- add -f[no-]short-wchar
[cparser] / parser.c
index 749a1ee..baa943a 100644 (file)
--- a/parser.c
+++ b/parser.c
 #include "adt/error.h"
 #include "adt/array.h"
 
+/** if wchar_t is equal to unsigned short. */
+bool opt_short_wchar_t =
+#ifdef _WIN32
+       true;
+#else
+       false;
+#endif
+
 //#define PRINT_TOKENS
 #define MAX_LOOKAHEAD 2
 
@@ -108,6 +116,7 @@ static declaration_t      *last_declaration  = NULL;
 static declaration_t      *current_function  = NULL;
 static switch_statement_t *current_switch    = NULL;
 static statement_t        *current_loop      = NULL;
+static statement_t        *current_parent    = NULL;
 static ms_try_statement_t *current_try       = NULL;
 static goto_statement_t   *goto_first        = NULL;
 static goto_statement_t   *goto_last         = NULL;
@@ -116,6 +125,11 @@ static label_statement_t  *label_last        = NULL;
 static translation_unit_t *unit              = NULL;
 static struct obstack      temp_obst;
 
+#define PUSH_PARENT(stmt)                          \
+       statement_t *const prev_parent = current_parent; \
+       current_parent = (stmt);
+#define POP_PARENT ((void)(current_parent = prev_parent))
+
 static source_position_t null_position = { NULL, 0 };
 
 /* symbols for Microsoft extended-decl-modifier */
@@ -165,7 +179,8 @@ static void semantic_comparison(binary_expression_t *expression);
        case T_extern:          \
        case T_static:          \
        case T_auto:            \
-       case T_register:
+       case T_register:        \
+       case T___thread:
 
 #define TYPE_QUALIFIERS     \
        case T_const:           \
@@ -320,7 +335,8 @@ static statement_t *allocate_statement_zero(statement_kind_t kind)
        size_t       size = get_statement_struct_size(kind);
        statement_t *res  = allocate_ast_zero(size);
 
-       res->base.kind = kind;
+       res->base.kind   = kind;
+       res->base.parent = current_parent;
        return res;
 }
 
@@ -540,10 +556,6 @@ static bool at_anchor(void)
  */
 static void eat_until_matching_token(int type)
 {
-       unsigned parenthesis_count = 0;
-       unsigned brace_count = 0;
-       unsigned bracket_count = 0;
-
        int end_token;
        switch (type) {
                case '(': end_token = ')';  break;
@@ -552,26 +564,40 @@ static void eat_until_matching_token(int type)
                default:  end_token = type; break;
        }
 
-       while (token.type != end_token ||
-             (parenthesis_count > 0 || brace_count > 0 || bracket_count > 0)) {
-
-               switch(token.type) {
+       unsigned parenthesis_count = 0;
+       unsigned brace_count       = 0;
+       unsigned bracket_count     = 0;
+       while (token.type        != end_token ||
+              parenthesis_count != 0         ||
+              brace_count       != 0         ||
+              bracket_count     != 0) {
+               switch (token.type) {
                case T_EOF: return;
                case '(': ++parenthesis_count; break;
                case '{': ++brace_count;       break;
                case '[': ++bracket_count;     break;
+
                case ')':
                        if (parenthesis_count > 0)
                                --parenthesis_count;
-                       break;
+                       goto check_stop;
+
                case '}':
                        if (brace_count > 0)
                                --brace_count;
-                       break;
+                       goto check_stop;
+
                case ']':
                        if (bracket_count > 0)
                                --bracket_count;
+check_stop:
+                       if (token.type        == end_token &&
+                           parenthesis_count == 0         &&
+                           brace_count       == 0         &&
+                           bracket_count     == 0)
+                               return;
                        break;
+
                default:
                        break;
                }
@@ -822,7 +848,7 @@ static void label_pop_to(size_t new_top)
 }
 
 
-static int get_rank(const type_t *type)
+static atomic_type_kind_t get_rank(const type_t *type)
 {
        assert(!is_typeref(type));
        /* The C-standard allows promoting enums to int or unsigned int (see ยง 7.2.2
@@ -941,9 +967,9 @@ static void report_assign_error(assign_error_t error, type_t *orig_type_left,
                /* the left type has all qualifiers from the right type */
                unsigned missing_qualifiers
                        = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
-               errorf(source_position,
-                      "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointed-to type",
-                      orig_type_left, context, orig_type_right, missing_qualifiers);
+               warningf(source_position,
+                        "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointed-to type",
+                        orig_type_left, context, orig_type_right, missing_qualifiers);
                return;
        }
 
@@ -1590,7 +1616,6 @@ static decl_modifiers_t parse_gnu_attribute(gnu_attribute_t **attributes)
                                switch(kind) {
                                case GNU_AK_CONST:
                                case GNU_AK_VOLATILE:
-                               case GNU_AK_DEPRECATED:
                                case GNU_AK_NAKED:
                                case GNU_AK_MALLOC:
                                case GNU_AK_WEAK:
@@ -1639,6 +1664,7 @@ static decl_modifiers_t parse_gnu_attribute(gnu_attribute_t **attributes)
                                case GNU_AK_TRANSPARENT_UNION: modifiers |= DM_TRANSPARENT_UNION; goto no_arg;
                                case GNU_AK_CONSTRUCTOR:       modifiers |= DM_CONSTRUCTOR;       goto no_arg;
                                case GNU_AK_DESTRUCTOR:        modifiers |= DM_DESTRUCTOR;        goto no_arg;
+                               case GNU_AK_DEPRECATED:        modifiers |= DM_DEPRECATED;        goto no_arg;
 
