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Auto merge of #1823 - hyd-dev:extern-crate-std, r=RalfJung

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Detect `std` by checking if the crate defines `#[lang = "start"]` rather than string comparison

I also considered to compare the crate name with `sym::std`, but it's easy to name any crate `std` by using `--crate-name std`, so I don't think that is robust enough.

Note that this only checks the crate, it does not check whether the call is in `sys::unix` or `sys::windows`, unlike the previous implementation, but I think it's already robust enough.

Fixes #1821.
This commit is contained in:
bors 2021-06-06 08:34:12 +00:00
commit 28fbf81c40
8 changed files with 44 additions and 25 deletions
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8
src/helpers.rs
View file

@ -628,6 +628,14 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
}
Ok(())
}
fn frame_in_std(&self) -> bool {
let this = self.eval_context_ref();
this.tcx.lang_items().start_fn().map_or(false, |start_fn| {
this.tcx.def_path(this.frame().instance.def_id()).krate
== this.tcx.def_path(start_fn).krate
})
}
}
/// Check that the number of args is what we expect.

10
src/shims/posix/foreign_items.rs
View file

@ -475,7 +475,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
// Incomplete shims that we "stub out" just to get pre-main initialization code to work.
// These shims are enabled only when the caller is in the standard library.
"pthread_attr_getguardsize"
if this.frame().instance.to_string().starts_with("std::sys::unix::") => {
if this.frame_in_std() => {
this.check_abi(abi, Abi::C { unwind: false })?;
let &[ref _attr, ref guard_size] = check_arg_count(args)?;
let guard_size = this.deref_operand(guard_size)?;
@ -488,13 +488,13 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
| "pthread_attr_init"
| "pthread_attr_destroy"
if this.frame().instance.to_string().starts_with("std::sys::unix::") => {
if this.frame_in_std() => {
this.check_abi(abi, Abi::C { unwind: false })?;
let &[_] = check_arg_count(args)?;
this.write_null(dest)?;
}
| "pthread_attr_setstacksize"
if this.frame().instance.to_string().starts_with("std::sys::unix::") => {
if this.frame_in_std() => {
this.check_abi(abi, Abi::C { unwind: false })?;
let &[_, _] = check_arg_count(args)?;
this.write_null(dest)?;
@ -502,14 +502,14 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
| "signal"
| "sigaltstack"
if this.frame().instance.to_string().starts_with("std::sys::unix::") => {
if this.frame_in_std() => {
this.check_abi(abi, Abi::C { unwind: false })?;
let &[_, _] = check_arg_count(args)?;
this.write_null(dest)?;
}
| "sigaction"
| "mprotect"
if this.frame().instance.to_string().starts_with("std::sys::unix::") => {
if this.frame_in_std() => {
this.check_abi(abi, Abi::C { unwind: false })?;
let &[_, _, _] = check_arg_count(args)?;
this.write_null(dest)?;

4
src/shims/posix/linux/foreign_items.rs
View file

@ -207,9 +207,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
// Incomplete shims that we "stub out" just to get pre-main initialization code to work.
// These shims are enabled only when the caller is in the standard library.
"pthread_getattr_np"
if this.frame().instance.to_string().starts_with("std::sys::unix::") =>
{
"pthread_getattr_np" if this.frame_in_std() => {
this.check_abi(abi, Abi::C { unwind: false })?;
let &[ref _thread, ref _attr] = check_arg_count(args)?;
this.write_null(dest)?;

2
src/shims/posix/macos/foreign_items.rs
View file

@ -149,7 +149,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
// Incomplete shims that we "stub out" just to get pre-main initialization code to work.
// These shims are enabled only when the caller is in the standard library.
"mmap" if this.frame().instance.to_string().starts_with("std::sys::unix::") => {
"mmap" if this.frame_in_std() => {
this.check_abi(abi, Abi::C { unwind: false })?;
// This is a horrible hack, but since the guard page mechanism calls mmap and expects a particular return value, we just give it that value.
let &[ref addr, _, _, _, _, _] = check_arg_count(args)?;

22
src/shims/windows/foreign_items.rs
View file

@ -348,35 +348,27 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
// Incomplete shims that we "stub out" just to get pre-main initialization code to work.
// These shims are enabled only when the caller is in the standard library.
"GetProcessHeap"
if this.frame().instance.to_string().starts_with("std::sys::windows::") =>
{
"GetProcessHeap" if this.frame_in_std() => {
this.check_abi(abi, Abi::System { unwind: false })?;
let &[] = check_arg_count(args)?;
// Just fake a HANDLE
this.write_scalar(Scalar::from_machine_isize(1, this), dest)?;
}
"SetConsoleTextAttribute"
if this.frame().instance.to_string().starts_with("std::sys::windows::") =>
{
"SetConsoleTextAttribute" if this.frame_in_std() => {
this.check_abi(abi, Abi::System { unwind: false })?;
#[allow(non_snake_case)]
let &[ref _hConsoleOutput, ref _wAttribute] = check_arg_count(args)?;
// Pretend these does not exist / nothing happened, by returning zero.
this.write_null(dest)?;
}
"AddVectoredExceptionHandler"
if this.frame().instance.to_string().starts_with("std::sys::windows::") =>
{
"AddVectoredExceptionHandler" if this.frame_in_std() => {
this.check_abi(abi, Abi::System { unwind: false })?;
#[allow(non_snake_case)]
let &[ref _First, ref _Handler] = check_arg_count(args)?;
// Any non zero value works for the stdlib. This is just used for stack overflows anyway.
this.write_scalar(Scalar::from_machine_usize(1, this), dest)?;
}
"SetThreadStackGuarantee"
if this.frame().instance.to_string().starts_with("std::sys::windows::") =>
{
"SetThreadStackGuarantee" if this.frame_in_std() => {
this.check_abi(abi, Abi::System { unwind: false })?;
#[allow(non_snake_case)]
let &[_StackSizeInBytes] = check_arg_count(args)?;
@ -387,7 +379,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
| "EnterCriticalSection"
| "LeaveCriticalSection"
| "DeleteCriticalSection"
if this.frame().instance.to_string().starts_with("std::sys::windows::") =>
if this.frame_in_std() =>
{
this.check_abi(abi, Abi::System { unwind: false })?;
#[allow(non_snake_case)]
@ -401,9 +393,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
// (Windows locks are reentrant, and we have only 1 thread,
// so not doing any futher checks here is at least not incorrect.)
}
"TryEnterCriticalSection"
if this.frame().instance.to_string().starts_with("std::sys::windows::") =>
{
"TryEnterCriticalSection" if this.frame_in_std() => {
this.check_abi(abi, Abi::System { unwind: false })?;
#[allow(non_snake_case)]
let &[ref _lpCriticalSection] = check_arg_count(args)?;

13
tests/compile-fail/unsupported_signal.rs Normal file
View file

@ -0,0 +1,13 @@
//! `signal()` is special on Linux and macOS that it's only supported within libstd.
//! The implementation is not complete enough to permit user code to call it.
// ignore-windows: No libc on Windows
#![feature(rustc_private)]
extern crate libc;
fn main() {
unsafe {
libc::signal(libc::SIGPIPE, libc::SIG_IGN);
//~^ ERROR unsupported operation: can't call foreign function: signal
}
}

5
tests/run-pass/extern_crate_std_in_main.rs Normal file
View file

@ -0,0 +1,5 @@
#![no_std]
fn main() {
extern crate std;
}

5
tests/run-pass/rename_std.rs Normal file
View file

@ -0,0 +1,5 @@
#![no_std]
extern crate std as foo;
fn main() {}