From fae40c507068b2d7aa5dc7bda729762e536aa8c2 Mon Sep 17 00:00:00 2001 From: Lucas Kent Date: Sun, 12 Dec 2021 13:04:00 +1100 Subject: [PATCH] Suggest to specify a target triple when eh_personality lang item is missing --- compiler/rustc_passes/src/weak_lang_items.rs | 10 ++++++++-- src/test/ui/extern-flag/empty-extern-arg.stderr | 3 +++ src/test/ui/missing/missing-alloc_error_handler.stderr | 2 +- src/test/ui/panic-handler/weak-lang-item.stderr | 3 +++ 4 files changed, 15 insertions(+), 3 deletions(-) diff --git a/compiler/rustc_passes/src/weak_lang_items.rs b/compiler/rustc_passes/src/weak_lang_items.rs index c6c32e69aab..61c82f031dd 100644 --- a/compiler/rustc_passes/src/weak_lang_items.rs +++ b/compiler/rustc_passes/src/weak_lang_items.rs @@ -67,10 +67,16 @@ fn verify<'tcx>(tcx: TyCtxt<'tcx>, items: &lang_items::LanguageItems) { } else if item == LangItem::Oom { if !tcx.features().default_alloc_error_handler { tcx.sess.err("`#[alloc_error_handler]` function required, but not found"); - tcx.sess.note_without_error("Use `#![feature(default_alloc_error_handler)]` for a default error handler"); + tcx.sess.note_without_error("use `#![feature(default_alloc_error_handler)]` for a default error handler"); } } else { - tcx.sess.err(&format!("language item required, but not found: `{}`", name)); + tcx + .sess + .diagnostic() + .struct_err(&format!("language item required, but not found: `{}`", name)) + .note(&format!("this can occur when a binary crate with `#![no_std]` is compiled for a target where `{}` is defined in the standard library", name)) + .help(&format!("you may be able to compile for a target that doesn't need `{}`, specify a target with `--target` or in `.cargo/config`", name)) + .emit(); } } } diff --git a/src/test/ui/extern-flag/empty-extern-arg.stderr b/src/test/ui/extern-flag/empty-extern-arg.stderr index b0628a4f6dd..39a66c08de0 100644 --- a/src/test/ui/extern-flag/empty-extern-arg.stderr +++ b/src/test/ui/extern-flag/empty-extern-arg.stderr @@ -1,6 +1,9 @@ error: extern location for std does not exist: error: language item required, but not found: `eh_personality` + | + = note: this can occur when a binary crate with `#![no_std]` is compiled for a target where `eh_personality` is defined in the standard library + = help: you may be able to compile for a target that doesn't need `eh_personality`, specify a target with `--target` or in `.cargo/config` error: `#[panic_handler]` function required, but not found diff --git a/src/test/ui/missing/missing-alloc_error_handler.stderr b/src/test/ui/missing/missing-alloc_error_handler.stderr index ed84493deb5..995fa7cf85e 100644 --- a/src/test/ui/missing/missing-alloc_error_handler.stderr +++ b/src/test/ui/missing/missing-alloc_error_handler.stderr @@ -1,6 +1,6 @@ error: `#[alloc_error_handler]` function required, but not found -note: Use `#![feature(default_alloc_error_handler)]` for a default error handler +note: use `#![feature(default_alloc_error_handler)]` for a default error handler error: aborting due to previous error diff --git a/src/test/ui/panic-handler/weak-lang-item.stderr b/src/test/ui/panic-handler/weak-lang-item.stderr index 1f14b20e451..cc25f08e33a 100644 --- a/src/test/ui/panic-handler/weak-lang-item.stderr +++ b/src/test/ui/panic-handler/weak-lang-item.stderr @@ -11,6 +11,9 @@ LL | extern crate core as other_core; | error: language item required, but not found: `eh_personality` + | + = note: this can occur when a binary crate with `#![no_std]` is compiled for a target where `eh_personality` is defined in the standard library + = help: you may be able to compile for a target that doesn't need `eh_personality`, specify a target with `--target` or in `.cargo/config` error: `#[panic_handler]` function required, but not found