Removed EXPR_BUILTIN_SYMBOL: Builtins are now predefined functions
[cparser] / parser.c
index df8da65..238422a 100644 (file)
--- a/parser.c
+++ b/parser.c
@@ -42,7 +42,7 @@
 #include "adt/array.h"
 
 //#define PRINT_TOKENS
-#define MAX_LOOKAHEAD 2
+#define MAX_LOOKAHEAD 1
 
 typedef struct {
        entity_t           *old_entity;
@@ -113,7 +113,7 @@ static token_t              token;
 /** The lookahead ring-buffer. */
 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
 /** Position of the next token in the lookahead buffer. */
-static int                  lookahead_bufpos;
+static size_t               lookahead_bufpos;
 static stack_entry_t       *environment_stack = NULL;
 static stack_entry_t       *label_stack       = NULL;
 static scope_t             *file_scope        = NULL;
@@ -206,6 +206,9 @@ static entity_t *record_entity(entity_t *entity, bool is_definition);
 
 static void semantic_comparison(binary_expression_t *expression);
 
+static void create_gnu_builtins(void);
+static void create_microsoft_intrinsics(void);
+
 #define STORAGE_CLASSES       \
        STORAGE_CLASSES_NO_EXTERN \
        case T_extern:
@@ -288,27 +291,16 @@ static void semantic_comparison(binary_expression_t *expression);
        case T___FUNCTION__:             \
        case T___PRETTY_FUNCTION__:      \
        case T___alignof__:              \
-       case T___builtin_alloca:         \
        case T___builtin_classify_type:  \
        case T___builtin_constant_p:     \
-       case T___builtin_expect:         \
-       case T___builtin_huge_val:       \
-       case T___builtin_inf:            \
-       case T___builtin_inff:           \
-       case T___builtin_infl:           \
        case T___builtin_isgreater:      \
        case T___builtin_isgreaterequal: \
        case T___builtin_isless:         \
        case T___builtin_islessequal:    \
        case T___builtin_islessgreater:  \
        case T___builtin_isunordered:    \
-       case T___builtin_nan:            \
-       case T___builtin_nanf:           \
-       case T___builtin_nanl:           \
        case T___builtin_offsetof:       \
-       case T___builtin_prefetch:       \
        case T___builtin_va_arg:         \
-       case T___builtin_va_end:         \
        case T___builtin_va_start:       \
        case T___func__:                 \
        case T___noop:                   \
@@ -351,7 +343,7 @@ static size_t get_entity_struct_size(entity_kind_t kind)
                [ENTITY_LOCAL_LABEL]     = sizeof(label_t),
                [ENTITY_NAMESPACE]       = sizeof(namespace_t)
        };
-       assert(kind < sizeof(sizes) / sizeof(sizes[0]));
+       assert(kind < lengthof(sizes));
        assert(sizes[kind] != 0);
        return sizes[kind];
 }
@@ -396,7 +388,7 @@ static size_t get_statement_struct_size(statement_kind_t kind)
                [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
                [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
        };
-       assert(kind < sizeof(sizes) / sizeof(sizes[0]));
+       assert(kind < lengthof(sizes));
        assert(sizes[kind] != 0);
        return sizes[kind];
 }
@@ -409,33 +401,32 @@ static size_t get_statement_struct_size(statement_kind_t kind)
 static size_t get_expression_struct_size(expression_kind_t kind)
 {
        static const size_t sizes[] = {
-               [EXPR_INVALID]                 = sizeof(expression_base_t),
-               [EXPR_REFERENCE]               = sizeof(reference_expression_t),
-               [EXPR_REFERENCE_ENUM_VALUE]    = sizeof(reference_expression_t),
-               [EXPR_CONST]                   = sizeof(const_expression_t),
-               [EXPR_CHARACTER_CONSTANT]      = sizeof(const_expression_t),
-               [EXPR_WIDE_CHARACTER_CONSTANT] = sizeof(const_expression_t),
-               [EXPR_STRING_LITERAL]          = sizeof(string_literal_expression_t),
-               [EXPR_WIDE_STRING_LITERAL]     = sizeof(wide_string_literal_expression_t),
-               [EXPR_COMPOUND_LITERAL]        = sizeof(compound_literal_expression_t),
-               [EXPR_CALL]                    = sizeof(call_expression_t),
-               [EXPR_UNARY_FIRST]             = sizeof(unary_expression_t),
-               [EXPR_BINARY_FIRST]            = sizeof(binary_expression_t),
-               [EXPR_CONDITIONAL]             = sizeof(conditional_expression_t),
-               [EXPR_SELECT]                  = sizeof(select_expression_t),
-               [EXPR_ARRAY_ACCESS]            = sizeof(array_access_expression_t),
-               [EXPR_SIZEOF]                  = sizeof(typeprop_expression_t),
-               [EXPR_ALIGNOF]                 = sizeof(typeprop_expression_t),
-               [EXPR_CLASSIFY_TYPE]           = sizeof(classify_type_expression_t),
-               [EXPR_FUNCNAME]                = sizeof(funcname_expression_t),
-               [EXPR_BUILTIN_SYMBOL]          = sizeof(builtin_symbol_expression_t),
-               [EXPR_BUILTIN_CONSTANT_P]      = sizeof(builtin_constant_expression_t),
-               [EXPR_BUILTIN_PREFETCH]        = sizeof(builtin_prefetch_expression_t),
-               [EXPR_OFFSETOF]                = sizeof(offsetof_expression_t),
-               [EXPR_VA_START]                = sizeof(va_start_expression_t),
-               [EXPR_VA_ARG]                  = sizeof(va_arg_expression_t),
-               [EXPR_STATEMENT]               = sizeof(statement_expression_t),
-               [EXPR_LABEL_ADDRESS]           = sizeof(label_address_expression_t),
+               [EXPR_INVALID]                    = sizeof(expression_base_t),
+               [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
+               [EXPR_REFERENCE_ENUM_VALUE]       = sizeof(reference_expression_t),
+               [EXPR_CONST]                      = sizeof(const_expression_t),
+               [EXPR_CHARACTER_CONSTANT]         = sizeof(const_expression_t),
+               [EXPR_WIDE_CHARACTER_CONSTANT]    = sizeof(const_expression_t),
+               [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
+               [EXPR_WIDE_STRING_LITERAL]        = sizeof(wide_string_literal_expression_t),
+               [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
+               [EXPR_CALL]                       = sizeof(call_expression_t),
+               [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
+               [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
+               [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
+               [EXPR_SELECT]                     = sizeof(select_expression_t),
+               [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
+               [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
+               [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
+               [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
+               [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
+               [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
+               [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
+               [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
+               [EXPR_VA_START]                   = sizeof(va_start_expression_t),
+               [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
+               [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
+               [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
        };
        if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
                return sizes[EXPR_UNARY_FIRST];
@@ -443,7 +434,7 @@ static size_t get_expression_struct_size(expression_kind_t kind)
        if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
                return sizes[EXPR_BINARY_FIRST];
        }
-       assert(kind < sizeof(sizes) / sizeof(sizes[0]));
+       assert(kind < lengthof(sizes));
        assert(sizes[kind] != 0);
        return sizes[kind];
 }
@@ -526,7 +517,7 @@ static size_t get_type_struct_size(type_kind_t kind)
                [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
                [TYPE_TYPEOF]          = sizeof(typeof_type_t),
        };
-       assert(sizeof(sizes) / sizeof(sizes[0]) == (int) TYPE_TYPEOF + 1);
+       assert(lengthof(sizes) == (int)TYPE_TYPEOF + 1);
        assert(kind <= TYPE_TYPEOF);
        assert(sizes[kind] != 0);
        return sizes[kind];
@@ -562,7 +553,7 @@ static size_t get_initializer_size(initializer_kind_t kind)
                [INITIALIZER_LIST]        = sizeof(initializer_list_t),
                [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
        };
-       assert(kind < sizeof(sizes) / sizeof(*sizes));
+       assert(kind < lengthof(sizes));
        assert(sizes[kind] != 0);
        return sizes[kind];
 }
@@ -604,7 +595,7 @@ static inline void next_token(void)
        lookahead_buffer[lookahead_bufpos] = lexer_token;
        lexer_next_token();
 
