Add test for rust-lang#7650

Author: Jarcho

tests/ui/auxiliary/proc_macro_suspicious_else_formatting.rs

@@ -0,0 +1,75 @@
+// compile-flags: --emit=link
+// no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+
+extern crate proc_macro;
+use proc_macro::{token_stream, Delimiter, Group, Ident, Span, TokenStream, TokenTree};
+use std::iter::FromIterator;
+
+fn read_ident(iter: &mut token_stream::IntoIter) -> Ident {
+    match iter.next() {
+        Some(TokenTree::Ident(i)) => i,
+        _ => panic!("expected ident"),
+    }
+}
+
+#[proc_macro_derive(DeriveBadSpan)]
+pub fn derive_bad_span(input: TokenStream) -> TokenStream {
+    let mut input = input.into_iter();
+    assert_eq!(read_ident(&mut input).to_string(), "struct");
+    let ident = read_ident(&mut input);
+    let mut tys = match input.next() {
+        Some(TokenTree::Group(g)) if g.delimiter() == Delimiter::Parenthesis => g.stream().into_iter(),
+        _ => panic!(),
+    };
+    let field1 = read_ident(&mut tys);
+    tys.next();
+    let field2 = read_ident(&mut tys);
+
+    <TokenStream as FromIterator<TokenTree>>::from_iter(
+        [
+            Ident::new("impl", Span::call_site()).into(),
+            ident.into(),
+            Group::new(
+                Delimiter::Brace,
+                <TokenStream as FromIterator<TokenTree>>::from_iter(
+                    [
+                        Ident::new("fn", Span::call_site()).into(),
+                        Ident::new("_foo", Span::call_site()).into(),
+                        Group::new(Delimiter::Parenthesis, TokenStream::new()).into(),
+                        Group::new(
+                            Delimiter::Brace,
+                            <TokenStream as FromIterator<TokenTree>>::from_iter(
+                                [
+                                    Ident::new("if", field1.span()).into(),
+                                    Ident::new("true", field1.span()).into(),
+                                    {
+                                        let mut group = Group::new(Delimiter::Brace, TokenStream::new());
+                                        group.set_span(field1.span());
+                                        group.into()
+                                    },
+                                    Ident::new("if", field2.span()).into(),
+                                    Ident::new("true", field2.span()).into(),
+                                    {
+                                        let mut group = Group::new(Delimiter::Brace, TokenStream::new());
+                                        group.set_span(field2.span());
+                                        group.into()
+                                    },
+                                ]
+                                .iter()
+                                .cloned(),
+                            ),
+                        )
+                        .into(),
+                    ]
+                    .iter()
+                    .cloned(),
+                ),
+            )
+            .into(),
+        ]
+        .iter()
+        .cloned(),
+    )
+}

tests/ui/suspicious_else_formatting.rs

@@ -1,5 +1,10 @@
+// aux-build:proc_macro_suspicious_else_formatting.rs
+
 #![warn(clippy::suspicious_else_formatting)]
 
+extern crate proc_macro_suspicious_else_formatting;
+use proc_macro_suspicious_else_formatting::DeriveBadSpan;
+
 fn foo() -> bool {
     true
 }
@@ -103,3 +108,7 @@ fn main() {
     {
     }
 }
+
+// #7650 - Don't lint. Proc-macro using bad spans for `if` expressions.
+#[derive(DeriveBadSpan)]
+struct _Foo(u32, u32);

tests/ui/suspicious_else_formatting.stderr

@@ -1,5 +1,5 @@
 error: this looks like an `else {..}` but the `else` is missing
-  --> $DIR/suspicious_else_formatting.rs:11:6
+  --> $DIR/suspicious_else_formatting.rs:16:6
    |
 LL |     } {
    |      ^
@@ -8,31 +8,31 @@ LL |     } {
    = note: to remove this lint, add the missing `else` or add a new line before the next block
 
 error: this looks like an `else if` but the `else` is missing
-  --> $DIR/suspicious_else_formatting.rs:15:6
+  --> $DIR/suspicious_else_formatting.rs:20:6
    |
 LL |     } if foo() {
    |      ^
    |
    = note: to remove this lint, add the missing `else` or add a new line before the second `if`
 
 error: this looks like an `else if` but the `else` is missing
-  --> $DIR/suspicious_else_formatting.rs:22:10
+  --> $DIR/suspicious_else_formatting.rs:27:10
    |
 LL |         } if foo() {
    |          ^
    |
    = note: to remove this lint, add the missing `else` or add a new line before the second `if`
 
 error: this looks like an `else if` but the `else` is missing
-  --> $DIR/suspicious_else_formatting.rs:30:10
+  --> $DIR/suspicious_else_formatting.rs:35:10
    |
 LL |         } if foo() {
    |          ^
    |
    = note: to remove this lint, add the missing `else` or add a new line before the second `if`
 
 error: this is an `else {..}` but the formatting might hide it
-  --> $DIR/suspicious_else_formatting.rs:39:6
+  --> $DIR/suspicious_else_formatting.rs:44:6
    |
 LL |       } else
    |  ______^
@@ -42,7 +42,7 @@ LL | |     {
    = note: to remove this lint, remove the `else` or remove the new line between `else` and `{..}`
 
 error: this is an `else if` but the formatting might hide it
-  --> $DIR/suspicious_else_formatting.rs:51:6
+  --> $DIR/suspicious_else_formatting.rs:56:6
    |
 LL |       } else
    |  ______^
@@ -52,7 +52,7 @@ LL | |     if foo() { // the span of the above error should continue here
    = note: to remove this lint, remove the `else` or remove the new line between `else` and `if`
 
 error: this is an `else if` but the formatting might hide it
-  --> $DIR/suspicious_else_formatting.rs:56:6
+  --> $DIR/suspicious_else_formatting.rs:61:6
    |
 LL |       }
    |  ______^
@@ -63,7 +63,7 @@ LL | |     if foo() { // the span of the above error should continue here
    = note: to remove this lint, remove the `else` or remove the new line between `else` and `if`
 
 error: this is an `else {..}` but the formatting might hide it
-  --> $DIR/suspicious_else_formatting.rs:83:6
+  --> $DIR/suspicious_else_formatting.rs:88:6
    |
 LL |       }
    |  ______^
@@ -75,7 +75,7 @@ LL | |     {
    = note: to remove this lint, remove the `else` or remove the new line between `else` and `{..}`
 
 error: this is an `else {..}` but the formatting might hide it
-  --> $DIR/suspicious_else_formatting.rs:91:6
+  --> $DIR/suspicious_else_formatting.rs:96:6
    |
 LL |       }
    |  ______^