Return a value from find_format_args instead of using a callback

clippy_lints/src/utils/format_args_collector.rs

@@ -1,12 +1,15 @@
-use clippy_utils::macros::collect_ast_format_args;
+use clippy_utils::macros::AST_FORMAT_ARGS;
 use clippy_utils::source::snippet_opt;
 use itertools::Itertools;
-use rustc_ast::{Expr, ExprKind, FormatArgs};
+use rustc_ast::{Crate, Expr, ExprKind, FormatArgs};
+use rustc_data_structures::fx::FxHashMap;
 use rustc_lexer::{tokenize, TokenKind};
 use rustc_lint::{EarlyContext, EarlyLintPass};
-use rustc_session::{declare_lint_pass, declare_tool_lint};
-use rustc_span::hygiene;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::{hygiene, Span};
 use std::iter::once;
+use std::mem;
+use std::rc::Rc;
 
 declare_clippy_lint! {
     /// ### What it does
@@ -17,7 +20,12 @@ declare_clippy_lint! {
     "collects `format_args` AST nodes for use in later lints"
 }
 
-declare_lint_pass!(FormatArgsCollector => [FORMAT_ARGS_COLLECTOR]);
+#[derive(Default)]
+pub struct FormatArgsCollector {
+    format_args: FxHashMap<Span, Rc<FormatArgs>>,
+}
+
+impl_lint_pass!(FormatArgsCollector => [FORMAT_ARGS_COLLECTOR]);
 
 impl EarlyLintPass for FormatArgsCollector {
     fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
@@ -26,9 +34,17 @@ impl EarlyLintPass for FormatArgsCollector {
                 return;
             }
 
-            collect_ast_format_args(expr.span, args);
+            self.format_args
+                .insert(expr.span.with_parent(None), Rc::new((**args).clone()));
         }
     }
+
+    fn check_crate_post(&mut self, _: &EarlyContext<'_>, _: &Crate) {
+        AST_FORMAT_ARGS.with(|ast_format_args| {
+            let result = ast_format_args.set(mem::take(&mut self.format_args));
+            debug_assert!(result.is_ok());
+        });
+    }
 }
 
 /// Detects if the format string or an argument has its span set by a proc macro to something inside