From: Ian Lance Taylor <ian@gcc.gnu.org>
Date: Tue, 10 Jul 2018 00:55:28 +0000 (+0000)
Subject: compiler: fix double evaluation with interface field expression
X-Git-Tag: basepoints/gcc-10~5455
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c0cb9a9da0a7e257297deb25193cc9f113ee672a;p=thirdparty%2Fgcc.git

compiler: fix double evaluation with interface field expression

    In Interface_field_reference_expression, the interface expression
    is used in two places, so a temporary variable is used. Previously,
    we used a Set_and_use_temporary_expression, which, when evaluated
    twice, causes double evaluation of the underlying expression. Fix
    by setting the temporary once and use Temporary_reference_expression
    instead.

    Fixes golang/go#26248.

    Reviewed-on: https://go-review.googlesource.com/122756

From-SVN: r262533
---

diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index e65c0bc574b1..8a63818951be 100644
--- a/gcc/go/gofrontend/MERGE
+++ b/gcc/go/gofrontend/MERGE
@@ -1,4 +1,4 @@
-94738979a3422e845acf358a766aabf8b9275d43
+8ad67a72a4fa59efffc891e73ecf10020e3c565d
 
 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 75b8b69383ce..89b265b9b6bb 100644
--- a/gcc/go/gofrontend/expressions.cc
+++ b/gcc/go/gofrontend/expressions.cc
@@ -11886,10 +11886,9 @@ Interface_field_reference_expression::do_flatten(Gogo*, Named_object*,
   if (!this->expr_->is_variable())
     {
       Temporary_statement* temp =
-	Statement::make_temporary(this->expr_->type(), NULL, this->location());
+	Statement::make_temporary(NULL, this->expr_, this->location());
       inserter->insert(temp);
-      this->expr_ = Expression::make_set_and_use_temporary(temp, this->expr_,
-							   this->location());
+      this->expr_ = Expression::make_temporary_reference(temp, this->location());
     }
   return this;
 }