Rollup merge of rust-lang#67770 - Centril:reduce-diversity-2, r=petrochenkov

More reductions in error handling diversity

In this follow up to rust-lang#67744, we:

- Remove all fatal / error / warning macros in `syntax` except for `struct_span_err`, which is moved to `rustc_errors`.

- Lintify some hard-coded warnings which used warning macros.

- Defatalize some errors.

In general, the goal here is to make it painful to use fatal or unstructured errors and so we hopefully won't see many of these creep in.

Author: Centril

Cargo.lock

@@ -3774,6 +3774,7 @@ version = "0.0.0"
 dependencies = [
  "rustc",
  "rustc_error_codes",
+ "rustc_errors",
  "rustc_metadata",
  "rustc_span",
  "syntax",
@@ -3787,6 +3788,7 @@ dependencies = [
  "rustc",
  "rustc_data_structures",
  "rustc_error_codes",
+ "rustc_errors",
  "rustc_span",
  "rustc_typeck",
  "syntax",

src/librustc/hir/check_attr.rs

@@ -12,7 +12,9 @@ use crate::lint::builtin::UNUSED_ATTRIBUTES;
 use crate::ty::query::Providers;
 use crate::ty::TyCtxt;
 
+use errors::struct_span_err;
 use rustc_span::Span;
+
 use std::fmt::{self, Display};
 use syntax::{attr, symbol::sym};
 
@@ -428,21 +430,27 @@ impl CheckAttrVisitor<'tcx> {
         // Error on repr(transparent, <anything else>).
         if is_transparent && hints.len() > 1 {
             let hint_spans: Vec<_> = hint_spans.clone().collect();
-            span_err!(
+            struct_span_err!(
                 self.tcx.sess,
                 hint_spans,
                 E0692,
                 "transparent {} cannot have other repr hints",
                 target
-            );
+            )
+            .emit();
         }
         // Warn on repr(u8, u16), repr(C, simd), and c-like-enum-repr(C, u8)
         if (int_reprs > 1)
             || (is_simd && is_c)
             || (int_reprs == 1 && is_c && item.map_or(false, |item| is_c_like_enum(item)))
         {
-            let hint_spans: Vec<_> = hint_spans.collect();
-            span_warn!(self.tcx.sess, hint_spans, E0566, "conflicting representation hints");
+            struct_span_err!(
+                self.tcx.sess,
+                hint_spans.collect::<Vec<Span>>(),
+                E0566,
+                "conflicting representation hints",
+            )
+            .emit();
         }
     }
 

src/librustc/infer/error_reporting/mod.rs

@@ -65,7 +65,7 @@ use crate::ty::{
     Region, Ty, TyCtxt, TypeFoldable,
 };
 
-use errors::{Applicability, DiagnosticBuilder, DiagnosticStyledString};
+use errors::{struct_span_err, Applicability, DiagnosticBuilder, DiagnosticStyledString};
 use rustc_error_codes::*;
 use rustc_span::{Pos, Span};
 use rustc_target::spec::abi;

src/librustc/infer/error_reporting/need_type_info.rs

@@ -5,7 +5,7 @@ use crate::infer::type_variable::TypeVariableOriginKind;
 use crate::infer::InferCtxt;
 use crate::ty::print::Print;
 use crate::ty::{self, DefIdTree, Infer, Ty, TyVar};
-use errors::{Applicability, DiagnosticBuilder};
+use errors::{struct_span_err, Applicability, DiagnosticBuilder};
 use rustc_span::Span;
 use std::borrow::Cow;
 use syntax::source_map::DesugaringKind;
@@ -153,14 +153,11 @@ pub enum TypeAnnotationNeeded {
 
 impl Into<errors::DiagnosticId> for TypeAnnotationNeeded {
     fn into(self) -> errors::DiagnosticId {
-        syntax::diagnostic_used!(E0282);
-        syntax::diagnostic_used!(E0283);
-        syntax::diagnostic_used!(E0284);
-        errors::DiagnosticId::Error(match self {
-            Self::E0282 => "E0282".to_string(),
-            Self::E0283 => "E0283".to_string(),
-            Self::E0284 => "E0284".to_string(),
-        })
+        match self {
+            Self::E0282 => errors::error_code!(E0282),
+            Self::E0283 => errors::error_code!(E0283),
+            Self::E0284 => errors::error_code!(E0284),
+        }
     }
 }
 

src/librustc/infer/error_reporting/nice_region_error/different_lifetimes.rs

@@ -5,6 +5,7 @@ use crate::infer::error_reporting::nice_region_error::util::AnonymousParamInfo;
 use crate::infer::error_reporting::nice_region_error::NiceRegionError;
 use crate::util::common::ErrorReported;
 
