Fix segfault in -fsave-optimization-record (PR tree-optimization/86636)

There are various ways that it's possible for a gimple statement to
have an UNKNOWN_LOCATION, and for that UNKNOWN_LOCATION to be wrapped
in an ad-hoc location to capture inlining information.

For such a location, LOCATION_FILE (loc) is NULL.

Various places in -fsave-optimization-record were checking for
  loc != UNKNOWN_LOCATION
and were passing LOCATION_FILE (loc) to code that assumed a non-NULL
filename, thus leading to segfaults for the above cases.

This patch updates the tests to use
  LOCATION_LOCUS (loc) != UNKNOWN_LOCATION
instead, to look through ad-hoc location wrappers, fixing the segfaults.

It also adds various assertions to the affected code.

gcc/ChangeLog:
	PR tree-optimization/86636
	* json.cc (json::object::set): Fix comment.  Add assertions.
	(json::array::append): Move here from json.h.  Add comment and an
	assertion.
	(json::string::string): Likewise.
	* json.h (json::array::append): Move to json.cc.
	(json::string::string): Likewise.
	* optinfo-emit-json.cc
	(optrecord_json_writer::impl_location_to_json): Assert that we
	aren't attempting to write out UNKNOWN_LOCATION, or an ad-hoc
	wrapper around it.  Expand the location once, rather than three
	times.
	(optrecord_json_writer::inlining_chain_to_json): Fix the check for
	UNKNOWN_LOCATION, to use LOCATION_LOCUS to look through ad-hoc
	wrappers.
	(optrecord_json_writer::optinfo_to_json): Likewise, in four
	places.  Fix some overlong lines.

gcc/testsuite/ChangeLog:
	PR tree-optimization/86636
	* gcc.c-torture/compile/pr86636.c: New test.

From-SVN: r262950

gcc/ChangeLog

+2018-07-24  David Malcolm  <dmalcolm@redhat.com>
+
+	PR tree-optimization/86636
+	* json.cc (json::object::set): Fix comment.  Add assertions.
+	(json::array::append): Move here from json.h.  Add comment and an
+	assertion.
+	(json::string::string): Likewise.
+	* json.h (json::array::append): Move to json.cc.
+	(json::string::string): Likewise.
+	* optinfo-emit-json.cc
+	(optrecord_json_writer::impl_location_to_json): Assert that we
+	aren't attempting to write out UNKNOWN_LOCATION, or an ad-hoc
+	wrapper around it.  Expand the location once, rather than three
+	times.
+	(optrecord_json_writer::inlining_chain_to_json): Fix the check for
+	UNKNOWN_LOCATION, to use LOCATION_LOCUS to look through ad-hoc
+	wrappers.
+	(optrecord_json_writer::optinfo_to_json): Likewise, in four
+	places.  Fix some overlong lines.
+
 2018-07-24  Matthew Malcomson  <matthew.malcomson@arm.com>
 
 	* config/aarch64/aarch64-simd.md

gcc/json.cc

@@ -76,12 +76,15 @@ object::print (pretty_printer *pp) const
   pp_character (pp, '}');
 }
 
-/* Set the json::value * for KEY, taking ownership of VALUE
+/* Set the json::value * for KEY, taking ownership of V
    (and taking a copy of KEY if necessary).  */
 
 void
 object::set (const char *key, value *v)
 {
+  gcc_assert (key);
+  gcc_assert (v);
+
   value **ptr = m_map.get (key);
   if (ptr)
     {
@@ -126,6 +129,15 @@ array::print (pretty_printer *pp) const
   pp_character (pp, ']');
 }
 
+/* Append non-NULL value V to a json::array, taking ownership of V.  */
+
+void
+array::append (value *v)
+{
+  gcc_assert (v);
+  m_elements.safe_push (v);
+}
+
 /* class json::number, a subclass of json::value, wrapping a double.  */
 
 /* Implementation of json::value::print for json::number.  */
@@ -140,6 +152,16 @@ number::print (pretty_printer *pp) const
 
 /* class json::string, a subclass of json::value.  */
 
+/* json::string's ctor.  */
+
+string::string (const char *utf8)
+{
+  gcc_assert (utf8);
+  m_utf8 = xstrdup (utf8);
+}
+
+/* Implementation of json::value::print for json::string.  */
+
 void
 string::print (pretty_printer *pp) const
 {

gcc/json.h

@@ -107,7 +107,7 @@ class array : public value
   enum kind get_kind () const FINAL OVERRIDE { return JSON_ARRAY; }
   void print (pretty_printer *pp) const FINAL OVERRIDE;
 
