gccrs: Add check for super traits being implemented by Self

We need to recursively check the super traits of the predicate the Self
type is trying to implement. Otherwise its cannot implement it.

Fixes Rust-GCC#3553

gcc/rust/ChangeLog:

	* typecheck/rust-hir-type-check-item.cc (TypeCheckItem::resolve_impl_block_substitutions):
	Track the polarity
	* typecheck/rust-tyty-bounds.cc (TypeBoundPredicate::validate_type_implements_this):
	new validator
	* typecheck/rust-tyty.h: new prototypes

gcc/testsuite/ChangeLog:

	* rust/compile/issue-3553.rs: New test.

Signed-off-by: Philip Herron <herron.philip@googlemail.com>

diff --git a/gcc/rust/typecheck/rust-hir-type-check-item.cc b/gcc/rust/typecheck/rust-hir-type-check-item.cc
index 25da29b3178657a1f5dd33ac65debc5ba96fce65..f13e3a960d98191045854db502c2dbdadc3caccb 100644 (file)
--- a/gcc/rust/typecheck/rust-hir-type-check-item.cc
+++ b/gcc/rust/typecheck/rust-hir-type-check-item.cc
@@ -725,11 +725,11 @@ TypeCheckItem::resolve_impl_block_substitutions (HIR::ImplBlock &impl_block,
 
       // we don't error out here see: gcc/testsuite/rust/compile/traits2.rs
       // for example
-      specified_bound = get_predicate_from_bound (ref, impl_block.get_type ());
+      specified_bound = get_predicate_from_bound (ref, impl_block.get_type (),
+                                                 impl_block.get_polarity ());
     }
 
   TyTy::BaseType *self = TypeCheckType::Resolve (impl_block.get_type ());
-
   if (self->is<TyTy::ErrorType> ())
     {
       // we cannot check for unconstrained type arguments when the Self type is
@@ -771,7 +771,14 @@ TypeCheckItem::validate_trait_impl_block (
 
       // we don't error out here see: gcc/testsuite/rust/compile/traits2.rs
       // for example
-      specified_bound = get_predicate_from_bound (ref, impl_block.get_type ());
+      specified_bound = get_predicate_from_bound (ref, impl_block.get_type (),
+                                                 impl_block.get_polarity ());
+
+      // need to check that if this specified bound has super traits does this
+      // Self
+      // implement them?
+      specified_bound.validate_type_implements_super_traits (
+       *self, impl_block.get_type (), impl_block.get_trait_ref ());
     }
 
   bool is_trait_impl_block = !trait_reference->is_error ();

diff --git a/gcc/rust/typecheck/rust-tyty-bounds.cc b/gcc/rust/typecheck/rust-tyty-bounds.cc
index dc42941da23308860be5ab653e6af900e168b8a6..853ed7ee3e8730bd328fda42200f0d5dbe440af4 100644 (file)
--- a/gcc/rust/typecheck/rust-tyty-bounds.cc
+++ b/gcc/rust/typecheck/rust-tyty-bounds.cc
@@ -828,6 +828,65 @@ TypeBoundPredicate::is_equal (const TypeBoundPredicate &other) const
   return true;
 }
 
+bool
+TypeBoundPredicate::validate_type_implements_super_traits (
+  TyTy::BaseType &self, HIR::Type &impl_type, HIR::Type &trait) const
+{
+  if (get_polarity () != BoundPolarity::RegularBound)
+    return true;
+
+  auto &ptref = *get ();
+  for (auto &super : super_traits)
+    {
+      if (super.get_polarity () != BoundPolarity::RegularBound)
+       continue;
+
+      if (!super.validate_type_implements_this (self, impl_type, trait))
+       {
+         auto &sptref = *super.get ();
+
+         // emit error
+         std::string fixit1
+           = "required by this bound in: " + ptref.get_name ();
+         std::string fixit2 = "the trait " + sptref.get_name ()
+                              + " is not implemented for "
+                              + impl_type.as_string ();
+
+         rich_location r (line_table, trait.get_locus ());
+         r.add_fixit_insert_after (super.get_locus (), fixit1.c_str ());
+         r.add_fixit_insert_after (trait.get_locus (), fixit2.c_str ());
+         rust_error_at (r, ErrorCode::E0277,
+                        "the trait bound %<%s: %s%> is not satisfied",
+                        impl_type.as_string ().c_str (),
+                        sptref.get_name ().c_str ());
+
+         return false;
+       }
+
+      if (!super.validate_type_implements_super_traits (self, impl_type, trait))
+       return false;
+    }
+
+  return true;
+}
+
+bool
+TypeBoundPredicate::validate_type_implements_this (TyTy::BaseType &self,
+                                                  HIR::Type &impl_type,
+                                                  HIR::Type &trait) const
+{
+  const auto &ptref = *get ();
+  auto probed_bounds = Resolver::TypeBoundsProbe::Probe (&self);
+  for (auto &elem : probed_bounds)
+    {
+      auto &tref = *(elem.first);
+      if (ptref.is_equal (tref))
+       return true;
+    }
+
+  return false;
+}
+
 // trait item reference
 
 const Resolver::TraitItemReference *

diff --git a/gcc/rust/typecheck/rust-tyty.h b/gcc/rust/typecheck/rust-tyty.h
index a5840544de42ecc24429cbb7a0731d3a1264b19e..dc30d7dd0686e13488628e754c5bf848ef37315c 100644 (file)
--- a/gcc/rust/typecheck/rust-tyty.h
+++ b/gcc/rust/typecheck/rust-tyty.h
@@ -578,6 +578,14 @@ public:
 
   bool is_equal (const TypeBoundPredicate &other) const;
 
+  bool validate_type_implements_super_traits (TyTy::BaseType &self,
+                                             HIR::Type &impl_type,
+                                             HIR::Type &trait) const;
+
+  bool validate_type_implements_this (TyTy::BaseType &self,
+                                     HIR::Type &impl_type,
+                                     HIR::Type &trait) const;
+
 private:
   struct mark_is_error
   {

diff --git a/gcc/testsuite/rust/compile/issue-3553.rs b/gcc/testsuite/rust/compile/issue-3553.rs
new file mode 100644 (file)
index 0000000..546f3c1
--- /dev/null
+++ b/gcc/testsuite/rust/compile/issue-3553.rs
@@ -0,0 +1,18 @@
+trait Foo {
+    fn f(&self) -> isize;
+}
+
+trait Bar: Foo {
+    fn g(&self) -> isize;
+}
+
+struct A {
+    x: isize,
+}
+
+impl Bar for A {
+    // { dg-error "the trait bound .A: Foo. is not satisfied .E0277." "" { target *-*-* } .-1 }
+    fn g(&self) -> isize {
+        self.f()
+    }
+}