Handle const Pointer as const pointer to const data

3 files changed, 186 insertions, 133 deletions

diff --git a/include/elna/boot/name_analysis.h b/include/elna/boot/name_analysis.h
new file mode 100644
index 0000000..4498d0c
--- /dev/null
+++ b/include/elna/boot/name_analysis.h
@@ -0,0 +1,153 @@
+/* Name analysis.
+   Copyright (C) 2025 Free Software Foundation, Inc.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#pragma once
+
+#include <string>
+#include <memory>
+#include <map>
+
+#include "elna/boot/ast.h"
+#include "elna/boot/result.h"
+#include "elna/boot/symbol.h"
+#include "elna/boot/type_check.h"
+
+namespace elna::boot
+{
+    /**
+     * Error declaring a symbol.
+     */
+    class declaration_error : public error
+    {
+    public:
+        enum class kind
+        {
+            undeclared,
+            local_export
+        };
+
+    private:
+        std::string identifier;
+        kind error_kind;
+
+    public:
+
+        declaration_error(const kind error_kind,
+                const boot::identifier& identifier);
+
+        std::string what() const override;
+    };
+
+    /**
+     * Attempted to redefine a name that is already in use in the
+     * current scope.
+     */
+    class redefinition_error : public error
+    {
+        std::string identifier;
+        std::optional<source_position> original;
+
+    public:
+        redefinition_error(const boot::identifier& identifier,
+                std::optional<source_position> original);
+
+        std::string what() const override;
+
+        std::optional<std::pair<std::string, source_position>> note() const override;
+    };
+
+    /**
+     * Origin of a field in a composite type.
+     */
+    struct field_origin
+    {
+        std::optional<source_position> declaration;
+        type base_type;
+    };
+
+    /**
+     * Performs name analysis.
+     */
+    class name_analysis_visitor final : public walking_visitor, public error_container
+    {
+        type current_type;
+
+        symbol_bag bag;
+
+        std::pair<procedure_type, std::vector<std::string>> build_procedure(
+                procedure_type_expression& expression);
+        std::vector<type_field> build_composite_type(const std::vector<field_declaration>& fields,
+                std::map<std::string, field_origin>& known_names,
+                type aggregate);
+        std::shared_ptr<variable_info> register_variable(const std::string& name,
+                const bool is_extern, const source_position position);
+
+        type lookup_primitive_type(const std::string& name);
+        type lookup_field(const type& composite_type, const std::string& field_name);
+
+    public:
+        name_analysis_visitor(symbol_bag bag);
+
+        void visit(array_type_expression *expression) override;
+        void visit(pointer_type_expression *expression) override;
+        void visit(constant_type_expression *expression) override;
+        void visit(type_declaration *declaration) override;
+        void visit(record_type_expression *expression) override;
+        void visit(record_constructor_expression *expression) override;
+        void visit(array_constructor_expression *expression) override;
+        void visit(procedure_type_expression *expression) override;
+        void visit(enumeration_type_expression *expression) override;
+
+        void visit(variable_declaration *declaration) override;
+        void visit(procedure_declaration *declaration) override;
+
+        void visit(procedure_call *call) override;
+        void visit(unit *unit) override;
+        void visit(cast_expression *expression) override;
+        void visit(traits_expression *trait) override;
+        void visit(binary_expression *expression) override;
+        void visit(unary_expression *expression) override;
+        void visit(named_expression *expression) override;
+        void visit(array_access_expression *expression) override;
+        void visit(field_access_expression *expression) override;
+        void visit(dereference_expression *expression) override;
+        void visit(literal<std::int32_t> *literal) override;
+        void visit(literal<std::uint32_t> *literal) override;
+        void visit(literal<double> *literal) override;
+        void visit(literal<bool> *literal) override;
+        void visit(literal<unsigned char> *literal) override;
+        void visit(literal<std::nullptr_t> *literal) override;
+        void visit(literal<std::string> *literal) override;
+    };
+
+    /**
+     * Collects global declarations without resolving any symbols.
+     */
+    class declaration_visitor final : public empty_visitor, public error_container
+    {
+    public:
+        forward_table unresolved;
+
+        explicit declaration_visitor();
+
+        void visit(import_declaration *) override;
+        void visit(unit *unit) override;
+        void visit(type_declaration *declaration) override;
+        void visit(procedure_declaration *declaration) override;
+        void visit(variable_declaration *declaration) override;
+    };
+}
diff --git a/include/elna/boot/semantic.h b/include/elna/boot/type_check.h
index 3d2de10..b250f48 100644
--- a/include/elna/boot/semantic.h
+++ b/include/elna/boot/type_check.h
@@ -1,4 +1,4 @@
-/* Name analysis.
+/* Type analysis.
    Copyright (C) 2025 Free Software Foundation, Inc.
 
 GCC is free software; you can redistribute it and/or modify
@@ -19,7 +19,7 @@ along with GCC; see the file COPYING3.  If not see
 
 #include <string>
 #include <memory>
-#include <map>
+#include <vector>
 
 #include "elna/boot/ast.h"
 #include "elna/boot/result.h"
@@ -28,48 +28,6 @@ along with GCC; see the file COPYING3.  If not see
 namespace elna::boot
 {
     /**
-     * Error declaring a symbol.
-     */
-    class declaration_error : public error
-    {
-    public:
-        enum class kind
-        {
-            undeclared,
-            local_export
-        };
-
-    private:
-        std::string identifier;
-        kind error_kind;
-
-    public:
-
-        declaration_error(const kind error_kind,
-                const boot::identifier& identifier);
-
-        std::string what() const override;
-    };
-
-    /**
-     * Attempted to redefine a name that is already in use in the
-     * current scope.
-     */
-    class redefinition_error : public error
-    {
-        std::string identifier;
-        std::optional<source_position> original;
-
-    public:
-        redefinition_error(const boot::identifier& identifier,
-                std::optional<source_position> original);
-
-        std::string what() const override;
-
-        std::optional<std::pair<std::string, source_position>> note() const override;
-    };
-
-    /**
      * Expected type does not match the actual type of an expression.
      */
     class type_mismatch_error : public error
@@ -205,7 +163,37 @@ namespace elna::boot
     };
 
