From 84b058ac47e2ea5f29887a4ed5ae286e37b22194 Mon Sep 17 00:00:00 2001
From: DrMeepster <19316085+DrMeepster@users.noreply.github.com>
Date: Thu, 2 Sep 2021 15:41:10 -0700
Subject: [PATCH] add support for #[start]
---
benches/helpers/miri_helper.rs | 5 +-
src/bin/miri.rs | 6 +--
src/eval.rs | 90 +++++++++++++++++++++++-----------
src/lib.rs | 2 +-
tests/run-pass/start.rs | 8 +++
tests/run-pass/start.stdout | 1 +
6 files changed, 78 insertions(+), 34 deletions(-)
create mode 100644 tests/run-pass/start.rs
create mode 100644 tests/run-pass/start.stdout
diff --git a/benches/helpers/miri_helper.rs b/benches/helpers/miri_helper.rs
index 2d27616a361..be542c2bc0a 100644
--- a/benches/helpers/miri_helper.rs
+++ b/benches/helpers/miri_helper.rs
@@ -20,11 +20,12 @@ impl rustc_driver::Callbacks for MiriCompilerCalls<'_> {
compiler.session().abort_if_errors();
queries.global_ctxt().unwrap().peek_mut().enter(|tcx| {
- let (entry_def_id, _) = tcx.entry_fn(()).expect("no main or start function found");
+ let (entry_def_id, entry_type) =
+ tcx.entry_fn(()).expect("no main or start function found");
self.bencher.iter(|| {
let config = miri::MiriConfig::default();
- miri::eval_main(tcx, entry_def_id, config);
+ miri::eval_entry(tcx, entry_def_id, entry_type, config);
});
});
diff --git a/src/bin/miri.rs b/src/bin/miri.rs
index 18c393815ca..fbc87148ec7 100644
--- a/src/bin/miri.rs
+++ b/src/bin/miri.rs
@@ -58,8 +58,8 @@ impl rustc_driver::Callbacks for MiriCompilerCalls {
queries.global_ctxt().unwrap().peek_mut().enter(|tcx| {
init_late_loggers(tcx);
- let (entry_def_id, _) = if let Some((entry_def, x)) = tcx.entry_fn(()) {
- (entry_def, x)
+ let (entry_def_id, entry_type) = if let Some(entry_def) = tcx.entry_fn(()) {
+ entry_def
} else {
let output_ty = ErrorOutputType::HumanReadable(HumanReadableErrorType::Default(
ColorConfig::Auto,
@@ -79,7 +79,7 @@ impl rustc_driver::Callbacks for MiriCompilerCalls {
env::set_current_dir(cwd).unwrap();
}
- if let Some(return_code) = miri::eval_main(tcx, entry_def_id, config) {
+ if let Some(return_code) = miri::eval_entry(tcx, entry_def_id, entry_type, config) {
std::process::exit(
i32::try_from(return_code).expect("Return value was too large!"),
);
diff --git a/src/eval.rs b/src/eval.rs
index 2b8fc0f5ade..f90a77fafd5 100644
--- a/src/eval.rs
+++ b/src/eval.rs
@@ -10,6 +10,8 @@ use rustc_middle::ty::{self, layout::LayoutCx, TyCtxt};
use rustc_target::abi::LayoutOf;
use rustc_target::spec::abi::Abi;
+use rustc_session::config::EntryFnType;
+
use crate::*;
#[derive(Copy, Clone, Debug, PartialEq)]
@@ -117,12 +119,13 @@ impl Default for MiriConfig {
}
/// Returns a freshly created `InterpCx`, along with an `MPlaceTy` representing
-/// the location where the return value of the `start` lang item will be
+/// the location where the return value of the `start` function will be
/// written to.
/// Public because this is also used by `priroda`.
pub fn create_ecx<'mir, 'tcx: 'mir>(
tcx: TyCtxt<'tcx>,
- main_id: DefId,
+ entry_id: DefId,
+ entry_type: EntryFnType,
config: MiriConfig,
) -> InterpResult<'tcx, (InterpCx<'mir, 'tcx, Evaluator<'mir, 'tcx>>, MPlaceTy<'tcx, Tag>)> {
let param_env = ty::ParamEnv::reveal_all();
@@ -145,26 +148,14 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
}
// Setup first stack-frame
- let main_instance = ty::Instance::mono(tcx, main_id);
- let main_mir = ecx.load_mir(main_instance.def, None)?;
+ let entry_instance = ty::Instance::mono(tcx, entry_id);
+ /*let entry_mir = ecx.load_mir(entry_instance.def, None)?;
if main_mir.arg_count != 0 {
bug!("main function must not take any arguments");
- }
+ }*/
- let start_id = tcx.lang_items().start_fn().unwrap();
- let main_ret_ty = tcx.fn_sig(main_id).output();
- let main_ret_ty = main_ret_ty.no_bound_vars().unwrap();
- let start_instance = ty::Instance::resolve(
- tcx,
- ty::ParamEnv::reveal_all(),
- start_id,
- tcx.mk_substs(::std::iter::once(ty::subst::GenericArg::from(main_ret_ty))),
- )
- .unwrap()
- .unwrap();
+ // First argument is constructed later, because its skipped if the entry function uses #[start]
- // First argument: pointer to `main()`.
