commit 263e8d2a2ab57c6f2b3035f370d40476bda87c9f
author Ian Lance Taylor <iant@golang.org> Tue Feb 08 20:16:38 2022 -0800
committer Ian Lance Taylor <iant@golang.org> Wed Feb 09 22:13:09 2022 +0000
tree 55d131c4ed0fa2c2a67d9aa57b1013439a6eedce
parent 7dffb933d33ff288675c8094d05c31b35cbf7e4d

compiler: use nil pointer for zero length string constant

We used to pointlessly set the pointer of a zero length string
constant to point to a zero byte constant.  Instead, just use nil.

Change-Id: I73fb28dcfcf547565dcab4ec26412f6e6e7ca951
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/384354
Trust: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>

go/expressions.cc

diff --git a/go/expressions.cc b/go/expressions.cc
index d7b6476..3f59765 100644
--- a/go/expressions.cc
+++ b/go/expressions.cc
@@ -2123,9 +2123,15 @@
 
   Location loc = this->location();
   std::vector<Bexpression*> init(2);
-  Bexpression* str_cst =
-      gogo->backend()->string_constant_expression(this->val_);
-  init[0] = gogo->backend()->address_expression(str_cst, loc);
+
+  if (this->val_.size() == 0)
+    init[0] = gogo->backend()->nil_pointer_expression();
+  else
+    {
+      Bexpression* str_cst =
+	gogo->backend()->string_constant_expression(this->val_);
+      init[0] = gogo->backend()->address_expression(str_cst, loc);
+    }
 
   Btype* int_btype = Type::lookup_integer_type("int")->get_backend(gogo);
   mpz_t lenval;