[pph] Namespaces, step 1. Trace formatting.

[Lawrence Crowl, 2011-04-19 00:15:10]

First stab at getting namespaces working with PPH.  This change will
put top-level namespaces into the global namespace.  It does not,
however, appear to their members in any place useful.

Some tuning of tracing output.

Index: gcc/cp/ChangeLog.pph

2011-04-18  Lawrence Crowl <crowl@google.com>

	* pph.c (pth_save_identifiers): Fix FIXME comment.
        (pph_add_names_to_namespace): Add contained namespaces to scope as
	well as regular symbols.
	* pph-streamer.c (enum pph_trace_type): Add a trace for refs.
        (pph_stream_trace): Add the ref printing.  Reduce bulk of trace
	messages.  Filter off uninteresting traces, primarily traces of null
	pointers.
	(pph_stream_trace_tree): Convert ref_p to trace value.
	* pph-streamer.h: Adjust flag_pph_tracer comparisons for better traces.
	(pph_stream_trace_tree): Add ref_p parameter.  Propogate such
	parameters at all call sites.
        (pph_output_tree_lst): New.  Like pph_output_tree, but for list and
	chain contexts.
	(pph_stream_write_tree): The callback is auxillary.
	(pph_output_chain_filtered): Call pph_output_tree_lst.

Index: libcpp/ChangeLog.pph

2011-04-18  Lawrence Crowl  <crowl@google.com>

	* init.c: Fix spelling in comment.


Index: gcc/cp/pph.c
===================================================================
--- gcc/cp/pph.c	(revision 172514)
+++ gcc/cp/pph.c	(working copy)
@@ -792,7 +792,7 @@ pth_save_identifiers (cpp_idents_used *i
       if (!(entry->used_by_directive || entry->expanded_to_text))
         continue;
 
-      /* FIX pph: We are wasting space; ident_len, used_by_directive
+      /* FIXME pph: We are wasting space; ident_len, used_by_directive
       and expanded_to_text together could fit into a single uint. */
 
       pph_output_uint (stream, entry->used_by_directive);
@@ -1956,6 +1956,21 @@ pph_add_names_to_namespace (tree ns, tre
       chain = DECL_CHAIN (t);
       pushdecl_with_scope (t, level, /*is_friend=*/false);
     }
+
+  for (t = new_level->namespaces; t; t = chain)
+    {
+      /* Pushing a decl into a scope clobbers its DECL_CHAIN.
+	 Preserve it.  */
+      /* FIXME pph: we should first check to see if it isn't already there.  */
+      chain = DECL_CHAIN (t);
+      pushdecl_with_scope (t, level, /*is_friend=*/false);
+      /* FIXME pph: The change above enables the namespace,
+         but its symbols are still missing.
+         The recursive call below causes multiple errors.
+      pph_add_names_to_namespace (t, t);
+      */
+    }
+
 }
 
 
Index: gcc/cp/pph-streamer.c
===================================================================
--- gcc/cp/pph-streamer.c	(revision 172514)
+++ gcc/cp/pph-streamer.c	(working copy)
@@ -118,6 +118,7 @@ pph_stream_close (pph_stream *stream)
 enum pph_trace_type
 {
     PPH_TRACE_TREE,
+    PPH_TRACE_REF,
     PPH_TRACE_UINT,
     PPH_TRACE_BYTES,
     PPH_TRACE_STRING,
@@ -134,11 +135,15 @@ static void
 pph_stream_trace (pph_stream *stream, const void *data, unsigned int nbytes,
 		  enum pph_trace_type type)
 {
-  const char *op = (stream->write_p) ? "write" : "read";
-  const char *type_s[] = { "tree", "uint", "bytes", "string", "chain",
+  const char *op = (stream->write_p) ? "<<" : ">>";
+  const char *type_s[] = { "tree", "ref", "uint", "bytes", "string", "chain",
                            "bitpack" };
 
-  fprintf (pph_logfile, "*** %s: op=%s, type=%s, size=%u, value=",
+  if ((type == PPH_TRACE_TREE || type == PPH_TRACE_CHAIN)
+      && !data && flag_pph_tracer <= 3)
+    return;
+
+  fprintf (pph_logfile, "*** %s: %s%s/%u, value=",
 	   stream->name, op, type_s[type], (unsigned) nbytes);
 
   switch (type)
@@ -157,6 +162,20 @@ pph_stream_trace (pph_stream *stream, co
       }
       break;
 