- let main_ptr = ecx.memory.create_fn_alloc(FnVal::Instance(main_instance));
// Second argument (argc): length of `config.args`.
let argc = Scalar::from_machine_usize(u64::try_from(config.args.len()).unwrap(), &ecx);
// Third argument (`argv`): created from `config.args`.
@@ -237,28 +228,71 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
argv
};
+ /*let args: &[_] = match entry_type {
+ EntryFnType::Main => {
+ // First argument: pointer to `main()`.
+ let main_ptr = ecx.memory.create_fn_alloc(FnVal::Instance(main_instance));
+
+ &[Scalar::from_pointer(main_ptr, &ecx).into(), argc.into(), argv]
+ }
+ EntryFnType::Start => &[argc.into(), argv],
+ };*/
+
// Return place (in static memory so that it does not count as leak).
let ret_place = ecx.allocate(ecx.machine.layouts.isize, MiriMemoryKind::Machine.into())?;
// Call start function.
- ecx.call_function(
- start_instance,
- Abi::Rust,
- &[Scalar::from_pointer(main_ptr, &ecx).into(), argc.into(), argv],
- Some(&ret_place.into()),
- StackPopCleanup::None { cleanup: true },
- )?;
+
+ match entry_type {
+ EntryFnType::Main => {
+ let start_id = tcx.lang_items().start_fn().unwrap();
+ let main_ret_ty = tcx.fn_sig(entry_id).output();
+ let main_ret_ty = main_ret_ty.no_bound_vars().unwrap();
+ let start_instance = ty::Instance::resolve(
+ tcx,
+ ty::ParamEnv::reveal_all(),
+ start_id,
+ tcx.mk_substs(::std::iter::once(ty::subst::GenericArg::from(main_ret_ty))),
+ )
+ .unwrap()
+ .unwrap();
+
+ let main_ptr = ecx.memory.create_fn_alloc(FnVal::Instance(entry_instance));
+
+ ecx.call_function(
+ start_instance,
+ Abi::Rust,
+ &[Scalar::from_pointer(main_ptr, &ecx).into(), argc.into(), argv],
+ Some(&ret_place.into()),
+ StackPopCleanup::None { cleanup: true },
+ )?;
+ }
+ EntryFnType::Start => {
+ ecx.call_function(
+ entry_instance,
+ Abi::Rust,
+ &[argc.into(), argv],
+ Some(&ret_place.into()),
+ StackPopCleanup::None { cleanup: true },
+ )?;
+ }
+ }
Ok((ecx, ret_place))
}
-/// Evaluates the main function specified by `main_id`.
+/// Evaluates the entry function specified by `entry_id`.
/// Returns `Some(return_code)` if program executed completed.
/// Returns `None` if an evaluation error occured.
-pub fn eval_main<'tcx>(tcx: TyCtxt<'tcx>, main_id: DefId, config: MiriConfig) -> Option<i64> {
+pub fn eval_entry<'tcx>(
+ tcx: TyCtxt<'tcx>,
+ entry_id: DefId,
+ entry_type: EntryFnType,
+ config: MiriConfig,
+) -> Option<i64> {
// Copy setting before we move `config`.
let ignore_leaks = config.ignore_leaks;
- let (mut ecx, ret_place) = match create_ecx(tcx, main_id, config) {
+ let (mut ecx, ret_place) = match create_ecx(tcx, entry_id, entry_type, config) {
Ok(v) => v,
Err(err) => {
err.print_backtrace();
diff --git a/src/lib.rs b/src/lib.rs
index f8d8aacce3c..7ed915b6d1d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -60,7 +60,7 @@ pub use crate::diagnostics::{
NonHaltingDiagnostic, TerminationInfo,
};
pub use crate::eval::{
- create_ecx, eval_main, AlignmentCheck, IsolatedOp, MiriConfig, RejectOpWith,
+ create_ecx, eval_entry, AlignmentCheck, IsolatedOp, MiriConfig, RejectOpWith,
};
pub use crate::helpers::EvalContextExt as HelpersEvalContextExt;
pub use crate::machine::{
diff --git a/tests/run-pass/start.rs b/tests/run-pass/start.rs
new file mode 100644
index 00000000000..f25d62fa8c3
--- /dev/null
+++ b/tests/run-pass/start.rs
@@ -0,0 +1,8 @@
+#![feature(start)]
+
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+ println!("Hello from start!");
+
+ 0
+}
diff --git a/tests/run-pass/start.stdout b/tests/run-pass/start.stdout
new file mode 100644
index 00000000000..d7f627d237c
--- /dev/null
+++ b/tests/run-pass/start.stdout
@@ -0,0 +1 @@
+Hello from start!