Auto merge of #142728 - kornelski:string-track, r=tgross35

Let String pass #[track_caller] to its Vec calls

I've added `#[track_caller]` to `String` methods that delegate to `Vec` methods that already have `#[track_caller]`.

I've also added `#[track_caller]` to methods that have `assert!` or `panic!` due to invalid inputs.

Author: bors

library/alloc/src/string.rs

@@ -1105,6 +1105,7 @@ impl String {
     /// ```
     #[cfg(not(no_global_oom_handling))]
     #[inline]
+    #[track_caller]
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_confusables("append", "push")]
     #[rustc_diagnostic_item = "string_push_str"]
@@ -1135,6 +1136,7 @@ impl String {
     /// ```
     #[cfg(not(no_global_oom_handling))]
     #[stable(feature = "string_extend_from_within", since = "1.87.0")]
+    #[track_caller]
     pub fn extend_from_within<R>(&mut self, src: R)
     where
         R: RangeBounds<usize>,
@@ -1206,6 +1208,7 @@ impl String {
     /// ```
     #[cfg(not(no_global_oom_handling))]
     #[inline]
+    #[track_caller]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn reserve(&mut self, additional: usize) {
         self.vec.reserve(additional)
@@ -1257,6 +1260,7 @@ impl String {
     #[cfg(not(no_global_oom_handling))]
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[track_caller]
     pub fn reserve_exact(&mut self, additional: usize) {
         self.vec.reserve_exact(additional)
     }
@@ -1352,6 +1356,7 @@ impl String {
     /// ```
     #[cfg(not(no_global_oom_handling))]
     #[inline]
+    #[track_caller]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn shrink_to_fit(&mut self) {
         self.vec.shrink_to_fit()
@@ -1379,6 +1384,7 @@ impl String {
     /// ```
     #[cfg(not(no_global_oom_handling))]
     #[inline]
+    #[track_caller]
     #[stable(feature = "shrink_to", since = "1.56.0")]
     pub fn shrink_to(&mut self, min_capacity: usize) {
         self.vec.shrink_to(min_capacity)
@@ -1400,6 +1406,7 @@ impl String {
     #[cfg(not(no_global_oom_handling))]
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[track_caller]
     pub fn push(&mut self, ch: char) {
         let len = self.len();
         let ch_len = ch.len_utf8();
@@ -1456,6 +1463,7 @@ impl String {
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[track_caller]
     pub fn truncate(&mut self, new_len: usize) {
         if new_len <= self.len() {
             assert!(self.is_char_boundary(new_len));
@@ -1511,6 +1519,7 @@ impl String {
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[track_caller]
     #[rustc_confusables("delete", "take")]
     pub fn remove(&mut self, idx: usize) -> char {
         let ch = match self[idx..].chars().next() {
@@ -1705,6 +1714,7 @@ impl String {
     /// ```
     #[cfg(not(no_global_oom_handling))]
     #[inline]
+    #[track_caller]
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_confusables("set")]
     pub fn insert(&mut self, idx: usize, ch: char) {
@@ -1761,6 +1771,7 @@ impl String {
     /// ```
     #[cfg(not(no_global_oom_handling))]
     #[inline]
+    #[track_caller]
     #[stable(feature = "insert_str", since = "1.16.0")]
     #[rustc_diagnostic_item = "string_insert_str"]
     pub fn insert_str(&mut self, idx: usize, string: &str) {
@@ -1889,6 +1900,7 @@ impl String {
     /// ```
     #[cfg(not(no_global_oom_handling))]
     #[inline]
+    #[track_caller]
     #[stable(feature = "string_split_off", since = "1.16.0")]
     #[must_use = "use `.truncate()` if you don't need the other half"]
     pub fn split_off(&mut self, at: usize) -> String {
@@ -1953,6 +1965,7 @@ impl String {
     /// assert_eq!(s, "");
     /// ```
     #[stable(feature = "drain", since = "1.6.0")]
+    #[track_caller]
     pub fn drain<R>(&mut self, range: R) -> Drain<'_>
     where
         R: RangeBounds<usize>,
@@ -2052,6 +2065,7 @@ impl String {
     /// ```
     #[cfg(not(no_global_oom_handling))]
     #[stable(feature = "splice", since = "1.27.0")]
+    #[track_caller]
     pub fn replace_range<R>(&mut self, range: R, replace_with: &str)
     where
         R: RangeBounds<usize>,
@@ -2101,6 +2115,7 @@ impl String {
     #[stable(feature = "box_str", since = "1.4.0")]
     #[must_use = "`self` will be dropped if the result is not used"]
     #[inline]
+    #[track_caller]
     pub fn into_boxed_str(self) -> Box<str> {
         let slice = self.vec.into_boxed_slice();
         unsafe { from_boxed_utf8_unchecked(slice) }
@@ -2288,6 +2303,7 @@ impl Error for FromUtf16Error {
 #[cfg(not(no_global_oom_handling))]
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Clone for String {
+    #[track_caller]
     fn clone(&self) -> Self {
         String { vec: self.vec.clone() }
     }
@@ -2296,6 +2312,7 @@ impl Clone for String {
     ///
     /// This method is preferred over simply assigning `source.clone()` to `self`,
     /// as it avoids reallocation if possible.
+    #[track_caller]
     fn clone_from(&mut self, source: &Self) {
         self.vec.clone_from(&source.vec);
     }
@@ -2469,11 +2486,14 @@ impl<'a> Extend<Cow<'a, str>> for String {
 #[cfg(not(no_global_oom_handling))]
 #[unstable(feature = "ascii_char", issue = "110998")]
 impl Extend<core::ascii::Char> for String {
+    #[inline]
+    #[track_caller]
     fn extend<I: IntoIterator<Item = core::ascii::Char>>(&mut self, iter: I) {
         self.vec.extend(iter.into_iter().map(|c| c.to_u8()));
     }
 
     #[inline]
+    #[track_caller]
     fn extend_one(&mut self, c: core::ascii::Char) {
         self.vec.push(c.to_u8());
     }
@@ -2482,11 +2502,14 @@ impl Extend<core::ascii::Char> for String {
 #[cfg(not(no_global_oom_handling))]
 #[unstable(feature = "ascii_char", issue = "110998")]
 impl<'a> Extend<&'a core::ascii::Char> for String {
+    #[inline]
+    #[track_caller]
     fn extend<I: IntoIterator<Item = &'a core::ascii::Char>>(&mut self, iter: I) {
         self.extend(iter.into_iter().cloned());
     }
 
     #[inline]
+    #[track_caller]
     fn extend_one(&mut self, c: &'a core::ascii::Char) {
         self.vec.push(c.to_u8());
     }