lint: port improper ctypes diagnostics
Signed-off-by: David Wood <david.wood@huawei.com>
This commit is contained in:
David Wood
parent
7a9bef4d83
commit
e5f2e0e16c
2 changed files with 124 additions and 63 deletions
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@ -2,7 +2,7 @@ use crate::{LateContext, LateLintPass, LintContext};
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use rustc_ast as ast;
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use rustc_attr as attr;
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use rustc_data_structures::fx::FxHashSet;
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use rustc_errors::{fluent, Applicability};
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use rustc_errors::{fluent, Applicability, DiagnosticMessage};
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use rustc_hir as hir;
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use rustc_hir::{is_range_literal, Expr, ExprKind, Node};
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use rustc_middle::ty::layout::{IntegerExt, LayoutOf, SizeSkeleton};
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@ -664,7 +664,7 @@ struct ImproperCTypesVisitor<'a, 'tcx> {
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enum FfiResult<'tcx> {
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FfiSafe,
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FfiPhantom(Ty<'tcx>),
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FfiUnsafe { ty: Ty<'tcx>, reason: String, help: Option<String> },
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FfiUnsafe { ty: Ty<'tcx>, reason: DiagnosticMessage, help: Option<DiagnosticMessage> },
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}
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pub(crate) fn nonnull_optimization_guaranteed<'tcx>(
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@ -824,8 +824,8 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
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self.emit_ffi_unsafe_type_lint(
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ty,
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sp,
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"passing raw arrays by value is not FFI-safe",
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Some("consider passing a pointer to the array"),
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fluent::lint::improper_ctypes_array_reason,
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Some(fluent::lint::improper_ctypes_array_help),
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);
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true
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} else {
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@ -868,11 +868,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
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} else {
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// All fields are ZSTs; this means that the type should behave
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// like (), which is FFI-unsafe
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FfiUnsafe {
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ty,
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reason: "this struct contains only zero-sized fields".into(),
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help: None,
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}
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FfiUnsafe { ty, reason: fluent::lint::improper_ctypes_struct_zst, help: None }
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}
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} else {
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// We can't completely trust repr(C) markings; make sure the fields are
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@ -886,7 +882,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
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FfiPhantom(..) if def.is_enum() => {
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return FfiUnsafe {
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ty,
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reason: "this enum contains a PhantomData field".into(),
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reason: fluent::lint::improper_ctypes_enum_phantomdata,
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help: None,
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};
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}
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@ -922,7 +918,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
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} else {
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return FfiUnsafe {
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ty,
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reason: "box cannot be represented as a single pointer".to_string(),
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reason: fluent::lint::improper_ctypes_box,
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help: None,
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};
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}
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@ -932,17 +928,19 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
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}
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match def.adt_kind() {
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AdtKind::Struct | AdtKind::Union => {
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let kind = if def.is_struct() { "struct" } else { "union" };
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if !def.repr().c() && !def.repr().transparent() {
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return FfiUnsafe {
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ty,
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reason: format!("this {} has unspecified layout", kind),
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help: Some(format!(
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"consider adding a `#[repr(C)]` or \
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`#[repr(transparent)]` attribute to this {}",
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kind
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)),
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reason: if def.is_struct() {
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fluent::lint::improper_ctypes_struct_layout_reason
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} else {
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fluent::lint::improper_ctypes_union_layout_reason
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},
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help: if def.is_struct() {
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Some(fluent::lint::improper_ctypes_struct_layout_help)
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} else {
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Some(fluent::lint::improper_ctypes_union_layout_help)
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},
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};
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}
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@ -951,7 +949,11 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
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if is_non_exhaustive && !def.did().is_local() {
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return FfiUnsafe {
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ty,
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reason: format!("this {} is non-exhaustive", kind),
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reason: if def.is_struct() {
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fluent::lint::improper_ctypes_struct_non_exhaustive
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} else {
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fluent::lint::improper_ctypes_union_non_exhaustive
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},
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help: None,
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};
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}
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@ -959,8 +961,16 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
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if def.non_enum_variant().fields.is_empty() {
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return FfiUnsafe {
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ty,
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reason: format!("this {} has no fields", kind),
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help: Some(format!("consider adding a member to this {}", kind)),
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reason: if def.is_struct() {
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fluent::lint::improper_ctypes_struct_fieldless_reason
