[gcc r17-3059] gccrs: Return empty file name for inline string source

https://gcc.gnu.org/g:d182d582c0f15ec9868b283f93b4ecb2eeae485f

commit r17-3059-gd182d582c0f15ec9868b283f93b4ecb2eeae485f
Author: Pierre-Emmanuel Patry <[email protected]>
Date:   Sun May 24 23:14:18 2026 +0200

    gccrs: Return empty file name for inline string source
    
    The compiler would crash if the file name was requested from the lexer
    whilst lexing from a non-file source (mainly string sources). Now return
    an empty file name instead.
    
    gcc/rust/ChangeLog:
    
            * lex/rust-lex.h: Return an empty file name when file is missing.
    
    Signed-off-by: Pierre-Emmanuel Patry <[email protected]>

Diff:
---
 gcc/rust/lex/rust-lex.h | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/gcc/rust/lex/rust-lex.h b/gcc/rust/lex/rust-lex.h
index 8d65a6ddf551..530eafbe5457 100644
--- a/gcc/rust/lex/rust-lex.h
+++ b/gcc/rust/lex/rust-lex.h
@@ -207,7 +207,13 @@ public:
   void split_current_token (std::vector<TokenPtr> new_tokens);
 
   Linemap *get_line_map () { return line_map; }
-  std::string get_filename () { return std::string (input.get_filename ()); }
+  std::string get_filename ()
+  {
+    if (input.ok ())
+      return std::string (input.get_filename ());
+    else
+      return "";
+  }
 
 private:
   void start_line (int current_line, int current_column);