-       lookahead_bufpos = (lookahead_bufpos+1) % MAX_LOOKAHEAD;
+       lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 
 #ifdef PRINT_TOKENS
        print_token(stderr, &token);
@@ -615,10 +606,10 @@ static inline void next_token(void)
 /**
  * Return the next token with a given lookahead.
  */
-static inline const token_t *look_ahead(int num)
+static inline const token_t *look_ahead(size_t num)
 {
-       assert(num > 0 && num <= MAX_LOOKAHEAD);
-       int pos = (lookahead_bufpos+num-1) % MAX_LOOKAHEAD;
+       assert(0 < num && num <= MAX_LOOKAHEAD);
+       size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
        return &lookahead_buffer[pos];
 }
 
@@ -1120,7 +1111,7 @@ static void report_assign_error(assign_error_t error, type_t *orig_type_left,
        }
 }
 
-/** Implements the rules from § 6.5.16.1 */
+/** Implements the rules from §6.5.16.1 */
 static assign_error_t semantic_assign(type_t *orig_type_left,
                                       const expression_t *const right)
 {
@@ -2137,9 +2128,8 @@ unary:
                case EXPR_CLASSIFY_TYPE:
                case EXPR_ALIGNOF:
                case EXPR_FUNCNAME:
-               case EXPR_BUILTIN_SYMBOL:
                case EXPR_BUILTIN_CONSTANT_P:
-               case EXPR_BUILTIN_PREFETCH:
+               case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
                case EXPR_OFFSETOF:
                case EXPR_STATEMENT: // TODO
                case EXPR_LABEL_ADDRESS:
@@ -2229,7 +2219,7 @@ static initializer_t *initializer_from_expression(type_t *orig_type,
 {
        /* TODO check that expression is a constant expression */
 
-       /* § 6.7.8.14/15 char array may be initialized by string literals */
+       /* §6.7.8.14/15 char array may be initialized by string literals */
        type_t *type           = skip_typeref(orig_type);
        type_t *expr_type_orig = expression->base.type;
        type_t *expr_type      = skip_typeref(expr_type_orig);
@@ -2293,7 +2283,7 @@ static bool is_initializer_constant(const expression_t *expression)
 /**
  * Parses an scalar initializer.
  *
- * § 6.7.8.11; eat {} without warning
+ * §6.7.8.11; eat {} without warning
  */
 static initializer_t *parse_scalar_initializer(type_t *type,
                                                bool must_be_constant)
@@ -2909,7 +2899,7 @@ static initializer_t *parse_initializer(parse_initializer_env_t *env)
                result = parse_scalar_initializer(type, env->must_be_constant);
        }
 
-       /* § 6.7.8:22 array initializers for arrays with unknown size determine
+       /* §6.7.8:22 array initializers for arrays with unknown size determine
         * the array type size */
        if (is_type_array(type) && type->array.size_expression == NULL
                        && result != NULL) {
@@ -3201,7 +3191,7 @@ static type_t *parse_typeof(void)
                        type = parse_typename();
                } else {
                        expression = parse_expression();
-                       type       = expression->base.type;
+                       type       = revert_automatic_type_conversion(expression);
                }
                break;
 
@@ -4089,7 +4079,11 @@ warn_about_long_long:
        type->base.qualifiers = qualifiers;
        type->base.modifiers  = modifiers;
 
-       type = identify_new_type(type);
+       if (newtype) {
+               type = identify_new_type(type);
+       } else {
+               type = typehash_insert(type);
+       }
 
        type = handle_type_attributes(specifiers->gnu_attributes, type);
        specifiers->type = type;
@@ -4995,6 +4989,16 @@ static void error_redefined_as_different_kind(const source_position_t *pos,
               get_entity_kind_name(new_kind), &old->base.source_position);
 }
 
+static bool is_error_entity(entity_t *const ent)
+{
+       if (is_declaration(ent)) {
+               return is_type_valid(skip_typeref(ent->declaration.type));
+       } else if (ent->kind == ENTITY_TYPEDEF) {
+               return is_type_valid(skip_typeref(ent->typedefe.type));
+       }
+       return false;
+}
+
 /**
  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
  * for various problems that occur for multiple definitions
@@ -5009,7 +5013,7 @@ static entity_t *record_entity(entity_t *entity, const bool is_definition)
        if (symbol == NULL)
                return entity;
 
-       entity_t *previous_entity = get_entity(symbol, namespc);
+       entity_t *const previous_entity = get_entity(symbol, namespc);
        /* pushing the same entity twice will break the stack structure */
        assert(previous_entity != entity);
 
@@ -5039,160 +5043,167 @@ static entity_t *record_entity(entity_t *entity, const bool is_definition)
                         entity->declaration.type, symbol);
        }
 
-       if (previous_entity != NULL &&
-                       previous_entity->base.parent_scope == &current_function->parameters &&
-                       previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
-               assert(previous_entity->kind == ENTITY_PARAMETER);
-               errorf(pos,
-                      "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
-                                        entity->declaration.type, symbol,
-                                        previous_entity->declaration.type, symbol,
-                                        &previous_entity->base.source_position);
-               goto finish;
-       }
-
-       if (previous_entity != NULL &&
-                       previous_entity->base.parent_scope == current_scope) {
-               if (previous_entity->kind != entity->kind) {
-                       error_redefined_as_different_kind(pos, previous_entity,
-                                                         entity->kind);
-                       goto finish;
-               }
-               if (previous_entity->kind == ENTITY_ENUM_VALUE) {
-                       errorf(pos, "redeclaration of enum entry '%Y' (declared %P)",
-                                  symbol, &previous_entity->base.source_position);
-                       goto finish;
-               }
-               if (previous_entity->kind == ENTITY_TYPEDEF) {
-                       /* TODO: C++ allows this for exactly the same type */
-                       errorf(pos, "redefinition of typedef '%Y' (declared %P)",
-                              symbol, &previous_entity->base.source_position);
+       if (previous_entity != NULL) {
+               if (previous_entity->base.parent_scope == &current_function->parameters &&
+                               previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
+                       assert(previous_entity->kind == ENTITY_PARAMETER);
+                       errorf(pos,
+                                       "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
+                                       entity->declaration.type, symbol,
+                                       previous_entity->declaration.type, symbol,
+                                       &previous_entity->base.source_position);
                        goto finish;
                }
 
