diff --git a/boot/driver.cc b/boot/driver.cc
index 8ecdc1a..0257d44 100644
--- a/boot/driver.cc
+++ b/boot/driver.cc
@@ -42,20 +42,10 @@ namespace boot
     }
 
     driver::driver(const char *input_file)
-        : input_file(input_file)
+        : error_container(input_file)
     {
     }
 
-    void driver::error(const yy::location& loc, const std::string& message)
-    {
-        m_errors.emplace_back(new boot::syntax_error(message, input_file, loc));
-    }
-
-    const std::list<std::unique_ptr<struct error>>& driver::errors() const noexcept
-    {
-        return m_errors;
-    }
-
     char escape_char(char escape)
     {
         switch (escape)
diff --git a/boot/lexer.ll b/boot/lexer.ll
index bb7ca06..941b66c 100644
--- a/boot/lexer.ll
+++ b/boot/lexer.ll
@@ -290,6 +290,6 @@ defer                   {
                             std::stringstream ss;
 
                             ss << "Illegal character 0x" << std::hex << static_cast<unsigned int>(yytext[0]);
-                            driver.error(this->location, ss.str());
+                            driver.add_error<elna::boot::syntax_error>(ss.str(), driver.input_file, this->location);
                         }
 %%
diff --git a/boot/parser.yy b/boot/parser.yy
index e5ed856..2959d2e 100644
--- a/boot/parser.yy
+++ b/boot/parser.yy
@@ -578,5 +578,5 @@ actual_parameter_list:
 
 void yy::parser::error(const location_type& loc, const std::string& message)
 {
-    driver.error(loc, message);
+    driver.add_error<elna::boot::syntax_error>(message, driver.input_file, loc);
 }
diff --git a/boot/result.cc b/boot/result.cc
index 74c6277..11d85ac 100644
--- a/boot/result.cc
+++ b/boot/result.cc
@@ -35,5 +35,15 @@ namespace boot
     {
         return this->position.column;
     }
+
+    error_container::error_container(const char *input_file)
+        : input_file(input_file)
+    {
+    }
+
+    std::deque<std::unique_ptr<error>>& error_container::errors()
+    {
+        return m_errors;
+    }
 }
 }
diff --git a/boot/semantic.cc b/boot/semantic.cc
index e54c5f1..a7187f3 100644
--- a/boot/semantic.cc
+++ b/boot/semantic.cc
@@ -32,7 +32,7 @@ namespace boot
     }
 
     declaration_visitor::declaration_visitor(const char *path, std::shared_ptr<symbol_table> symbols)
-        : path(path), symbols(symbols)
+        : error_container(path), symbols(symbols)
     {
     }
 
@@ -66,10 +66,8 @@ namespace boot
         }
         else
         {
-            auto new_error = std::make_unique<declaration_error>(type_expression->name,
-                    path, type_expression->position());
-            this->errors.emplace_back(std::move(new_error));
-            // TODO: Delete the next line.
+            // TODO:
+            // add_error<declaration_error>(type_expression->name, this->input_file, type_expression->position());
             this->current_type = type(std::make_shared<primitive_type>(type_expression->name));
         }
     }
diff --git a/gcc/elna-diagnostic.cc b/gcc/elna-diagnostic.cc
index 7e75de0..b988f61 100644
--- a/gcc/elna-diagnostic.cc
+++ b/gcc/elna-diagnostic.cc
@@ -133,5 +133,15 @@ namespace gcc
         }
         gcc_unreachable();
     }
+
+    void report_errors(const std::deque<std::unique_ptr<boot::error>>& errors)
+    {
+        for (const auto& error : errors)
+        {
+            auto gcc_location = elna::gcc::get_location(&error->position);
+
+            error_at(gcc_location, error->what().c_str());
+        }
+    }
 }
 }
diff --git a/gcc/elna-generic.cc b/gcc/elna-generic.cc
index c189833..3144b86 100644
--- a/gcc/elna-generic.cc
+++ b/gcc/elna-generic.cc
@@ -63,18 +63,23 @@ namespace gcc
         return error_mark_node;
     }
 
-    void do_semantic_analysis(const char *path, std::unique_ptr<boot::program>& ast,
-            std::shared_ptr<symbol_table> symbols)
+    std::deque<std::unique_ptr<boot::error>> do_semantic_analysis(const char *path,
+            std::unique_ptr<boot::program>& ast, std::shared_ptr<symbol_table> symbols)
     {
         auto info_table = boot::builtin_symbol_table();
         boot::declaration_visitor declaration_visitor(path, info_table);
 
         declaration_visitor.visit(ast.get());
-        for (auto unresolved : declaration_visitor.unresolved)
+
+        if (declaration_visitor.errors().empty())
         {
-            auto inner_alias = get_inner_alias(symbols, boot::type(unresolved.second));
-            symbols->enter(unresolved.first, inner_alias);
+            for (auto unresolved : declaration_visitor.unresolved)
+            {
+                auto inner_alias = get_inner_alias(symbols, boot::type(unresolved.second));
+                symbols->enter(unresolved.first, inner_alias);
+            }
         }
+        return std::move(declaration_visitor.errors());
     }
 
     generic_visitor::generic_visitor(std::shared_ptr<symbol_table> symbol_table)
diff --git a/gcc/elna1.cc b/gcc/elna1.cc
index c56dd7f..eac5d76 100644
--- a/gcc/elna1.cc
+++ b/gcc/elna1.cc
@@ -79,12 +79,7 @@ static void elna_parse_file(const char *filename)
     linemap_add(line_table, LC_ENTER, 0, filename, 1);
     if (parser())
     {
-        for (const auto& error : driver.errors())
-        {
-            auto gcc_location = elna::gcc::get_location(&error->position);
-
-            error_at(gcc_location, error->what().c_str());
-        }
+        elna::gcc::report_errors(driver.errors());
     }
     else
     {
@@ -98,10 +93,17 @@ static void elna_parse_file(const char *filename)
         symbol_table->enter("Float", elna_float_type_node);
         symbol_table->enter("String", elna_string_type_node);
 