+    case PPH_TRACE_REF:
+      {
+	const_tree t = (const_tree) data;
+	if (t)
+	  {
+	    print_generic_expr (pph_logfile, CONST_CAST (union tree_node *, t),
+				0);
+	    fprintf (pph_logfile, ", code=%s", tree_code_name[TREE_CODE (t)]);
+	  }
+	else
+	  fprintf (pph_logfile, "NULL_TREE");
+      }
+      break;
+
     case PPH_TRACE_UINT:
       {
 	unsigned int val = *((const unsigned int *) data);
@@ -212,10 +231,10 @@ pph_stream_trace (pph_stream *stream, co
 /* Show tracing information for T on STREAM.  */
 
 void
-pph_stream_trace_tree (pph_stream *stream, tree t)
+pph_stream_trace_tree (pph_stream *stream, tree t, bool ref_p)
 {
   pph_stream_trace (stream, t, t ? tree_code_size (TREE_CODE (t)) : 0,
-		    PPH_TRACE_TREE);
+		    ref_p ? PPH_TRACE_REF : PPH_TRACE_TREE);
 }
 
 
Index: gcc/cp/pph-streamer.h
===================================================================
--- gcc/cp/pph-streamer.h	(revision 172514)
+++ gcc/cp/pph-streamer.h	(working copy)
@@ -93,7 +93,7 @@ enum chain_filter { NONE, NO_BUILTINS };
 /* In pph-streamer.c.  */
 pph_stream *pph_stream_open (const char *, const char *);
 void pph_stream_close (pph_stream *);
-void pph_stream_trace_tree (pph_stream *, tree);
+void pph_stream_trace_tree (pph_stream *, tree, bool ref_p);
 void pph_stream_trace_uint (pph_stream *, unsigned int);
 void pph_stream_trace_bytes (pph_stream *, const void *, size_t);
 void pph_stream_trace_string (pph_stream *, const char *);
@@ -134,17 +134,27 @@ static inline void
 pph_output_tree (pph_stream *stream, tree t, bool ref_p)
 {
   if (flag_pph_tracer >= 1)
-    pph_stream_trace_tree (stream, t);
+    pph_stream_trace_tree (stream, t, ref_p);
   lto_output_tree (stream->ob, t, ref_p);
 }
 
 /* Output AST T to STREAM.  If REF_P is true, output all the leaves of T
-   as references.  this function is an internal auxillary routine.  */
+   as references.  This function is an list auxillary routine.  */
+static inline void
+pph_output_tree_lst (pph_stream *stream, tree t, bool ref_p)
+{
+  if (flag_pph_tracer >= 2)
+    pph_stream_trace_tree (stream, t, ref_p);
+  lto_output_tree (stream->ob, t, ref_p);
+}
+
+/* Output AST T to STREAM.  If REF_P is true, output all the leaves of T
+   as references.  This function is an internal auxillary routine.  */
 static inline void
 pph_output_tree_aux (pph_stream *stream, tree t, bool ref_p)
 {
   if (flag_pph_tracer >= 3)
-    pph_stream_trace_tree (stream, t);
+    pph_stream_trace_tree (stream, t, ref_p);
   lto_output_tree (stream->ob, t, ref_p);
 }
 
@@ -153,7 +163,7 @@ static inline void
 pph_output_tree_or_ref (pph_stream *stream, tree t, bool ref_p)
 {
   if (flag_pph_tracer >= 2)
-    pph_stream_trace_tree (stream, t);
+    pph_stream_trace_tree (stream, t, ref_p);
   lto_output_tree_or_ref (stream->ob, t, ref_p);
 }
 
