Auto merge of #113476 - fee1-dead-contrib:c-str-lit, r=petrochenkov

Reimplement C-str literals

This reverts #113334, cc `@fmease.`

While converting lexer tokens to ast Tokens in `rustc_parse`, we check the edition of the span of the token. If the edition < 2021, we split the token into two, one being the identifier and other being the str literal.

9 files changed, 42 insertions, 88 deletions

diff --git a/tests/ui/rfcs/rfc-3348-c-string-literals/auxiliary/count.rs b/tests/ui/rfcs/rfc-3348-c-string-literals/auxiliary/count.rs
new file mode 100644
index 00000000000..0907061d64a
--- /dev/null
+++ b/tests/ui/rfcs/rfc-3348-c-string-literals/auxiliary/count.rs
@@ -0,0 +1,14 @@
+// force-host
+// edition: 2018
+// no-prefer-dynamic
+#![crate_type = "proc-macro"]
+
+extern crate proc_macro;
+
+use proc_macro::TokenStream;
+use std::str::FromStr;
+
+#[proc_macro]
+pub fn number_of_tokens(_: TokenStream) -> TokenStream {
+    TokenStream::from_str("c\"\"").unwrap().into_iter().count().to_string().parse().unwrap()
+}
diff --git a/tests/ui/rfcs/rfc-3348-c-string-literals/basic.rs b/tests/ui/rfcs/rfc-3348-c-string-literals/basic.rs
index 3fc5fd481ea..5037396000b 100644
--- a/tests/ui/rfcs/rfc-3348-c-string-literals/basic.rs
+++ b/tests/ui/rfcs/rfc-3348-c-string-literals/basic.rs
@@ -1,5 +1,4 @@
-// FIXME(c_str_literals): This should be `run-pass`
-// known-bug: #113333
+// run-pass
 // edition: 2021
 
 #![feature(c_str_literals)]
diff --git a/tests/ui/rfcs/rfc-3348-c-string-literals/basic.stderr b/tests/ui/rfcs/rfc-3348-c-string-literals/basic.stderr
deleted file mode 100644
index 571c319d8c5..00000000000
--- a/tests/ui/rfcs/rfc-3348-c-string-literals/basic.stderr
+++ /dev/null
@@ -1,25 +0,0 @@
-error: prefix `c` is unknown
-  --> $DIR/basic.rs:8:27
-   |
-LL |     assert_eq!(b"test\0", c"test".to_bytes_with_nul());
-   |                           ^ unknown prefix
-   |
-   = note: prefixed identifiers and literals are reserved since Rust 2021
-help: consider inserting whitespace here
-   |
-LL |     assert_eq!(b"test\0", c "test".to_bytes_with_nul());
-   |                            +
-
-error: no rules expected the token `"test"`
-  --> $DIR/basic.rs:8:28
-   |
-LL |     assert_eq!(b"test\0", c"test".to_bytes_with_nul());
-   |                            -^^^^^
-   |                            |
-   |                            no rules expected this token in macro call
-   |                            help: missing comma here
-   |
-   = note: while trying to match sequence start
-
-error: aborting due to 2 previous errors
-
diff --git a/tests/ui/rfcs/rfc-3348-c-string-literals/edition-spans.rs b/tests/ui/rfcs/rfc-3348-c-string-literals/edition-spans.rs
new file mode 100644
index 00000000000..b3557c71b74
--- /dev/null
+++ b/tests/ui/rfcs/rfc-3348-c-string-literals/edition-spans.rs
@@ -0,0 +1,16 @@
+// even if this crate is edition 2021, proc macros compiled using older
+// editions should still be able to observe the pre-2021 token behavior
+//
+// adapted from tests/ui/rust-2021/reserved-prefixes-via-macro.rs
+
+// edition: 2021
+// check-pass
+
+// aux-build: count.rs
+extern crate count;
+
+const _: () = {
+    assert!(count::number_of_tokens!() == 2);
+};
+
+fn main() {}
diff --git a/tests/ui/rfcs/rfc-3348-c-string-literals/gate.stderr b/tests/ui/rfcs/rfc-3348-c-string-literals/gate.stderr
index 8de36ca4a6e..ea666e43308 100644
--- a/tests/ui/rfcs/rfc-3348-c-string-literals/gate.stderr
+++ b/tests/ui/rfcs/rfc-3348-c-string-literals/gate.stderr
@@ -1,32 +1,21 @@
-error: prefix `c` is unknown
+error[E0658]: `c".."` literals are experimental
   --> $DIR/gate.rs:10:5
    |
 LL |     c"foo";
-   |     ^ unknown prefix
+   |     ^^^^^^
    |
-   = note: prefixed identifiers and literals are reserved since Rust 2021
-help: consider inserting whitespace here
-   |
-LL |     c "foo";
-   |      +
+   = note: see issue #105723 <https://github.com/rust-lang/rust/issues/105723> for more information
+   = help: add `#![feature(c_str_literals)]` to the crate attributes to enable
 
