cpplib: more dependency tweaks

[Neil Booth <neil at daikokuya dot demon dot co dot uk>]

This patch

o Adds Tom's suggestion of -MQ: it quotes the file name supplied.  -MT
  does not.

o Simplifies code by allocating pfile->deps in one place only, during
  cpp_reader creation.  Since we don't need this struct most of the time,
  we no longer pre-allocate any space for the dependency and target
  vectors unless they are needed.

o Doesn't strip the path from the default target.  For example:-

bash-2.04$ ./cpp0 -MM /tmp/test.c
/tmp/test.o: /tmp/test.c /tmp/test.h
^^^^^
New.

Zack, can't we just remove base_name?  We have an implementation in
libiberty if we ever need one.

Neil.

	* cpp.texi: Update for -MQ.
	* cppinit.c (cpp_create_reader): Always create pfile->deps.
	(cpp_cleanup): Don't create pfile->deps.
	(initialize_dependency_output): Similarly.
	(cpp_handle_option): Similarly.
	(OPT_MQ): New.
	* gcc.c (cpp_options): Handle -MQ.
	(DEFAULT_WORD_SWITCH_TAKES_ARG): Add -MQ.
	* mkdeps.c (base_name): Comment out.
	(deps_init): Don't allocate vector space until it's needed.
	(deps_free): Only free vectors if allocated.
	(deps_add_target, deps_add_dep): Update for initial allocation.
	(deps_add_default_target): Don't strip to the base_name.

Index: cpp.texi
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cpp.texi,v
retrieving revision 1.39
diff -u -p -r1.39 cpp.texi
--- cpp.texi	2001/01/05 07:50:22	1.39
+++ cpp.texi	2001/01/05 19:06:09
@@ -3491,23 +3491,28 @@ This is typical output:-
 /tmp/test.h:
 @end smallexample
 
-@item -MT @var{target}
+@item -MT @var{target} or -MQ @var{target}
 @findex -MT
-By default CPP uses the base file name and appends the object suffix,
-normally ``.o'', to it to obtain the name of the target for dependency
-generation.  With @samp{-MT} you can specify a target yourself,
-overriding the default one.
+@findex -MQ
+By default CPP uses the main file name, including any path, and appends
+the object suffix, normally ``.o'', to it to obtain the name of the
+target for dependency generation.  With @samp{-MT} you can specify a
+target yourself, overriding the default one.
 
 If you want multiple targets, you can specify them as a single argument
 to @samp{-MT}, or use multiple @samp{-MT} options.
 
 The targets you specify are output in the order they appear on the
-command line, and, unlike the default target, are not quoted for MAKE.
-This allows you to do things like, for example,
+command line.  @samp{-MQ} is identical to @samp{-MT}, except that the
+target name is quoted for Make, but with @samp{-MT} it isn't.  This
+allows you to do things like, for example,
 
 @smallexample
 -MT '$(objpfx)foo.o $(objpfx)foo.os $(objpfx)foo.op'
 @end smallexample
+
+The default target is quoted for Make, as if it were given with
+@samp{-MQ}.
 
 @item -H
 @findex -H
Index: cppinit.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cppinit.c,v
retrieving revision 1.129
diff -u -p -r1.129 cppinit.c
--- cppinit.c	2001/01/05 07:50:22	1.129
+++ cppinit.c	2001/01/05 19:06:14
@@ -499,6 +499,10 @@ cpp_create_reader (lang)
   /* After creating pfile->pending.  */
   set_lang (pfile, lang);
 
+  /* It's simplest to just create this struct whether or not it will
+     be needed.  */
+  pfile->deps = deps_init ();
+
   /* Initialize lexer state.  */
   pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
 
@@ -552,8 +556,7 @@ cpp_cleanup (pfile)
   if (pfile->macro_buffer)
     free ((PTR) pfile->macro_buffer);
 
-  if (pfile->deps)
-    deps_free (pfile->deps);
+  deps_free (pfile->deps);
 
   _cpp_cleanup_includes (pfile);
   _cpp_cleanup_stacks (pfile);
@@ -753,9 +756,6 @@ initialize_dependency_output (pfile)
 	    return;
 	}
 
-      if (! pfile->deps)
-	pfile->deps = deps_init ();
-
       /* Find the space before the DEPS_TARGET, if there is one.  */
       s = strchr (spec, ' ');
       if (s)
@@ -1083,6 +1083,7 @@ new_pending_directive (pend, text, handl
   DEF_OPT("MM",                       0,      OPT_MM)                         \
   DEF_OPT("MMD",                      no_fil, OPT_MMD)                        \
   DEF_OPT("MP",                       0,      OPT_MP)                         \
+  DEF_OPT("MQ",                       no_tgt, OPT_MQ)                         \
   DEF_OPT("MT",                       no_tgt, OPT_MT)                         \
   DEF_OPT("P",                        0,      OPT_P)                          \
   DEF_OPT("U",                        no_mac, OPT_U)                          \
@@ -1485,9 +1486,6 @@ cpp_handle_option (pfile, argc, argv)
 	case OPT_MD:
 	case OPT_MM:
 	case OPT_MMD:
-	  if (! pfile->deps)
-	    pfile->deps = deps_init ();
-
 	  if (opt_code == OPT_M || opt_code == OPT_MD)
 	    CPP_OPTION (pfile, print_deps) = 2;
  	  else
@@ -1506,11 +1504,10 @@ cpp_handle_option (pfile, argc, argv)
 	  CPP_OPTION (pfile, deps_phony_targets) = 1;
 	  break;
 