-        elna::gcc::do_semantic_analysis(filename, driver.tree, symbol_table);
-        elna::gcc::generic_visitor generic_visitor{ symbol_table };
+        auto semantic_errors = elna::gcc::do_semantic_analysis(filename, driver.tree, symbol_table);
 
-        generic_visitor.visit(driver.tree.get());
+        if (semantic_errors.empty())
+        {
+            elna::gcc::generic_visitor generic_visitor{ symbol_table };
+            generic_visitor.visit(driver.tree.get());
+        }
+        else
+        {
+            elna::gcc::report_errors(semantic_errors);
+        }
     }
     linemap_add(line_table, LC_LEAVE, 0, NULL, 0);
 }
diff --git a/include/elna/boot/driver.h b/include/elna/boot/driver.h
index fdbe63a..f09da87 100644
--- a/include/elna/boot/driver.h
+++ b/include/elna/boot/driver.h
@@ -17,7 +17,6 @@ along with GCC; see the file COPYING3.  If not see
 
 #pragma once
 
-#include <list>
 #include <optional>
 #include "elna/boot/ast.h"
 #include "location.hh"
@@ -39,18 +38,12 @@ namespace boot
         virtual std::string what() const override;
     };
 
-    class driver
+    class driver : public error_container
     {
-        std::list<std::unique_ptr<struct error>> m_errors;
-        const char *input_file;
-
     public:
         std::unique_ptr<program> tree;
 
         driver(const char *input_file);
-
-        void error(const yy::location& loc, const std::string& message);
-        const std::list<std::unique_ptr<struct error>>& errors() const noexcept;
     };
 
     constexpr char escape_invalid_char = '\xff';
diff --git a/include/elna/boot/result.h b/include/elna/boot/result.h
index b64d66f..65bfe59 100644
--- a/include/elna/boot/result.h
+++ b/include/elna/boot/result.h
@@ -19,6 +19,8 @@ along with GCC; see the file COPYING3.  If not see
 
 #include <cstddef>
 #include <string>
+#include <deque>
+#include <memory>
 
 namespace elna
 {
@@ -59,5 +61,25 @@ namespace boot
         /// Error column in the source text.
         std::size_t column() const;
     };
+
+    class error_container
+    {
+    protected:
+        std::deque<std::unique_ptr<error>> m_errors;
+
+        error_container(const char *input_file);
+
+    public:
+        const char *input_file;
+
+        std::deque<std::unique_ptr<error>>& errors();
+
+        template<typename T, typename... Args>
+        void add_error(Args... arguments)
+        {
+            auto new_error = std::make_unique<T>(arguments...);
+            m_errors.emplace_back(std::move(new_error));
+        }
+    };
 }
 }
diff --git a/include/elna/boot/semantic.h b/include/elna/boot/semantic.h
index dfe6aa1..86e97aa 100644
--- a/include/elna/boot/semantic.h
+++ b/include/elna/boot/semantic.h
@@ -18,6 +18,7 @@ along with GCC; see the file COPYING3.  If not see
 #include <string>
 #include <unordered_map>
 #include <memory>
+#include <deque>
 
 #include "elna/boot/ast.h"
 #include "elna/boot/result.h"
@@ -37,12 +38,10 @@ namespace boot
         virtual std::string what() const override;
     };
 
-    class declaration_visitor final : public empty_visitor
+    class declaration_visitor final : public empty_visitor, public error_container
     {
         type current_type;
-        const char *path;
         symbol_table symbols;
-        std::vector<std::unique_ptr<error>> errors;
 
     public:
         std::unordered_map<std::string, std::shared_ptr<alias_type>> unresolved;
diff --git a/include/elna/gcc/elna-diagnostic.h b/include/elna/gcc/elna-diagnostic.h
index b86f864..d225505 100644
--- a/include/elna/gcc/elna-diagnostic.h
+++ b/include/elna/gcc/elna-diagnostic.h
@@ -22,6 +22,10 @@ along with GCC; see the file COPYING3.  If not see
 #include "coretypes.h"
 #include "input.h"
 #include "tree.h"
+#include "diagnostic.h"
+
+#include <deque>
+#include <memory>
 
 #include "elna/boot/result.h"
 
@@ -30,7 +34,7 @@ namespace elna
 namespace gcc
 {
     location_t get_location(const boot::position *position);
-
     std::string print_type(tree type);
+    void report_errors(const std::deque<std::unique_ptr<boot::error>>& errors);
 }
 }
diff --git a/include/elna/gcc/elna-generic.h b/include/elna/gcc/elna-generic.h
index 4c1bea1..a426f8a 100644
--- a/include/elna/gcc/elna-generic.h
+++ b/include/elna/gcc/elna-generic.h
@@ -34,8 +34,8 @@ namespace elna
 {
 namespace gcc
 {
-    void do_semantic_analysis(const char *path, std::unique_ptr<boot::program>& ast,
-            std::shared_ptr<symbol_table> symbols);
+    std::deque<std::unique_ptr<boot::error>> do_semantic_analysis(const char *path,
+            std::unique_ptr<boot::program>& ast, std::shared_ptr<symbol_table> symbols);
 
     class generic_visitor final : public boot::empty_visitor
     {