[gcc r14-8842] gccrs: Parse normal functions with `self` parameter correctly

[gcc r14-8842] gccrs: Parse normal functions with `self` parameter correctly

[Arthur Cohen]

https://gcc.gnu.org/g:f89186f962421f6d972035fc4b4c20490e7b1c5b

commit r14-8842-gf89186f962421f6d972035fc4b4c20490e7b1c5b
Author: Kushal Pal <kushalpal109@gmail.com>
Date:   Tue Jan 23 17:23:05 2024 +0530

    gccrs: Parse normal functions with `self` parameter correctly
    
    Fixes #2812
    
    gcc/rust/ChangeLog:
    
            * parse/rust-parse-impl.h (Parser::parse_function):
            Skip token if its a COMMA.
    
    gcc/testsuite/ChangeLog:
    
            * rust/compile/issue-2812.rs: New test.
    
    Signed-off-by: Kushal Pal <kushalpal109@gmail.com>

Diff:
---
 gcc/rust/parse/rust-parse-impl.h         | 4 ++--
 gcc/testsuite/rust/compile/issue-2812.rs | 4 ++++
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/gcc/rust/parse/rust-parse-impl.h b/gcc/rust/parse/rust-parse-impl.h
index c622ed7bc971..89e3731a8984 100644
--- a/gcc/rust/parse/rust-parse-impl.h
+++ b/gcc/rust/parse/rust-parse-impl.h
@@ -2946,8 +2946,8 @@ Parser<ManagedTokenSource>::parse_function (AST::Visibility vis,
       && initial_param.error () != ParseSelfError::NOT_SELF)
     return nullptr;
 
-  if (initial_param.has_value ())
-    skip_token (COMMA);
+  if (initial_param.has_value () && lexer.peek_token ()->get_id () == COMMA)
+    skip_token ();
 
   // parse function parameters (only if next token isn't right paren)
   std::vector<std::unique_ptr<AST::Param>> function_params;
diff --git a/gcc/testsuite/rust/compile/issue-2812.rs b/gcc/testsuite/rust/compile/issue-2812.rs
new file mode 100644
index 000000000000..173259b12914
--- /dev/null
+++ b/gcc/testsuite/rust/compile/issue-2812.rs
@@ -0,0 +1,4 @@
+// { dg-additional-options "-frust-compile-until=astvalidation" }
+fn foo_1(&self);
+fn foo_1(&mut self);
+fn foo_1(self);