Enforce Duplicate definition rules

Rust does not allow functions/methods/constants/static definitions to
shadow otherwise you end up with unuseable items.

10 files changed, 159 insertions, 23 deletions

diff --git a/gcc/rust/resolve/rust-ast-resolve-implitem.h b/gcc/rust/resolve/rust-ast-resolve-implitem.h
index 74f2cdc..9cbef53 100644
--- a/gcc/rust/resolve/rust-ast-resolve-implitem.h
+++ b/gcc/rust/resolve/rust-ast-resolve-implitem.h
@@ -39,8 +39,12 @@ public:
   {
     std::string identifier
       = base->as_string () + "::" + constant.get_identifier ();
-    resolver->get_name_scope ().insert (identifier, constant.get_node_id (),
-					constant.get_locus ());
+    resolver->get_name_scope ().insert (
+      identifier, constant.get_node_id (), constant.get_locus (), false,
+      [&] (std::string, NodeId, Location locus) -> void {
+	rust_error_at (constant.get_locus (), "redefined multiple times");
+	rust_error_at (locus, "was defined here");
+      });
     resolver->insert_new_definition (constant.get_node_id (),
 				     Definition{constant.get_node_id (),
 						constant.get_node_id ()});
@@ -50,8 +54,12 @@ public:
   {
     std::string identifier
       = base->as_string () + "::" + function.get_function_name ();
-    resolver->get_name_scope ().insert (identifier, function.get_node_id (),
-					function.get_locus ());
+    resolver->get_name_scope ().insert (
+      identifier, function.get_node_id (), function.get_locus (), false,
+      [&] (std::string, NodeId, Location locus) -> void {
+	rust_error_at (function.get_locus (), "redefined multiple times");
+	rust_error_at (locus, "was defined here");
+      });
     resolver->insert_new_definition (function.get_node_id (),
 				     Definition{function.get_node_id (),
 						function.get_node_id ()});
@@ -61,8 +69,12 @@ public:
   {
     std::string identifier
       = base->as_string () + "::" + method.get_method_name ();
-    resolver->get_name_scope ().insert (identifier, method.get_node_id (),
-					method.get_locus ());
+    resolver->get_name_scope ().insert (
+      identifier, method.get_node_id (), method.get_locus (), false,
+      [&] (std::string, NodeId, Location locus) -> void {
+	rust_error_at (method.get_locus (), "redefined multiple times");
+	rust_error_at (locus, "was defined here");
+      });
     resolver->insert_new_definition (method.get_node_id (),
 				     Definition{method.get_node_id (),
 						method.get_node_id ()});
diff --git a/gcc/rust/resolve/rust-ast-resolve-toplevel.h b/gcc/rust/resolve/rust-ast-resolve-toplevel.h
index 7ca8275..0ed838a 100644
--- a/gcc/rust/resolve/rust-ast-resolve-toplevel.h
+++ b/gcc/rust/resolve/rust-ast-resolve-toplevel.h
@@ -38,22 +38,34 @@ public:
 
   void visit (AST::TupleStruct &struct_decl)
   {
-    resolver->get_type_scope ().insert (struct_decl.get_identifier (),
-					struct_decl.get_node_id (),
-					struct_decl.get_locus ());
+    resolver->get_type_scope ().insert (
+      struct_decl.get_identifier (), struct_decl.get_node_id (),
+      struct_decl.get_locus (), false,
+      [&] (std::string, NodeId, Location locus) -> void {
+	rust_error_at (struct_decl.get_locus (), "redefined multiple times");
+	rust_error_at (locus, "was defined here");
+      });
   }
 
   void visit (AST::StructStruct &struct_decl)
   {
-    resolver->get_type_scope ().insert (struct_decl.get_identifier (),
-					struct_decl.get_node_id (),
-					struct_decl.get_locus ());
+    resolver->get_type_scope ().insert (
+      struct_decl.get_identifier (), struct_decl.get_node_id (),
+      struct_decl.get_locus (), false,
+      [&] (std::string, NodeId, Location locus) -> void {
+	rust_error_at (struct_decl.get_locus (), "redefined multiple times");
+	rust_error_at (locus, "was defined here");
+      });
   }
 
