Various macro fixes for loop lints (#14631)

The `explicit_into_iter_loop`, `explicit_iter_loop` and `iter_next_loop`
will now:

- trigger only when the triggering expression is not located into macro
code;
- properly expose code rewrite proposal with code coming from the root
context.

changelog: [`explicit_into_iter_loop`, `explicit_iter_loop`,
`iter_next_loop`]: behave in macro context

Fixes rust-lang/rust-clippy#14630

8 files changed, 86 insertions, 3 deletions

diff --git a/tests/ui/explicit_into_iter_loop.fixed b/tests/ui/explicit_into_iter_loop.fixed
index 2b68906ae39..c1b3c478eeb 100644
--- a/tests/ui/explicit_into_iter_loop.fixed
+++ b/tests/ui/explicit_into_iter_loop.fixed
@@ -73,3 +73,16 @@ fn main() {
 
     for _ in S.into_iter::<u32>() {}
 }
+
+fn issue14630() {
+    macro_rules! mac {
+        (into_iter $e:expr) => {
+            $e.into_iter()
+        };
+    }
+
+    for _ in dbg!([1, 2]) {}
+    //~^ explicit_into_iter_loop
+
+    for _ in mac!(into_iter [1, 2]) {}
+}
diff --git a/tests/ui/explicit_into_iter_loop.rs b/tests/ui/explicit_into_iter_loop.rs
index ca335b62d90..581e0dadcec 100644
--- a/tests/ui/explicit_into_iter_loop.rs
+++ b/tests/ui/explicit_into_iter_loop.rs
@@ -73,3 +73,16 @@ fn main() {
 
     for _ in S.into_iter::<u32>() {}
 }
+
+fn issue14630() {
+    macro_rules! mac {
+        (into_iter $e:expr) => {
+            $e.into_iter()
+        };
+    }
+
+    for _ in dbg!([1, 2]).into_iter() {}
+    //~^ explicit_into_iter_loop
+
+    for _ in mac!(into_iter [1, 2]) {}
+}
diff --git a/tests/ui/explicit_into_iter_loop.stderr b/tests/ui/explicit_into_iter_loop.stderr
index 1c3156755d4..26fb11e0048 100644
--- a/tests/ui/explicit_into_iter_loop.stderr
+++ b/tests/ui/explicit_into_iter_loop.stderr
@@ -37,5 +37,11 @@ error: it is more concise to loop over containers instead of using explicit iter
 LL |     for _ in mr.into_iter() {}
    |              ^^^^^^^^^^^^^^ help: to write this more concisely, try: `&mut *mr`
 
-error: aborting due to 6 previous errors
+error: it is more concise to loop over containers instead of using explicit iteration methods
+  --> tests/ui/explicit_into_iter_loop.rs:84:14
+   |
+LL |     for _ in dbg!([1, 2]).into_iter() {}
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^ help: to write this more concisely, try: `dbg!([1, 2])`
+
+error: aborting due to 7 previous errors
 
diff --git a/tests/ui/explicit_iter_loop.fixed b/tests/ui/explicit_iter_loop.fixed
index cd0898dfc36..f246ec61800 100644
--- a/tests/ui/explicit_iter_loop.fixed
+++ b/tests/ui/explicit_iter_loop.fixed
@@ -183,3 +183,16 @@ pub fn issue_13184() {
     let rvalues = &values;
     for _ in rvalues.iter() {}
 }
+
+fn issue14630() {
+    macro_rules! mac {
+        (iter $e:expr) => {
+            $e.into_iter()
+        };
+    }
+
+    for _ in &dbg!([1, 2]) {}
+    //~^ explicit_iter_loop
+
+    for _ in mac!(iter [1, 2]) {}
+}
diff --git a/tests/ui/explicit_iter_loop.rs b/tests/ui/explicit_iter_loop.rs
index 02405280ce4..35f4fb7097d 100644
--- a/tests/ui/explicit_iter_loop.rs
+++ b/tests/ui/explicit_iter_loop.rs
@@ -183,3 +183,16 @@ pub fn issue_13184() {
     let rvalues = &values;
     for _ in rvalues.iter() {}
 }
+
+fn issue14630() {
+    macro_rules! mac {
+        (iter $e:expr) => {
+            $e.into_iter()
+        };
+    }
+
+    for _ in dbg!([1, 2]).iter() {}
+    //~^ explicit_iter_loop
+
+    for _ in mac!(iter [1, 2]) {}
+}
diff --git a/tests/ui/explicit_iter_loop.stderr b/tests/ui/explicit_iter_loop.stderr
index 3816bb4db98..575dbe7813d 100644
--- a/tests/ui/explicit_iter_loop.stderr
+++ b/tests/ui/explicit_iter_loop.stderr
@@ -112,5 +112,11 @@ error: it is more concise to loop over references to containers instead of using
 LL |     for _ in r.iter() {}
    |              ^^^^^^^^ help: to write this more concisely, try: `r`
 
-error: aborting due to 18 previous errors
+error: it is more concise to loop over references to containers instead of using explicit iteration methods
+  --> tests/ui/explicit_iter_loop.rs:194:14
+   |
+LL |     for _ in dbg!([1, 2]).iter() {}
+   |              ^^^^^^^^^^^^^^^^^^^ help: to write this more concisely, try: `&dbg!([1, 2])`
+
+error: aborting due to 19 previous errors
 
diff --git a/tests/ui/iter_next_loop.rs b/tests/ui/iter_next_loop.rs
index 32711c7ef62..8e62ed963b9 100644
--- a/tests/ui/iter_next_loop.rs
+++ b/tests/ui/iter_next_loop.rs
@@ -15,3 +15,16 @@ fn main() {
     let u = Unrelated(&[0]);
     for _v in u.next() {} // no error
 }
+
+fn issue14630() {
+    macro_rules! mac {
+        (next $e:expr) => {
+            $e.iter().next()
+        };
+    }
+
+    for _ in dbg!([1, 2].iter()).next() {}
+    //~^ iter_next_loop
+
+    for _ in mac!(next [1, 2]) {}
+}
diff --git a/tests/ui/iter_next_loop.stderr b/tests/ui/iter_next_loop.stderr
index acc55031c3b..c076e86db93 100644
--- a/tests/ui/iter_next_loop.stderr
+++ b/tests/ui/iter_next_loop.stderr
@@ -7,5 +7,11 @@ LL |     for _ in x.iter().next() {}
    = note: `-D clippy::iter-next-loop` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::iter_next_loop)]`
 
-error: aborting due to 1 previous error
+error: you are iterating over `Iterator::next()` which is an Option; this will compile but is probably not what you want
+  --> tests/ui/iter_next_loop.rs:26:14
+   |
+LL |     for _ in dbg!([1, 2].iter()).next() {}
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors