compiler: Issue channel type errors earlier.

    When asking for the type of a receive operation, the compiler would
    return an error type if the receive operator was being used on an
    invalid channel type and the error would be reported in a later pass.
    There are several ways that the type checking pass would not see
    the original node and fail to issue the error.  This patch modifies
    receive operations to give an error immediately once it is known that
    the channel type is invalid.

    Fixes golang/go#12323.

    Reviewed-on: https://go-review.googlesource.com/13987

From-SVN: r227863

diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index c150747ae36b0f3549f0c6e22b0b2011bc945497..f21c43a8c6d8ba7d8adf08d01d862dca57c16964 100644 (file)
--- a/gcc/go/gofrontend/MERGE
+++ b/gcc/go/gofrontend/MERGE
@@ -1,4 +1,4 @@
-1cb26dc898bda1e85f4dd2ee204adbce792e4813
+e069d4417a692c1261df99fe3323277e1a0193d2
 
 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 542f3de6fbbd76b9b39ea1a3460d3ea5eb3d3bc9..7ad271f109b9eef26f89a7421714cce127446542 100644 (file)
--- a/gcc/go/gofrontend/expressions.cc
+++ b/gcc/go/gofrontend/expressions.cc
@@ -13502,9 +13502,14 @@ Expression::make_heap_expression(Expression* expr, Location location)
 Type*
 Receive_expression::do_type()
 {
+  if (this->is_error_expression())
+    return Type::make_error_type();
   Channel_type* channel_type = this->channel_->type()->channel_type();
   if (channel_type == NULL)
-    return Type::make_error_type();
+    {
+      this->report_error(_("expected channel"));
+      return Type::make_error_type();
+    }
   return channel_type->element_type();
 }
 
@@ -13516,6 +13521,7 @@ Receive_expression::do_check_types(Gogo*)
   Type* type = this->channel_->type();
   if (type->is_error())
     {
+      go_assert(saw_errors());
       this->set_is_error();
       return;
     }

diff --git a/gcc/go/gofrontend/statements.cc b/gcc/go/gofrontend/statements.cc
index 5d102bf2e17e6a95a916a6f77ffb4a58f20f5270..a84203a5feabe6436d0ae2070f582c627e0d3055 100644 (file)
--- a/gcc/go/gofrontend/statements.cc
+++ b/gcc/go/gofrontend/statements.cc
@@ -3856,7 +3856,10 @@ Switch_statement::do_lower(Gogo*, Named_object*, Block* enclosing,
   if (this->val_ != NULL
       && (this->val_->is_error_expression()
          || this->val_->type()->is_error()))
-    return Statement::make_error_statement(loc);
+    {
+      go_assert(saw_errors());
+      return Statement::make_error_statement(loc);
+    }
 
   if (this->val_ != NULL
       && this->val_->type()->integer_type() != NULL