Merge GCC frontend into the branch

1 files changed, 315 insertions, 0 deletions

diff --git a/gcc/elna-tree.cc b/gcc/elna-tree.cc
new file mode 100644
index 0000000..93f796b
--- /dev/null
+++ b/gcc/elna-tree.cc
@@ -0,0 +1,315 @@
+/* Utilities to manipulate GCC trees.
+   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/>.  */
+
+#include "elna/gcc/elna-tree.h"
+#include "elna/gcc/elna-diagnostic.h"
+#include "elna/gcc/elna1.h"
+
+#include "function.h"
+#include "stor-layout.h"
+#include "diagnostic-core.h"
+
+namespace elna::gcc
+{
+    bool is_integral_type(tree type)
+    {
+        gcc_assert(TYPE_P(type));
+        return TREE_CODE(type) == INTEGER_TYPE && type != elna_char_type_node;
+    }
+
+    bool is_numeric_type(tree type)
+    {
+        return is_integral_type(type) || type == elna_float_type_node;
+    }
+
+    bool is_unique_type(tree type)
+    {
+        gcc_assert(TYPE_P(type));
+        return RECORD_OR_UNION_TYPE_P(type) || TREE_CODE(type) == ENUMERAL_TYPE;
+    }
+
+    bool is_void_type(tree type)
+    {
+        return type == NULL_TREE || type == void_type_node;
+    }
+
+    bool is_castable_type(tree type)
+    {
+        gcc_assert(TYPE_P(type));
+        return INTEGRAL_TYPE_P(type) || POINTER_TYPE_P(type) || TREE_CODE(type) == REAL_TYPE;
+    }
+
+    bool are_compatible_pointers(tree lhs_type, tree rhs)
+    {
+        gcc_assert(TYPE_P(lhs_type));
+        tree rhs_type = TREE_TYPE(rhs);
+
+        return (POINTER_TYPE_P(lhs_type) && rhs == elna_pointer_nil_node)
+            || (POINTER_TYPE_P(lhs_type) && lhs_type == rhs_type);
+    }
+
+    tree prepare_rvalue(tree rvalue)
+    {
+        if (DECL_P(rvalue) && TREE_CODE(TREE_TYPE(rvalue)) == FUNCTION_TYPE)
+        {
+            return build1(ADDR_EXPR, build_pointer_type_for_mode(TREE_TYPE(rvalue), VOIDmode, true), rvalue);
+        }
+        else
+        {
+            return rvalue;
+        }
+    }
+
+    bool is_assignable_from(tree assignee, tree assignment)
+    {
+        return get_qualified_type(TREE_TYPE(assignment), TYPE_UNQUALIFIED) == assignee
+            || are_compatible_pointers(assignee, assignment);
+    }
+
+    void append_statement(tree statement_tree)
+    {
+        if (!vec_safe_is_empty(f_binding_level->defers))
+        {
+            append_to_statement_list(statement_tree, &f_binding_level->defers->begin()->try_statements);
+        }
+        else
+        {
+            append_to_statement_list(statement_tree, &f_binding_level->statement_list);
+        }
+    }
+
+    void defer(tree statement_tree)
+    {
+        defer_scope new_defer{ statement_tree, alloc_stmt_list() };
+        vec_safe_insert(f_binding_level->defers, 0, new_defer);
+    }
+
+    tree chain_defer()
+    {
+        if (vec_safe_is_empty(f_binding_level->defers))
+        {
+            return f_binding_level->statement_list;
+        }
+        defer_scope *defer_iterator = f_binding_level->defers->begin();
+        tree defer_tree = build2(TRY_FINALLY_EXPR, void_type_node,
+                defer_iterator->try_statements, defer_iterator->defer_block);
+        int i;
+
+        FOR_EACH_VEC_ELT_FROM(*f_binding_level->defers, i, defer_iterator, 1)
+        {
+            append_to_statement_list(defer_tree, &defer_iterator->try_statements);
+            defer_tree = build2(TRY_FINALLY_EXPR, void_type_node,
+                    defer_iterator->try_statements, defer_iterator->defer_block);
+        }
+        return build2(COMPOUND_EXPR, TREE_TYPE(defer_tree), f_binding_level->statement_list, defer_tree);
+    }
+
+    tree build_field(location_t location, tree record_type, const std::string name, tree type)
+    {
+        tree field_declaration = build_decl(location,