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} else {
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fluent::lint::improper_ctypes_union_fieldless_reason
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},
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help: if def.is_struct() {
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Some(fluent::lint::improper_ctypes_struct_fieldless_help)
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} else {
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Some(fluent::lint::improper_ctypes_union_fieldless_help)
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},
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};
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}
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@ -980,13 +990,8 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
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if repr_nullable_ptr(self.cx, ty, self.mode).is_none() {
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return FfiUnsafe {
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ty,
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reason: "enum has no representation hint".into(),
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help: Some(
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"consider adding a `#[repr(C)]`, \
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`#[repr(transparent)]`, or integer `#[repr(...)]` \
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attribute to this enum"
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.into(),
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),
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reason: fluent::lint::improper_ctypes_enum_repr_reason,
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help: Some(fluent::lint::improper_ctypes_enum_repr_help),
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};
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}
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}
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@ -994,7 +999,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
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if def.is_variant_list_non_exhaustive() && !def.did().is_local() {
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return FfiUnsafe {
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ty,
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reason: "this enum is non-exhaustive".into(),
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reason: fluent::lint::improper_ctypes_non_exhaustive,
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help: None,
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};
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}
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@ -1005,7 +1010,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
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if is_non_exhaustive && !variant.def_id.is_local() {
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return FfiUnsafe {
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ty,
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reason: "this enum has non-exhaustive variants".into(),
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reason: fluent::lint::improper_ctypes_non_exhaustive_variant,
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help: None,
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};
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}
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@ -1023,39 +1028,37 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
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ty::Char => FfiUnsafe {
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ty,
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reason: "the `char` type has no C equivalent".into(),
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help: Some("consider using `u32` or `libc::wchar_t` instead".into()),
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reason: fluent::lint::improper_ctypes_char_reason,
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help: Some(fluent::lint::improper_ctypes_char_help),
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},
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ty::Int(ty::IntTy::I128) | ty::Uint(ty::UintTy::U128) => FfiUnsafe {
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ty,
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reason: "128-bit integers don't currently have a known stable ABI".into(),
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help: None,
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},
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ty::Int(ty::IntTy::I128) | ty::Uint(ty::UintTy::U128) => {
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FfiUnsafe { ty, reason: fluent::lint::improper_ctypes_128bit, help: None }
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}
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// Primitive types with a stable representation.
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ty::Bool | ty::Int(..) | ty::Uint(..) | ty::Float(..) | ty::Never => FfiSafe,
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ty::Slice(_) => FfiUnsafe {
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ty,
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reason: "slices have no C equivalent".into(),
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help: Some("consider using a raw pointer instead".into()),
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reason: fluent::lint::improper_ctypes_slice_reason,
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help: Some(fluent::lint::improper_ctypes_slice_help),
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},
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ty::Dynamic(..) => {
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FfiUnsafe { ty, reason: "trait objects have no C equivalent".into(), help: None }
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FfiUnsafe { ty, reason: fluent::lint::improper_ctypes_dyn, help: None }
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}
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ty::Str => FfiUnsafe {
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ty,
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reason: "string slices have no C equivalent".into(),
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help: Some("consider using `*const u8` and a length instead".into()),
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reason: fluent::lint::improper_ctypes_str_reason,
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help: Some(fluent::lint::improper_ctypes_str_help),
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},
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ty::Tuple(..) => FfiUnsafe {
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ty,
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reason: "tuples have unspecified layout".into(),
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help: Some("consider using a struct instead".into()),
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reason: fluent::lint::improper_ctypes_tuple_reason,
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help: Some(fluent::lint::improper_ctypes_tuple_help),
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},
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ty::RawPtr(ty::TypeAndMut { ty, .. }) | ty::Ref(_, ty, _)
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@ -1086,12 +1089,8 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
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if self.is_internal_abi(sig.abi()) {
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return FfiUnsafe {
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ty,
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reason: "this function pointer has Rust-specific calling convention".into(),
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help: Some(
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"consider using an `extern fn(...) -> ...` \
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function pointer instead"
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.into(),
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),
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reason: fluent::lint::improper_ctypes_fnptr_reason,
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help: Some(fluent::lint::improper_ctypes_fnptr_help),
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};
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}
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@ -1122,7 +1121,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
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// While opaque types are checked for earlier, if a projection in a struct field
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// normalizes to an opaque type, then it will reach this branch.