-               /* at this point we should have only VARIABLES or FUNCTIONS */
-               assert(is_declaration(previous_entity) && is_declaration(entity));
-
-               declaration_t *const prev_decl = &previous_entity->declaration;
-               declaration_t *const decl      = &entity->declaration;
+               if (previous_entity->base.parent_scope == current_scope) {
+                       if (previous_entity->kind != entity->kind) {
+                               if (!is_error_entity(previous_entity) && !is_error_entity(entity)) {
+                                       error_redefined_as_different_kind(pos, previous_entity,
+                                                       entity->kind);
+                               }
+                               goto finish;
+                       }
+                       if (previous_entity->kind == ENTITY_ENUM_VALUE) {
+                               errorf(pos, "redeclaration of enum entry '%Y' (declared %P)",
+                                               symbol, &previous_entity->base.source_position);
+                               goto finish;
+                       }
+                       if (previous_entity->kind == ENTITY_TYPEDEF) {
+                               /* TODO: C++ allows this for exactly the same type */
+                               errorf(pos, "redefinition of typedef '%Y' (declared %P)",
+                                               symbol, &previous_entity->base.source_position);
+                               goto finish;
+                       }
 
-               /* can happen for K&R style declarations */
-               if (prev_decl->type       == NULL             &&
-                               previous_entity->kind == ENTITY_PARAMETER &&
-                               entity->kind          == ENTITY_PARAMETER) {
-                       prev_decl->type                   = decl->type;
-                       prev_decl->storage_class          = decl->storage_class;
-                       prev_decl->declared_storage_class = decl->declared_storage_class;
-                       prev_decl->modifiers              = decl->modifiers;
-                       prev_decl->deprecated_string      = decl->deprecated_string;
-                       return previous_entity;
-               }
+                       /* at this point we should have only VARIABLES or FUNCTIONS */
+                       assert(is_declaration(previous_entity) && is_declaration(entity));
+
+                       declaration_t *const prev_decl = &previous_entity->declaration;
+                       declaration_t *const decl      = &entity->declaration;
+
+                       /* can happen for K&R style declarations */
+                       if (prev_decl->type       == NULL             &&
+                                       previous_entity->kind == ENTITY_PARAMETER &&
+                                       entity->kind          == ENTITY_PARAMETER) {
+                               prev_decl->type                   = decl->type;
+                               prev_decl->storage_class          = decl->storage_class;
+                               prev_decl->declared_storage_class = decl->declared_storage_class;
+                               prev_decl->modifiers              = decl->modifiers;
+                               prev_decl->deprecated_string      = decl->deprecated_string;
+                               return previous_entity;
+                       }
 
-               type_t *const orig_type = decl->type;
-               assert(orig_type != NULL);
-               type_t *const type      = skip_typeref(orig_type);
-               type_t *      prev_type = skip_typeref(prev_decl->type);
+                       type_t *const orig_type = decl->type;
+                       assert(orig_type != NULL);
+                       type_t *const type      = skip_typeref(orig_type);
+                       type_t *const prev_type = skip_typeref(prev_decl->type);
 
-               if (!types_compatible(type, prev_type)) {
-                       errorf(pos,
-                                  "declaration '%#T' is incompatible with '%#T' (declared %P)",
-                                  orig_type, symbol, prev_decl->type, symbol,
-                                  &previous_entity->base.source_position);
-               } else {
-                       unsigned old_storage_class = prev_decl->storage_class;
-                       if (warning.redundant_decls               &&
-                                       is_definition                     &&
-                                       !prev_decl->used                  &&
-                                       !(prev_decl->modifiers & DM_USED) &&
-                                       prev_decl->storage_class == STORAGE_CLASS_STATIC) {
-                               warningf(&previous_entity->base.source_position,
-                                        "unnecessary static forward declaration for '%#T'",
-                                        prev_decl->type, symbol);
-                       }
-
-                       unsigned new_storage_class = decl->storage_class;
-                       if (is_type_incomplete(prev_type)) {
-                               prev_decl->type = type;
-                               prev_type       = type;
-                       }
-
-                       /* pretend no storage class means extern for function
-                        * declarations (except if the previous declaration is neither
-                        * none nor extern) */
-                       if (entity->kind == ENTITY_FUNCTION) {
-                               if (prev_type->function.unspecified_parameters) {
-                                       prev_decl->type = type;
-                                       prev_type       = type;
+                       if (!types_compatible(type, prev_type)) {
+                               errorf(pos,
+                                               "declaration '%#T' is incompatible with '%#T' (declared %P)",
+                                               orig_type, symbol, prev_decl->type, symbol,
+                                               &previous_entity->base.source_position);
+                       } else {
+                               unsigned old_storage_class = prev_decl->storage_class;
+                               if (warning.redundant_decls               &&
+                                               is_definition                     &&
+                                               !prev_decl->used                  &&
+                                               !(prev_decl->modifiers & DM_USED) &&
+                                               prev_decl->storage_class == STORAGE_CLASS_STATIC) {
+                                       warningf(&previous_entity->base.source_position,
+                                                       "unnecessary static forward declaration for '%#T'",
+                                                       prev_decl->type, symbol);
                                }
 
-                               switch (old_storage_class) {
-                               case STORAGE_CLASS_NONE:
-                                       old_storage_class = STORAGE_CLASS_EXTERN;
-                                       /* FALLTHROUGH */
-
-                               case STORAGE_CLASS_EXTERN:
-                                       if (is_definition) {
-                                               if (warning.missing_prototypes &&
-                                                   prev_type->function.unspecified_parameters &&
-                                                   !is_sym_main(symbol)) {
-                                                       warningf(pos, "no previous prototype for '%#T'",
-                                                                        orig_type, symbol);
-                                               }
-                                       } else if (new_storage_class == STORAGE_CLASS_NONE) {
-                                               new_storage_class = STORAGE_CLASS_EXTERN;
-                                       }
-                                       break;
+                               storage_class_t new_storage_class = decl->storage_class;
+
+                               /* pretend no storage class means extern for function
+                                * declarations (except if the previous declaration is neither
+                                * none nor extern) */
+                               if (entity->kind == ENTITY_FUNCTION) {
+                                       /* the previous declaration could have unspecified parameters or
+                                        * be a typedef, so use the new type */
+                                       if (prev_type->function.unspecified_parameters || is_definition)
+                                               prev_decl->type = type;
+
+                                       switch (old_storage_class) {
+                                               case STORAGE_CLASS_NONE:
+                                                       old_storage_class = STORAGE_CLASS_EXTERN;
+                                                       /* FALLTHROUGH */
+
+                                               case STORAGE_CLASS_EXTERN:
+                                                       if (is_definition) {
+                                                               if (warning.missing_prototypes &&
+                                                                               prev_type->function.unspecified_parameters &&
+                                                                               !is_sym_main(symbol)) {
+                                                                       warningf(pos, "no previous prototype for '%#T'",
+                                                                                       orig_type, symbol);
+                                                               }
+                                                       } else if (new_storage_class == STORAGE_CLASS_NONE) {
+                                                               new_storage_class = STORAGE_CLASS_EXTERN;
+                                                       }
+                                                       break;
 
-                               default:
-                                       break;
+                                               default:
+                                                       break;
+                                       }
+                               } else if (is_type_incomplete(prev_type)) {
+                                       prev_decl->type = type;
                                }
-                       }
 
