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CFI: Skip non-passed arguments
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Rust will occasionally rely on fn((), X) -> Y being compatible with
fn(X) -> Y, since () is a non-passed argument. Relax CFI by choosing not
to encode non-passed arguments.
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@maurer
maurer committed Mar 21, 2024
1 parent e3df96c commit f2f0d25
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Showing 6 changed files with 65 additions and 39 deletions.
22 changes: 15 additions & 7 deletions compiler/rustc_symbol_mangling/src/typeid/typeid_itanium_cxx_abi.rs
View file
Expand Up @@ -18,7 +18,7 @@ use rustc_middle::ty::{
use rustc_middle::ty::{GenericArg, GenericArgKind, GenericArgsRef};
use rustc_span::def_id::DefId;
use rustc_span::sym;
use rustc_target::abi::call::{Conv, FnAbi};
use rustc_target::abi::call::{Conv, FnAbi, PassMode};
use rustc_target::abi::Integer;
use rustc_target::spec::abi::Abi;
use std::fmt::Write as _;
Expand Down Expand Up @@ -1040,19 +1040,27 @@ pub fn typeid_for_fnabi<'tcx>(
typeid.push_str(&encode_ty(tcx, ty, &mut dict, encode_ty_options));

// Encode the parameter types

// We erase ZSTs as we go if the argument is skipped. This is an implementation detail of how
// MIR is currently treated by rustc, and subject to change in the future. Specifically, MIR
// interpretation today will allow skipped arguments to simply not be passed at a call-site.
if !fn_abi.c_variadic {
if !fn_abi.args.is_empty() {
for arg in fn_abi.args.iter() {
let ty = transform_ty(tcx, arg.layout.ty, transform_ty_options);
typeid.push_str(&encode_ty(tcx, ty, &mut dict, encode_ty_options));
}
} else {
let mut pushed_arg = false;
for arg in fn_abi.args.iter().filter(|arg| arg.mode != PassMode::Ignore) {
pushed_arg = true;
let ty = transform_ty(tcx, arg.layout.ty, transform_ty_options);
typeid.push_str(&encode_ty(tcx, ty, &mut dict, encode_ty_options));
}
if !pushed_arg {
// Empty parameter lists, whether declared as () or conventionally as (void), are
// encoded with a void parameter specifier "v".
typeid.push('v');
}
} else {
for n in 0..fn_abi.fixed_count as usize {
if fn_abi.args[n].mode == PassMode::Ignore {
continue;
}
let ty = transform_ty(tcx, fn_abi.args[n].layout.ty, transform_ty_options);
typeid.push_str(&encode_ty(tcx, ty, &mut dict, encode_ty_options));
}
Expand Down
50 changes: 26 additions & 24 deletions tests/codegen/sanitizer/cfi/emit-type-metadata-id-itanium-cxx-abi-paths.rs
View file
Expand Up @@ -47,40 +47,42 @@ pub fn foo() where
let _: Type4 = <Foo>::bar;
}

pub fn foo1(_: Type1) { }
// Force arguments to be passed by using a reference. Otherwise, they may end up PassMode::Ignore

