Add debug (slp_tree) and dump infrastructure for this

This adds an alternate debug_dump_context similar to the one for
selftests but for interactive debugging routines.  This allows
to share code between user-visible dumping via the dump_* API
and those debugging routines.  The primary driver was SLP node
dumping which wasn't accessible from inside a gdb session up to
now.

2020-05-27  Richard Biener  <rguenther@suse.de>

	* dump-context.h (debug_dump_context): New class.
	(dump_context): Make it friend.
	* dumpfile.c (debug_dump_context::debug_dump_context):
	Implement.
	(debug_dump_context::~debug_dump_context): Likewise.
	* tree-vect-slp.c: Include dump-context.h.
	(vect_print_slp_tree): Dump a single SLP node.
	(debug): New overload for slp_tree.
	(vect_print_slp_graph): Rename from vect_print_slp_tree and
	use that.
	(vect_analyze_slp_instance): Adjust.

1 files changed, 21 insertions, 0 deletions

diff --git a/gcc/dump-context.h b/gcc/dump-context.h
index 347477f..3f72cc9 100644
--- a/gcc/dump-context.h
+++ b/gcc/dump-context.h
@@ -29,6 +29,7 @@ along with GCC; see the file COPYING3.  If not see
 
 class optrecord_json_writer;
 namespace selftest { class temp_dump_context; }
+class debug_dump_context;
 
 /* A class for handling the various dump_* calls.
 
@@ -42,6 +43,7 @@ namespace selftest { class temp_dump_context; }
 class dump_context
 {
   friend class selftest::temp_dump_context;
+  friend class debug_dump_context;
 
  public:
   static dump_context &get () { return *s_current; }
@@ -195,6 +197,25 @@ private:
   auto_vec<stashed_item> m_stashed_items;
 };
 
+/* An RAII-style class for use in debug dumpers for temporarily using a
+   different dump_context.  It enables full details and outputs to
+   stderr instead of the currently active dump_file.  */
+
+class debug_dump_context
+{
+ public:
+  debug_dump_context ();
+  ~debug_dump_context ();
+
+ private:
+  dump_context m_context;
+  dump_context *m_saved;
+  dump_flags_t m_saved_flags;
+  dump_flags_t m_saved_pflags;
+  FILE *m_saved_file;
+};
+
+
 #if CHECKING_P
 
 namespace selftest {