gccrs: Add improved error when no fields in initializer

If a struct type with a variant that has fields is initialized with some fields the expression  HIR StructExprStructFields is checked that all the fields are assigned. However, if no fields are initialized the HIR StructExprStruct is generated. This doesn't check if the struct is a unit during typechekc and only fails at the compile stage with a ICE.

Add a check at the typecheck stage that makes sure the struct does not have a variant with fields and give an error message based on the rustc one.

We have also updated the message given in the case where one field was present to list the missing fields and match more closely the new message.

gcc/rust/ChangeLog:

	* typecheck/rust-hir-type-check-expr.cc (TypeCheckExpr::visit) Add additional check
	* typecheck/rust-hir-type-check-struct-field.h: A helper method to make error added
	* typecheck/rust-hir-type-check-struct.cc (TypeCheckStructExpr::resolve) Update message

gcc/testsuite/ChangeLog:

	* rust/compile/missing_constructor_fields.rs: Added case with no initializers

Signed-off-by: Robert Goss <goss.robert@gmail.com>

diff --git a/gcc/rust/typecheck/rust-hir-type-check-expr.cc b/gcc/rust/typecheck/rust-hir-type-check-expr.cc
index 030e5f1b63ce2d645764ceec9a4e1aa09d8f2202..43d183f7a592092a596dd142756c6fbe6bab631c 100644 (file)
--- a/gcc/rust/typecheck/rust-hir-type-check-expr.cc
+++ b/gcc/rust/typecheck/rust-hir-type-check-expr.cc
@@ -1017,6 +1017,24 @@ TypeCheckExpr::visit (HIR::StructExprStruct &struct_expr)
       return;
     }
 
+  TyTy::ADTType *adt = static_cast<TyTy::ADTType *> (struct_path_ty);
+  for (auto variant : adt->get_variants ())
+    {
+      if (!variant->get_fields ().empty ())
+       {
+         std::vector<std::string> field_names;
+         for (auto &field : variant->get_fields ())
+           field_names.push_back (field->get_name ());
+         Error missing_fields_error
+           = TypeCheckStructExpr::make_missing_field_error (
+             struct_expr.get_locus (), field_names,
+             struct_path_ty->get_name ());
+         // We might want to return or handle these in the future emit for now.
+         missing_fields_error.emit ();
+         return;
+       }
+    }
+
   infered = struct_path_ty;
 }
 

diff --git a/gcc/rust/typecheck/rust-hir-type-check-struct-field.h b/gcc/rust/typecheck/rust-hir-type-check-struct-field.h
index 31d2896d0bbeff053f65d2db8630498249758a49..792eebf3ff5e184ff0e5bd3b1d554326446c8e62 100644 (file)
--- a/gcc/rust/typecheck/rust-hir-type-check-struct-field.h
+++ b/gcc/rust/typecheck/rust-hir-type-check-struct-field.h
@@ -25,6 +25,9 @@
 #include "rust-tyty.h"
 
 namespace Rust {
+
+struct Error;
+
 namespace Resolver {
 
 class TypeCheckStructExpr : public TypeCheckBase
@@ -32,6 +35,12 @@ class TypeCheckStructExpr : public TypeCheckBase
 public:
   static TyTy::BaseType *Resolve (HIR::StructExprStructFields *expr);
 
+  // Helper for making any errors
+  static Error
+  make_missing_field_error (location_t locus,
+                           const std::vector<std::string> &missing_field_names,
+                           const std::string &struct_name);
+
 protected:
   void resolve (HIR::StructExprStructFields &struct_expr);
 

diff --git a/gcc/rust/typecheck/rust-hir-type-check-struct.cc b/gcc/rust/typecheck/rust-hir-type-check-struct.cc
index 56aa3d869a497a23fd90a4c0b42e2d15fdc5b8cd..d2977ac8ea8461cede2f23d2dd7055df8e9efefe 100644 (file)
--- a/gcc/rust/typecheck/rust-hir-type-check-struct.cc
+++ b/gcc/rust/typecheck/rust-hir-type-check-struct.cc
@@ -142,7 +142,16 @@ TypeCheckStructExpr::resolve (HIR::StructExprStructFields &struct_expr)
     }
 
   // check the arguments are all assigned and fix up the ordering
-  if (fields_assigned.size () != variant->num_fields ())
+  std::vector<std::string> missing_field_names;
+  for (auto &field : variant->get_fields ())
+    {
+      auto it = fields_assigned.find (field->get_name ());
+      if (it == fields_assigned.end ())
+       {
+         missing_field_names.push_back (field->get_name ());
+       }
+    }
+  if (!missing_field_names.empty ())
     {
       if (struct_def->is_union ())
        {
@@ -156,8 +165,12 @@ TypeCheckStructExpr::resolve (HIR::StructExprStructFields &struct_expr)
        }
       else if (!struct_expr.has_struct_base ())
        {
-         rust_error_at (struct_expr.get_locus (), ErrorCode::E0063,
-                        "constructor is missing fields");
+         Error missing_fields_error
+           = make_missing_field_error (struct_expr.get_locus (),
+                                       missing_field_names,
+                                       struct_path_ty->get_name ());
+         // We might want to return or handle these in the future emit for now.
+         missing_fields_error.emit ();
          return;
        }
       else
@@ -392,5 +405,34 @@ TypeCheckStructExpr::visit (HIR::StructExprFieldIdentifier &field)
   return true;
 }
 
+Error
+TypeCheckStructExpr::make_missing_field_error (
+  location_t locus, const std::vector<std::string> &missing_field_names,
+  const std::string &struct_name)
+{
+  // Message plurality depends on size
+  if (missing_field_names.size () == 1)
+    {
+      return Error (locus, ErrorCode::E0063,
+                   "missing field %s in initializer of %qs",
+                   missing_field_names[0].c_str (), struct_name.c_str ());
+    }
+  // Make comma separated string for display
+  std::stringstream display_field_names;
+  bool first = true;
+  for (auto &name : missing_field_names)
+    {
+      if (!first)
+       {
+         display_field_names << ", ";
+       }
+      first = false;
+      display_field_names << name;
+    }
+  return Error (locus, ErrorCode::E0063,
+               "missing fields %s in initializer of %qs",
+               display_field_names.str ().c_str (), struct_name.c_str ());
+}
+
 } // namespace Resolver
 } // namespace Rust

diff --git a/gcc/testsuite/rust/compile/missing_constructor_fields.rs b/gcc/testsuite/rust/compile/missing_constructor_fields.rs
index 9d492101fbd58e56f369df7a5869e441a6a30ee2..6e3965b56870a953895a66c98f5ae60efad6fb30 100644 (file)
--- a/gcc/testsuite/rust/compile/missing_constructor_fields.rs
+++ b/gcc/testsuite/rust/compile/missing_constructor_fields.rs
@@ -6,5 +6,7 @@ struct Foo {
 }
 
 fn main() {
-    let x = Foo { x: 0 , y:1 }; // { dg-error "constructor is missing fields" }
-}
\ No newline at end of file
+    let z = Foo { x: 0 , y:1 }; // { dg-error "missing field z in initializer of 'Foo'" }
+    let xz = Foo { y:1 }; // { dg-error "missing fields x, z in initializer of 'Foo'" }
+    let xyz = Foo { }; // { dg-error "missing fields x, y, z in initializer of 'Foo'" }
+}