[COMMITTED 8/9] gccrs: Add variadic check on function params

[arthur . cohen]

From: 0xn4utilus <gyanendrabanja...@gmail.com>

gcc/rust/ChangeLog:

        * checks/errors/rust-ast-validation.cc (ASTValidation::visit):
        Add variadic check on all parameters.

gcc/testsuite/ChangeLog:

        * rust/compile/issue-2850.rs: New test.

Signed-off-by: 0xn4utilus <gyanendrabanja...@gmail.com>
---
 gcc/rust/checks/errors/rust-ast-validation.cc | 12 ++++++++----
 gcc/testsuite/rust/compile/issue-2850.rs      | 17 +++++++++++++++++
 2 files changed, 25 insertions(+), 4 deletions(-)
 create mode 100644 gcc/testsuite/rust/compile/issue-2850.rs

diff --git a/gcc/rust/checks/errors/rust-ast-validation.cc 
b/gcc/rust/checks/errors/rust-ast-validation.cc
index d57b7cb70fe..fcba57d0a92 100644
--- a/gcc/rust/checks/errors/rust-ast-validation.cc
+++ b/gcc/rust/checks/errors/rust-ast-validation.cc
@@ -132,10 +132,14 @@ ASTValidation::visit (AST::Function &function)
        rust_error_at (function.get_locus (), "free function without a body");
     }
 
-  if (function.is_variadic ())
-    rust_error_at (
-      function.get_function_params ().back ()->get_locus (),
-      "only foreign or %<unsafe extern \"C\"%> functions may be C-variadic");
+  auto &function_params = function.get_function_params ();
+  for (auto it = function_params.begin (); it != function_params.end (); it++)
+    {
+      if (it->get ()->is_variadic ())
+       rust_error_at (it->get ()->get_locus (),
+                      "only foreign or %<unsafe extern \"C\"%> functions may "
+                      "be C-variadic");
+    }
 
   AST::ContextualASTVisitor::visit (function);
 }
diff --git a/gcc/testsuite/rust/compile/issue-2850.rs 
b/gcc/testsuite/rust/compile/issue-2850.rs
new file mode 100644
index 00000000000..62cbe0f6524
--- /dev/null
+++ b/gcc/testsuite/rust/compile/issue-2850.rs
@@ -0,0 +1,17 @@
+fn myfun0(...,_:i32) {}
+// { dg-error "only foreign or .unsafe extern \"C\". functions may be 
C-variadic" "" { target *-*-* } .-1 }
+
+fn myfun1(a:i32,...,_:i32) {}
+// { dg-error "only foreign or .unsafe extern \"C\". functions may be 
C-variadic" "" { target *-*-* } .-1 }
+
+struct z {
+    x: f64,
+    y: f64,
+}
+
+impl z {
+    fn new(x: f64, ..., y: f64) -> z {
+        // { dg-error "only foreign or .unsafe extern \"C\". functions may be 
C-variadic" "" { target *-*-* } .-1 }
+        z { x: x, y: y }
+    }
+}
\ No newline at end of file
-- 
2.42.1