pub fn foo1(_: &Type1) { }
// CHECK: define{{.*}}4foo1{{.*}}!type ![[TYPE1:[0-9]+]] !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}
pub fn foo2(_: Type1, _: Type1) { }
pub fn foo2(_: &Type1, _: &Type1) { }
// CHECK: define{{.*}}4foo2{{.*}}!type ![[TYPE2:[0-9]+]] !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}
pub fn foo3(_: Type1, _: Type1, _: Type1) { }
pub fn foo3(_: &Type1, _: &Type1, _: &Type1) { }
// CHECK: define{{.*}}4foo3{{.*}}!type ![[TYPE3:[0-9]+]] !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}
pub fn foo4(_: Type2) { }
pub fn foo4(_: &Type2) { }
// CHECK: define{{.*}}4foo4{{.*}}!type ![[TYPE4:[0-9]+]] !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}
pub fn foo5(_: Type2, _: Type2) { }
pub fn foo5(_: &Type2, _: &Type2) { }
// CHECK: define{{.*}}4foo5{{.*}}!type ![[TYPE5:[0-9]+]] !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}
pub fn foo6(_: Type2, _: Type2, _: Type2) { }
pub fn foo6(_: &Type2, _: &Type2, _: &Type2) { }
// CHECK: define{{.*}}4foo6{{.*}}!type ![[TYPE6:[0-9]+]] !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}
pub fn foo7(_: Type3) { }
pub fn foo7(_: &Type3) { }
// CHECK: define{{.*}}4foo7{{.*}}!type ![[TYPE7:[0-9]+]] !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}
pub fn foo8(_: Type3, _: Type3) { }
pub fn foo8(_: &Type3, _: &Type3) { }
// CHECK: define{{.*}}4foo8{{.*}}!type ![[TYPE8:[0-9]+]] !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}
pub fn foo9(_: Type3, _: Type3, _: Type3) { }
pub fn foo9(_: &Type3, _: &Type3, _: &Type3) { }
// CHECK: define{{.*}}4foo9{{.*}}!type ![[TYPE9:[0-9]+]] !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}
pub fn foo10(_: Type4) { }
pub fn foo10(_: &Type4) { }
// CHECK: define{{.*}}5foo10{{.*}}!type ![[TYPE10:[0-9]+]] !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}
pub fn foo11(_: Type4, _: Type4) { }
pub fn foo11(_: &Type4, _: &Type4) { }
// CHECK: define{{.*}}5foo11{{.*}}!type ![[TYPE11:[0-9]+]] !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}
pub fn foo12(_: Type4, _: Type4, _: Type4) { }
pub fn foo12(_: &Type4, _: &Type4, _: &Type4) { }
// CHECK: define{{.*}}5foo12{{.*}}!type ![[TYPE12:[0-9]+]] !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}