-  void append (value *v) { m_elements.safe_push (v); }
+  void append (value *v);
 
  private:
   auto_vec<value *> m_elements;
@@ -134,7 +134,7 @@ class number : public value
 class string : public value
 {
  public:
-  string (const char *utf8) : m_utf8 (xstrdup (utf8)) {}
+  string (const char *utf8);
   ~string () { free (m_utf8); }
 
   enum kind get_kind () const FINAL OVERRIDE { return JSON_STRING; }

gcc/optinfo-emit-json.cc

@@ -202,10 +202,12 @@ optrecord_json_writer::impl_location_to_json (dump_impl_location_t loc)
 json::object *
 optrecord_json_writer::location_to_json (location_t loc)
 {
+  gcc_assert (LOCATION_LOCUS (loc) != UNKNOWN_LOCATION);
+  expanded_location exploc = expand_location (loc);
   json::object *obj = new json::object ();
-  obj->set ("file", new json::string (LOCATION_FILE (loc)));
-  obj->set ("line", new json::number (LOCATION_LINE (loc)));
-  obj->set ("column", new json::number (LOCATION_COLUMN (loc)));
+  obj->set ("file", new json::string (exploc.file));
+  obj->set ("line", new json::number (exploc.line));
+  obj->set ("column", new json::number (exploc.column));
   return obj;
 }
 
@@ -330,7 +332,7 @@ optrecord_json_writer::inlining_chain_to_json (location_t loc)
 	  const char *printable_name
 	    = lang_hooks.decl_printable_name (fndecl, 2);
 	  obj->set ("fndecl", new json::string (printable_name));
-	  if (*locus != UNKNOWN_LOCATION)
+	  if (LOCATION_LOCUS (*locus) != UNKNOWN_LOCATION)
 	    obj->set ("site", location_to_json (*locus));
 	  array->append (obj);
 	}
@@ -371,8 +373,9 @@ optrecord_json_writer::optinfo_to_json (const optinfo *optinfo)
 	    json_item->set ("expr", new json::string (item->get_text ()));
 
 	    /* Capture any location for the node.  */
-	    if (item->get_location () != UNKNOWN_LOCATION)
-	      json_item->set ("location", location_to_json (item->get_location ()));
+	    if (LOCATION_LOCUS (item->get_location ()) != UNKNOWN_LOCATION)
+	      json_item->set ("location",
+			      location_to_json (item->get_location ()));
 
 	    message->append (json_item);
 	  }
@@ -383,8 +386,9 @@ optrecord_json_writer::optinfo_to_json (const optinfo *optinfo)
 	    json_item->set ("stmt", new json::string (item->get_text ()));
 
 	    /* Capture any location for the stmt.  */
-	    if (item->get_location () != UNKNOWN_LOCATION)
-	      json_item->set ("location", location_to_json (item->get_location ()));
+	    if (LOCATION_LOCUS (item->get_location ()) != UNKNOWN_LOCATION)
+	      json_item->set ("location",
+			      location_to_json (item->get_location ()));
 
 	    message->append (json_item);
 	  }
@@ -395,8 +399,9 @@ optrecord_json_writer::optinfo_to_json (const optinfo *optinfo)
 	    json_item->set ("symtab_node", new json::string (item->get_text ()));
 
 	    /* Capture any location for the node.  */
-	    if (item->get_location () != UNKNOWN_LOCATION)
-	      json_item->set ("location", location_to_json (item->get_location ()));
+	    if (LOCATION_LOCUS (item->get_location ()) != UNKNOWN_LOCATION)
+	      json_item->set ("location",
+			      location_to_json (item->get_location ()));
 	    message->append (json_item);
 	  }
 	  break;

gcc/testsuite/ChangeLog

+2018-07-24  David Malcolm  <dmalcolm@redhat.com>
+
+	PR tree-optimization/86636
+	* gcc.c-torture/compile/pr86636.c: New test.
+
 2018-07-24  Matthew Malcomson  <matthew.malcomson@arm.com>
 
 	* gcc.target/aarch64/vect-su-add-sub.c: New.

gcc/testsuite/gcc.c-torture/compile/pr86636.c

+/* { dg-options "-fsave-optimization-record -ftree-loop-vectorize -ftree-parallelize-loops=2" } */
+
+void
+n2 (int ih)
+{
+  while (ih < 1)
+    ++ih;
+}