+                FIELD_DECL, get_identifier(name.c_str()), type);
+        TREE_ADDRESSABLE(field_declaration) = 1;
+        DECL_CONTEXT(field_declaration) = record_type;
+
+        return field_declaration;
+    }
+
+    tree do_pointer_arithmetic(frontend::binary_operator binary_operator,
+            tree left, tree right, location_t operation_location)
+    {
+        tree left_type = get_qualified_type(TREE_TYPE(left), TYPE_UNQUALIFIED);
+        tree right_type = get_qualified_type(TREE_TYPE(right), TYPE_UNQUALIFIED);
+        if (binary_operator == frontend::binary_operator::sum)
+        {
+            tree pointer{ NULL_TREE };
+            tree offset{ NULL_TREE };
+            tree pointer_type{ NULL_TREE };
+
+            if (POINTER_TYPE_P(left_type) && is_integral_type(right_type))
+            {
+                pointer = left;
+                offset = right;
+                pointer_type = left_type;
+            }
+            else if (is_integral_type(left_type) && POINTER_TYPE_P(right_type))
+            {
+                pointer = right;
+                offset = left;
+                pointer_type = right_type;
+            }
+            else
+            {
+                return error_mark_node;
+            }
+            tree size_exp = pointer_type == elna_pointer_type_node
+                ? size_one_node
+                : fold_convert(TREE_TYPE(offset), size_in_bytes(TREE_TYPE(TREE_TYPE(pointer))));
+
+            offset = fold_build2(MULT_EXPR, TREE_TYPE(offset), offset, size_exp);
+            offset = fold_convert(sizetype, offset);
+
+            return fold_build2_loc(operation_location, POINTER_PLUS_EXPR, TREE_TYPE(pointer), pointer, offset);
+        }
+        else if (binary_operator == frontend::binary_operator::subtraction)
+        {
+            if (POINTER_TYPE_P(left_type) && is_integral_type(right_type))
+            {
+                tree pointer_type = left_type;
+                tree offset_type = right_type;
+                tree size_exp = fold_convert(offset_type, size_in_bytes(TREE_TYPE(pointer_type)));
+
+                tree convert_expression = fold_build2(MULT_EXPR, offset_type, right, size_exp);
+                convert_expression = fold_convert(sizetype, convert_expression);
+
+                convert_expression = fold_build1(NEGATE_EXPR, sizetype, convert_expression);
+                return fold_build2_loc(operation_location, POINTER_PLUS_EXPR, pointer_type, left, convert_expression);
+            }
+            else if (POINTER_TYPE_P(left_type) && POINTER_TYPE_P(right_type) && left_type == right_type)
+            {
+                return fold_build2_loc(operation_location, POINTER_DIFF_EXPR, ssizetype, left, right);
+            }
+        }
+        gcc_unreachable();
+    }
+
+    tree build_binary_operation(bool condition, frontend::binary_expression *expression,
+            tree_code operator_code, tree left, tree right, tree target_type)
+    {
+        location_t expression_location = get_location(&expression->position());
+        tree left_type = get_qualified_type(TREE_TYPE(left), TYPE_UNQUALIFIED);
+        tree right_type = get_qualified_type(TREE_TYPE(right), TYPE_UNQUALIFIED);
+
+        if (condition)
+        {
+            return fold_build2_loc(expression_location, operator_code, target_type, left, right);
+        }
+        else
+        {
+            error_at(expression_location,
+                    "invalid operands of type '%s' and '%s' for operator %s",
+                    print_type(left_type).c_str(), print_type(right_type).c_str(),
+                    elna::frontend::print_binary_operator(expression->operation()));
+            return error_mark_node;
+        }
+    }
+