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ty::Opaque(..) => {
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FfiUnsafe { ty, reason: "opaque types have no C equivalent".into(), help: None }
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FfiUnsafe { ty, reason: fluent::lint::improper_ctypes_opaque, help: None }
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}
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// `extern "C" fn` functions can have type parameters, which may or may not be FFI-safe,
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@ -1148,8 +1147,8 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
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&mut self,
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ty: Ty<'tcx>,
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sp: Span,
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note: &str,
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help: Option<&str>,
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note: DiagnosticMessage,
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help: Option<DiagnosticMessage>,
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) {
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let lint = match self.mode {
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CItemKind::Declaration => IMPROPER_CTYPES,
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@ -1161,18 +1160,17 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
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CItemKind::Declaration => "block",
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CItemKind::Definition => "fn",
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};
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let mut diag = lint.build(&format!(
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"`extern` {} uses type `{}`, which is not FFI-safe",
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item_description, ty
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));
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diag.span_label(sp, "not FFI-safe");
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let mut diag = lint.build(fluent::lint::improper_ctypes);
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diag.set_arg("ty", ty);
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diag.set_arg("desc", item_description);
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diag.span_label(sp, fluent::lint::label);
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if let Some(help) = help {
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diag.help(help);
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}
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diag.note(note);
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if let ty::Adt(def, _) = ty.kind() {
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if let Some(sp) = self.cx.tcx.hir().span_if_local(def.did()) {
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diag.span_note(sp, "the type is defined here");
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diag.span_note(sp, fluent::lint::note);
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}
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}
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diag.emit();
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@ -1209,7 +1207,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
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}
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if let Some(ty) = ty.visit_with(&mut ProhibitOpaqueTypes { cx: self.cx }).break_value() {
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self.emit_ffi_unsafe_type_lint(ty, sp, "opaque types have no C equivalent", None);
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self.emit_ffi_unsafe_type_lint(ty, sp, fluent::lint::improper_ctypes_opaque, None);
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true
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} else {
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false
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@ -1251,13 +1249,18 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
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match self.check_type_for_ffi(&mut FxHashSet::default(), ty) {
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FfiResult::FfiSafe => {}
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FfiResult::FfiPhantom(ty) => {
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self.emit_ffi_unsafe_type_lint(ty, sp, "composed only of `PhantomData`", None);
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self.emit_ffi_unsafe_type_lint(
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ty,
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sp,
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fluent::lint::improper_ctypes_only_phantomdata,
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None,
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);
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}
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// If `ty` is a `repr(transparent)` newtype, and the non-zero-sized type is a generic
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// argument, which after substitution, is `()`, then this branch can be hit.
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FfiResult::FfiUnsafe { ty, .. } if is_return_type && ty.is_unit() => {}
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FfiResult::FfiUnsafe { ty, reason, help } => {
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self.emit_ffi_unsafe_type_lint(ty, sp, &reason, help.as_deref());
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self.emit_ffi_unsafe_type_lint(ty, sp, reason, help);
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}
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}
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}
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