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improper ctypes: adjust lint msg for extern fns
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Signed-off-by: David Wood <david@davidtw.co>
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@davidtwco
davidtwco committed Nov 5, 2019
1 parent 0128f8e commit cb60654
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Showing 2 changed files with 49 additions and 36 deletions.
37 changes: 25 additions & 12 deletions src/librustc_lint/types.rs
View file
Expand Up @@ -891,11 +891,16 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
sp: Span,
note: &str,
help: Option<&str>,
is_foreign_item: bool,
) {
let mut diag = self.cx.struct_span_lint(
IMPROPER_CTYPES,
sp,
&format!("`extern` block uses type `{}`, which is not FFI-safe", ty),
&format!(
"`extern` {} uses type `{}`, which is not FFI-safe",
if is_foreign_item { "block" } else { "fn" },
ty,
),
);
diag.span_label(sp, "not FFI-safe");
if let Some(help) = help {
Expand All @@ -910,7 +915,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
diag.emit();
}

fn check_for_opaque_ty(&mut self, sp: Span, ty: Ty<'tcx>) -> bool {
fn check_for_opaque_ty(&mut self, sp: Span, ty: Ty<'tcx>, is_foreign_item: bool) -> bool {
struct ProhibitOpaqueTypes<'tcx> {
ty: Option<Ty<'tcx>>,
};
Expand All @@ -934,17 +939,23 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
sp,
"opaque types have no C equivalent",
None,
is_foreign_item,
);
true
} else {
false
}
}

fn check_type_for_ffi_and_report_errors(&mut self, sp: Span, ty: Ty<'tcx>) {
fn check_type_for_ffi_and_report_errors(
&mut self,
sp: Span,
ty: Ty<'tcx>,
is_foreign_item: bool,
) {
// We have to check for opaque types before `normalize_erasing_regions`,
// which will replace opaque types with their underlying concrete type.
if self.check_for_opaque_ty(sp, ty) {
if self.check_for_opaque_ty(sp, ty, is_foreign_item) {
// We've already emitted an error due to an opaque type.
return;
}
Expand All @@ -953,35 +964,37 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
match self.check_type_for_ffi(&mut FxHashSet::default(), ty) {
FfiResult::FfiSafe => {}
FfiResult::FfiPhantom(ty) => {
self.emit_ffi_unsafe_type_lint(ty, sp, "composed only of `PhantomData`", None);
self.emit_ffi_unsafe_type_lint(
ty, sp, "composed only of `PhantomData`", None, is_foreign_item);
}
FfiResult::FfiUnsafe { ty, reason, help } => {
self.emit_ffi_unsafe_type_lint(ty, sp, reason, help);
self.emit_ffi_unsafe_type_lint(
ty, sp, reason, help, is_foreign_item);
}
}
}

fn check_foreign_fn(&mut self, id: hir::HirId, decl: &hir::FnDecl) {
fn check_foreign_fn(&mut self, id: hir::HirId, decl: &hir::FnDecl, is_foreign_item: bool) {
let def_id = self.cx.tcx.hir().local_def_id(id);
let sig = self.cx.tcx.fn_sig(def_id);
let sig = self.cx.tcx.erase_late_bound_regions(&sig);

for (input_ty, input_hir) in sig.inputs().iter().zip(&decl.inputs) {
self.check_type_for_ffi_and_report_errors(input_hir.span, input_ty);
self.check_type_for_ffi_and_report_errors(input_hir.span, input_ty, is_foreign_item);
}

if let hir::Return(ref ret_hir) = decl.output {
let ret_ty = sig.output();
if !ret_ty.is_unit() {
self.check_type_for_ffi_and_report_errors(ret_hir.span, ret_ty);
self.check_type_for_ffi_and_report_errors(ret_hir.span, ret_ty, is_foreign_item);
}
}
}

fn check_foreign_static(&mut self, id: hir::HirId, span: Span) {
let def_id = self.cx.tcx.hir().local_def_id(id);
let ty = self.cx.tcx.type_of(def_id);
self.check_type_for_ffi_and_report_errors(span, ty);
self.check_type_for_ffi_and_report_errors(span, ty, true);
}

fn is_internal_abi(&self, abi: Abi) -> bool {
Expand All @@ -1000,7 +1013,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ImproperCTypes {
if !vis.is_internal_abi(abi) {
match it.kind {
hir::ForeignItemKind::Fn(ref decl, _, _) => {
vis.check_foreign_fn(it.hir_id, decl);
vis.check_foreign_fn(it.hir_id, decl, true);
}
hir::ForeignItemKind::Static(ref ty, _) => {
vis.check_foreign_static(it.hir_id, ty.span);
Expand Down Expand Up @@ -1029,7 +1042,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ImproperCTypes {