@@ -220,7 +230,7 @@ pph_output_string_with_length (pph_strea
 static inline void
 pph_output_chain (pph_stream *stream, tree first, bool ref_p)
 {
-  if (flag_pph_tracer >= 3)
+  if (flag_pph_tracer >= 2)
     pph_stream_trace_chain (stream, first);
   lto_output_chain (stream->ob, first, ref_p);
 }
@@ -285,7 +295,7 @@ pph_input_tree (pph_stream *stream)
 {
   tree t = lto_input_tree (stream->ib, stream->data_in);
   if (flag_pph_tracer >= 4)
-    pph_stream_trace_tree (stream, t);
+    pph_stream_trace_tree (stream, t, false); /* FIXME pph: always false? */
   return t;
 }
 
Index: gcc/cp/pph-streamer-out.c
===================================================================
--- gcc/cp/pph-streamer-out.c	(revision 172514)
+++ gcc/cp/pph-streamer-out.c	(working copy)
@@ -791,7 +791,7 @@ pph_stream_write_tree (struct output_blo
 	}
 
       if (TREE_CODE (expr) == TYPE_DECL)
-	pph_output_tree (stream, DECL_ORIGINAL_TYPE (expr), ref_p);
+	pph_output_tree_aux (stream, DECL_ORIGINAL_TYPE (expr), ref_p);
     }
   else if (TREE_CODE (expr) == STATEMENT_LIST)
     {
@@ -855,7 +855,7 @@ pph_output_chain_filtered (pph_stream *s
       saved_chain = TREE_CHAIN (t);
       TREE_CHAIN (t) = NULL_TREE;
 
-      pph_output_tree (stream, t, ref_p);
+      pph_output_tree_lst (stream, t, ref_p);
 
       TREE_CHAIN (t) = saved_chain;
     }
Index: libcpp/init.c
===================================================================
--- libcpp/init.c	(revision 172514)
+++ libcpp/init.c	(working copy)
@@ -395,7 +395,7 @@ static const struct builtin_operator ope
 };
 #undef B
 
-/* Verify that the indicies of the named operators fit within the
+/* Verify that the indices of the named operators fit within the
    number of bits available. */
 
 #define B(n, t) unsigned char t ## _too_large_for_bitfield[ \

--
This patch is available for review at http://codereview.appspot.com/4433054

[Diego Novillo, 2011-04-20 15:12:13]

http://codereview.appspot.com/4433054/diff/1/gcc/cp/pph-streamer.c
File gcc/cp/pph-streamer.c (right):

http://codereview.appspot.com/4433054/diff/1/gcc/cp/pph-streamer.c#newcode144
gcc/cp/pph-streamer.c:144: return;
+  if ((type == PPH_TRACE_TREE || type == PPH_TRACE_CHAIN)
+      && !data && flag_pph_tracer <= 3)
+    return;

Line up the predicates vertically.

http://codereview.appspot.com/4433054/diff/1/gcc/cp/pph-streamer.c#newcode172
gcc/cp/pph-streamer.c:172: fprintf (pph_logfile, ", code=%s",
tree_code_name[TREE_CODE (t)]);
   case PPH_TRACE_REF:
+      {
+	const_tree t = (const_tree) data;
+	if (t)
+	  {
+	    print_generic_expr (pph_logfile, CONST_CAST (union tree_node *, t),
+				0);
+	    fprintf (pph_logfile, ", code=%s", tree_code_name[TREE_CODE (t)]);


But how are we going to tell if this is a REF instead of a tree?  The output
seems identical to the PPH_TRACE_TREE case.

http://codereview.appspot.com/4433054/diff/1/gcc/cp/pph-streamer.h
File gcc/cp/pph-streamer.h (right):

http://codereview.appspot.com/4433054/diff/1/gcc/cp/pph-streamer.h#newcode149
gcc/cp/pph-streamer.h:149: }
pph_output_tree_lst (pph_stream *stream, tree t, bool ref_p)
+{
+  if (flag_pph_tracer >= 2)
+    pph_stream_trace_tree (stream, t, ref_p);
+  lto_output_tree (stream->ob, t, ref_p);
+}

I don't really like all this code duplication.  Wouldn't it be better if instead
of having pph_output_tree_aux and pph_output_tree_lst, we added another argument
to pph_output_tree?  The argument would be an enum and we could have a default
'DONT_CARE' value.

http://codereview.appspot.com/4433054/diff/1/gcc/cp/pph-streamer.h#newcode298
gcc/cp/pph-streamer.h:298: pph_stream_trace_tree (stream, t, false); /* FIXME
pph: always false? */
@@ -285,7 +295,7 @@ pph_input_tree (pph_stream *stream)
 {
   tree t = lto_input_tree (stream->ib, stream->data_in);
   if (flag_pph_tracer >= 4)
-    pph_stream_trace_tree (stream, t);
+    pph_stream_trace_tree (stream, t, false); /* FIXME pph: always false? 

