From 3ba155dd1921b55f04866b35a2e054e092670cd6 Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Sat, 31 Aug 2019 03:07:48 +0000 Subject: [PATCH] compiler: check for notinheap struct at each struct field When generating write barriers, we were only checking for a notinheap struct at the outermost struct. That mishandled the case of setting a pointer to a notinheap struct as a field of another struct that is not notinheap. This caused an invalid write barrier error when building the 1.13 version of the runtime. Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/192279 From-SVN: r275240 --- gcc/go/gofrontend/MERGE | 2 +- gcc/go/gofrontend/wb.cc | 50 ++++++++++++++++++++--------------------- 2 files changed, 26 insertions(+), 26 deletions(-) diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE index 025e66ea99b..0add2f0a9ae 100644 --- a/gcc/go/gofrontend/MERGE +++ b/gcc/go/gofrontend/MERGE @@ -1,4 +1,4 @@ -289d94b9e6303ec74649d1f08d418300f2b4d0fd +3b8a505824abb2a69f4c04c555a4ba29ab8b102b 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/wb.cc b/gcc/go/gofrontend/wb.cc index 41d8f94c074..1eadb3e9e62 100644 --- a/gcc/go/gofrontend/wb.cc +++ b/gcc/go/gofrontend/wb.cc @@ -733,6 +733,31 @@ Gogo::assign_needs_write_barrier( && !lhs->type()->points_to()->in_heap()) return false; + // For a struct assignment, we don't need a write barrier if all + // the field types can not be in the heap. + Struct_type* st = lhs->type()->struct_type(); + if (st != NULL) + { + bool in_heap = false; + const Struct_field_list* fields = st->fields(); + for (Struct_field_list::const_iterator p = fields->begin(); + p != fields->end(); + p++) + { + Type* ft = p->type(); + if (!ft->has_pointer()) + continue; + if (!ft->in_heap()) + continue; + if (ft->points_to() != NULL && !ft->points_to()->in_heap()) + continue; + in_heap = true; + break; + } + if (!in_heap) + return false; + } + Field_reference_expression* fre = lhs->field_reference_expression(); if (fre != NULL) { @@ -788,31 +813,6 @@ Gogo::assign_needs_write_barrier( && this->is_nonwb_pointer(ue->operand(), nonwb_pointers)) return false; - // For a struct assignment, we don't need a write barrier if all the - // pointer types can not be in the heap. - Struct_type* st = lhs->type()->struct_type(); - if (st != NULL) - { - bool in_heap = false; - const Struct_field_list* fields = st->fields(); - for (Struct_field_list::const_iterator p = fields->begin(); - p != fields->end(); - p++) - { - Type* ft = p->type(); - if (!ft->has_pointer()) - continue; - if (!ft->in_heap()) - continue; - if (ft->points_to() != NULL && !ft->points_to()->in_heap()) - continue; - in_heap = true; - break; - } - if (!in_heap) - return false; - } - // Write barrier needed in other cases. return true; } -- 2.30.2