Auto merge of rust-lang#11401 - y21:issue11394, r=xFrednet

[`if_then_some_else_none`]: look into local initializers for early returns

Fixes rust-lang#11394

As the PR title says, problem was that it only looked for early returns in semi statements. Local variables don't count as such, so it didn't count `let _v = x?;` (or even just `let _ = return;`) as a possible early return and didn't realize that it can't lint then.

Imo the `stmts_contains_early_return` function that was used before is redundant. `contains_return` could already do that if we just made the parameter a bit more generic, just like `for_each_expr`, which can already accept `&[Stmt]`

changelog: [`if_then_some_else_none`]: look into local initializers for early returns

Author: bors

clippy_lints/src/if_then_some_else_none.rs

@@ -6,7 +6,7 @@ use clippy_utils::sugg::Sugg;
 use clippy_utils::{contains_return, higher, is_else_clause, is_res_lang_ctor, path_res, peel_blocks};
 use rustc_errors::Applicability;
 use rustc_hir::LangItem::{OptionNone, OptionSome};
-use rustc_hir::{Expr, ExprKind, Stmt, StmtKind};
+use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_tool_lint, impl_lint_pass};
@@ -83,7 +83,7 @@ impl<'tcx> LateLintPass<'tcx> for IfThenSomeElseNone {
             && then_expr.span.ctxt() == ctxt
             && is_res_lang_ctor(cx, path_res(cx, then_call), OptionSome)
             && is_res_lang_ctor(cx, path_res(cx, peel_blocks(els)), OptionNone)
-            && !stmts_contains_early_return(then_block.stmts)
+            && !contains_return(then_block.stmts)
         {
             let mut app = Applicability::Unspecified;
             let cond_snip = Sugg::hir_with_context(cx, cond, expr.span.ctxt(), "[condition]", &mut app).maybe_par().to_string();
@@ -116,17 +116,3 @@ impl<'tcx> LateLintPass<'tcx> for IfThenSomeElseNone {
 
     extract_msrv_attr!(LateContext);
 }
-
-fn stmts_contains_early_return(stmts: &[Stmt<'_>]) -> bool {
-    stmts.iter().any(|stmt| {
-        let Stmt {
-            kind: StmtKind::Semi(e),
-            ..
-        } = stmt
-        else {
-            return false;
-        };
-
-        contains_return(e)
-    })
-}

clippy_utils/src/lib.rs

@@ -111,6 +111,7 @@ use rustc_span::source_map::SourceMap;
 use rustc_span::symbol::{kw, Ident, Symbol};
 use rustc_span::{sym, Span};
 use rustc_target::abi::Integer;
+use visitors::Visitable;
 
 use crate::consts::{constant, miri_to_const, Constant};
 use crate::higher::Range;
@@ -1287,7 +1288,7 @@ pub fn contains_name<'tcx>(name: Symbol, expr: &'tcx Expr<'_>, cx: &LateContext<
 }
 
 /// Returns `true` if `expr` contains a return expression
-pub fn contains_return(expr: &hir::Expr<'_>) -> bool {
+pub fn contains_return<'tcx>(expr: impl Visitable<'tcx>) -> bool {
     for_each_expr(expr, |e| {
         if matches!(e.kind, hir::ExprKind::Ret(..)) {
             ControlFlow::Break(())

tests/ui/if_then_some_else_none.rs

@@ -117,3 +117,15 @@ fn f(b: bool, v: Option<()>) -> Option<()> {
         None
     }
 }
+
+fn issue11394(b: bool, v: Result<(), ()>) -> Result<(), ()> {
+    let x = if b {
+        #[allow(clippy::let_unit_value)]
+        let _ = v?;
+        Some(())
+    } else {
+        None
+    };
+
+    Ok(())
+}