-error: prefix `c` is unknown
+error[E0658]: `c".."` literals are experimental
   --> $DIR/gate.rs:13:8
    |
 LL |     m!(c"test");
-   |        ^ unknown prefix
-   |
-   = note: prefixed identifiers and literals are reserved since Rust 2021
-help: consider inserting whitespace here
+   |        ^^^^^^^
    |
-LL |     m!(c "test");
-   |         +
-
-error: expected one of `!`, `.`, `::`, `;`, `?`, `{`, `}`, or an operator, found `"foo"`
-  --> $DIR/gate.rs:10:6
-   |
-LL |     c"foo";
-   |      ^^^^^ expected one of 8 possible tokens
+   = note: see issue #105723 <https://github.com/rust-lang/rust/issues/105723> for more information
+   = help: add `#![feature(c_str_literals)]` to the crate attributes to enable
 
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
+For more information about this error, try `rustc --explain E0658`.
diff --git a/tests/ui/rfcs/rfc-3348-c-string-literals/no-nuls.rs b/tests/ui/rfcs/rfc-3348-c-string-literals/no-nuls.rs
index 96945f125da..369173e2318 100644
--- a/tests/ui/rfcs/rfc-3348-c-string-literals/no-nuls.rs
+++ b/tests/ui/rfcs/rfc-3348-c-string-literals/no-nuls.rs
Binary files differdiff --git a/tests/ui/rfcs/rfc-3348-c-string-literals/no-nuls.stderr b/tests/ui/rfcs/rfc-3348-c-string-literals/no-nuls.stderr
index 2226c7aa6a9..82d9f9cb320 100644
--- a/tests/ui/rfcs/rfc-3348-c-string-literals/no-nuls.stderr
+++ b/tests/ui/rfcs/rfc-3348-c-string-literals/no-nuls.stderr
Binary files differdiff --git a/tests/ui/rfcs/rfc-3348-c-string-literals/non-ascii.rs b/tests/ui/rfcs/rfc-3348-c-string-literals/non-ascii.rs
index 066505c23df..380445d7a7f 100644
--- a/tests/ui/rfcs/rfc-3348-c-string-literals/non-ascii.rs
+++ b/tests/ui/rfcs/rfc-3348-c-string-literals/non-ascii.rs
@@ -1,5 +1,4 @@
-// FIXME(c_str_literals): This should be `run-pass`
-// known-bug: #113333
+// run-pass
 // edition: 2021
 
 #![feature(c_str_literals)]
diff --git a/tests/ui/rfcs/rfc-3348-c-string-literals/non-ascii.stderr b/tests/ui/rfcs/rfc-3348-c-string-literals/non-ascii.stderr
deleted file mode 100644
index 47361fb61d2..00000000000
--- a/tests/ui/rfcs/rfc-3348-c-string-literals/non-ascii.stderr
+++ /dev/null
@@ -1,38 +0,0 @@
-error: prefix `c` is unknown
-  --> $DIR/non-ascii.rs:9:9
-   |
-LL |         c"\xEF\x80🦀\u{1F980}".to_bytes_with_nul(),
-   |         ^ unknown prefix
-   |
-   = note: prefixed identifiers and literals are reserved since Rust 2021
-help: consider inserting whitespace here
-   |
-LL |         c "\xEF\x80🦀\u{1F980}".to_bytes_with_nul(),
-   |          +
-
-error: out of range hex escape
-  --> $DIR/non-ascii.rs:9:11
-   |
-LL |         c"\xEF\x80🦀\u{1F980}".to_bytes_with_nul(),
-   |           ^^^^ must be a character in the range [\x00-\x7f]
-
-error: out of range hex escape
-  --> $DIR/non-ascii.rs:9:15
-   |
-LL |         c"\xEF\x80🦀\u{1F980}".to_bytes_with_nul(),
-   |               ^^^^ must be a character in the range [\x00-\x7f]
-
-error: no rules expected the token `"\xEF\x80🦀\u{1F980}"`
-  --> $DIR/non-ascii.rs:9:10
-   |
-LL |         c"\xEF\x80🦀\u{1F980}".to_bytes_with_nul(),
-   |          -^^^^^^^^^^^^^^^^^^^^
-   |          |
-   |          no rules expected this token in macro call
-   |          help: missing comma here
-   |
-note: while trying to match `,`
-  --> $SRC_DIR/core/src/macros/mod.rs:LL:COL
-
-error: aborting due to 4 previous errors
-