Add format_args_collector internal lint

Author: Alexendoo

clippy_lints/src/lib.rs

@@ -528,6 +528,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
                 .collect(),
         ))
     });
+    store.register_early_pass(|| Box::new(utils::format_args_collector::FormatArgsCollector));
     store.register_late_pass(|_| Box::new(utils::dump_hir::DumpHir));
     store.register_late_pass(|_| Box::new(utils::author::Author));
     let await_holding_invalid_types = conf.await_holding_invalid_types.clone();
@@ -862,7 +863,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     let allow_dbg_in_tests = conf.allow_dbg_in_tests;
     store.register_late_pass(move |_| Box::new(dbg_macro::DbgMacro::new(allow_dbg_in_tests)));
     let allow_print_in_tests = conf.allow_print_in_tests;
-    store.register_early_pass(move || Box::new(write::Write::new(allow_print_in_tests)));
     store.register_late_pass(move |_| Box::new(write::Write::new(allow_print_in_tests)));
     let cargo_ignore_publish = conf.cargo_ignore_publish;
     store.register_late_pass(move |_| {

clippy_lints/src/utils/format_args_collector.rs

@@ -0,0 +1,23 @@
+use clippy_utils::macros::collect_ast_format_args;
+use rustc_ast::{Expr, ExprKind};
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+    /// ### What it does
+    /// Collects [`rustc_ast::FormatArgs`] so that future late passes can call
+    /// [`clippy_utils::macros::find_format_args`]
+    pub FORMAT_ARGS_COLLECTOR,
+    internal_warn,
+    "collects `format_args` AST nodes for use in later lints"
+}
+
+declare_lint_pass!(FormatArgsCollector => [FORMAT_ARGS_COLLECTOR]);
+
+impl EarlyLintPass for FormatArgsCollector {
+    fn check_expr(&mut self, _: &EarlyContext<'_>, expr: &Expr) {
+        if let ExprKind::FormatArgs(args) = &expr.kind {
+            collect_ast_format_args(expr.span, args);
+        }
+    }
+}

clippy_lints/src/utils/mod.rs

@@ -1,5 +1,6 @@
 pub mod author;
 pub mod conf;
 pub mod dump_hir;
+pub mod format_args_collector;
 #[cfg(feature = "internal")]
 pub mod internal_lints;

clippy_lints/src/write.rs

@@ -1,14 +1,12 @@
 use clippy_utils::diagnostics::{span_lint, span_lint_and_then};
-use clippy_utils::macros::{
-    find_format_args, format_arg_removal_span, populate_ast_format_args, root_macro_call_first_node, MacroCall,
-};
+use clippy_utils::macros::{find_format_args, format_arg_removal_span, root_macro_call_first_node, MacroCall};
 use clippy_utils::source::{expand_past_previous_comma, snippet_opt};
 use clippy_utils::{is_in_cfg_test, is_in_test_function};
 use rustc_ast::token::LitKind;
 use rustc_ast::{FormatArgPosition, FormatArgs, FormatArgsPiece, FormatOptions, FormatPlaceholder, FormatTrait};
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, Impl, Item, ItemKind};
-use rustc_lint::{EarlyLintPass, LateContext, LateLintPass, LintContext};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::{sym, BytePos};
 
@@ -260,12 +258,6 @@ impl_lint_pass!(Write => [
     WRITE_LITERAL,
 ]);
 
-impl EarlyLintPass for Write {
-    fn check_expr(&mut self, _: &rustc_lint::EarlyContext<'_>, expr: &rustc_ast::Expr) {
-        populate_ast_format_args(expr);
-    }
-}
-
 impl<'tcx> LateLintPass<'tcx> for Write {
     fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
         if is_debug_impl(cx, item) {

clippy_utils/src/macros.rs

@@ -19,7 +19,7 @@ use rustc_span::hygiene::{self, MacroKind, SyntaxContext};
 use rustc_span::{sym, BytePos, ExpnData, ExpnId, ExpnKind, Pos, Span, SpanData, Symbol};
 use std::cell::RefCell;
 use std::iter::{once, zip};
-use std::ops::{ControlFlow, Deref};
+use std::ops::ControlFlow;
 use std::sync::atomic::{AtomicBool, Ordering};
 
 const FORMAT_MACRO_DIAG_ITEMS: &[Symbol] = &[
@@ -361,14 +361,12 @@ thread_local! {
     };
 }
 
-/// Record [`rustc_ast::FormatArgs`] for use in late lint passes, this only needs to be called by
-/// one lint pass.
-pub fn populate_ast_format_args(expr: &rustc_ast::Expr) {
-    if let rustc_ast::ExprKind::FormatArgs(args) = &expr.kind {
-        AST_FORMAT_ARGS.with(|ast_format_args| {
-            ast_format_args.borrow_mut().insert(expr.span, args.deref().clone());
-        });
-    }
+/// Record [`rustc_ast::FormatArgs`] for use in late lint passes, this should only be called by
+/// `FormatArgsCollector`
+pub fn collect_ast_format_args(span: Span, format_args: &FormatArgs) {
+    AST_FORMAT_ARGS.with(|ast_format_args| {
+        ast_format_args.borrow_mut().insert(span, format_args.clone());
+    });
 }
 
 /// Calls `callback` with an AST [`FormatArgs`] node if one is found