From d46699acb04b053a391abe3841543dfe0cfb5751 Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Sat, 9 Sep 2017 06:01:35 +0000 Subject: [PATCH] compiler: guard against implicit double pointer indirection The code that lowers field references can sometimes introduce a double pointer indirection in cases where it is not/safe appropriate. For example, in var p **struct { f int } p.f = 0 the assignment LHS was being incorrectly lowered to (*(*p)).f. Detect this situation and issue an error. Fixes golang/go#21770 Reviewed-on: https://go-review.googlesource.com/62330 From-SVN: r251918 --- gcc/go/gofrontend/MERGE | 2 +- gcc/go/gofrontend/types.cc | 6 ++++++ 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE index edcea96094c..9576230ee58 100644 --- a/gcc/go/gofrontend/MERGE +++ b/gcc/go/gofrontend/MERGE @@ -1,4 +1,4 @@ -9d0d5c03a8086f5dd3a23e910abd6e470196973c +52ebad939927e6cbfb48dd277cef8db451e36533 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/types.cc b/gcc/go/gofrontend/types.cc index 4d923733667..cde1408bbf3 100644 --- a/gcc/go/gofrontend/types.cc +++ b/gcc/go/gofrontend/types.cc @@ -11829,6 +11829,12 @@ Type::bind_field_or_method(Gogo* gogo, const Type* type, Expression* expr, go_assert(st != NULL); if (type->struct_type() == NULL) { + if (dereferenced) + { + go_error_at(location, "pointer type has no field %qs", + Gogo::message_name(name).c_str()); + return Expression::make_error(location); + } go_assert(type->points_to() != NULL); expr = Expression::make_unary(OPERATOR_MULT, expr, location); -- 2.30.2