+use errors::struct_span_err;
 use rustc_error_codes::*;
 
 impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {

src/librustc/infer/error_reporting/nice_region_error/named_anon_conflict.rs

@@ -3,7 +3,7 @@
 use crate::hir::{FunctionRetTy, TyKind};
 use crate::infer::error_reporting::nice_region_error::NiceRegionError;
 use crate::ty;
-use errors::{Applicability, DiagnosticBuilder};
+use errors::{struct_span_err, Applicability, DiagnosticBuilder};
 
 use rustc_error_codes::*;
 

src/librustc/infer/error_reporting/note.rs

@@ -2,7 +2,7 @@ use crate::infer::{self, InferCtxt, SubregionOrigin};
 use crate::middle::region;
 use crate::ty::error::TypeError;
 use crate::ty::{self, Region};
-use errors::DiagnosticBuilder;
+use errors::{struct_span_err, DiagnosticBuilder};
 
 use rustc_error_codes::*;
 

src/librustc/infer/opaque_types/mod.rs

@@ -9,7 +9,7 @@ use crate::ty::fold::{BottomUpFolder, TypeFoldable, TypeFolder, TypeVisitor};
 use crate::ty::subst::{GenericArg, GenericArgKind, InternalSubsts, SubstsRef};
 use crate::ty::{self, GenericParamDefKind, Ty, TyCtxt};
 use crate::util::nodemap::DefIdMap;
-use errors::DiagnosticBuilder;
+use errors::{struct_span_err, DiagnosticBuilder};
 use rustc::session::config::nightly_options;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync::Lrc;
@@ -523,11 +523,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         err.span_label(span, label);
 
         if nightly_options::is_nightly_build() {
-            help!(
-                err,
-                "add #![feature(member_constraints)] to the crate attributes \
-                   to enable"
-            );
+            err.help("add #![feature(member_constraints)] to the crate attributes to enable");
         }
 
         err.emit();

src/librustc/lint/builtin.rs

@@ -95,6 +95,12 @@ declare_lint! {
     "detects overlapping patterns"
 }
 
+declare_lint! {
+    pub BINDINGS_WITH_VARIANT_NAME,
+    Warn,
+    "detects pattern bindings with the same name as one of the matched variants"
+}
+
 declare_lint! {
     pub UNUSED_MACROS,
     Warn,
@@ -459,6 +465,7 @@ declare_lint_pass! {
         UNREACHABLE_CODE,
         UNREACHABLE_PATTERNS,
         OVERLAPPING_PATTERNS,
+        BINDINGS_WITH_VARIANT_NAME,
         UNUSED_MACROS,
         WARNINGS,
         UNUSED_FEATURES,

src/librustc/lint/context.rs

@@ -32,9 +32,9 @@ use crate::ty::{self, print::Printer, subst::GenericArg, Ty, TyCtxt};
 use crate::util::common::time;
 use crate::util::nodemap::FxHashMap;
 
-use errors::DiagnosticBuilder;
+use errors::{struct_span_err, DiagnosticBuilder};
 use rustc_data_structures::sync::{self, join, par_iter, ParallelIterator};
-use rustc_span::{symbol::Symbol, MultiSpan, Span};
+use rustc_span::{symbol::Symbol, MultiSpan, Span, DUMMY_SP};
 use std::slice;
 use syntax::ast;
 use syntax::util::lev_distance::find_best_match_for_name;
@@ -295,7 +295,8 @@ impl LintStore {
             CheckLintNameResult::Ok(_) => None,
             CheckLintNameResult::Warning(ref msg, _) => Some(sess.struct_warn(msg)),
             CheckLintNameResult::NoLint(suggestion) => {
-                let mut err = struct_err!(sess, E0602, "unknown lint: `{}`", lint_name);
+                let mut err =
+                    struct_span_err!(sess, DUMMY_SP, E0602, "unknown lint: `{}`", lint_name);
 
                 if let Some(suggestion) = suggestion {
                     err.help(&format!("did you mean: `{}`", suggestion));