From e1b76fde8ffaa74dffc895c2e2e625e30428b435 Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Thu, 26 Oct 2017 23:04:12 +0000 Subject: [PATCH] compiler: explicitly convert between type aliases Otherwise we can get a crash in the backend. Test case is https://golang.org/cl/73790. Reviewed-on: https://go-review.googlesource.com/73810 From-SVN: r254126 --- gcc/go/gofrontend/MERGE | 2 +- gcc/go/gofrontend/expressions.cc | 16 +++++++++++----- 2 files changed, 12 insertions(+), 6 deletions(-) diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE index 8b1846d07c4..0fa2cccebfe 100644 --- a/gcc/go/gofrontend/MERGE +++ b/gcc/go/gofrontend/MERGE @@ -1,4 +1,4 @@ -a409ac2c78899e638a014c97891925bec93cb3ad +64d570c590a76921cbdca4efb22e4675e19cc809 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 8337cbeb602..dad22ebd2c9 100644 --- a/gcc/go/gofrontend/expressions.cc +++ b/gcc/go/gofrontend/expressions.cc @@ -144,8 +144,8 @@ Expression::convert_for_assignment(Gogo*, Type* lhs_type, || rhs->is_error_expression()) return Expression::make_error(location); - if (lhs_type->forwarded() != rhs_type->forwarded() - && lhs_type->interface_type() != NULL) + bool are_identical = Type::are_identical(lhs_type, rhs_type, false, NULL); + if (!are_identical && lhs_type->interface_type() != NULL) { if (rhs_type->interface_type() == NULL) return Expression::convert_type_to_interface(lhs_type, rhs, location); @@ -153,8 +153,7 @@ Expression::convert_for_assignment(Gogo*, Type* lhs_type, return Expression::convert_interface_to_interface(lhs_type, rhs, false, location); } - else if (lhs_type->forwarded() != rhs_type->forwarded() - && rhs_type->interface_type() != NULL) + else if (!are_identical && rhs_type->interface_type() != NULL) return Expression::convert_interface_to_type(lhs_type, rhs, location); else if (lhs_type->is_slice_type() && rhs_type->is_nil_type()) { @@ -165,8 +164,15 @@ Expression::convert_for_assignment(Gogo*, Type* lhs_type, } else if (rhs_type->is_nil_type()) return Expression::make_nil(location); - else if (Type::are_identical(lhs_type, rhs_type, false, NULL)) + else if (are_identical) { + if (lhs_type->forwarded() != rhs_type->forwarded()) + { + // Different but identical types require an explicit + // conversion. This happens with type aliases. + return Expression::make_cast(lhs_type, rhs, location); + } + // No conversion is needed. return rhs; } -- 2.30.2