[COMMITTED 74/83] gccrs: Refactor query_type to only fully-const resolve const fns

[arthur.cohen@opensrcsec.com]

From: Philip Herron <herron.philip@googlemail.com>

When we are in a const context what can happen is we start to query all
non const types during method resolution for example which means its going
to query fn signitures and fully resolve their blocks for non const
candidates.

gcc/rust/ChangeLog:

	* typecheck/rust-type-util.cc (query_type): dont query non const candidates

Signed-off-by: Philip Herron <herron.philip@googlemail.com>
---
 gcc/rust/typecheck/rust-type-util.cc | 48 +++++++++++++++++-----------
 1 file changed, 30 insertions(+), 18 deletions(-)

diff --git a/gcc/rust/typecheck/rust-type-util.cc b/gcc/rust/typecheck/rust-type-util.cc
index 226ea747b02..8f97d60e3a3 100644
--- a/gcc/rust/typecheck/rust-type-util.cc
+++ b/gcc/rust/typecheck/rust-type-util.cc
@@ -79,26 +79,28 @@ query_type (HirId reference, TyTy::BaseType **result)
       bool is_local = item_defid.crateNum == mappings.get_current_crate ();
       bool is_fn
 	= item.value ()->get_item_kind () == HIR::Item::ItemKind::Function;
-      if (!context->const_context_p ())
+      bool is_const_fn = false;
+      if (is_fn)
 	{
-	  if (is_fn && is_local)
-	    {
-	      HIR::Function &fn = *static_cast<HIR::Function *> (item.value ());
-	      *result = TypeCheckItem::ResolveFunctionSignature (fn);
-	    }
-	  else if (item.value ()->get_item_kind () == HIR::Item::ItemKind::Trait
-		   && is_local)
-	    {
-	      HIR::Trait &trait = *static_cast<HIR::Trait *> (item.value ());
-	      *result = TypeCheckItem::ResolveTraitSignature (trait);
-	    }
-	  else
-	    *result = TypeCheckItem::Resolve (*item.value ());
+	  auto &fn = *static_cast<HIR::Function *> (item.value ());
+	  is_const_fn = fn.get_qualifiers ().is_const ();
 	}
-      else
+
+      bool needs_full_resolve_for_const
+	= is_fn && context->const_context_p () && is_const_fn;
+      if (is_fn && is_local && !needs_full_resolve_for_const)
 	{
-	  *result = TypeCheckItem::Resolve (*item.value ());
+	  HIR::Function &fn = *static_cast<HIR::Function *> (item.value ());
+	  *result = TypeCheckItem::ResolveFunctionSignature (fn);
 	}
+      else if (item.value ()->get_item_kind () == HIR::Item::ItemKind::Trait
+	       && is_local && !context->const_context_p ())
+	{
+	  HIR::Trait &trait = *static_cast<HIR::Trait *> (item.value ());
+	  *result = TypeCheckItem::ResolveTraitSignature (trait);
+	}
+      else
+	*result = TypeCheckItem::Resolve (*item.value ());
 
       context->query_completed (reference);
       return true;
@@ -163,8 +165,18 @@ query_type (HirId reference, TyTy::BaseType **result)
 
       DefId item_defid = impl_item->first->get_impl_mappings ().get_defid ();
       bool is_local = item_defid.crateNum == mappings.get_current_crate ();
-      if (impl_item->first->get_impl_item_type () == HIR::ImplItem::FUNCTION
-	  && is_local && !context->const_context_p ())
+      bool is_fn
+	= impl_item->first->get_impl_item_type () == HIR::ImplItem::FUNCTION;
+      bool is_const_fn = false;
+      if (is_fn)
+	{
+	  auto &fn = *static_cast<HIR::Function *> (impl_item->first);
+	  is_const_fn = fn.get_qualifiers ().is_const ();
+	}
+
+      bool needs_full_resolve_for_const
+	= is_fn && context->const_context_p () && is_const_fn;
+      if (is_fn && is_local && !needs_full_resolve_for_const)
 	{
 	  HIR::Function &fn = *static_cast<HIR::Function *> (impl_item->first);
 	  *result = TypeCheckImplItem::ResolveFunctionSignature (
-- 
2.50.1