-                       if (old_storage_class == STORAGE_CLASS_EXTERN &&
-                                       new_storage_class == STORAGE_CLASS_EXTERN) {
+                               if (old_storage_class == STORAGE_CLASS_EXTERN &&
+                                               new_storage_class == STORAGE_CLASS_EXTERN) {
 warn_redundant_declaration:
-                               if (!is_definition           &&
-                                   warning.redundant_decls  &&
-                                   is_type_valid(prev_type) &&
-                                   strcmp(previous_entity->base.source_position.input_name,
-                                          "<builtin>") != 0) {
-                                       warningf(pos,
-                                                "redundant declaration for '%Y' (declared %P)",
-                                                symbol, &previous_entity->base.source_position);
-                               }
-                       } else if (current_function == NULL) {
-                               if (old_storage_class != STORAGE_CLASS_STATIC &&
-                                   new_storage_class == STORAGE_CLASS_STATIC) {
-                                       errorf(pos,
-                                              "static declaration of '%Y' follows non-static declaration (declared %P)",
-                                              symbol, &previous_entity->base.source_position);
-                               } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
-                                       prev_decl->storage_class          = STORAGE_CLASS_NONE;
-                                       prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
-                               } else {
-                                       /* ISO/IEC 14882:1998(E) §C.1.2:1 */
-                                       if (c_mode & _CXX)
-                                               goto error_redeclaration;
-                                       goto warn_redundant_declaration;
-                               }
-                       } else if (is_type_valid(prev_type)) {
-                               if (old_storage_class == new_storage_class) {
+                                       if (!is_definition           &&
+                                                       warning.redundant_decls  &&
+                                                       is_type_valid(prev_type) &&
+                                                       strcmp(previous_entity->base.source_position.input_name,
+                                                               "<builtin>") != 0) {
+                                               warningf(pos,
+                                                               "redundant declaration for '%Y' (declared %P)",
+                                                               symbol, &previous_entity->base.source_position);
+                                       }
+                               } else if (current_function == NULL) {
+                                       if (old_storage_class != STORAGE_CLASS_STATIC &&
+                                                       new_storage_class == STORAGE_CLASS_STATIC) {
+                                               errorf(pos,
+                                                               "static declaration of '%Y' follows non-static declaration (declared %P)",
+                                                               symbol, &previous_entity->base.source_position);
+                                       } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
+                                               prev_decl->storage_class          = STORAGE_CLASS_NONE;
+                                               prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
+                                       } else {
+                                               /* ISO/IEC 14882:1998(E) §C.1.2:1 */
+                                               if (c_mode & _CXX)
+                                                       goto error_redeclaration;
+                                               goto warn_redundant_declaration;
+                                       }
+                               } else if (is_type_valid(prev_type)) {
+                                       if (old_storage_class == new_storage_class) {
 error_redeclaration:
-                                       errorf(pos, "redeclaration of '%Y' (declared %P)",
-                                              symbol, &previous_entity->base.source_position);
-                               } else {
-                                       errorf(pos,
-                                              "redeclaration of '%Y' with different linkage (declared %P)",
-                                              symbol, &previous_entity->base.source_position);
+                                               errorf(pos, "redeclaration of '%Y' (declared %P)",
+                                                               symbol, &previous_entity->base.source_position);
+                                       } else {
+                                               errorf(pos,
+                                                               "redeclaration of '%Y' with different linkage (declared %P)",
+                                                               symbol, &previous_entity->base.source_position);
+                                       }
                                }
                        }
+
+                       prev_decl->modifiers |= decl->modifiers;
+                       if (entity->kind == ENTITY_FUNCTION) {
+                               previous_entity->function.is_inline |= entity->function.is_inline;
+                       }
+                       return previous_entity;
                }
 
-               prev_decl->modifiers |= decl->modifiers;
-               if (entity->kind == ENTITY_FUNCTION) {
-                       previous_entity->function.is_inline |= entity->function.is_inline;
+               if (warning.shadow) {
+                       warningf(pos, "%s '%Y' shadows %s (declared %P)",
+                                       get_entity_kind_name(entity->kind), symbol,
+                                       get_entity_kind_name(previous_entity->kind),
+                                       &previous_entity->base.source_position);
                }
-               return previous_entity;
        }
 
        if (entity->kind == ENTITY_FUNCTION) {
@@ -5292,7 +5303,7 @@ static void parse_init_declarator_rest(entity_t *entity)
        current_init_decl = NULL;
 
        if (entity->kind == ENTITY_VARIABLE) {
-               /* § 6.7.5:22  array initializers for arrays with unknown size
+               /* §6.7.5:22  array initializers for arrays with unknown size
                 * determine the array type size */
                declaration->type            = env.type;
                entity->variable.initializer = initializer;
@@ -5350,11 +5361,9 @@ static void check_variable_type_complete(entity_t *ent)
        if (!is_type_incomplete(type))
                return;
 
-       /* GCC allows global arrays without size and assigns them a length of one,
-        * if no different declaration follows */
-       if (is_type_array(type) &&
-                       c_mode & _GNUC      &&
-                       ent->base.parent_scope == file_scope) {
+       /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
+        * are given length one. */
+       if (is_type_array(type) && ent->base.parent_scope == file_scope) {
                ARR_APP1(declaration_t*, incomplete_arrays, decl);
                return;
        }
@@ -5457,7 +5466,7 @@ static type_t *get_default_promoted_type(type_t *orig_type)
        type_t *type = skip_typeref(orig_type);
        if (is_type_integer(type)) {
                result = promote_integer(type);
-       } else if (type == type_float) {
+       } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
                result = type_double;
        }
 
@@ -5518,6 +5527,9 @@ decl_list_end:
 
        parameter = entity->function.parameters.entities;
        for (; parameter != NULL; parameter = parameter->base.next) {
+               if (parameter->kind != ENTITY_PARAMETER)
+                       continue;
+
                type_t *parameter_type = parameter->declaration.type;
                if (parameter_type == NULL) {
                        if (strict_mode) {
@@ -5554,7 +5566,7 @@ decl_list_end:
                last_parameter = function_parameter;
        }
 
-       /* § 6.9.1.7: A K&R style parameter list does NOT act as a function
+       /* §6.9.1.7: A K&R style parameter list does NOT act as a function
         * prototype */
        new_type->function.parameters             = parameters;
        new_type->function.unspecified_parameters = true;
@@ -5732,9 +5744,8 @@ static bool expression_returns(expression_t const *const expr)
                case EXPR_SIZEOF: // TODO handle obscure VLA case
                case EXPR_ALIGNOF:
                case EXPR_FUNCNAME:
-               case EXPR_BUILTIN_SYMBOL:
                case EXPR_BUILTIN_CONSTANT_P:
-               case EXPR_BUILTIN_PREFETCH:
+               case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
                case EXPR_OFFSETOF:
                case EXPR_INVALID:
                        return true;
@@ -6377,7 +6388,7 @@ static void parse_external_declaration(void)
                        ndeclaration->base.symbol);
        }
 
-       /* § 6.7.5.3:14 a function definition with () means no
+       /* §6.7.5.3:14 a function definition with () means no
         * parameters (and not unspecified parameters) */
        if (type->function.unspecified_parameters &&
                        type->function.parameters == NULL     &&
@@ -6890,6 +6901,19 @@ static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
        return identify_new_type(type);
 }
 
+static type_t *make_function_1_type_variadic(type_t *return_type, type_t *argument_type)
+{
+       type_t *res = make_function_1_type(return_type, argument_type);
+       res->function.variadic = 1;
+       return res;
+}
+
+/**
+ * Creates a return_type (func)(void) function type if not
+ * already exists.
+ *
+ * @param return_type    the return type
+ */
 static type_t *make_function_0_type(type_t *return_type)
 {
        type_t *type               = allocate_type_zero(TYPE_FUNCTION);
@@ -6900,40 +6924,24 @@ static type_t *make_function_0_type(type_t *return_type)
 }
 