let mut vis = ImproperCTypesVisitor { cx };
if !vis.is_internal_abi(abi) {
vis.check_foreign_fn(hir_id, decl);
vis.check_foreign_fn(hir_id, decl, false);
}
}
}
Expand Down
48 changes: 24 additions & 24 deletions src/test/ui/lint/lint-ctypes-fn.stderr
View file
@@ -1,4 +1,4 @@
error: `extern` block uses type `Foo`, which is not FFI-safe
error: `extern` fn uses type `Foo`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:63:35
|
LL | pub extern "C" fn ptr_type1(size: *const Foo) { }
Expand All @@ -17,7 +17,7 @@ note: type defined here
LL | pub struct Foo;
| ^^^^^^^^^^^^^^^

error: `extern` block uses type `Foo`, which is not FFI-safe
error: `extern` fn uses type `Foo`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:66:35
|
LL | pub extern "C" fn ptr_type2(size: *const Foo) { }
Expand All @@ -31,7 +31,7 @@ note: type defined here
LL | pub struct Foo;
| ^^^^^^^^^^^^^^^

error: `extern` block uses type `[u32]`, which is not FFI-safe
error: `extern` fn uses type `[u32]`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:69:33
|
LL | pub extern "C" fn slice_type(p: &[u32]) { }
Expand All @@ -40,7 +40,7 @@ LL | pub extern "C" fn slice_type(p: &[u32]) { }
= help: consider using a raw pointer instead
= note: slices have no C equivalent

error: `extern` block uses type `str`, which is not FFI-safe
error: `extern` fn uses type `str`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:72:31
|
LL | pub extern "C" fn str_type(p: &str) { }
Expand All @@ -49,7 +49,7 @@ LL | pub extern "C" fn str_type(p: &str) { }
= help: consider using `*const u8` and a length instead
= note: string slices have no C equivalent

error: `extern` block uses type `std::boxed::Box<u32>`, which is not FFI-safe
error: `extern` fn uses type `std::boxed::Box<u32>`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:75:31
|
LL | pub extern "C" fn box_type(p: Box<u32>) { }
Expand All @@ -58,7 +58,7 @@ LL | pub extern "C" fn box_type(p: Box<u32>) { }
= help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
= note: this struct has unspecified layout

error: `extern` block uses type `char`, which is not FFI-safe
error: `extern` fn uses type `char`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:78:32
|
LL | pub extern "C" fn char_type(p: char) { }
Expand All @@ -67,23 +67,23 @@ LL | pub extern "C" fn char_type(p: char) { }
= help: consider using `u32` or `libc::wchar_t` instead
= note: the `char` type has no C equivalent

error: `extern` block uses type `i128`, which is not FFI-safe
error: `extern` fn uses type `i128`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:81:32
|
LL | pub extern "C" fn i128_type(p: i128) { }
| ^^^^ not FFI-safe
|
= note: 128-bit integers don't currently have a known stable ABI

error: `extern` block uses type `u128`, which is not FFI-safe
error: `extern` fn uses type `u128`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:84:32
|
LL | pub extern "C" fn u128_type(p: u128) { }
| ^^^^ not FFI-safe
|
= note: 128-bit integers don't currently have a known stable ABI

error: `extern` block uses type `(i32, i32)`, which is not FFI-safe
error: `extern` fn uses type `(i32, i32)`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:87:33
|
LL | pub extern "C" fn tuple_type(p: (i32, i32)) { }
Expand All @@ -92,7 +92,7 @@ LL | pub extern "C" fn tuple_type(p: (i32, i32)) { }
= help: consider using a struct instead
= note: tuples have unspecified layout

error: `extern` block uses type `(i32, i32)`, which is not FFI-safe
error: `extern` fn uses type `(i32, i32)`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:90:34
|
LL | pub extern "C" fn tuple_type2(p: I32Pair) { }
Expand All @@ -101,7 +101,7 @@ LL | pub extern "C" fn tuple_type2(p: I32Pair) { }
= help: consider using a struct instead
= note: tuples have unspecified layout

error: `extern` block uses type `ZeroSize`, which is not FFI-safe
error: `extern` fn uses type `ZeroSize`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:93:32
|
LL | pub extern "C" fn zero_size(p: ZeroSize) { }
Expand All @@ -115,7 +115,7 @@ note: type defined here
LL | pub struct ZeroSize;
| ^^^^^^^^^^^^^^^^^^^^

