Auto merge of #75130 - lcnr:array_chunks, r=ecstatic-morse

forbid `#[track_caller]` on main

fixes #75125

cc @anp

7 files changed, 75 insertions, 6 deletions

diff --git a/src/librustc_typeck/lib.rs b/src/librustc_typeck/lib.rs
index 9ba2545ba63..e203d51f612 100644
--- a/src/librustc_typeck/lib.rs
+++ b/src/librustc_typeck/lib.rs
@@ -100,7 +100,7 @@ use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_middle::util;
 use rustc_session::config::EntryFnType;
-use rustc_span::{Span, DUMMY_SP};
+use rustc_span::{symbol::sym, Span, DUMMY_SP};
 use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::traits::error_reporting::InferCtxtExt as _;
 use rustc_trait_selection::traits::{
@@ -194,6 +194,23 @@ fn check_main_fn_ty(tcx: TyCtxt<'_>, main_def_id: LocalDefId) {
                         .emit();
                         error = true;
                     }
+
+                    for attr in it.attrs {
+                        if attr.check_name(sym::track_caller) {
+                            tcx.sess
+                                .struct_span_err(
+                                    attr.span,
+                                    "`main` function is not allowed to be `#[track_caller]`",
+                                )
+                                .span_label(
+                                    main_span,
+                                    "`main` function is not allowed to be `#[track_caller]`",
+                                )
+                                .emit();
+                            error = true;
+                        }
+                    }
+
                     if error {
                         return;
                     }
@@ -268,12 +285,29 @@ fn check_start_fn_ty(tcx: TyCtxt<'_>, start_def_id: LocalDefId) {
                             tcx.sess,
                             span,
                             E0752,
-                            "start is not allowed to be `async`"
+                            "`start` is not allowed to be `async`"
                         )
-                        .span_label(span, "start is not allowed to be `async`")
+                        .span_label(span, "`start` is not allowed to be `async`")
                         .emit();
                         error = true;
                     }
+
+                    for attr in it.attrs {
+                        if attr.check_name(sym::track_caller) {
+                            tcx.sess
+                                .struct_span_err(
+                                    attr.span,
+                                    "`start` is not allowed to be `#[track_caller]`",
+                                )
+                                .span_label(
+                                    start_span,
+                                    "`start` is not allowed to be `#[track_caller]`",
+                                )
+                                .emit();
+                            error = true;
+                        }
+                    }
+
                     if error {
                         return;
                     }
diff --git a/src/test/ui/async-await/issue-68523-start.rs b/src/test/ui/async-await/issue-68523-start.rs
index 5988dffd68f..2ced88a16cc 100644
--- a/src/test/ui/async-await/issue-68523-start.rs
+++ b/src/test/ui/async-await/issue-68523-start.rs
@@ -4,6 +4,6 @@
 
 #[start]
 pub async fn start(_: isize, _: *const *const u8) -> isize {
-//~^ ERROR start is not allowed to be `async`
+//~^ ERROR `start` is not allowed to be `async`
     0
 }
diff --git a/src/test/ui/async-await/issue-68523-start.stderr b/src/test/ui/async-await/issue-68523-start.stderr
index e471945900e..3a0a3b5dece 100644
--- a/src/test/ui/async-await/issue-68523-start.stderr
+++ b/src/test/ui/async-await/issue-68523-start.stderr
@@ -1,8 +1,8 @@
-error[E0752]: start is not allowed to be `async`
+error[E0752]: `start` is not allowed to be `async`
   --> $DIR/issue-68523-start.rs:6:1
    |
 LL | pub async fn start(_: isize, _: *const *const u8) -> isize {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ start is not allowed to be `async`
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `start` is not allowed to be `async`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/rfc-2091-track-caller/error-with-main.rs b/src/test/ui/rfc-2091-track-caller/error-with-main.rs
new file mode 100644
index 00000000000..b2ea31bb517
--- /dev/null
+++ b/src/test/ui/rfc-2091-track-caller/error-with-main.rs
@@ -0,0 +1,4 @@
+#[track_caller] //~ ERROR `main` function is not allowed to be
+fn main() {
+    panic!("{}: oh no", std::panic::Location::caller());
+}
diff --git a/src/test/ui/rfc-2091-track-caller/error-with-main.stderr b/src/test/ui/rfc-2091-track-caller/error-with-main.stderr
new file mode 100644
index 00000000000..f05f88e7d71
--- /dev/null
+++ b/src/test/ui/rfc-2091-track-caller/error-with-main.stderr
@@ -0,0 +1,12 @@
+error: `main` function is not allowed to be `#[track_caller]`
+  --> $DIR/error-with-main.rs:1:1
+   |
+LL |   #[track_caller]
+   |   ^^^^^^^^^^^^^^^
+LL | / fn main() {
+LL | |     panic!("{}: oh no", std::panic::Location::caller());
+LL | | }
+   | |_- `main` function is not allowed to be `#[track_caller]`
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/rfc-2091-track-caller/error-with-start.rs b/src/test/ui/rfc-2091-track-caller/error-with-start.rs
new file mode 100644
index 00000000000..0cab4717063
--- /dev/null
+++ b/src/test/ui/rfc-2091-track-caller/error-with-start.rs
@@ -0,0 +1,7 @@
+#![feature(start)]
+
+#[start]
+#[track_caller] //~ ERROR `start` is not allowed to be `#[track_caller]`
+fn start(_argc: isize, _argv: *const *const u8) -> isize {
+    panic!("{}: oh no", std::panic::Location::caller());
+}
diff --git a/src/test/ui/rfc-2091-track-caller/error-with-start.stderr b/src/test/ui/rfc-2091-track-caller/error-with-start.stderr
new file mode 100644
index 00000000000..1a1f3e04491
--- /dev/null
+++ b/src/test/ui/rfc-2091-track-caller/error-with-start.stderr
@@ -0,0 +1,12 @@
+error: `start` is not allowed to be `#[track_caller]`
+  --> $DIR/error-with-start.rs:4:1
+   |
+LL |   #[track_caller]
+   |   ^^^^^^^^^^^^^^^
+LL | / fn start(_argc: isize, _argv: *const *const u8) -> isize {
+LL | |     panic!("{}: oh no", std::panic::Location::caller());
+LL | | }
+   | |_- `start` is not allowed to be `#[track_caller]`
+
+error: aborting due to previous error
+