compiler: avoid knock-on errors from invalid interfaces

The test case for this is issue11614.go.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/278192

3 files changed, 37 insertions, 9 deletions

diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index a596b24..a28294c 100644
--- a/gcc/go/gofrontend/MERGE
+++ b/gcc/go/gofrontend/MERGE
@@ -1,4 +1,4 @@
-85c390ec75c6c3f3fbfe08f6dac58585588c6211
+10d3dd939d4cea7f40b76f8ff82c16aa12c01188
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
diff --git a/gcc/go/gofrontend/expressions.cc b/gcc/go/gofrontend/expressions.cc
index 79ed445..adc1ebb 100644
--- a/gcc/go/gofrontend/expressions.cc
+++ b/gcc/go/gofrontend/expressions.cc
@@ -174,7 +174,13 @@ Expression::export_name(Export_function_body* efb, const Named_object* no)
 void
 Expression::unused_value_error()
 {
-  this->report_error(_("value computed is not used"));
+  if (this->type()->is_error())
+    {
+      go_assert(saw_errors());
+      this->set_is_error();
+    }
+  else
+    this->report_error(_("value computed is not used"));
 }
 
 // Note that this expression is an error.  This is called by children
@@ -888,8 +894,7 @@ Type_expression : public Expression
   { }
 
   void
-  do_check_types(Gogo*)
-  { this->report_error(_("invalid use of type")); }
+  do_check_types(Gogo*);
 
   Expression*
   do_copy()
@@ -907,6 +912,18 @@ Type_expression : public Expression
 };
 
 void
+Type_expression::do_check_types(Gogo*)
+{
+  if (this->type_->is_error())
+    {
+      go_assert(saw_errors());
+      this->set_is_error();
+    }
+  else
+    this->report_error(_("invalid use of type"));
+}
+
+void
 Type_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const
 {
   ast_dump_context->dump_type(this->type_);
diff --git a/gcc/go/gofrontend/types.cc b/gcc/go/gofrontend/types.cc
index f9097d5..ecb93b0 100644
--- a/gcc/go/gofrontend/types.cc
+++ b/gcc/go/gofrontend/types.cc
@@ -8984,8 +8984,11 @@ Interface_type::finalize_methods()
       else if (this->find_method(p->name()) == NULL)
 	this->all_methods_->push_back(*p);
       else
-	go_error_at(p->location(), "duplicate method %qs",
-		 Gogo::message_name(p->name()).c_str());
+	{
+	  go_error_at(p->location(), "duplicate method %qs",
+		      Gogo::message_name(p->name()).c_str());
+	  this->set_is_error();
+	}
     }
 
   std::vector<Named_type*> seen;
@@ -9001,7 +9004,10 @@ Interface_type::finalize_methods()
       if (it == NULL)
 	{
 	  if (!t->is_error())
-	    go_error_at(tl, "interface contains embedded non-interface");
+	    {
+	      go_error_at(tl, "interface contains embedded non-interface");
+	      this->set_is_error();
+	    }
 	  continue;
 	}
       if (it == this)
@@ -9009,6 +9015,7 @@ Interface_type::finalize_methods()
 	  if (!issued_recursive_error)
 	    {
 	      go_error_at(tl, "invalid recursive interface");
+	      this->set_is_error();
 	      issued_recursive_error = true;
 	    }
 	  continue;
@@ -9027,6 +9034,7 @@ Interface_type::finalize_methods()
 	      if (*q == nt)
 		{
 		  go_error_at(tl, "inherited interface loop");
+		  this->set_is_error();
 		  break;
 		}
 	    }
@@ -9049,8 +9057,11 @@ Interface_type::finalize_methods()
 							       q->type(), tl));
 	      else if (!Type::are_identical(q->type(), oldm->type(),
 					    Type::COMPARE_TAGS, NULL))
-		go_error_at(tl, "duplicate method %qs",
-			    Gogo::message_name(q->name()).c_str());
+		{
+		  go_error_at(tl, "duplicate method %qs",
+			      Gogo::message_name(q->name()).c_str());
+		  this->set_is_error();
+		}
 	    }
 	}