Go patch committed: Avoid type check failure for converted recover call

[Ian Lance Taylor]

The Go frontend converts recover calls to add an argument passed down
to the middle end.  In some cases a recover call would be type checked
even after that argument is added, causing an incorrect error.  This
patch from Chris Manghane fixes the problem.  This is GCC PR 61248.
Bootstrapped and ran Go testsuite on x86_64-unknown-linux-gnu.
Committed to mainline.

Ian

diff -r 86515da29da6 go/expressions.cc
--- a/go/expressions.cc Mon Dec 15 09:10:59 2014 -0800
+++ b/go/expressions.cc Mon Dec 15 09:30:12 2014 -0800
@@ -6627,6 +6627,8 @@
   // Used to stop endless loops when the length of an array uses len
   // or cap of the array itself.
   mutable bool seen_;
+  // Whether the argument is set for calls to BUILTIN_RECOVER.
+  bool recover_arg_is_set_;
 };
 
 Builtin_call_expression::Builtin_call_expression(Gogo* gogo,
@@ -6635,7 +6637,8 @@
                                                 bool is_varargs,
                                                 Location location)
   : Call_expression(fn, args, is_varargs, location),
-    gogo_(gogo), code_(BUILTIN_INVALID), seen_(false)
+    gogo_(gogo), code_(BUILTIN_INVALID), seen_(false),
+    recover_arg_is_set_(false)
 {
   Func_expression* fnexp = this->fn()->func_expression();
   go_assert(fnexp != NULL);
@@ -6701,6 +6704,7 @@
   Expression_list* new_args = new Expression_list();
   new_args->push_back(arg);
   this->set_args(new_args);
+  this->recover_arg_is_set_ = true;
 }
 
 // Lower a builtin call expression.  This turns new and make into
@@ -7841,7 +7845,9 @@
       break;
 
     case BUILTIN_RECOVER:
-      if (this->args() != NULL && !this->args()->empty())
+      if (this->args() != NULL
+         && !this->args()->empty()
+         && !this->recover_arg_is_set_)
        this->report_error(_("too many arguments"));
       break;