                                case GNU_AK_ALIGNED:
                                        /* __align__ may be used without an argument */
@@ -2328,7 +2354,16 @@ static initializer_t *parse_sub_initializer(type_path_t *path,
                designator_t *designator = NULL;
                if (token.type == '.' || token.type == '[') {
                        designator = parse_designation();
+                       goto finish_designator;
+               } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
+                       /* GNU-style designator ("identifier: value") */
+                       designator = allocate_ast_zero(sizeof(designator[0]));
+                       designator->source_position = token.source_position;
+                       designator->symbol          = token.v.symbol;
+                       eat(T_IDENTIFIER);
+                       eat(':');
 
+finish_designator:
                        /* reset path to toplevel, evaluate designator from there */
                        ascend_to(path, top_path_level);
                        if (!walk_designator(path, designator, false)) {
@@ -3026,7 +3061,8 @@ static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
        type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
        type_modifiers_t   modifiers       = TYPE_MODIFIER_NONE;
        unsigned           type_specifiers = 0;
-       int                newtype         = 0;
+       bool               newtype         = false;
+       bool               saw_error       = false;
 
        specifiers->source_position = token.source_position;
 
@@ -3136,6 +3172,7 @@ static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
                case T__forceinline:
                        /* only in microsoft mode */
                        specifiers->modifiers |= DM_FORCEINLINE;
+                       /* FALLTHROUGH */
 
                case T_inline:
                        next_token();
@@ -3179,13 +3216,50 @@ static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
 
                case T_IDENTIFIER: {
                        /* only parse identifier if we haven't found a type yet */
-                       if (type != NULL || type_specifiers != 0)
-                               goto finish_specifiers;
+                       if (type != NULL || type_specifiers != 0) {
+                               /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
+                                * declaration, so it doesn't generate errors about expecting '(' or
+                                * '{' later on. */
+                               switch (look_ahead(1)->type) {
+                                       STORAGE_CLASSES
+                                       TYPE_SPECIFIERS
+                                       case T_const:
+                                       case T_restrict:
+                                       case T_volatile:
+                                       case T_inline:
+                                       case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
+                                       case T_IDENTIFIER:
+                                       case '*':
+                                               errorf(HERE, "discarding stray %K in declaration specifer", &token);
+                                               next_token();
+                                               continue;
 
-                       type_t *typedef_type = get_typedef_type(token.v.symbol);
+                                       default:
+                                               goto finish_specifiers;
+                               }
+                       }
+
+                       type_t *const typedef_type = get_typedef_type(token.v.symbol);
+                       if (typedef_type == NULL) {
+                               /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
+                                * declaration, so it doesn't generate 'implicit int' followed by more
+                                * errors later on. */
+                               token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
+                               switch (la1_type) {
+                                       DECLARATION_START
+                                       case T_IDENTIFIER:
+                                       case '*':
+                                               errorf(HERE, "%K does not name a type", &token);
+                                               next_token();
+                                               saw_error = true;
+                                               if (la1_type == '*')
+                                                       goto finish_specifiers;
+                                               continue;
 
-                       if (typedef_type == NULL)
-                               goto finish_specifiers;
+                                       default:
+                                               goto finish_specifiers;
+                               }
+                       }
 
                        next_token();
                        type = typedef_type;
@@ -3246,17 +3320,24 @@ finish_specifiers:
                case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
                        atomic_type = ATOMIC_TYPE_ULONG;
                        break;
+
                case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
                case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
                case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
                case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
                        | SPECIFIER_INT:
                        atomic_type = ATOMIC_TYPE_LONGLONG;
-                       break;
+                       goto warn_about_long_long;
+
                case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
                case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
                        | SPECIFIER_INT:
                        atomic_type = ATOMIC_TYPE_ULONGLONG;
+warn_about_long_long:
+                       if (warning.long_long) {
+                               warningf(&specifiers->source_position,
+                                        "ISO C90 does not support 'long long'");
+                       }
                        break;
 
                case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
@@ -3331,7 +3412,12 @@ finish_specifiers:
                default:
                        /* invalid specifier combination, give an error message */
                        if (type_specifiers == 0) {
-                               if (! strict_mode) {
+                               if (saw_error) {
+                                       specifiers->type = type_error_type;
+                                       return;
+                               }
+
+                               if (!strict_mode) {
                                        if (warning.implicit_int) {
                                                warningf(HERE, "no type specifiers in declaration, using 'int'");
                                        }
@@ -3342,7 +3428,7 @@ finish_specifiers:
                                }
                        } else if ((type_specifiers & SPECIFIER_SIGNED) &&
                                  (type_specifiers & SPECIFIER_UNSIGNED)) {
-                               errorf(HERE, "signed and unsigned specifiers gives");
+                               errorf(HERE, "signed and unsigned specifiers given");
                        } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
                                errorf(HERE, "only integer types can be signed or unsigned");
                        } else {
@@ -3363,11 +3449,9 @@ finish_specifiers:
                        type               = allocate_type_zero(TYPE_ATOMIC, &builtin_source_position);
                        type->atomic.akind = atomic_type;
                }
-               newtype = 1;
-       } else {
-               if (type_specifiers != 0) {
-                       errorf(HERE, "multiple datatypes in declaration");
-               }
+               newtype = true;
+       } else if (type_specifiers != 0) {
+               errorf(HERE, "multiple datatypes in declaration");
        }
 