+    tree find_field_by_name(location_t expression_location, tree type, const std::string& field_name)
+    {
+        if (type == error_mark_node)
+        {
+            return type;
+        }
+        tree field_declaration = TYPE_FIELDS(type);
+
+        if (!RECORD_OR_UNION_TYPE_P(type))
+        {
+            error_at(expression_location, "Type '%s' does not have a field named '%s'",
+                    print_type(type).c_str(), field_name.c_str());
+            return error_mark_node;
+        }
+        while (field_declaration != NULL_TREE)
+        {
+            tree declaration_name = DECL_NAME(field_declaration);
+            const char *identifier_pointer = IDENTIFIER_POINTER(declaration_name);
+
+            if (field_name == identifier_pointer)
+            {
+                break;
+            }
+            field_declaration = TREE_CHAIN(field_declaration);
+        }
+        if (field_declaration == NULL_TREE)
+        {
+            error_at(expression_location, "Aggregate type does not have a field '%s'", field_name.c_str());
+            return error_mark_node;
+        }
+        return field_declaration;
+    }
+
+    tree build_global_pointer_type(tree type)
+    {
+        return build_pointer_type_for_mode(type, VOIDmode, true);
+    }
+
+    tree build_static_array_type(tree type, const std::uint64_t size)
+    {
+        tree upper_bound = build_int_cst_type(integer_type_node, size);
+        tree range_type = build_range_type(integer_type_node, size_one_node, upper_bound);
+
+        return build_array_type(type, range_type);
+    }
+
+    tree build_enumeration_type(const std::vector<std::string>& members)
+    {
+        tree composite_type_node = make_node(ENUMERAL_TYPE);
+        const tree base_type = integer_type_node;
+
+        TREE_TYPE(composite_type_node) = base_type;
+        ENUM_IS_SCOPED(composite_type_node) = 1;
+
+        tree *pp = &TYPE_VALUES(composite_type_node);
+        std::size_t order{ 1 };
+
+        for (const std::string& member : members)
+        {
+            tree member_name = get_identifier(member.c_str());
+            tree member_declaration = build_decl(UNKNOWN_LOCATION, CONST_DECL, member_name, composite_type_node);
+
+            DECL_CONTEXT(member_declaration) = composite_type_node;
+            DECL_INITIAL(member_declaration) = build_int_cst_type(composite_type_node, order++);
+            TREE_CONSTANT(member_declaration) = 1;
+            TREE_READONLY(member_declaration) = 1;
+
+            TYPE_MAX_VALUE(composite_type_node) = DECL_INITIAL(member_declaration);
+
+            *pp = build_tree_list(member_name, member_declaration);
+            pp = &TREE_CHAIN(*pp);
+        }
+        TYPE_MIN_VALUE(composite_type_node) = DECL_INITIAL(TREE_VALUE(TYPE_VALUES(composite_type_node)));
+        TYPE_UNSIGNED(composite_type_node) = TYPE_UNSIGNED(base_type);
+        SET_TYPE_ALIGN(composite_type_node, TYPE_ALIGN(base_type));
+        TYPE_SIZE(composite_type_node) = NULL_TREE;
+        TYPE_PRECISION(composite_type_node) = TYPE_PRECISION(base_type);
+
+        layout_type(composite_type_node);
+        return composite_type_node;
+    }
+
+    tree build_label_decl(const char *name, location_t loc)
+    {
+        auto label_decl = build_decl(loc, LABEL_DECL, get_identifier(name), void_type_node);
+
+        DECL_CONTEXT(label_decl) = current_function_decl;
+
+        return label_decl;
+    }
+
+    tree extract_constant(tree expression)
+    {
+        int code = TREE_CODE(expression);
+
+        if (code == CONST_DECL)
+        {
+            return DECL_INITIAL(expression);
+        }
+        else if (TREE_CODE_CLASS(code) == tcc_constant)
+        {
+            return expression;
+        }
+        return NULL_TREE;
+    }
+}