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

1 files changed, 23 insertions, 1 deletions

diff --git a/gcc/json.cc b/gcc/json.cc
index 3c2aa77..3ead980 100644
--- a/gcc/json.cc
+++ b/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
 {