        /* FIXME: check type qualifiers here */
@@ -3440,12 +3524,21 @@ static type_t *automatic_type_conversion(type_t *orig_type);
 static void semantic_parameter(declaration_t *declaration)
 {
        /* TODO: improve error messages */
+       source_position_t const* const pos = &declaration->source_position;
+
+       switch (declaration->declared_storage_class) {
+               case STORAGE_CLASS_TYPEDEF:
+                       errorf(pos, "typedef not allowed in parameter list");
+                       break;
+
+               /* Allowed storage classes */
+               case STORAGE_CLASS_NONE:
+               case STORAGE_CLASS_REGISTER:
+                       break;
 
-       if (declaration->declared_storage_class == STORAGE_CLASS_TYPEDEF) {
-               errorf(HERE, "typedef not allowed in parameter list");
-       } else if (declaration->declared_storage_class != STORAGE_CLASS_NONE
-                       && declaration->declared_storage_class != STORAGE_CLASS_REGISTER) {
-               errorf(HERE, "parameter may only have none or register storage class");
+               default:
+                       errorf(pos, "parameter may only have none or register storage class");
+                       break;
        }
 
        type_t *const orig_type = declaration->type;
@@ -3458,7 +3551,7 @@ static void semantic_parameter(declaration_t *declaration)
        declaration->type = type;
 
        if (is_type_incomplete(skip_typeref(type))) {
-               errorf(HERE, "incomplete type '%T' not allowed for parameter '%Y'",
+               errorf(pos, "incomplete type '%T' not allowed for parameter '%Y'",
                       orig_type, declaration->symbol);
        }
 }
@@ -3671,7 +3764,7 @@ static construct_type_t *parse_function_declarator(declaration_t *declaration)
                                else if (second == NULL) second = "stdcall";
                        }
                        if (declaration->modifiers & DM_FASTCALL) {
-                               if (first == NULL)       first = "faslcall";
+                               if (first == NULL)       first = "fastcall";
                                else if (second == NULL) second = "fastcall";
                        }
                        if (declaration->modifiers & DM_THISCALL) {
@@ -3756,6 +3849,9 @@ static construct_type_t *parse_inner_declarator(declaration_t *declaration,
                modifiers |= parse_attributes(&attributes);
        }
 
+       if (declaration != NULL)
+               declaration->modifiers |= modifiers;
+
        construct_type_t *inner_types = NULL;
 
        switch(token.type) {
@@ -3772,6 +3868,8 @@ static construct_type_t *parse_inner_declarator(declaration_t *declaration,
                next_token();
                add_anchor_token(')');
                inner_types = parse_inner_declarator(declaration, may_be_abstract);
+               /* All later declarators only modify the return type, not declaration */
+               declaration = NULL;
                rem_anchor_token(')');
                expect(')');
                break;
@@ -3961,9 +4059,9 @@ static declaration_t *parse_declarator(
                const declaration_specifiers_t *specifiers, bool may_be_abstract)
 {
        declaration_t *const declaration    = allocate_declaration_zero();
+       declaration->source_position        = specifiers->source_position;
        declaration->declared_storage_class = specifiers->declared_storage_class;
        declaration->modifiers              = specifiers->modifiers;
-       declaration->deprecated             = specifiers->deprecated;
        declaration->deprecated_string      = specifiers->deprecated_string;
        declaration->get_property_sym       = specifiers->get_property_sym;
        declaration->put_property_sym       = specifiers->put_property_sym;
@@ -4087,7 +4185,7 @@ static declaration_t *internal_record_declaration(
        const symbol_t *const symbol  = declaration->symbol;
        const namespace_t     namespc = (namespace_t)declaration->namespc;
 
-       assert(declaration->symbol != NULL);
+       assert(symbol != NULL);
        declaration_t *previous_declaration = get_declaration(symbol, namespc);
 
        type_t *const orig_type = declaration->type;
@@ -4105,6 +4203,13 @@ static declaration_t *internal_record_declaration(
                check_type_of_main(declaration, &type->function);
        }
 
+       if (warning.nested_externs                             &&
+           declaration->storage_class == STORAGE_CLASS_EXTERN &&
+           scope                      != global_scope) {
+               warningf(&declaration->source_position,
+                        "nested extern declaration of '%#T'", declaration->type, symbol);
+       }
+
        assert(declaration != previous_declaration);
        if (previous_declaration != NULL
                        && previous_declaration->parent_scope == scope) {
@@ -4211,8 +4316,8 @@ warn_redundant_declaration:
                        }
                }
 
-               if (declaration->is_inline)
-                       previous_declaration->is_inline = true;
+               previous_declaration->modifiers |= declaration->modifiers;
+               previous_declaration->is_inline |= declaration->is_inline;
                return previous_declaration;
        } else if (is_type_function(type)) {
                if (is_definition &&
@@ -4609,6 +4714,10 @@ static void check_declarations(void)
        if (warning.unused_parameter) {
                const scope_t *scope = &current_function->scope;
 
