep (pfile->deps, fname);
       else
 	{
 	  char *p;
 	  struct file_name_list *ptr;
+	  int len = strlen (ptr->name);
+
 	  /* If requested as a system header, assume it belongs in
 	     the first system header directory. */
 	  if (CPP_OPTION (pfile, bracket_include))
@@ -661,14 +663,13 @@ _cpp_execute_include (pfile, header, no_
 	  else
 	    ptr = CPP_OPTION (pfile, quote_include);
 
-	  p = (char *) alloca (strlen (ptr->name)
-			       + strlen (fname) + 2);
-	  if (*ptr->name != '\0')
+	  p = (char *) alloca (len + strlen (fname) + 2);
+	  if (len)
 	    {
-	      strcpy (p, ptr->name);
-	      strcat (p, "/");
+	      memcpy (p, ptr->name, len);
+	      p[len++] = '/';
 	    }
-	  strcat (p, fname);
+	  strcpy (p + len, fname);
 	  _cpp_simplify_pathname (p);
 	  deps_add_dep (pfile->deps, p);
 	}

	Jakub