Rollup merge of rust-lang#31926 - llogiq:more_post, r=eddyb

These `_post` methods are quite helpful to control lint behavior without storing e.g. block node ids. So here are a few more I believe will be helpful.

r? @Manishearth

Author: Manishearth

src/librustc/lint/context.rs

@@ -766,6 +766,7 @@ impl<'a, 'tcx, 'v> hir_visit::Visitor<'v> for LateContext<'a, 'tcx> {
         self.with_lint_attrs(&it.attrs, |cx| {
             run_lints!(cx, check_foreign_item, late_passes, it);
             hir_visit::walk_foreign_item(cx, it);
+            run_lints!(cx, check_foreign_item_post, late_passes, it);
         })
     }
 
@@ -795,6 +796,7 @@ impl<'a, 'tcx, 'v> hir_visit::Visitor<'v> for LateContext<'a, 'tcx> {
                 body: &'v hir::Block, span: Span, id: ast::NodeId) {
         run_lints!(self, check_fn, late_passes, fk, decl, body, span, id);
         hir_visit::walk_fn(self, fk, decl, body, span);
+        run_lints!(self, check_fn_post, late_passes, fk, decl, body, span, id);
     }
 
     fn visit_variant_data(&mut self,
@@ -835,6 +837,7 @@ impl<'a, 'tcx, 'v> hir_visit::Visitor<'v> for LateContext<'a, 'tcx> {
     fn visit_mod(&mut self, m: &hir::Mod, s: Span, n: ast::NodeId) {
         run_lints!(self, check_mod, late_passes, m, s, n);
         hir_visit::walk_mod(self, m);
+        run_lints!(self, check_mod_post, late_passes, m, s, n);
     }
 
     fn visit_local(&mut self, l: &hir::Local) {
@@ -874,6 +877,7 @@ impl<'a, 'tcx, 'v> hir_visit::Visitor<'v> for LateContext<'a, 'tcx> {
             run_lints!(cx, check_trait_item, late_passes, trait_item);
             cx.visit_ids(|v| v.visit_trait_item(trait_item));
             hir_visit::walk_trait_item(cx, trait_item);
+            run_lints!(cx, check_trait_item_post, late_passes, trait_item);
         });
     }
 
@@ -882,6 +886,7 @@ impl<'a, 'tcx, 'v> hir_visit::Visitor<'v> for LateContext<'a, 'tcx> {
             run_lints!(cx, check_impl_item, late_passes, impl_item);
             cx.visit_ids(|v| v.visit_impl_item(impl_item));
             hir_visit::walk_impl_item(cx, impl_item);
+            run_lints!(cx, check_impl_item_post, late_passes, impl_item);
         });
     }
 
@@ -928,6 +933,7 @@ impl<'a, 'v> ast_visit::Visitor<'v> for EarlyContext<'a> {
         self.with_lint_attrs(&it.attrs, |cx| {
             run_lints!(cx, check_foreign_item, early_passes, it);
             ast_visit::walk_foreign_item(cx, it);
+            run_lints!(cx, check_foreign_item_post, early_passes, it);
         })
     }
 
@@ -952,6 +958,7 @@ impl<'a, 'v> ast_visit::Visitor<'v> for EarlyContext<'a> {
                 body: &'v ast::Block, span: Span, id: ast::NodeId) {
         run_lints!(self, check_fn, early_passes, fk, decl, body, span, id);
         ast_visit::walk_fn(self, fk, decl, body, span);
+        run_lints!(self, check_fn_post, early_passes, fk, decl, body, span, id);
     }
 
     fn visit_variant_data(&mut self,
@@ -992,6 +999,7 @@ impl<'a, 'v> ast_visit::Visitor<'v> for EarlyContext<'a> {
     fn visit_mod(&mut self, m: &ast::Mod, s: Span, n: ast::NodeId) {
         run_lints!(self, check_mod, early_passes, m, s, n);
         ast_visit::walk_mod(self, m);
+        run_lints!(self, check_mod_post, early_passes, m, s, n);
     }
 
     fn visit_local(&mut self, l: &ast::Local) {
@@ -1031,6 +1039,7 @@ impl<'a, 'v> ast_visit::Visitor<'v> for EarlyContext<'a> {
             run_lints!(cx, check_trait_item, early_passes, trait_item);
             cx.visit_ids(|v| v.visit_trait_item(trait_item));
             ast_visit::walk_trait_item(cx, trait_item);
+            run_lints!(cx, check_trait_item_post, early_passes, trait_item);
         });
     }
 