+               if (is_sym_main(current_function->symbol)) {
+                       /* do not issue unused warnings for main */
+                       return;
+               }
                const declaration_t *parameter = scope->declarations;
                for (; parameter != NULL; parameter = parameter->next) {
                        if (! parameter->used) {
@@ -4622,6 +4731,432 @@ static void check_declarations(void)
        }
 }
 
+static int determine_truth(expression_t const* const cond)
+{
+       return
+               !is_constant_expression(cond) ? 0 :
+               fold_constant(cond) != 0      ? 1 :
+               -1;
+}
+
+static bool noreturn_candidate;
+
+static void check_reachable(statement_t *const stmt)
+{
+       if (stmt->base.reachable)
+               return;
+       if (stmt->kind != STATEMENT_DO_WHILE)
+               stmt->base.reachable = true;
+
+       statement_t *last = stmt;
+       statement_t *next;
+       switch (stmt->kind) {
+               case STATEMENT_INVALID:
+               case STATEMENT_EMPTY:
+               case STATEMENT_DECLARATION:
+               case STATEMENT_ASM:
+                       next = stmt->base.next;
+                       break;
+
+               case STATEMENT_COMPOUND:
+                       next = stmt->compound.statements;
+                       break;
+
+               case STATEMENT_RETURN:
+                       noreturn_candidate = false;
+                       return;
+
+               case STATEMENT_IF: {
+                       if_statement_t const* const ifs = &stmt->ifs;
+                       int            const        val = determine_truth(ifs->condition);
+
+                       if (val >= 0)
+                               check_reachable(ifs->true_statement);
+
+                       if (val > 0)
+                               return;
+
+                       if (ifs->false_statement != NULL) {
+                               check_reachable(ifs->false_statement);
+                               return;
+                       }
+
+                       next = stmt->base.next;
+                       break;
+               }
+
+               case STATEMENT_SWITCH: {
+                       switch_statement_t const *const switchs = &stmt->switchs;
+                       expression_t       const *const expr    = switchs->expression;
+
+                       if (is_constant_expression(expr)) {
+                               long                    const val      = fold_constant(expr);
+                               case_label_statement_t *      defaults = NULL;
+                               for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
+                                       if (i->expression == NULL) {
+                                               defaults = i;
+                                               continue;
+                                       }
+
+                                       if (i->first_case <= val && val <= i->last_case) {
+                                               check_reachable((statement_t*)i);
+                                               return;
+                                       }
+                               }
+
+                               if (defaults != NULL) {
+                                       check_reachable((statement_t*)defaults);
+                                       return;
+                               }
+                       } else {
+                               bool has_default = false;
+                               for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
+                                       if (i->expression == NULL)
+                                               has_default = true;
+
+                                       check_reachable((statement_t*)i);
+                               }
+
+                               if (has_default)
+                                       return;
+                       }
+
+                       next = stmt->base.next;
+                       break;
+               }
+
+               case STATEMENT_EXPRESSION: {
+                       /* Check for noreturn function call */
+                       expression_t const *const expr = stmt->expression.expression;
+                       if (expr->kind == EXPR_CALL) {
+                               expression_t const *const func = expr->call.function;
+                               if (func->kind == EXPR_REFERENCE) {
+                                       declaration_t const *const decl = func->reference.declaration;
+                                       if (decl != NULL && decl->modifiers & DM_NORETURN) {
+                                               return;
+                                       }
+                               }
+                       }
+
+                       next = stmt->base.next;
+                       break;
+               }
+
+               case STATEMENT_CONTINUE: {
+                       statement_t *parent = stmt;
+                       for (;;) {
+                               parent = parent->base.parent;
+                               if (parent == NULL) /* continue not within loop */
+                                       return;
+
+                               next = parent;
+                               switch (parent->kind) {
+                                       case STATEMENT_WHILE:    goto continue_while;
+                                       case STATEMENT_DO_WHILE: goto continue_do_while;
+                                       case STATEMENT_FOR:      goto continue_for;
+
+                                       default: break;
+                               }
+                       }
+               }
+
+               case STATEMENT_BREAK: {
+                       statement_t *parent = stmt;
+                       for (;;) {
+                               parent = parent->base.parent;
+                               if (parent == NULL) /* break not within loop/switch */
+                                       return;
+
+                               switch (parent->kind) {
+                                       case STATEMENT_SWITCH:
+                                       case STATEMENT_WHILE:
+                                       case STATEMENT_DO_WHILE:
+                                       case STATEMENT_FOR:
+                                               last = parent;
+                                               next = parent->base.next;
+                                               goto found_break_parent;
+
+                                       default: break;
+                               }
+                       }
+found_break_parent:
+                       break;
+               }
+
+               case STATEMENT_GOTO:
+                       next = stmt->gotos.label->init.statement;
+                       if (next == NULL) /* missing label */
+                               return;
+                       break;
+
+               case STATEMENT_LABEL:
+                       next = stmt->label.statement;
+                       break;
+
+               case STATEMENT_CASE_LABEL:
+                       next = stmt->case_label.statement;
+                       break;
+
+               case STATEMENT_WHILE: {
+                       while_statement_t const *const whiles = &stmt->whiles;
+                       int                      const val    = determine_truth(whiles->condition);
+
+                       if (val >= 0)
+                               check_reachable(whiles->body);
+
+                       if (val > 0)
+                               return;
+
+                       next = stmt->base.next;
+                       break;
+               }
+
+               case STATEMENT_DO_WHILE:
+                       next = stmt->do_while.body;
+                       break;
+
+               case STATEMENT_FOR: {
+                       for_statement_t *const fors = &stmt->fors;
+
+                       if (fors->condition_reachable)
+                               return;
+                       fors->condition_reachable = true;
+
+                       expression_t const *const cond = fors->condition;
+                       int          const        val  =
+                               cond == NULL ? 1 : determine_truth(cond);
+
+                       if (val >= 0)
+                               check_reachable(fors->body);
+
+                       if (val > 0)
+                               return;
+
+                       next = stmt->base.next;
+                       break;
+               }
+
+               case STATEMENT_MS_TRY:
+               case STATEMENT_LEAVE:
+                       panic("unimplemented");
+       }
+
+       while (next == NULL) {
+               next = last->base.parent;
+               if (next == NULL) {
+                       noreturn_candidate = false;
+
+                       type_t *const type = current_function->type;
+                       assert(is_type_function(type));
+                       type_t *const ret  = skip_typeref(type->function.return_type);
+                       if (warning.return_type                    &&
+                           !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
+                           is_type_valid(ret)                     &&
