Rollup merge of #128207 - folkertdev:asm-parser-generalize, r=Amanieu

improve error message when `global_asm!` uses `asm!` options

specifically, what was

    error: expected one of `)`, `att_syntax`, or `raw`, found `preserves_flags`
      --> $DIR/bad-options.rs:45:25
       |
    LL | global_asm!("", options(preserves_flags));
       |                         ^^^^^^^^^^^^^^^ expected one of `)`, `att_syntax`, or `raw`

is now

    error: the `preserves_flags` option cannot be used with `global_asm!`
      --> $DIR/bad-options.rs:45:25
       |
    LL | global_asm!("", options(preserves_flags));
       |                         ^^^^^^^^^^^^^^^ the `preserves_flags` option is not meaningful for global-scoped inline assembly

mirroring the phrasing of the [reference](https://doc.rust-lang.org/reference/inline-assembly.html#options).

This is also a bit of a refactor for a future `naked_asm!` macro (for use in `#[naked]` functions). Currently this sort of error can come up when switching from inline to global asm, or when a user just isn't that experienced with assembly. With  `naked_asm!` added to the mix hitting this error is more likely.

1 files changed, 5 insertions, 2 deletions

diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
index 7326b9ec51f..e7240869a39 100644
--- a/compiler/rustc_parse/src/parser/mod.rs
+++ b/compiler/rustc_parse/src/parser/mod.rs
@@ -599,7 +599,7 @@ impl<'a> Parser<'a> {
 
     /// If the next token is the given keyword, eats it and returns `true`.
     /// Otherwise, returns `false`. An expectation is also added for diagnostics purposes.
-    // Public for rustfmt usage.
+    // Public for rustc_builtin_macros and rustfmt usage.
     #[inline]
     pub fn eat_keyword(&mut self, kw: Symbol) -> bool {
         if self.check_keyword(kw) {
@@ -631,8 +631,11 @@ impl<'a> Parser<'a> {
         false
     }
 
+    /// If the next token is the given keyword, eats it and returns `true`.
+    /// Otherwise, returns `false`. No expectation is added.
+    // Public for rustc_builtin_macros usage.
     #[inline]
-    fn eat_keyword_noexpect(&mut self, kw: Symbol) -> bool {
+    pub fn eat_keyword_noexpect(&mut self, kw: Symbol) -> bool {
         if self.token.is_keyword(kw) {
             self.bump();
             true