Yes, on input we can't tell if we read a reference or a real tree.  We could,
but not at this level.  That's inside the actual LTO streaming code.

[Lawrence Crowl, 2011-04-20 17:33:38]

On 4/20/11, dnovillo@google.com <dnovillo@google.com> wrote:
> http://codereview.appspot.com/4433054/diff/1/gcc/cp/pph-streamer.c
> File gcc/cp/pph-streamer.c (right):
>
> http://codereview.appspot.com/4433054/diff/1/gcc/cp/pph-streamer.c#newcode144
> gcc/cp/pph-streamer.c:144: return;
> +  if ((type == PPH_TRACE_TREE || type == PPH_TRACE_CHAIN)
> +      && !data && flag_pph_tracer <= 3)
> +    return;
>
> Line up the predicates vertically.

Can you be more specific?

>
> http://codereview.appspot.com/4433054/diff/1/gcc/cp/pph-streamer.c#newcode172
> gcc/cp/pph-streamer.c:172: fprintf (pph_logfile, ", code=%s",
> tree_code_name[TREE_CODE (t)]);
>     case PPH_TRACE_REF:
> +      {
> +	const_tree t = (const_tree) data;
> +	if (t)
> +	  {
> +	    print_generic_expr (pph_logfile, CONST_CAST (union tree_node *,
> t),
> +				0);
> +	    fprintf (pph_logfile, ", code=%s", tree_code_name[TREE_CODE (t)]);
>
>
> But how are we going to tell if this is a REF instead of a tree?

The type_s array is indexed by PPH_TRACE_REF.

> The output seems identical to the PPH_TRACE_TREE case.

Well, the case in those branches is identical.  The splitting was
a bit preemptive, as I was planning to see what changes I needed
after seeing what items were refs.  None actually were refs, so
the distinction isn't there.

> http://codereview.appspot.com/4433054/diff/1/gcc/cp/pph-streamer.h
> File gcc/cp/pph-streamer.h (right):
>
> http://codereview.appspot.com/4433054/diff/1/gcc/cp/pph-streamer.h#newcode149
> gcc/cp/pph-streamer.h:149: }
> pph_output_tree_lst (pph_stream *stream, tree t, bool ref_p)
> +{
> +  if (flag_pph_tracer >= 2)
> +    pph_stream_trace_tree (stream, t, ref_p);
> +  lto_output_tree (stream->ob, t, ref_p);
> +}
>
> I don't really like all this code duplication.  Wouldn't it be better if
> instead of having pph_output_tree_aux and pph_output_tree_lst, we added
> another argument to pph_output_tree?  The argument would be an enum and
> we could have a default 'DONT_CARE' value.

I'm not sure that would save much code.  It would induce some
runtime overhead (unless the compiler specialized routines).
It would also change the callbacks.

> http://codereview.appspot.com/4433054/diff/1/gcc/cp/pph-streamer.h#newcode298
> gcc/cp/pph-streamer.h:298: pph_stream_trace_tree (stream, t, false); /*
> FIXME pph: always false? */
> @@ -285,7 +295,7 @@ pph_input_tree (pph_stream *stream)
>   {
>     tree t = lto_input_tree (stream->ib, stream->data_in);
>     if (flag_pph_tracer >= 4)
> -    pph_stream_trace_tree (stream, t);
> +    pph_stream_trace_tree (stream, t, false); /* FIXME pph: always
> false?
>
> Yes, on input we can't tell if we read a reference or a real tree.  We
> could, but not at this level.  That's inside the actual LTO streaming
> code.

It would be nice to have an indication, but it is not something I want
to do now.

>
> http://codereview.appspot.com/4433054/

-- 
Lawrence Crowl