+                           !is_sym_main(current_function->symbol)) {
+                               warningf(&stmt->base.source_position,
+                                        "control reaches end of non-void function");
+                       }
+                       return;
+               }
+
+               switch (next->kind) {
+                       case STATEMENT_INVALID:
+                       case STATEMENT_EMPTY:
+                       case STATEMENT_DECLARATION:
+                       case STATEMENT_EXPRESSION:
+                       case STATEMENT_ASM:
+                       case STATEMENT_RETURN:
+                       case STATEMENT_CONTINUE:
+                       case STATEMENT_BREAK:
+                       case STATEMENT_GOTO:
+                       case STATEMENT_LEAVE:
+                               panic("invalid control flow in function");
+
+                       case STATEMENT_COMPOUND:
+                       case STATEMENT_IF:
+                       case STATEMENT_SWITCH:
+                       case STATEMENT_LABEL:
+                       case STATEMENT_CASE_LABEL:
+                               last = next;
+                               next = next->base.next;
+                               break;
+
+                       case STATEMENT_WHILE: {
+continue_while:
+                               if (next->base.reachable)
+                                       return;
+                               next->base.reachable = true;
+
+                               while_statement_t const *const whiles = &next->whiles;
+                               int                      const val    = determine_truth(whiles->condition);
+
+                               if (val >= 0)
+                                       check_reachable(whiles->body);
+
+                               if (val > 0)
+                                       return;
+
+                               last = next;
+                               next = next->base.next;
+                               break;
+                       }
+
+                       case STATEMENT_DO_WHILE: {
+continue_do_while:
+                               if (next->base.reachable)
+                                       return;
+                               next->base.reachable = true;
+
+                               do_while_statement_t const *const dw  = &next->do_while;
+                               int                  const        val = determine_truth(dw->condition);
+
+                               if (val >= 0)
+                                       check_reachable(dw->body);
+
+                               if (val > 0)
+                                       return;
+
+                               last = next;
+                               next = next->base.next;
+                               break;
+                       }
+
+                       case STATEMENT_FOR: {
+continue_for:;
+                               for_statement_t *const fors = &next->fors;
+
+                               fors->step_reachable = true;
+
+                               if (fors->condition_reachable)
+                                       return;
+                               fors->condition_reachable = true;
+
+                               expression_t const *const cond = fors->condition;
+                               int          const        val  =
+                                       cond == NULL ? 1 : determine_truth(cond);
+
+                               if (val >= 0)
+                                       check_reachable(fors->body);
+
+                               if (val > 0)
+                                       return;
+
+                               last = next;
+                               next = next->base.next;
+                               break;
+                       }
+
+                       case STATEMENT_MS_TRY:
+                               panic("unimplemented");
+               }
+       }
+
+       if (next == NULL) {
+               next = stmt->base.parent;
+               if (next == NULL) {
+                       warningf(&stmt->base.source_position,
+                                "control reaches end of non-void function");
+               }
+       }
+
+       check_reachable(next);
+}
+
+static void check_unreachable(statement_t const* const stmt)
+{
+       if (!stmt->base.reachable            &&
+           stmt->kind != STATEMENT_COMPOUND &&
+           stmt->kind != STATEMENT_DO_WHILE &&
+           stmt->kind != STATEMENT_FOR) {
+               warningf(&stmt->base.source_position, "statement is unreachable");
+       }
+
+       switch (stmt->kind) {
+               case STATEMENT_INVALID:
+               case STATEMENT_EMPTY:
+               case STATEMENT_RETURN:
+               case STATEMENT_DECLARATION:
+               case STATEMENT_EXPRESSION:
+               case STATEMENT_CONTINUE:
+               case STATEMENT_BREAK:
+               case STATEMENT_GOTO:
+               case STATEMENT_ASM:
+               case STATEMENT_LEAVE:
+                       break;
+
+               case STATEMENT_COMPOUND:
+                       if (stmt->compound.statements)
+                               check_unreachable(stmt->compound.statements);
+                       break;
+
+               case STATEMENT_IF:
+                       check_unreachable(stmt->ifs.true_statement);
+                       if (stmt->ifs.false_statement != NULL)
+                               check_unreachable(stmt->ifs.false_statement);
+                       break;
+
+               case STATEMENT_SWITCH:
+                       check_unreachable(stmt->switchs.body);
+                       break;
+
+               case STATEMENT_LABEL:
+                       check_unreachable(stmt->label.statement);
+                       break;
+
+               case STATEMENT_CASE_LABEL:
+                       check_unreachable(stmt->case_label.statement);
+                       break;
+
+               case STATEMENT_WHILE:
+                       check_unreachable(stmt->whiles.body);
+                       break;
+
+               case STATEMENT_DO_WHILE:
+                       check_unreachable(stmt->do_while.body);
+                       if (!stmt->base.reachable) {
+                               expression_t const *const cond = stmt->do_while.condition;
+                               if (determine_truth(cond) >= 0) {
+                                       warningf(&cond->base.source_position,
+                                                "condition of do-while-loop is unreachable");
+                               }
+                       }
+                       break;
+
+               case STATEMENT_FOR: {
+                       for_statement_t const* const fors = &stmt->fors;
+
+                       // if init and step are unreachable, cond is unreachable, too
+                       if (!stmt->base.reachable && !fors->step_reachable) {
+                               warningf(&stmt->base.source_position, "statement is unreachable");
+                       } else {
+                               if (!stmt->base.reachable && fors->initialisation != NULL) {
+                                       warningf(&fors->initialisation->base.source_position,
+                                                "initialisation of for-statement is unreachable");
+                               }
+
+                               if (!fors->condition_reachable && fors->condition != NULL) {
+                                       warningf(&fors->condition->base.source_position,
+                                                "condition of for-statement is unreachable");
+                               }
+
+                               if (!fors->step_reachable && fors->step != NULL) {
+                                       warningf(&fors->step->base.source_position,
+                                                "step of for-statement is unreachable");
+                               }
+                       }
+
+                       check_unreachable(stmt->fors.body);
+                       break;
+               }
+
+               case STATEMENT_MS_TRY:
+                       panic("unimplemented");
+       }
+
+       if (stmt->base.next)
+               check_unreachable(stmt->base.next);
+}
+
 static void parse_external_declaration(void)
 {
        /* function-definitions and declarations both start with declaration
@@ -4719,7 +5254,7 @@ static void parse_external_declaration(void)
                                || parameter->parent_scope == scope);
                parameter->parent_scope = scope;
                if (parameter->symbol == NULL) {
-                       errorf(&ndeclaration->source_position, "parameter name omitted");
+                       errorf(&parameter->source_position, "parameter name omitted");
                        continue;
                }
                environment_push(parameter);
@@ -4733,12 +5268,30 @@ static void parse_external_declaration(void)
                int            label_stack_top      = label_top();
                declaration_t *old_current_function = current_function;
                current_function                    = declaration;
+               current_parent                      = NULL;
 