 /**
- * Creates a function type for some function like builtins.
+ * Creates a NO_RETURN return_type (func)(void) function type if not
+ * already exists.
  *
- * @param symbol   the symbol describing the builtin
- */
-static type_t *get_builtin_symbol_type(symbol_t *symbol)
-{
-       switch (symbol->ID) {
-       case T___builtin_alloca:
-               return make_function_1_type(type_void_ptr, type_size_t);
-       case T___builtin_huge_val:
-               return make_function_0_type(type_double);
-       case T___builtin_inf:
-               return make_function_0_type(type_double);
-       case T___builtin_inff:
-               return make_function_0_type(type_float);
-       case T___builtin_infl:
-               return make_function_0_type(type_long_double);
-       case T___builtin_nan:
-               return make_function_1_type(type_double, type_char_ptr);
-       case T___builtin_nanf:
-               return make_function_1_type(type_float, type_char_ptr);
-       case T___builtin_nanl:
-               return make_function_1_type(type_long_double, type_char_ptr);
-       case T___builtin_va_end:
-               return make_function_1_type(type_void, type_valist);
-       case T___builtin_expect:
-               return make_function_2_type(type_long, type_long, type_long);
-       default:
-               internal_errorf(HERE, "not implemented builtin identifier found");
-       }
+ * @param return_type    the return type
+ */
+static type_t *make_function_0_type_noreturn(type_t *return_type)
+{
+       type_t *type               = allocate_type_zero(TYPE_FUNCTION);
+       type->function.return_type = return_type;
+       type->function.parameters  = NULL;
+       type->function.base.modifiers |= DM_NORETURN;
+       return type;
+
+       return identify_new_type(type);
 }
 
 /**
- * Performs automatic type cast as described in § 6.3.2.1.
+ * Performs automatic type cast as described in §6.3.2.1.
  *
  * @param orig_type  the original type
  */
@@ -6957,7 +6965,7 @@ static type_t *automatic_type_conversion(type_t *orig_type)
 
 /**
  * reverts the automatic casts of array to pointer types and function
- * to function-pointer types as defined § 6.3.2.1
+ * to function-pointer types as defined §6.3.2.1
  */
 type_t *revert_automatic_type_conversion(const expression_t *expression)
 {
@@ -6989,9 +6997,6 @@ type_t *revert_automatic_type_conversion(const expression_t *expression)
                        return type->pointer.points_to;
                }
 
-               case EXPR_BUILTIN_SYMBOL:
-                       return get_builtin_symbol_type(expression->builtin_symbol.symbol);
-
                case EXPR_ARRAY_ACCESS: {
                        const expression_t *array_ref = expression->array_access.array_ref;
                        type_t             *type_left = skip_typeref(array_ref->base.type);
@@ -7491,24 +7496,8 @@ end_error:
        return create_invalid_expression();
 }
 
-static expression_t *parse_builtin_symbol(void)
-{
-       expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_SYMBOL);
-
-       symbol_t *symbol = token.v.symbol;
-
-       expression->builtin_symbol.symbol = symbol;
-       next_token();
-
-       type_t *type = get_builtin_symbol_type(symbol);
-       type = automatic_type_conversion(type);
-
-       expression->base.type = type;
-       return expression;
-}
-
 /**
- * Parses a __builtin_constant() expression.
+ * Parses a __builtin_constant_p() expression.
  */
 static expression_t *parse_builtin_constant(void)
 {
@@ -7529,28 +7518,24 @@ end_error:
 }
 
 /**
- * Parses a __builtin_prefetch() expression.
+ * Parses a __builtin_types_compatible_p() expression.
  */
-static expression_t *parse_builtin_prefetch(void)
+static expression_t *parse_builtin_types_compatible(void)
 {
-       expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_PREFETCH);
+       expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
 
-       eat(T___builtin_prefetch);
+       eat(T___builtin_types_compatible_p);
 
        expect('(', end_error);
        add_anchor_token(')');
-       expression->builtin_prefetch.adr = parse_assignment_expression();
-       if (token.type == ',') {
-               next_token();
-               expression->builtin_prefetch.rw = parse_assignment_expression();
-       }
-       if (token.type == ',') {
-               next_token();
-               expression->builtin_prefetch.locality = parse_assignment_expression();
-       }
+       add_anchor_token(',');
+       expression->builtin_types_compatible.left = parse_typename();
+       rem_anchor_token(',');
+       expect(',', end_error);
+       expression->builtin_types_compatible.right = parse_typename();
        rem_anchor_token(')');
        expect(')', end_error);
-       expression->base.type = type_void;
+       expression->base.type = type_int;
 
        return expression;
 end_error:
@@ -7769,49 +7754,39 @@ end_error:
 static expression_t *parse_primary_expression(void)
 {
        switch (token.type) {
-               case T_false:                    return parse_bool_const(false);
-               case T_true:                     return parse_bool_const(true);
-               case T_INTEGER:                  return parse_int_const();
-               case T_CHARACTER_CONSTANT:       return parse_character_constant();
-               case T_WIDE_CHARACTER_CONSTANT:  return parse_wide_character_constant();
-               case T_FLOATINGPOINT:            return parse_float_const();
+               case T_false:                        return parse_bool_const(false);
+               case T_true:                         return parse_bool_const(true);
+               case T_INTEGER:                      return parse_int_const();
+               case T_CHARACTER_CONSTANT:           return parse_character_constant();
+               case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
+               case T_FLOATINGPOINT:                return parse_float_const();
                case T_STRING_LITERAL:
-               case T_WIDE_STRING_LITERAL:      return parse_string_const();
-               case T_IDENTIFIER:               return parse_reference();
+               case T_WIDE_STRING_LITERAL:          return parse_string_const();
+               case T_IDENTIFIER:                   return parse_reference();
                case T___FUNCTION__:
-               case T___func__:                 return parse_function_keyword();
-               case T___PRETTY_FUNCTION__:      return parse_pretty_function_keyword();
-               case T___FUNCSIG__:              return parse_funcsig_keyword();
-               case T___FUNCDNAME__:            return parse_funcdname_keyword();
-               case T___builtin_offsetof:       return parse_offsetof();
-               case T___builtin_va_start:       return parse_va_start();
-               case T___builtin_va_arg:         return parse_va_arg();
-               case T___builtin_expect:
-               case T___builtin_alloca:
-               case T___builtin_inf:
-               case T___builtin_inff:
-               case T___builtin_infl:
-               case T___builtin_nan:
-               case T___builtin_nanf:
-               case T___builtin_nanl:
-               case T___builtin_huge_val:
-               case T___builtin_va_end:         return parse_builtin_symbol();
+               case T___func__:                     return parse_function_keyword();
+               case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
+               case T___FUNCSIG__:                  return parse_funcsig_keyword();
+               case T___FUNCDNAME__:                return parse_funcdname_keyword();
+               case T___builtin_offsetof:           return parse_offsetof();
+               case T___builtin_va_start:           return parse_va_start();
+               case T___builtin_va_arg:             return parse_va_arg();
                case T___builtin_isgreater:
                case T___builtin_isgreaterequal:
                case T___builtin_isless:
                case T___builtin_islessequal:
                case T___builtin_islessgreater:
-               case T___builtin_isunordered:    return parse_compare_builtin();
-               case T___builtin_constant_p:     return parse_builtin_constant();
-               case T___builtin_prefetch:       return parse_builtin_prefetch();
-               case T__assume:                  return parse_assume();
+               case T___builtin_isunordered:        return parse_compare_builtin();
+               case T___builtin_constant_p:         return parse_builtin_constant();
+               case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
+               case T__assume:                      return parse_assume();
                case T_ANDAND:
                        if (GNU_MODE)
                                return parse_label_address();
                        break;
 