   void visit (AST::StaticItem &var)
   {
-    resolver->get_name_scope ().insert (var.get_identifier (),
-					var.get_node_id (), var.get_locus ());
+    resolver->get_name_scope ().insert (
+      var.get_identifier (), var.get_node_id (), var.get_locus (), false,
+      [&] (std::string, NodeId, Location locus) -> void {
+	rust_error_at (var.get_locus (), "redefined multiple times");
+	rust_error_at (locus, "was defined here");
+      });
     resolver->insert_new_definition (var.get_node_id (),
 				     Definition{var.get_node_id (),
 						var.get_node_id ()});
@@ -62,9 +74,13 @@ public:
 
   void visit (AST::ConstantItem &constant)
   {
-    resolver->get_name_scope ().insert (constant.get_identifier (),
-					constant.get_node_id (),
-					constant.get_locus ());
+    resolver->get_name_scope ().insert (
+      constant.get_identifier (), constant.get_node_id (),
+      constant.get_locus (), false,
+      [&] (std::string, NodeId, Location locus) -> void {
+	rust_error_at (constant.get_locus (), "redefined multiple times");
+	rust_error_at (locus, "was defined here");
+      });
     resolver->insert_new_definition (constant.get_node_id (),
 				     Definition{constant.get_node_id (),
 						constant.get_node_id ()});
@@ -72,9 +88,13 @@ public:
 
   void visit (AST::Function &function)
   {
-    resolver->get_name_scope ().insert (function.get_function_name (),
-					function.get_node_id (),
-					function.get_locus ());
+    resolver->get_name_scope ().insert (
+      function.get_function_name (), function.get_node_id (),
+      function.get_locus (), false,
+      [&] (std::string, NodeId, Location locus) -> void {
+	rust_error_at (function.get_locus (), "redefined multiple times");
+	rust_error_at (locus, "was defined here");
+      });
     resolver->insert_new_definition (function.get_node_id (),
 				     Definition{function.get_node_id (),
 						function.get_node_id ()});
diff --git a/gcc/rust/resolve/rust-ast-resolve.cc b/gcc/rust/resolve/rust-ast-resolve.cc
index c6d7148..fd49720 100644
--- a/gcc/rust/resolve/rust-ast-resolve.cc
+++ b/gcc/rust/resolve/rust-ast-resolve.cc
@@ -110,7 +110,8 @@ Resolver::insert_builtin_types (Rib *r)
   auto builtins = get_builtin_types ();
   for (auto &builtin : builtins)
     r->insert_name (builtin->as_string (), builtin->get_node_id (),
-		    Linemap::predeclared_location ());
+		    Linemap::predeclared_location (), false,
+		    [] (std::string, NodeId, Location) -> void {});
 }
 
 std::vector<AST::Type *> &
diff --git a/gcc/rust/resolve/rust-name-resolver.h b/gcc/rust/resolve/rust-name-resolver.h
index 5bc6aba..f22eba7 100644
--- a/gcc/rust/resolve/rust-name-resolver.h
+++ b/gcc/rust/resolve/rust-name-resolver.h
@@ -37,8 +37,25 @@ public:
 
   ~Rib () {}
 
-  void insert_name (std::string ident, NodeId id, Location locus)
+  void insert_name (std::string ident, NodeId id, Location locus, bool shadow,
+		    std::function<void (std::string, NodeId, Location)> dup_cb)
   {
+    auto it = mappings.find (ident);
+    bool already_exists = it != mappings.end ();
+    if (already_exists && !shadow)
+      {
+	for (auto &decl : decls_within_rib)
+	  {
+	    if (decl.first == it->second)
+	      {
+		dup_cb (ident, it->second, decl.second);
+		return;
+	      }
+	  }
+	dup_cb (ident, it->second, locus);
+	return;
+      }
+
     mappings[ident] = id;
     decls_within_rib.insert (std::pair<NodeId, Location> (id, locus));
     references[id] = {};
@@ -117,9 +134,16 @@ public:
   Scope (CrateNum crate_num) : crate_num (crate_num) {}
   ~Scope () {}
 