-               declaration->init.statement = parse_compound_statement(false);
+               statement_t *const body = parse_compound_statement(false);
+               declaration->init.statement = body;
                first_err = true;
                check_labels();
                check_declarations();
+               if (warning.return_type      ||
+                   warning.unreachable_code ||
+                   (warning.missing_noreturn && !(declaration->modifiers & DM_NORETURN))) {
+                       noreturn_candidate = true;
+                       check_reachable(body);
+                       if (warning.unreachable_code)
+                               check_unreachable(body);
+                       if (warning.missing_noreturn &&
+                           noreturn_candidate       &&
+                           !(declaration->modifiers & DM_NORETURN)) {
+                               warningf(&body->base.source_position,
+                                        "function '%#T' is candidate for attribute 'noreturn'",
+                                        type, declaration->symbol);
+                       }
+               }
 
+               assert(current_parent   == NULL);
                assert(current_function == declaration);
                current_function = old_current_function;
                label_pop_to(label_stack_top);
@@ -4971,7 +5524,7 @@ static expression_t *parse_string_const(void)
                        /* note: that we use type_char_ptr here, which is already the
                         * automatic converted type. revert_automatic_type_conversion
                         * will construct the array type */
-                       cnst->base.type    = type_char_ptr;
+                       cnst->base.type    = warning.write_strings ? type_const_char_ptr : type_char_ptr;
                        cnst->string.value = res;
                        return cnst;
                }
@@ -4994,7 +5547,7 @@ static expression_t *parse_string_const(void)
 
                        default: {
                                expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
-                               cnst->base.type         = type_wchar_t_ptr;
+                               cnst->base.type         = warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
                                cnst->wide_string.value = wres;
                                return cnst;
                        }
@@ -5316,18 +5869,20 @@ static expression_t *parse_reference(void)
        declaration->used = true;
 
        /* check for deprecated functions */
-       if (declaration->deprecated != 0) {
-               const char *prefix = "";
-               if (is_type_function(declaration->type))
-                       prefix = "function ";
+       if (warning.deprecated_declarations &&
+           declaration->modifiers & DM_DEPRECATED) {
+               char const *const prefix = is_type_function(declaration->type) ?
+                       "function" : "variable";
 
                if (declaration->deprecated_string != NULL) {
                        warningf(&source_position,
-                               "%s'%Y' was declared 'deprecated(\"%s\")'", prefix, declaration->symbol,
+                               "%s '%Y' is deprecated (declared %P): \"%s\"", prefix,
+                               declaration->symbol, &declaration->source_position,
                                declaration->deprecated_string);
                } else {
                        warningf(&source_position,
-                               "%s'%Y' was declared 'deprecated'", prefix, declaration->symbol);
+                               "%s '%Y' is deprecated (declared %P)", prefix,
+                               declaration->symbol, &declaration->source_position);
                }
        }
 
