Auto merge of #1001 - aeleos:master, r=fitzgen

Ensure all derive analyses check array limit on bitfields

Fixes #982

r? @fitzgen

Author: bors-servo

src/ir/analysis/derive_copy.rs

@@ -9,6 +9,7 @@ use ir::derive::CanTriviallyDeriveCopy;
 use ir::item::IsOpaque;
 use ir::template::TemplateParameters;
 use ir::traversal::EdgeKind;
+use ir::ty::RUST_DERIVE_IN_ARRAY_LIMIT;
 use ir::ty::TypeKind;
 use std::collections::HashMap;
 use std::collections::HashSet;
@@ -266,6 +267,14 @@ impl<'ctx> MonotoneFramework for CannotDeriveCopy<'ctx> {
                             self.is_not_copy(data.ty())
                         }
                         Field::Bitfields(ref bfu) => {
+                            if bfu.layout().align > RUST_DERIVE_IN_ARRAY_LIMIT {
+                                trace!(
+                                    "   we cannot derive Copy for a bitfield larger then \
+                                        the limit"
+                                );
+                                return true;
+                            }
+
                             bfu.bitfields().iter().any(|b| {
                                 self.is_not_copy(b.ty())
                             })

src/ir/analysis/derive_debug.rs

@@ -268,6 +268,14 @@ impl<'ctx> MonotoneFramework for CannotDeriveDebug<'ctx> {
                             self.is_not_debug(data.ty())
                         }
                         Field::Bitfields(ref bfu) => {
+                            if bfu.layout().align > RUST_DERIVE_IN_ARRAY_LIMIT {
+                                trace!(
+                                    "   we cannot derive Debug for a bitfield larger then \
+                                        the limit"
+                                );
+                                return true;
+                            }
+
                             bfu.bitfields().iter().any(|b| {
                                 self.is_not_debug(b.ty())
                             })

src/ir/analysis/derive_default.rs

@@ -308,6 +308,14 @@ impl<'ctx> MonotoneFramework for CannotDeriveDefault<'ctx> {
                                 self.is_not_default(data.ty())
                         }
                         Field::Bitfields(ref bfu) => {
+                            if bfu.layout().align > RUST_DERIVE_IN_ARRAY_LIMIT {
+                                trace!(
+                                    "   we cannot derive Default for a bitfield larger then \
+                                        the limit"
+                                );
+                                return true;
+                            }
+
                             bfu.bitfields().iter().any(|b| {
                                 !self.ctx.whitelisted_items().contains(
                                     &b.ty(),

src/ir/analysis/derive_hash.rs

@@ -283,6 +283,14 @@ impl<'ctx> MonotoneFramework for CannotDeriveHash<'ctx> {
                                 self.cannot_derive_hash.contains(&data.ty())
                         }
                         Field::Bitfields(ref bfu) => {
+                            if bfu.layout().align > RUST_DERIVE_IN_ARRAY_LIMIT {
+                                trace!(
+                                    "   we cannot derive Hash for a bitfield larger then \
+                                        the limit"
+                                );
+                                return true;
+                            }
+
                             bfu.bitfields().iter().any(|b| {
                                 !self.ctx.whitelisted_items().contains(
                                     &b.ty(),

src/ir/analysis/derive_partial_eq_or_partial_ord.rs

@@ -292,6 +292,14 @@ impl<'ctx> MonotoneFramework for CannotDerivePartialEqOrPartialOrd<'ctx> {
                                 )
                         }
                         Field::Bitfields(ref bfu) => {
+                            if bfu.layout().align > RUST_DERIVE_IN_ARRAY_LIMIT {
+                                trace!(
+                                    "   we cannot derive PartialEq for a bitfield larger then \
+                                        the limit"
+                                );
+                                return true;
+                            }
+
                             bfu.bitfields().iter().any(|b| {
                                 !self.ctx.whitelisted_items().contains(
                                     &b.ty(),

tests/expectations/tests/bitfield_large_overflow.rs

@@ -0,0 +1,21 @@
+/* automatically generated by rust-bindgen */
+
+
+#![allow(dead_code, non_snake_case, non_camel_case_types, non_upper_case_globals)]
+
+
+#[repr(C)]
+pub struct _bindgen_ty_1 {
+    pub _bitfield_1: [u8; 128usize],
+    pub __bindgen_align: [u64; 0usize],
+}
+impl Default for _bindgen_ty_1 {
+    fn default() -> Self {
+        unsafe { ::std::mem::zeroed() }
+    }
+}
+extern "C" {
+    #[link_name = "a"]
+    pub static mut a: _bindgen_ty_1;
+}
+

tests/headers/bitfield_large_overflow.hpp

@@ -0,0 +1,5 @@
+// bindgen-flags: --no-layout-tests
+
+struct {
+  unsigned : 632;
+} a;