[gcc r14-8135] gccrs: Add lifetime name validation pass

[Arthur Cohen]

https://gcc.gnu.org/g:ea4cd6453d3a3af501edcc97d362f7c4e9e83995

commit r14-8135-gea4cd6453d3a3af501edcc97d362f7c4e9e83995
Author: Pierre-Emmanuel Patry <pierre-emmanuel.patry@embecosm.com>
Date:   Tue Nov 7 18:32:58 2023 +0100

    gccrs: Add lifetime name validation pass
    
    Add lifetime name check in ast validation visitor.
    
    gcc/rust/ChangeLog:
    
            * checks/errors/rust-ast-validation.cc (RS_TOKEN): Add keyword set.
            (RS_TOKEN_KEYWORD): Likewise.
            (ASTValidation::visit): Add validation on lifetime visit.
            * checks/errors/rust-ast-validation.h: Add function prototype.
    
    Signed-off-by: Pierre-Emmanuel Patry <pierre-emmanuel.patry@embecosm.com>

Diff:
---
 gcc/rust/checks/errors/rust-ast-validation.cc | 23 +++++++++++++++++++++++
 gcc/rust/checks/errors/rust-ast-validation.h  |  1 +
 2 files changed, 24 insertions(+)

diff --git a/gcc/rust/checks/errors/rust-ast-validation.cc b/gcc/rust/checks/errors/rust-ast-validation.cc
index 92822fe96f3..d27d3e861ef 100644
--- a/gcc/rust/checks/errors/rust-ast-validation.cc
+++ b/gcc/rust/checks/errors/rust-ast-validation.cc
@@ -21,6 +21,29 @@
 
 namespace Rust {
 
+namespace {
+// TODO: make constexpr when update to c++20
+const std::map<std::string, TokenId> keywords = {
+#define RS_TOKEN(x, y)
+#define RS_TOKEN_KEYWORD(tok, key) {key, tok},
+  RS_TOKEN_LIST
+#undef RS_TOKEN_KEYWORD
+#undef RS_TOKEN
+};
+} // namespace
+
+void
+ASTValidation::visit (AST::Lifetime &lifetime)
+{
+  auto name = lifetime.get_lifetime_name ();
+  auto valid = std::set<std::string>{"static", "_"};
+  if (valid.find (name) == valid.end ()
+      && keywords.find (name) != keywords.end ())
+    rust_error_at (lifetime.get_locus (), "lifetimes cannot use keyword names");
+
+  AST::ContextualASTVisitor::visit (lifetime);
+}
+
 void
 ASTValidation::visit (AST::ConstantItem &const_item)
 {
diff --git a/gcc/rust/checks/errors/rust-ast-validation.h b/gcc/rust/checks/errors/rust-ast-validation.h
index 1b1403fe72d..ef0b2ac0538 100644
--- a/gcc/rust/checks/errors/rust-ast-validation.h
+++ b/gcc/rust/checks/errors/rust-ast-validation.h
@@ -34,6 +34,7 @@ public:
   void check (AST::Crate &crate) { AST::ContextualASTVisitor::visit (crate); }
 
   virtual void visit (AST::ConstantItem &const_item);
+  virtual void visit (AST::Lifetime &lifetime);
 };
 
 } // namespace Rust