-               case '(':                        return parse_parenthesized_expression();
-               case T___noop:                   return parse_noop_expression();
+               case '(':                            return parse_parenthesized_expression();
+               case T___noop:                       return parse_noop_expression();
        }
 
        errorf(HERE, "unexpected token %K, expected an expression", &token);
@@ -8087,6 +8062,51 @@ static void check_call_argument(const function_parameter_t *parameter,
        }
 }
 
+/**
+ * Handle the semantic restrictions of builtin calls
+ */
+static void handle_builtin_argument_restrictions(call_expression_t *call) {
+       switch (call->function->reference.entity->function.btk) {
+               case bk_gnu_builtin_return_address:
+               case bk_gnu_builtin_frame_address: {
+                       /* argument must be constant */
+                       call_argument_t *argument = call->arguments;
+
+                       if (! is_constant_expression(argument->expression)) {
+                               errorf(&call->base.source_position,
+                                      "argument of '%Y' must be a constant expression",
+                                      call->function->reference.entity->base.symbol);
+                       }
+                       break;
+               }
+               case bk_gnu_builtin_prefetch: {
+                       /* second and third argument must be constant if existent */
+                       call_argument_t *rw = call->arguments->next;
+                       call_argument_t *locality = NULL;
+
+                       if (rw != NULL) {
+                               if (! is_constant_expression(rw->expression)) {
+                                       errorf(&call->base.source_position,
+                                              "second argument of '%Y' must be a constant expression",
+                                              call->function->reference.entity->base.symbol);
+                               }
+                               locality = rw->next;
+                       }
+                       if (locality != NULL) {
+                               if (! is_constant_expression(locality->expression)) {
+                                       errorf(&call->base.source_position,
+                                              "third argument of '%Y' must be a constant expression",
+                                              call->function->reference.entity->base.symbol);
+                               }
+                               locality = rw->next;
+                       }
+                       break;
+               }
+               default:
+                       break;
+       }
+}
+
 /**
  * Parse a call expression, ie. expression '( ... )'.
  *
@@ -8179,6 +8199,13 @@ static expression_t *parse_call_expression(expression_t *expression)
                         "function call has aggregate value");
        }
 
+       if (call->function->kind == EXPR_REFERENCE) {
+               reference_expression_t *reference = &call->function->reference;
+               if (reference->entity->kind == ENTITY_FUNCTION &&
+                   reference->entity->function.btk != bk_none)
+                       handle_builtin_argument_restrictions(call);
+       }
+
 end_error:
        return result;
 }
@@ -8768,7 +8795,7 @@ static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
        type_left  = get_unqualified_type(type_left);
        type_right = get_unqualified_type(type_right);
 
-       /* § 6.3.1.8 Usual arithmetic conversions */
+       /* §6.3.1.8 Usual arithmetic conversions */
        if (type_left == type_long_double || type_right == type_long_double) {
                return type_long_double;
        } else if (type_left == type_double || type_right == type_double) {
@@ -8870,7 +8897,8 @@ static void warn_div_by_zero(binary_expression_t const *const expression)
 /**
  * Check the semantic restrictions for a div/mod expression.
  */
-static void semantic_divmod_arithmetic(binary_expression_t *expression) {
+static void semantic_divmod_arithmetic(binary_expression_t *expression)
+{
        semantic_binexpr_arithmetic(expression);
        warn_div_by_zero(expression);
 }
@@ -8931,7 +8959,7 @@ static void semantic_add(binary_expression_t *expression)
        type_t       *const type_left       = skip_typeref(orig_type_left);
        type_t       *const type_right      = skip_typeref(orig_type_right);
 
-       /* § 6.5.6 */
+       /* §6.5.6 */
        if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
                type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
                expression->left  = create_implicit_cast(left, arithmetic_type);
@@ -8962,7 +8990,7 @@ static void semantic_sub(binary_expression_t *expression)
        type_t                  *const type_right      = skip_typeref(orig_type_right);
        source_position_t const *const pos             = &expression->base.source_position;
 
-       /* § 5.6.5 */
+       /* §5.6.5 */
        if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
                type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
                expression->left        = create_implicit_cast(left, arithmetic_type);
@@ -9306,64 +9334,65 @@ static void semantic_binexpr_assign(binary_expression_t *expression)
 static bool expression_has_effect(const expression_t *const expr)
 {
        switch (expr->kind) {
-               case EXPR_UNKNOWN:                   break;
-               case EXPR_INVALID:                   return true; /* do NOT warn */
-               case EXPR_REFERENCE:                 return false;
-               case EXPR_REFERENCE_ENUM_VALUE:      return false;
+               case EXPR_UNKNOWN:                    break;
+               case EXPR_INVALID:                    return true; /* do NOT warn */
+               case EXPR_REFERENCE:                  return false;
+               case EXPR_REFERENCE_ENUM_VALUE:       return false;
                /* suppress the warning for microsoft __noop operations */
-               case EXPR_CONST:                     return expr->conste.is_ms_noop;
-               case EXPR_CHARACTER_CONSTANT:        return false;
-               case EXPR_WIDE_CHARACTER_CONSTANT:   return false;
-               case EXPR_STRING_LITERAL:            return false;
-               case EXPR_WIDE_STRING_LITERAL:       return false;
-               case EXPR_LABEL_ADDRESS:             return false;
+               case EXPR_CONST:                      return expr->conste.is_ms_noop;
+               case EXPR_CHARACTER_CONSTANT:         return false;
+               case EXPR_WIDE_CHARACTER_CONSTANT:    return false;
+               case EXPR_STRING_LITERAL:             return false;
+               case EXPR_WIDE_STRING_LITERAL:        return false;
+               case EXPR_LABEL_ADDRESS:              return false;
 
                case EXPR_CALL: {
                        const call_expression_t *const call = &expr->call;
-                       if (call->function->kind != EXPR_BUILTIN_SYMBOL)
+                       if (call->function->kind != EXPR_REFERENCE)
                                return true;
 
-                       switch (call->function->builtin_symbol.symbol->ID) {
-                               case T___builtin_va_end: return true;
-                               default:                 return false;
+                       switch (call->function->reference.entity->function.btk) {
+                               case bk_gnu_builtin_prefetch:
+                               case bk_gnu_builtin_va_end:   return true;
+                               default:                      return false;
                        }
                }
 
                /* Generate the warning if either the left or right hand side of a
                 * conditional expression has no effect */
                case EXPR_CONDITIONAL: {
-                       const conditional_expression_t *const cond = &expr->conditional;
+                       conditional_expression_t const *const cond = &expr->conditional;
+                       expression_t             const *const t    = cond->true_expression;
                        return
-                               expression_has_effect(cond->true_expression) &&
+                               (t == NULL || expression_has_effect(t)) &&
                                expression_has_effect(cond->false_expression);
                }
 