@@ -5425,9 +5980,9 @@ end_error:
 }
 
 /**
- * Parse a braced expression.
+ * Parse a parenthesized expression.
  */
-static expression_t *parse_brace_expression(void)
+static expression_t *parse_parenthesized_expression(void)
 {
        eat('(');
        add_anchor_token(')');
@@ -5913,7 +6468,7 @@ static expression_t *parse_primary_expression(void)
                case T___builtin_prefetch:       return parse_builtin_prefetch();
                case T__assume:                  return parse_assume();
 
-               case '(':                        return parse_brace_expression();
+               case '(':                        return parse_parenthesized_expression();
                case T___noop:                   return parse_noop_expression();
        }
 
@@ -6289,13 +6844,14 @@ static bool same_compound_type(const type_t *type1, const type_t *type2)
 static expression_t *parse_conditional_expression(unsigned precedence,
                                                   expression_t *expression)
 {
-       eat('?');
-       add_anchor_token(':');
-
        expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
 
        conditional_expression_t *conditional = &result->conditional;
-       conditional->condition = expression;
+       conditional->base.source_position = *HERE;
+       conditional->condition            = expression;
+
+       eat('?');
+       add_anchor_token(':');
 
        /* 6.5.15.2 */
        type_t *const condition_type_orig = expression->base.type;
@@ -6321,7 +6877,7 @@ static expression_t *parse_conditional_expression(unsigned precedence,
                is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
                if (!is_type_atomic(true_type, ATOMIC_TYPE_VOID)
                    || !is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
-                       warningf(&expression->base.source_position,
+                       warningf(&conditional->base.source_position,
                                        "ISO C forbids conditional expression with only one void side");
                }
                result_type = type_void;
@@ -6367,7 +6923,7 @@ static expression_t *parse_conditional_expression(unsigned precedence,
                                                    get_unqualified_type(to2))) {
                                to = to1;
                        } else {
-                               warningf(&expression->base.source_position,
+                               warningf(&conditional->base.source_position,
                                        "pointer types '%T' and '%T' in conditional expression are incompatible",
                                        true_type, false_type);
                                to = type_void;
@@ -6382,7 +6938,7 @@ static expression_t *parse_conditional_expression(unsigned precedence,
 
                        result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
                } else if (is_type_integer(other_type)) {
-                       warningf(&expression->base.source_position,
+                       warningf(&conditional->base.source_position,
                                        "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
                        result_type = pointer_type;
                } else {
@@ -6395,7 +6951,7 @@ static expression_t *parse_conditional_expression(unsigned precedence,
 
                if (is_type_valid(true_type) && is_type_valid(false_type)) {
                        type_error_incompatible("while parsing conditional",
-                                               &expression->base.source_position, true_type,
+                                               &conditional->base.source_position, true_type,
                                                false_type);
                }
                result_type = type_error_type;
@@ -6446,24 +7002,37 @@ end_error:
        return create_invalid_expression();
 }
 
-static void check_pointer_arithmetic(const source_position_t *source_position,
+static bool check_pointer_arithmetic(const source_position_t *source_position,
                                      type_t *pointer_type,
                                      type_t *orig_pointer_type)
 {
        type_t *points_to = pointer_type->pointer.points_to;
        points_to = skip_typeref(points_to);
 
-       if (is_type_incomplete(points_to) &&
-                       (! (c_mode & _GNUC)
-                        || !is_type_atomic(points_to, ATOMIC_TYPE_VOID))) {
-               errorf(source_position,
-                          "arithmetic with pointer to incomplete type '%T' not allowed",
-                          orig_pointer_type);
+       if (is_type_incomplete(points_to)) {
+               if (!(c_mode & _GNUC) || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
+                       errorf(source_position,
+                              "arithmetic with pointer to incomplete type '%T' not allowed",
+                              orig_pointer_type);
+                       return false;
+               } else if (warning.pointer_arith) {
+                       warningf(source_position,
+                                "pointer of type '%T' used in arithmetic",
+                                orig_pointer_type);
+               }
        } else if (is_type_function(points_to)) {
-               errorf(source_position,
-                          "arithmetic with pointer to function type '%T' not allowed",
-                          orig_pointer_type);
+               if (!(c_mode && _GNUC)) {
+                       errorf(source_position,
+                              "arithmetic with pointer to function type '%T' not allowed",
+                              orig_pointer_type);
+                       return false;
+               } else if (warning.pointer_arith) {
+                       warningf(source_position,
+                                "pointer to a function '%T' used in arithmetic",
+                                orig_pointer_type);
+               }
        }
+       return true;
 }
 