     /**
-     * Checks types.
+     * Chain of responsibility for type compatibility checks.
+     *
+     * Populate \c ctx with pre-resolved types, then call \c run().
+     * Each handler inspects the context and returns a verdict —
+     * the first non-\c pass verdict wins.
+     */
+    struct assign_check
+    {
+        enum class verdict { pass, accept, reject };
+
+        struct context
+        {
+            type aliased_assignee;
+            type aliased_assignment;
+            type resolved_assignee;
+            type resolved_assignment;
+        };
+        context ctx;
+
+        verdict guard_const_laundering();
+        verdict check_exact_match();
+        verdict check_pointer_hatch();
+        verdict check_pointer_conversion();
+
+        bool run();
+    };
+
+    /**
+     * Checks types: assignment compatibility, const-correctness,
+     * procedure argument counts, record field validity,
+     * and type declaration well-formedness.
      */
     class type_analysis_visitor final : public walking_visitor, public error_container
     {
@@ -217,12 +205,6 @@ namespace elna::boot
          * of type assignee.
          */
         static bool is_assignable_from(const type& assignee, const type& assignment);
-        /*
-         * Checks whether derived has base in its parent chain.
-         * base should not be null, derived can be null.
-         */
-        static bool is_base_of(const std::shared_ptr<record_type>& base,
-                const std::shared_ptr<record_type>& derived);
         static bool check_unresolved_symbol(std::shared_ptr<alias_type> alias,
                 std::vector<std::string>& path);
 
@@ -240,85 +222,4 @@ namespace elna::boot
         void visit(record_constructor_expression *expression) override;
         void visit(array_constructor_expression *expression) override;
     };
-
-    /**
-     * Origin of a field in a composite type.
-     */
-    struct field_origin
-    {
-        std::optional<source_position> declaration;
-        type base_type;
-    };
-
-    /**
-     * Performs name analysis.
-     */
-    class name_analysis_visitor final : public walking_visitor, public error_container
-    {
-        type current_type;
-
-        symbol_bag bag;
-
-        std::pair<procedure_type, std::vector<std::string>> build_procedure(
-                procedure_type_expression& expression);
-        std::vector<type_field> build_composite_type(const std::vector<field_declaration>& fields,
-                std::map<std::string, field_origin>& known_names,
-                type aggregate);
-        std::shared_ptr<variable_info> register_variable(const std::string& name,
-                const bool is_extern, const source_position position);
-
-        type lookup_primitive_type(const std::string& name);
-        type lookup_field(const type& composite_type, const std::string& field_name);
-
-    public:
-        name_analysis_visitor(symbol_bag bag);
-
-        void visit(array_type_expression *expression) override;
-        void visit(pointer_type_expression *expression) override;
-        void visit(constant_type_expression *expression) override;
-        void visit(type_declaration *declaration) override;
-        void visit(record_type_expression *expression) override;
-        void visit(record_constructor_expression *expression) override;
-        void visit(array_constructor_expression *expression) override;
-        void visit(procedure_type_expression *expression) override;
-        void visit(enumeration_type_expression *expression) override;
-
-        void visit(variable_declaration *declaration) override;
-        void visit(procedure_declaration *declaration) override;
-
-        void visit(procedure_call *call) override;
-        void visit(unit *unit) override;
-        void visit(cast_expression *expression) override;
-        void visit(traits_expression *trait) override;
-        void visit(binary_expression *expression) override;
-        void visit(unary_expression *expression) override;
-        void visit(named_expression *expression) override;
-        void visit(array_access_expression *expression) override;
-        void visit(field_access_expression *expression) override;
-        void visit(dereference_expression *expression) override;
-        void visit(literal<std::int32_t> *literal) override;
-        void visit(literal<std::uint32_t> *literal) override;
-        void visit(literal<double> *literal) override;
-        void visit(literal<bool> *literal) override;
-        void visit(literal<unsigned char> *literal) override;
-        void visit(literal<std::nullptr_t> *literal) override;
-        void visit(literal<std::string> *literal) override;
-    };
-
-    /**
-     * Collects global declarations without resolving any symbols.
-     */
-    class declaration_visitor final : public empty_visitor, public error_container
-    {
-    public:
-        forward_table unresolved;
-
-        explicit declaration_visitor();
-
-        void visit(import_declaration *) override;
-        void visit(unit *unit) override;
-        void visit(type_declaration *declaration) override;
-        void visit(procedure_declaration *declaration) override;
-        void visit(variable_declaration *declaration) override;
-    };
 }
diff --git a/include/elna/gcc/elna-generic.h b/include/elna/gcc/elna-generic.h
index a1689be..dd5c9ef 100644
--- a/include/elna/gcc/elna-generic.h
+++ b/include/elna/gcc/elna-generic.h
@@ -20,7 +20,6 @@ along with GCC; see the file COPYING3.  If not see
 #include <string>
 #include "elna/boot/ast.h"
 #include "elna/boot/symbol.h"
-#include "elna/boot/semantic.h"
 #include "elna/gcc/elna-tree.h"
 
 #include "config.h"