-               case EXPR_SELECT:                    return false;
-               case EXPR_ARRAY_ACCESS:              return false;
-               case EXPR_SIZEOF:                    return false;
-               case EXPR_CLASSIFY_TYPE:             return false;
-               case EXPR_ALIGNOF:                   return false;
-
-               case EXPR_FUNCNAME:                  return false;
-               case EXPR_BUILTIN_SYMBOL:            break; /* handled in EXPR_CALL */
-               case EXPR_BUILTIN_CONSTANT_P:        return false;
-               case EXPR_BUILTIN_PREFETCH:          return true;
-               case EXPR_OFFSETOF:                  return false;
-               case EXPR_VA_START:                  return true;
-               case EXPR_VA_ARG:                    return true;
-               case EXPR_STATEMENT:                 return true; // TODO
-               case EXPR_COMPOUND_LITERAL:          return false;
-
-               case EXPR_UNARY_NEGATE:              return false;
-               case EXPR_UNARY_PLUS:                return false;
-               case EXPR_UNARY_BITWISE_NEGATE:      return false;
-               case EXPR_UNARY_NOT:                 return false;
-               case EXPR_UNARY_DEREFERENCE:         return false;
-               case EXPR_UNARY_TAKE_ADDRESS:        return false;
-               case EXPR_UNARY_POSTFIX_INCREMENT:   return true;
-               case EXPR_UNARY_POSTFIX_DECREMENT:   return true;
-               case EXPR_UNARY_PREFIX_INCREMENT:    return true;
-               case EXPR_UNARY_PREFIX_DECREMENT:    return true;
+               case EXPR_SELECT:                     return false;
+               case EXPR_ARRAY_ACCESS:               return false;
+               case EXPR_SIZEOF:                     return false;
+               case EXPR_CLASSIFY_TYPE:              return false;
+               case EXPR_ALIGNOF:                    return false;
+
+               case EXPR_FUNCNAME:                   return false;
+               case EXPR_BUILTIN_CONSTANT_P:         return false;
+               case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
+               case EXPR_OFFSETOF:                   return false;
+               case EXPR_VA_START:                   return true;
+               case EXPR_VA_ARG:                     return true;
+               case EXPR_STATEMENT:                  return true; // TODO
+               case EXPR_COMPOUND_LITERAL:           return false;
+
+               case EXPR_UNARY_NEGATE:               return false;
+               case EXPR_UNARY_PLUS:                 return false;
+               case EXPR_UNARY_BITWISE_NEGATE:       return false;
+               case EXPR_UNARY_NOT:                  return false;
+               case EXPR_UNARY_DEREFERENCE:          return false;
+               case EXPR_UNARY_TAKE_ADDRESS:         return false;
+               case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
+               case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
+               case EXPR_UNARY_PREFIX_INCREMENT:     return true;
+               case EXPR_UNARY_PREFIX_DECREMENT:     return true;
 
                /* Treat void casts as if they have an effect in order to being able to
                 * suppress the warning */
@@ -9372,39 +9401,39 @@ static bool expression_has_effect(const expression_t *const expr)
                        return is_type_atomic(type, ATOMIC_TYPE_VOID);
                }
 
-               case EXPR_UNARY_CAST_IMPLICIT:       return true;
-               case EXPR_UNARY_ASSUME:              return true;
-               case EXPR_UNARY_DELETE:              return true;
-               case EXPR_UNARY_DELETE_ARRAY:        return true;
-               case EXPR_UNARY_THROW:               return true;
-
-               case EXPR_BINARY_ADD:                return false;
-               case EXPR_BINARY_SUB:                return false;
-               case EXPR_BINARY_MUL:                return false;
-               case EXPR_BINARY_DIV:                return false;
-               case EXPR_BINARY_MOD:                return false;
-               case EXPR_BINARY_EQUAL:              return false;
-               case EXPR_BINARY_NOTEQUAL:           return false;
-               case EXPR_BINARY_LESS:               return false;
-               case EXPR_BINARY_LESSEQUAL:          return false;
-               case EXPR_BINARY_GREATER:            return false;
-               case EXPR_BINARY_GREATEREQUAL:       return false;
-               case EXPR_BINARY_BITWISE_AND:        return false;
-               case EXPR_BINARY_BITWISE_OR:         return false;
-               case EXPR_BINARY_BITWISE_XOR:        return false;
-               case EXPR_BINARY_SHIFTLEFT:          return false;
-               case EXPR_BINARY_SHIFTRIGHT:         return false;
-               case EXPR_BINARY_ASSIGN:             return true;
-               case EXPR_BINARY_MUL_ASSIGN:         return true;
-               case EXPR_BINARY_DIV_ASSIGN:         return true;
-               case EXPR_BINARY_MOD_ASSIGN:         return true;
-               case EXPR_BINARY_ADD_ASSIGN:         return true;
-               case EXPR_BINARY_SUB_ASSIGN:         return true;
-               case EXPR_BINARY_SHIFTLEFT_ASSIGN:   return true;
-               case EXPR_BINARY_SHIFTRIGHT_ASSIGN:  return true;
-               case EXPR_BINARY_BITWISE_AND_ASSIGN: return true;
-               case EXPR_BINARY_BITWISE_XOR_ASSIGN: return true;
-               case EXPR_BINARY_BITWISE_OR_ASSIGN:  return true;
+               case EXPR_UNARY_CAST_IMPLICIT:        return true;
+               case EXPR_UNARY_ASSUME:               return true;
+               case EXPR_UNARY_DELETE:               return true;
+               case EXPR_UNARY_DELETE_ARRAY:         return true;
+               case EXPR_UNARY_THROW:                return true;
+
+               case EXPR_BINARY_ADD:                 return false;
+               case EXPR_BINARY_SUB:                 return false;
+               case EXPR_BINARY_MUL:                 return false;
+               case EXPR_BINARY_DIV:                 return false;
+               case EXPR_BINARY_MOD:                 return false;
+               case EXPR_BINARY_EQUAL:               return false;
+               case EXPR_BINARY_NOTEQUAL:            return false;
+               case EXPR_BINARY_LESS:                return false;
+               case EXPR_BINARY_LESSEQUAL:           return false;
+               case EXPR_BINARY_GREATER:             return false;
+               case EXPR_BINARY_GREATEREQUAL:        return false;
+               case EXPR_BINARY_BITWISE_AND:         return false;
+               case EXPR_BINARY_BITWISE_OR:          return false;
+               case EXPR_BINARY_BITWISE_XOR:         return false;
+               case EXPR_BINARY_SHIFTLEFT:           return false;
+               case EXPR_BINARY_SHIFTRIGHT:          return false;
+               case EXPR_BINARY_ASSIGN:              return true;
+               case EXPR_BINARY_MUL_ASSIGN:          return true;
+               case EXPR_BINARY_DIV_ASSIGN:          return true;
+               case EXPR_BINARY_MOD_ASSIGN:          return true;
+               case EXPR_BINARY_ADD_ASSIGN:          return true;
+               case EXPR_BINARY_SUB_ASSIGN:          return true;
+               case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
+               case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
+               case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
+               case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
+               case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
 
                /* Only examine the right hand side of && and ||, because the left hand
                 * side already has the effect of controlling the execution of the right
@@ -9416,12 +9445,12 @@ static bool expression_has_effect(const expression_t *const expr)
                case EXPR_BINARY_COMMA:
                        return expression_has_effect(expr->binary.right);
 