// CHECK: ![[TYPE1]] = !{i64 0, !"_ZTSFvu{{[0-9]+}}NvNFNvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo10{{[{}][{}]}}extern{{[}][}]}}3barE"}
// CHECK: ![[TYPE2]] = !{i64 0, !"_ZTSFvu{{[0-9]+}}NvNFNvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo10{{[{}][{}]}}extern{{[}][}]}}3barS_E"}
// CHECK: ![[TYPE3]] = !{i64 0, !"_ZTSFvu{{[0-9]+}}NvNFNvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo10{{[{}][{}]}}extern{{[}][}]}}3barS_S_E"}
// CHECK: ![[TYPE4]] = !{i64 0, !"_ZTSFvu{{[0-9]+}}NtNCNvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo11{{[{}][{}]}}closure{{[}][}]}}3FooE"}
// CHECK: ![[TYPE5]] = !{i64 0, !"_ZTSFvu{{[0-9]+}}NtNCNvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo11{{[{}][{}]}}closure{{[}][}]}}3FooS_E"}
// CHECK: ![[TYPE6]] = !{i64 0, !"_ZTSFvu{{[0-9]+}}NtNCNvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo11{{[{}][{}]}}closure{{[}][}]}}3FooS_S_E"}
// CHECK: ![[TYPE7]] = !{i64 0, !"_ZTSFvu{{[0-9]+}}NtNkNvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo12{{[{}][{}]}}constant{{[}][}]}}3FooE"}
// CHECK: ![[TYPE8]] = !{i64 0, !"_ZTSFvu{{[0-9]+}}NtNkNvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo12{{[{}][{}]}}constant{{[}][}]}}3FooS_E"}
// CHECK: ![[TYPE9]] = !{i64 0, !"_ZTSFvu{{[0-9]+}}NtNkNvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo12{{[{}][{}]}}constant{{[}][}]}}3FooS_S_E"}
// CHECK: ![[TYPE10]] = !{i64 0, !"_ZTSFvu{{[0-9]+}}NvNINvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo8{{[{}][{}]}}impl{{[}][}]}}3barE"}
// CHECK: ![[TYPE11]] = !{i64 0, !"_ZTSFvu{{[0-9]+}}NvNINvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo8{{[{}][{}]}}impl{{[}][}]}}3barS_E"}
// CHECK: ![[TYPE12]] = !{i64 0, !"_ZTSFvu{{[0-9]+}}NvNINvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo8{{[{}][{}]}}impl{{[}][}]}}3barS_S_E"}
// CHECK: ![[TYPE1]] = !{i64 0, !"_ZTSFvu3refIu{{[0-9]+}}NvNFNvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo10{{[{}][{}]}}extern{{[}][}]}}3barEE"}
// CHECK: ![[TYPE2]] = !{i64 0, !"_ZTSFvu3refIu{{[0-9]+}}NvNFNvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo10{{[{}][{}]}}extern{{[}][}]}}3barES0_E"}
// CHECK: ![[TYPE3]] = !{i64 0, !"_ZTSFvu3refIu{{[0-9]+}}NvNFNvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo10{{[{}][{}]}}extern{{[}][}]}}3barES0_S0_E"}
// CHECK: ![[TYPE4]] = !{i64 0, !"_ZTSFvu3refIu{{[0-9]+}}NtNCNvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo11{{[{}][{}]}}closure{{[}][}]}}3FooEE"}
// CHECK: ![[TYPE5]] = !{i64 0, !"_ZTSFvu3refIu{{[0-9]+}}NtNCNvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo11{{[{}][{}]}}closure{{[}][}]}}3FooES0_E"}
// CHECK: ![[TYPE6]] = !{i64 0, !"_ZTSFvu3refIu{{[0-9]+}}NtNCNvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo11{{[{}][{}]}}closure{{[}][}]}}3FooES0_S0_E"}
// CHECK: ![[TYPE7]] = !{i64 0, !"_ZTSFvu3refIu{{[0-9]+}}NtNkNvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo12{{[{}][{}]}}constant{{[}][}]}}3FooEE"}
// CHECK: ![[TYPE8]] = !{i64 0, !"_ZTSFvu3refIu{{[0-9]+}}NtNkNvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo12{{[{}][{}]}}constant{{[}][}]}}3FooES0_E"}
// CHECK: ![[TYPE9]] = !{i64 0, !"_ZTSFvu3refIu{{[0-9]+}}NtNkNvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo12{{[{}][{}]}}constant{{[}][}]}}3FooES0_S0_E"}
// CHECK: ![[TYPE10]] = !{i64 0, !"_ZTSFvu3refIu{{[0-9]+}}NvNINvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo8{{[{}][{}]}}impl{{[}][}]}}3barEE"}
// CHECK: ![[TYPE11]] = !{i64 0, !"_ZTSFvu3refIu{{[0-9]+}}NvNINvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo8{{[{}][{}]}}impl{{[}][}]}}3barES0_E"}
// CHECK: ![[TYPE12]] = !{i64 0, !"_ZTSFvu3refIu{{[0-9]+}}NvNINvC{{[[:print:]]+}}_{{[[:print:]]+}}3foo8{{[{}][{}]}}impl{{[}][}]}}3barES0_S0_E"}
6 changes: 2 additions & 4 deletions tests/codegen/sanitizer/cfi/emit-type-metadata-id-itanium-cxx-abi-primitive-types.rs
View file
Expand Up @@ -12,9 +12,9 @@ use core::ffi::*;
pub fn foo1(_: ()) { }
// CHECK: define{{.*}}4foo1{{.*}}!type ![[TYPE1:[0-9]+]] !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}
pub fn foo2(_: (), _: c_void) { }
// CHECK: define{{.*}}4foo2{{.*}}!type ![[TYPE2:[0-9]+]] !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}
// CHECK: define{{.*}}4foo2{{.*}}!type ![[TYPE1:[0-9]+]] !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}
pub fn foo3(_: (), _: c_void, _: c_void) { }
// CHECK: define{{.*}}4foo3{{.*}}!type ![[TYPE3:[0-9]+]] !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}
// CHECK: define{{.*}}4foo3{{.*}}!type ![[TYPE2:[0-9]+]] !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}
pub fn foo4(_: *mut ()) { }
// CHECK: define{{.*}}4foo4{{.*}}!type ![[TYPE4:[0-9]+]] !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}
pub fn foo5(_: *mut (), _: *mut c_void) { }
Expand Down Expand Up @@ -131,8 +131,6 @@ pub fn foo60(_: &str, _: &str, _: &str) { }
// CHECK: define{{.*}}5foo60{{.*}}!type ![[TYPE60:[0-9]+]] !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}