+	case OPT_MQ:
 	case OPT_MT:
-	  /* Add a target.  */
-	  if (! pfile->deps)
-	    pfile->deps = deps_init ();
-	  deps_add_target (pfile->deps, arg, 0);
+	  /* Add a target.  -MQ quotes for Make.  */
+	  deps_add_target (pfile->deps, arg, opt_code == OPT_MQ);
 	  break;
 
 	case OPT_A:
Index: gcc.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/gcc.c,v
retrieving revision 1.192
diff -u -p -r1.192 gcc.c
--- gcc.c	2001/01/05 07:50:23	1.192
+++ gcc.c	2001/01/05 19:06:32
@@ -584,7 +584,7 @@ static const char *cpp_options =
 "%{C:%{!E:%eGNU C does not support -C without using -E}}\
  %{std*} %{nostdinc*}\
  %{C} %{v} %{I*} %{P} %{$} %I\
- %{M} %{MM} %{MD:-MD %b.d} %{MMD:-MMD %b.d} %{MG} %{MP} %{MT}\
+ %{M} %{MM} %{MD:-MD %b.d} %{MMD:-MMD %b.d} %{MG} %{MP} %{MQ} %{MT}\
  %{!no-gcc:-D__GNUC__=%v1 -D__GNUC_MINOR__=%v2 -D__GNUC_PATCHLEVEL__=%v3}\
  %{!undef:%{!ansi:%{!std=*:%p}%{std=gnu*:%p}} %P} %{trigraphs}\
  %c %{Os:-D__OPTIMIZE_SIZE__} %{O*:%{!O0:-D__OPTIMIZE__}}\
@@ -663,7 +663,7 @@ static struct user_specs *user_specs_hea
   || !strcmp (STR, "idirafter") || !strcmp (STR, "iprefix") \
   || !strcmp (STR, "iwithprefix") || !strcmp (STR, "iwithprefixbefore") \
   || !strcmp (STR, "isystem") || !strcmp (STR, "specs") \
-  || !strcmp (STR, "MF") || !strcmp (STR, "MT"))
+  || !strcmp (STR, "MF") || !strcmp (STR, "MT") || !strcmp (STR, "MQ"))
 
 #ifndef WORD_SWITCH_TAKES_ARG
 #define WORD_SWITCH_TAKES_ARG(STR) DEFAULT_WORD_SWITCH_TAKES_ARG (STR)
Index: mkdeps.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/mkdeps.c,v
retrieving revision 1.9
diff -u -p -r1.9 mkdeps.c
--- mkdeps.c	2001/01/05 07:50:23	1.9
+++ mkdeps.c	2001/01/05 19:06:37
@@ -38,7 +38,6 @@ struct deps
 };
 
 static const char *munge	PARAMS ((const char *));
-static const char *base_name	PARAMS ((const char *));
 
 /* Given a filename, quote characters in that filename which are
    significant to Make.  Note that it's not possible to quote all such
@@ -107,6 +106,7 @@ munge (filename)
   return buffer;
 }
 
+#if 0				/* May be useful later.  */
 /* Given a pathname, calculate the non-directory part.  This always
    knows how to handle Unix-style pathnames, and understands VMS and
    DOS paths on those systems.  */
@@ -133,6 +133,7 @@ base_name (fname)
   if ((p = strrchr (s, '/'))) s = p + 1;
   return s;
 }
+#endif /* 0 */
 
 /* Public routines.  */
 
@@ -141,15 +142,15 @@ deps_init ()
 {
   struct deps *d = (struct deps *) xmalloc (sizeof (struct deps));
 
-  /* Allocate space for the vectors now.  */
+  /* Allocate space for the vectors only if we need it.  */
 
-  d->targetv = (const char **) xmalloc (2 * sizeof (const char *));
-  d->depv = (const char **) xmalloc (8 * sizeof (const char *));
+  d->targetv = 0;
+  d->depv = 0;
 
   d->ntargets = 0;
-  d->targets_size = 2;
+  d->targets_size = 0;
   d->ndeps = 0;
-  d->deps_size = 8;
+  d->deps_size = 0;
 
   return d;
 }
@@ -160,14 +161,20 @@ deps_free (d)
 {
   unsigned int i;
 
-  for (i = 0; i < d->ntargets; i++)
-    free ((PTR) d->targetv[i]);
+  if (d->targetv)
+    {
+      for (i = 0; i < d->ntargets; i++)
+	free ((PTR) d->targetv[i]);
+      free (d->targetv);
+    }
 
-  for (i = 0; i < d->ndeps; i++)
-    free ((PTR) d->depv[i]);
+  if (d->depv)
+    {
+      for (i = 0; i < d->ndeps; i++)
+	free ((PTR) d->depv[i]);
+      free (d->depv);
+    }
 
-  free (d->targetv);
-  free (d->depv);
   free (d);
 }
 
@@ -181,7 +188,7 @@ deps_add_target (d, t, quote)
 {
   if (d->ntargets == d->targets_size)
     {
-      d->targets_size *= 2;
+      d->targets_size = d->targets_size * 2 + 4;
       d->targetv = (const char **) xrealloc (d->targetv,
 			     d->targets_size * sizeof (const char *));
     }
@@ -212,7 +219,6 @@ deps_add_default_target (d, tgt)
     deps_add_target (d, "-", 1);
   else
     {
-      tgt = base_name (tgt);
       o = (char *) alloca (strlen (tgt) + 8);
 
       strcpy (o, tgt);
@@ -239,7 +245,7 @@ deps_add_dep (d, t)
 
   if (d->ndeps == d->deps_size)
     {
-      d->deps_size *= 2;
+      d->deps_size *= 2 + 8;
       d->depv = (const char **)
 	xrealloc (d->depv, d->deps_size * sizeof (const char *));
     }