-               case EXPR_BINARY_ISGREATER:          return false;
-               case EXPR_BINARY_ISGREATEREQUAL:     return false;
-               case EXPR_BINARY_ISLESS:             return false;
-               case EXPR_BINARY_ISLESSEQUAL:        return false;
-               case EXPR_BINARY_ISLESSGREATER:      return false;
-               case EXPR_BINARY_ISUNORDERED:        return false;
+               case EXPR_BINARY_ISGREATER:           return false;
+               case EXPR_BINARY_ISGREATEREQUAL:      return false;
+               case EXPR_BINARY_ISLESS:              return false;
+               case EXPR_BINARY_ISLESSEQUAL:         return false;
+               case EXPR_BINARY_ISLESSGREATER:       return false;
+               case EXPR_BINARY_ISUNORDERED:         return false;
        }
 
        internal_errorf(HERE, "unexpected expression");
@@ -10075,7 +10104,8 @@ end_error:
  *
  * @param statement  the switch statement to check
  */
-static void check_enum_cases(const switch_statement_t *statement) {
+static void check_enum_cases(const switch_statement_t *statement)
+{
        const type_t *type = skip_typeref(statement->expression->base.type);
        if (! is_type_enum(type))
                return;
@@ -10568,12 +10598,11 @@ static statement_t *parse_declaration_statement(void)
                parse_declaration(record_entity, DECL_FLAGS_NONE);
        }
 
-       if (before == NULL) {
-               statement->declaration.declarations_begin = current_scope->entities;
-       } else {
-               statement->declaration.declarations_begin = before->base.next;
-       }
-       statement->declaration.declarations_end = current_scope->last_entity;
+       declaration_statement_t *const decl  = &statement->declaration;
+       entity_t                *const begin =
+               before != NULL ? before->base.next : current_scope->entities;
+       decl->declarations_begin = begin;
+       decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
 
        return statement;
 }
@@ -10713,10 +10742,13 @@ static void parse_namespace_definition(void)
                next_token();
 
                entity = get_entity(symbol, NAMESPACE_NORMAL);
-               if (entity != NULL && entity->kind != ENTITY_NAMESPACE
-                               && entity->base.parent_scope == current_scope) {
-                       error_redefined_as_different_kind(&token.source_position,
-                                                         entity, ENTITY_NAMESPACE);
+               if (entity       != NULL             &&
+                               entity->kind != ENTITY_NAMESPACE &&
+                               entity->base.parent_scope == current_scope) {
+                       if (!is_error_entity(entity)) {
+                               error_redefined_as_different_kind(&token.source_position,
+                                               entity, ENTITY_NAMESPACE);
+                       }
                        entity = NULL;
                }
        }
@@ -11337,6 +11369,10 @@ void start_parsing(void)
 
        assert(current_scope == NULL);
        scope_push(&unit->scope);
+
+       create_gnu_builtins();
+       if (c_mode & _MS)
+               create_microsoft_intrinsics();
 }
 
 translation_unit_t *finish_parsing(void)
@@ -11356,8 +11392,8 @@ translation_unit_t *finish_parsing(void)
        return result;
 }
 
-/* GCC allows global arrays without size and assigns them a length of one,
- * if no different declaration follows */
+/* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
+ * are given length one. */
 static void complete_incomplete_arrays(void)
 {
        size_t n = ARR_LEN(incomplete_arrays);
@@ -11400,6 +11436,84 @@ void parse(void)
        incomplete_arrays = NULL;
 }
 
+/**
+ * create a builtin function.
+ */
+static entity_t *create_builtin_function(builtin_kind_t kind, const char *name, type_t *function_type)
+{
+       symbol_t *symbol = symbol_table_insert(name);
+       entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
+       entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
+       entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
+       entity->declaration.type                   = function_type;
+       entity->declaration.implicit               = true;
+       entity->base.symbol                        = symbol;
+       entity->base.source_position               = builtin_source_position;
+
+       entity->function.btk                       = kind;
+
+       record_entity(entity, /*is_definition=*/false);
+       return entity;
+}
+
+
+/**
+ * Create predefined gnu builtins.
+ */
+static void create_gnu_builtins(void) {
+#define _STR(a)              #a
+#define STR(a)               _STR(a)
+#define CONCAT(a,b)          a##b
+#define GNU_BUILTIN_NAME(a)  STR(CONCAT(__builtin_, a))
+#define GNU_BUILTIN(a, b)    create_builtin_function(CONCAT(bk_gnu_builtin_, a), GNU_BUILTIN_NAME(a), b)
+
+       GNU_BUILTIN(alloca,         make_function_1_type(type_void_ptr, type_size_t));
+       GNU_BUILTIN(huge_val,       make_function_0_type(type_double));
+       GNU_BUILTIN(inf,            make_function_0_type(type_double));
+       GNU_BUILTIN(inff,           make_function_0_type(type_float));
+       GNU_BUILTIN(infl,           make_function_0_type(type_long_double));
+       GNU_BUILTIN(nan,            make_function_1_type(type_double, type_char_ptr));
+       GNU_BUILTIN(nanf,           make_function_1_type(type_float, type_char_ptr));
+       GNU_BUILTIN(nanl,           make_function_1_type(type_long_double, type_char_ptr));
+       GNU_BUILTIN(va_end,         make_function_1_type(type_void, type_valist));
+       GNU_BUILTIN(expect,         make_function_2_type(type_long, type_long, type_long));
+       GNU_BUILTIN(return_address, make_function_1_type(type_void_ptr, type_unsigned_int));
+       GNU_BUILTIN(frame_address,  make_function_1_type(type_void_ptr, type_unsigned_int));
+       GNU_BUILTIN(ffs,            make_function_1_type(type_int, type_unsigned_int));
+       GNU_BUILTIN(clz,            make_function_1_type(type_int, type_unsigned_int));
+       GNU_BUILTIN(ctz,            make_function_1_type(type_int, type_unsigned_int));
+       GNU_BUILTIN(popcount,       make_function_1_type(type_int, type_unsigned_int));
+       GNU_BUILTIN(parity,         make_function_1_type(type_int, type_unsigned_int));
+       GNU_BUILTIN(prefetch,       make_function_1_type_variadic(type_float, type_void_ptr));
+       GNU_BUILTIN(trap,           make_function_0_type_noreturn(type_void));
+
+#undef GNU_BUILTIN
+#undef GNU_BUILTIN_NAME
+#undef CONCAT
+#undef STR
+#undef _STR
+}
+
+/**
+ * Create predefined MS intrinsics.
+ */
+static void create_microsoft_intrinsics(void) {
+#define _STR(a)              #a
+#define STR(a)               _STR(a)
+#define CONCAT(a,b)          a##b
+#define MS_BUILTIN(a, b)  create_builtin_function(CONCAT(bk_ms, a), STR(a), b)
+
+       MS_BUILTIN(__debugbreak,    make_function_0_type(type_void));
+       MS_BUILTIN(_ReturnAddress,  make_function_0_type(type_void_ptr));
+       MS_BUILTIN(__popcount,      make_function_1_type(type_unsigned_int, type_unsigned_int));
+       MS_BUILTIN(__ud2,           make_function_0_type_noreturn(type_void));
+
+#undef MS_BUILTIN
+#undef CONCAT
+#undef STR
+#undef _STR
+}
+
 /**
  * Initialize the parser.
  */