+  void insert (std::string ident, NodeId id, Location locus, bool shadow,
+	       std::function<void (std::string, NodeId, Location)> dup_cb)
+  {
+    peek ()->insert_name (ident, id, locus, shadow, dup_cb);
+  }
+
   void insert (std::string ident, NodeId id, Location locus)
   {
-    peek ()->insert_name (ident, id, locus);
+    peek ()->insert_name (ident, id, locus, true,
+			  [] (std::string, NodeId, Location) -> void {});
   }
 
   bool lookup (std::string ident, NodeId *id)
diff --git a/gcc/testsuite/rust.test/compilable/name_resolve1.rs b/gcc/testsuite/rust.test/compilable/name_resolve1.rs
new file mode 100644
index 0000000..817f48b
--- /dev/null
+++ b/gcc/testsuite/rust.test/compilable/name_resolve1.rs
@@ -0,0 +1,23 @@
+struct Foo(i32, bool);
+
+impl Foo {
+    fn new(a: i32, b: bool) -> Foo {
+        Foo(a, b)
+    }
+
+    fn test() -> i32 {
+        test()
+    }
+}
+
+fn test() -> i32 {
+    123
+}
+
+fn main() {
+    let a;
+    a = Foo::new(1, true);
+
+    let b;
+    b = Foo::test();
+}
diff --git a/gcc/testsuite/rust.test/fail_compilation/redef_error1.rs b/gcc/testsuite/rust.test/fail_compilation/redef_error1.rs
new file mode 100644
index 0000000..9acdf5f
--- /dev/null
+++ b/gcc/testsuite/rust.test/fail_compilation/redef_error1.rs
@@ -0,0 +1,8 @@
+struct S1 {
+    x: f64,
+    y: f64,
+}
+
+struct S1(i32, bool);
+
+fn main() {}
diff --git a/gcc/testsuite/rust.test/fail_compilation/redef_error2.rs b/gcc/testsuite/rust.test/fail_compilation/redef_error2.rs
new file mode 100644
index 0000000..c04d2cf
--- /dev/null
+++ b/gcc/testsuite/rust.test/fail_compilation/redef_error2.rs
@@ -0,0 +1,4 @@
+const TEST: i32 = 2;
+const TEST: f32 = 3.0;
+
+fn main() {}
diff --git a/gcc/testsuite/rust.test/fail_compilation/redef_error3.rs b/gcc/testsuite/rust.test/fail_compilation/redef_error3.rs
new file mode 100644
index 0000000..9ffa4e5
--- /dev/null
+++ b/gcc/testsuite/rust.test/fail_compilation/redef_error3.rs
@@ -0,0 +1,9 @@
+fn test() -> bool {
+    true
+}
+
+fn test() -> i32 {
+    123
+}
+
+fn main() {}
diff --git a/gcc/testsuite/rust.test/fail_compilation/redef_error4.rs b/gcc/testsuite/rust.test/fail_compilation/redef_error4.rs
new file mode 100644
index 0000000..5b20e1b
--- /dev/null
+++ b/gcc/testsuite/rust.test/fail_compilation/redef_error4.rs
@@ -0,0 +1,27 @@
+struct Foo(i32, bool);
+
+impl Foo {
+    fn new(a: i32, b: bool) -> Foo {
+        Foo(a, b)
+    }
+
+    fn test() -> i32 {
+        test()
+    }
+
+    fn test() -> bool {
+        true
+    }
+}
+
+fn test() -> i32 {
+    123
+}
+
+fn main() {
+    let a;
+    a = Foo::new(1, true);
+
+    let b;
+    b = Foo::test();
+}
diff --git a/gcc/testsuite/rust.test/fail_compilation/redef_error5.rs b/gcc/testsuite/rust.test/fail_compilation/redef_error5.rs
new file mode 100644
index 0000000..342a67e
--- /dev/null
+++ b/gcc/testsuite/rust.test/fail_compilation/redef_error5.rs
@@ -0,0 +1,8 @@
+struct Foo(i32, bool);
+
+impl Foo {
+    const TEST: i32 = 123;
+    const TEST: bool = false;
+}
+
+fn main() {}