commit 10a1671d94ddc0c39f2f4b039e5ea33358f414c0
author Than McIntosh <thanm@google.com> Wed Sep 25 09:04:45 2019 -0400
committer Ian Lance Taylor <iant@golang.org> Sat Sep 28 00:16:21 2019 +0000
tree 7cff346b5432ea3acc5858ea45c1fcd149f55cc4
parent 9112ea664ed9ee5f108158a913812adaf03edf6e

compiler: resolve importing ambiguity for more complex function calls

Tweak the exporter for inlinable function bodies to work around a
problem with importing of function calls whose function expressions
are not simple function names. In the bug in question, the function
body exporter was writing out a function call of the form

       (*(*FuncTyp)(var))(arg)

which produced an export data representation of

       *$convert(<type 5>, var)(x)

which is hard to parse unambiguously. Fix: change the export data
emitter to introduce parens around the function expression for more
complex calls.

Testcase for this bug is in CL 197217.

Fixes golang/go#34503.

Change-Id: I54bb01b261c54770751fb150d54aa64765b94f09
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/197122
Reviewed-by: Ian Lance Taylor <iant@golang.org>

go/expressions.cc

diff --git a/go/expressions.cc b/go/expressions.cc
index 7d8963e..a72ba24 100644
--- a/go/expressions.cc
+++ b/go/expressions.cc
@@ -12373,7 +12373,12 @@
 void
 Call_expression::do_export(Export_function_body* efb) const
 {
+  bool simple_call = (this->fn_->func_expression() != NULL);
+  if (!simple_call)
+    efb->write_c_string("(");
   this->fn_->export_expression(efb);
+  if (!simple_call)
+    efb->write_c_string(")");
   this->export_arguments(efb);
 }