error: `extern` block uses type `ZeroSizeWithPhantomData`, which is not FFI-safe
error: `extern` fn uses type `ZeroSizeWithPhantomData`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:96:40
|
LL | pub extern "C" fn zero_size_phantom(p: ZeroSizeWithPhantomData) { }
Expand All @@ -128,15 +128,15 @@ note: type defined here
LL | pub struct ZeroSizeWithPhantomData(PhantomData<i32>);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: `extern` block uses type `std::marker::PhantomData<bool>`, which is not FFI-safe
error: `extern` fn uses type `std::marker::PhantomData<bool>`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:99:51
|
LL | pub extern "C" fn zero_size_phantom_toplevel() -> PhantomData<bool> {
| ^^^^^^^^^^^^^^^^^ not FFI-safe
|
= note: composed only of `PhantomData`

error: `extern` block uses type `fn()`, which is not FFI-safe
error: `extern` fn uses type `fn()`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:104:30
|
LL | pub extern "C" fn fn_type(p: RustFn) { }
Expand All @@ -145,7 +145,7 @@ LL | pub extern "C" fn fn_type(p: RustFn) { }
= help: consider using an `extern fn(...) -> ...` function pointer instead
= note: this function pointer has Rust-specific calling convention

error: `extern` block uses type `fn()`, which is not FFI-safe
error: `extern` fn uses type `fn()`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:107:31
|
LL | pub extern "C" fn fn_type2(p: fn()) { }
Expand All @@ -154,7 +154,7 @@ LL | pub extern "C" fn fn_type2(p: fn()) { }
= help: consider using an `extern fn(...) -> ...` function pointer instead
= note: this function pointer has Rust-specific calling convention

error: `extern` block uses type `std::boxed::Box<u32>`, which is not FFI-safe
error: `extern` fn uses type `std::boxed::Box<u32>`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:110:35
|
LL | pub extern "C" fn fn_contained(p: RustBadRet) { }
Expand All @@ -163,15 +163,15 @@ LL | pub extern "C" fn fn_contained(p: RustBadRet) { }
= help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
= note: this struct has unspecified layout

error: `extern` block uses type `i128`, which is not FFI-safe
error: `extern` fn uses type `i128`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:113:39
|
LL | pub extern "C" fn transparent_i128(p: TransparentI128) { }
| ^^^^^^^^^^^^^^^ not FFI-safe
|
= note: 128-bit integers don't currently have a known stable ABI

error: `extern` block uses type `str`, which is not FFI-safe
error: `extern` fn uses type `str`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:116:38
|
LL | pub extern "C" fn transparent_str(p: TransparentStr) { }
Expand All @@ -180,7 +180,7 @@ LL | pub extern "C" fn transparent_str(p: TransparentStr) { }
= help: consider using `*const u8` and a length instead
= note: string slices have no C equivalent

error: `extern` block uses type `std::boxed::Box<u32>`, which is not FFI-safe
error: `extern` fn uses type `std::boxed::Box<u32>`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:119:37
|
LL | pub extern "C" fn transparent_fn(p: TransparentBadFn) { }
Expand All @@ -189,7 +189,7 @@ LL | pub extern "C" fn transparent_fn(p: TransparentBadFn) { }
= help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
= note: this struct has unspecified layout

error: `extern` block uses type `Foo`, which is not FFI-safe
error: `extern` fn uses type `Foo`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:161:44
|
LL | pub extern "C" fn unused_generic1<T>(size: *const Foo) { }
Expand All @@ -203,15 +203,15 @@ note: type defined here
LL | pub struct Foo;
| ^^^^^^^^^^^^^^^

error: `extern` block uses type `std::marker::PhantomData<bool>`, which is not FFI-safe
error: `extern` fn uses type `std::marker::PhantomData<bool>`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:164:43
|
LL | pub extern "C" fn unused_generic2<T>() -> PhantomData<bool> {
| ^^^^^^^^^^^^^^^^^ not FFI-safe
|
= note: composed only of `PhantomData`

error: `extern` block uses type `Foo`, which is not FFI-safe
error: `extern` fn uses type `Foo`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:171:48
|
LL | pub extern "C" fn used_generic2<T>(x: T, size: *const Foo) { }
Expand All @@ -225,7 +225,7 @@ note: type defined here
LL | pub struct Foo;
| ^^^^^^^^^^^^^^^

error: `extern` block uses type `std::vec::Vec<T>`, which is not FFI-safe
error: `extern` fn uses type `std::vec::Vec<T>`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:178:39
|
LL | pub extern "C" fn used_generic4<T>(x: Vec<T>) { }
Expand All @@ -234,7 +234,7 @@ LL | pub extern "C" fn used_generic4<T>(x: Vec<T>) { }
= help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
= note: this struct has unspecified layout

error: `extern` block uses type `std::vec::Vec<T>`, which is not FFI-safe
error: `extern` fn uses type `std::vec::Vec<T>`, which is not FFI-safe
--> $DIR/lint-ctypes-fn.rs:181:41
|
LL | pub extern "C" fn used_generic5<T>() -> Vec<T> {
Expand Down

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