@@ -1039,6 +1048,7 @@ impl<'a, 'v> ast_visit::Visitor<'v> for EarlyContext<'a> {
             run_lints!(cx, check_impl_item, early_passes, impl_item);
             cx.visit_ids(|v| v.visit_impl_item(impl_item));
             ast_visit::walk_impl_item(cx, impl_item);
+            run_lints!(cx, check_impl_item_post, early_passes, impl_item);
         });
     }
 

src/librustc/lint/mod.rs

@@ -134,7 +134,9 @@ pub trait LateLintPass: LintPass {
     fn check_crate(&mut self, _: &LateContext, _: &hir::Crate) { }
     fn check_crate_post(&mut self, _: &LateContext, _: &hir::Crate) { }
     fn check_mod(&mut self, _: &LateContext, _: &hir::Mod, _: Span, _: ast::NodeId) { }
+    fn check_mod_post(&mut self, _: &LateContext, _: &hir::Mod, _: Span, _: ast::NodeId) { }
     fn check_foreign_item(&mut self, _: &LateContext, _: &hir::ForeignItem) { }
+    fn check_foreign_item_post(&mut self, _: &LateContext, _: &hir::ForeignItem) { }
     fn check_item(&mut self, _: &LateContext, _: &hir::Item) { }
     fn check_item_post(&mut self, _: &LateContext, _: &hir::Item) { }
     fn check_local(&mut self, _: &LateContext, _: &hir::Local) { }
@@ -150,8 +152,12 @@ pub trait LateLintPass: LintPass {
     fn check_generics(&mut self, _: &LateContext, _: &hir::Generics) { }
     fn check_fn(&mut self, _: &LateContext,
         _: FnKind, _: &hir::FnDecl, _: &hir::Block, _: Span, _: ast::NodeId) { }
+    fn check_fn_post(&mut self, _: &LateContext,
+        _: FnKind, _: &hir::FnDecl, _: &hir::Block, _: Span, _: ast::NodeId) { }
     fn check_trait_item(&mut self, _: &LateContext, _: &hir::TraitItem) { }
+    fn check_trait_item_post(&mut self, _: &LateContext, _: &hir::TraitItem) { }
     fn check_impl_item(&mut self, _: &LateContext, _: &hir::ImplItem) { }
+    fn check_impl_item_post(&mut self, _: &LateContext, _: &hir::ImplItem) { }
     fn check_struct_def(&mut self, _: &LateContext,
         _: &hir::VariantData, _: ast::Name, _: &hir::Generics, _: ast::NodeId) { }
     fn check_struct_def_post(&mut self, _: &LateContext,
@@ -179,7 +185,9 @@ pub trait EarlyLintPass: LintPass {
     fn check_crate(&mut self, _: &EarlyContext, _: &ast::Crate) { }
     fn check_crate_post(&mut self, _: &EarlyContext, _: &ast::Crate) { }
     fn check_mod(&mut self, _: &EarlyContext, _: &ast::Mod, _: Span, _: ast::NodeId) { }
+    fn check_mod_post(&mut self, _: &EarlyContext, _: &ast::Mod, _: Span, _: ast::NodeId) { }
     fn check_foreign_item(&mut self, _: &EarlyContext, _: &ast::ForeignItem) { }
+    fn check_foreign_item_post(&mut self, _: &EarlyContext, _: &ast::ForeignItem) { }
     fn check_item(&mut self, _: &EarlyContext, _: &ast::Item) { }
     fn check_item_post(&mut self, _: &EarlyContext, _: &ast::Item) { }
     fn check_local(&mut self, _: &EarlyContext, _: &ast::Local) { }
@@ -195,8 +203,12 @@ pub trait EarlyLintPass: LintPass {
     fn check_generics(&mut self, _: &EarlyContext, _: &ast::Generics) { }
     fn check_fn(&mut self, _: &EarlyContext,
         _: ast_visit::FnKind, _: &ast::FnDecl, _: &ast::Block, _: Span, _: ast::NodeId) { }
+    fn check_fn_post(&mut self, _: &EarlyContext,
+        _: ast_visit::FnKind, _: &ast::FnDecl, _: &ast::Block, _: Span, _: ast::NodeId) { }
     fn check_trait_item(&mut self, _: &EarlyContext, _: &ast::TraitItem) { }
+    fn check_trait_item_post(&mut self, _: &EarlyContext, _: &ast::TraitItem) { }
     fn check_impl_item(&mut self, _: &EarlyContext, _: &ast::ImplItem) { }
+    fn check_impl_item_post(&mut self, _: &EarlyContext, _: &ast::ImplItem) { }
     fn check_struct_def(&mut self, _: &EarlyContext,
         _: &ast::VariantData, _: ast::Ident, _: &ast::Generics, _: ast::NodeId) { }
     fn check_struct_def_post(&mut self, _: &EarlyContext,