// CHECK: ![[TYPE1]] = !{i64 0, !"_ZTSFvvE"}
// CHECK: ![[TYPE2]] = !{i64 0, !"_ZTSFvvvE"}
// CHECK: ![[TYPE3]] = !{i64 0, !"_ZTSFvvvvE"}
// CHECK: ![[TYPE4]] = !{i64 0, !"_ZTSFvPvE"}
// CHECK: ![[TYPE5]] = !{i64 0, !"_ZTSFvPvS_E"}
// CHECK: ![[TYPE6]] = !{i64 0, !"_ZTSFvPvS_S_E"}
Expand Down
2 changes: 1 addition & 1 deletion tests/codegen/sanitizer/cfi/emit-type-metadata-id-itanium-cxx-abi-repr-transparent-types.rs
View file
Expand Up @@ -28,7 +28,7 @@ pub struct Type2<'a> {
member3: &'a Type2<'a>,
}

pub struct Bar;
pub struct Bar(i32);

// repr(transparent) user-defined generic type
#[repr(transparent)]
Expand Down
6 changes: 3 additions & 3 deletions tests/codegen/sanitizer/cfi/normalize-integers.rs
View file
Expand Up @@ -41,6 +41,6 @@ pub fn foo11(_: (), _: usize, _: usize, _: usize) { }
// CHECK: ![[TYPE6]] = !{i64 0, !"_ZTSFv{{u3i16|u3i32|u3i64|u4i128}}E.normalized"}
// CHECK: ![[TYPE7]] = !{i64 0, !"_ZTSFv{{u3i16|u3i32|u3i64|u4i128}}S_E.normalized"}
// CHECK: ![[TYPE8]] = !{i64 0, !"_ZTSFv{{u3i16|u3i32|u3i64|u4i128}}S_S_E.normalized"}
// CHECK: ![[TYPE9]] = !{i64 0, !"_ZTSFvv{{u3u16|u3u32|u3u64|u4u128}}E.normalized"}
// CHECK: ![[TYPE10]] = !{i64 0, !"_ZTSFvv{{u3u16|u3u32|u3u64|u4u128}}S_E.normalized"}
// CHECK: ![[TYPE11]] = !{i64 0, !"_ZTSFvv{{u3u16|u3u32|u3u64|u4u128}}S_S_E.normalized"}
// CHECK: ![[TYPE9]] = !{i64 0, !"_ZTSFv{{u3u16|u3u32|u3u64|u4u128}}E.normalized"}
// CHECK: ![[TYPE10]] = !{i64 0, !"_ZTSFv{{u3u16|u3u32|u3u64|u4u128}}S_E.normalized"}
// CHECK: ![[TYPE11]] = !{i64 0, !"_ZTSFv{{u3u16|u3u32|u3u64|u4u128}}S_S_E.normalized"}
18 changes: 18 additions & 0 deletions tests/ui/sanitizer/cfi-closure-fn-ptr-cast.rs
View file
@@ -0,0 +1,18 @@
// Tests that converting a closure to a function pointer works
// The notable thing being tested here is that when the closure does not capture anything,
// the call method from its Fn trait takes a ZST representing its environment. The compiler then
// uses the assumption that the ZST is non-passed to reify this into a function pointer.
//
// This checks that the reified function pointer will have the expected alias set at its call-site.

//@ needs-sanitizer-cfi
// FIXME(#122848) Remove only-linux once OSX CFI binaries work
//@ only-linux
//@ compile-flags: --crate-type=bin -Cprefer-dynamic=off -Clto -Zsanitizer=cfi
//@ compile-flags: -C target-feature=-crt-static -C codegen-units=1 -C opt-level=0
//@ run-pass

pub fn main() {
let f: &fn() = &((|| ()) as _);
f();
}

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