 static void semantic_incdec(unary_expression_t *expression)
@@ -6471,11 +7040,15 @@ static void semantic_incdec(unary_expression_t *expression)
        type_t *const orig_type = expression->value->base.type;
        type_t *const type      = skip_typeref(orig_type);
        if (is_type_pointer(type)) {
-               check_pointer_arithmetic(&expression->base.source_position,
-                                        type, orig_type);
+               if (!check_pointer_arithmetic(&expression->base.source_position,
+                                             type, orig_type)) {
+                       return;
+               }
        } else if (!is_type_real(type) && is_type_valid(type)) {
                /* TODO: improve error message */
-               errorf(HERE, "operation needs an arithmetic or pointer type");
+               errorf(&expression->base.source_position,
+                      "operation needs an arithmetic or pointer type");
+               return;
        }
        expression->base.type = orig_type;
 }
@@ -6487,7 +7060,8 @@ static void semantic_unexpr_arithmetic(unary_expression_t *expression)
        if (!is_type_arithmetic(type)) {
                if (is_type_valid(type)) {
                        /* TODO: improve error message */
-                       errorf(HERE, "operation needs an arithmetic type");
+                       errorf(&expression->base.source_position,
+                              "operation needs an arithmetic type");
                }
                return;
        }
@@ -6495,18 +7069,16 @@ static void semantic_unexpr_arithmetic(unary_expression_t *expression)
        expression->base.type = orig_type;
 }
 
-static void semantic_unexpr_scalar(unary_expression_t *expression)
+static void semantic_not(unary_expression_t *expression)
 {
        type_t *const orig_type = expression->value->base.type;
        type_t *const type      = skip_typeref(orig_type);
-       if (!is_type_scalar(type)) {
-               if (is_type_valid(type)) {
-                       errorf(HERE, "operand of ! must be of scalar type");
-               }
-               return;
+       if (!is_type_scalar(type) && is_type_valid(type)) {
+               errorf(&expression->base.source_position,
+                      "operand of ! must be of scalar type");
        }
 
-       expression->base.type = orig_type;
+       expression->base.type = type_int;
 }
 
 static void semantic_unexpr_integer(unary_expression_t *expression)
@@ -6515,7 +7087,8 @@ static void semantic_unexpr_integer(unary_expression_t *expression)
        type_t *const type      = skip_typeref(orig_type);
        if (!is_type_integer(type)) {
                if (is_type_valid(type)) {
-                       errorf(HERE, "operand of ~ must be of integer type");
+                       errorf(&expression->base.source_position,
+                              "operand of ~ must be of integer type");
                }
                return;
        }
@@ -6529,7 +7102,8 @@ static void semantic_dereference(unary_expression_t *expression)
        type_t *const type      = skip_typeref(orig_type);
        if (!is_type_pointer(type)) {
                if (is_type_valid(type)) {
-                       errorf(HERE, "Unary '*' needs pointer or arrray type, but type '%T' given", orig_type);
+                       errorf(&expression->base.source_position,
+                              "Unary '*' needs pointer or arrray type, but type '%T' given", orig_type);
                }
                return;
        }
@@ -6578,11 +7152,10 @@ static void semantic_take_addr(unary_expression_t *expression)
 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc)   \
 static expression_t *parse_##unexpression_type(unsigned precedence)            \
 {                                                                              \
-       eat(token_type);                                                           \
-                                                                                  \
        expression_t *unary_expression                                             \
                = allocate_expression_zero(unexpression_type);                         \
        unary_expression->base.source_position = *HERE;                            \
+       eat(token_type);                                                           \
        unary_expression->unary.value = parse_sub_expression(precedence);          \
                                                                                   \
        sfunc(&unary_expression->unary);                                           \
@@ -6595,7 +7168,7 @@ CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
                                semantic_unexpr_arithmetic)
 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
-                               semantic_unexpr_scalar)
+                               semantic_not)
 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
                                semantic_dereference)
 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
@@ -6613,11 +7186,12 @@ static expression_t *parse_##unexpression_type(unsigned precedence,           \
                                                expression_t *left)            \
 {                                                                             \
        (void) precedence;                                                        \
-       eat(token_type);                                                          \
                                                                               \
        expression_t *unary_expression                                            \
                = allocate_expression_zero(unexpression_type);                        \
-       unary_expression->unary.value = left;                                     \
+       unary_expression->base.source_position = *HERE;                           \
+       eat(token_type);                                                          \
+       unary_expression->unary.value          = left;                            \
                                                                                  \
        sfunc(&unary_expression->unary);                                          \
                                                                               \
@@ -6652,16 +7226,16 @@ static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
 
        bool const signed_left  = is_type_signed(type_left);
        bool const signed_right = is_type_signed(type_right);
-       int  const rank_left    = get_rank(type_left);
-       int  const rank_right   = get_rank(type_right);
+       atomic_type_kind_t const rank_left  = get_rank(type_left);
+       atomic_type_kind_t const rank_right = get_rank(type_right);
 
        if (signed_left == signed_right)
                return rank_left >= rank_right ? type_left : type_right;
 
-       int     s_rank;
-       int     u_rank;
-       type_t *s_type;
-       type_t *u_type;
+       atomic_type_kind_t  s_rank;
+       atomic_type_kind_t  u_rank;
+       type_t             *s_type;
+       type_t             *u_type;
        if (signed_left) {
                s_rank = rank_left;
                s_type = type_left;
@@ -6680,21 +7254,13 @@ static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
        if (get_atomic_type_size(s_rank) > get_atomic_type_size(u_rank))
                return s_type;
 
-       /* FIXME ugly */
-       type_t *const type = allocate_type_zero(TYPE_ATOMIC, &builtin_source_position);
        switch (s_rank) {
-               case ATOMIC_TYPE_INT:      type->atomic.akind = ATOMIC_TYPE_UINT;      break;
-               case ATOMIC_TYPE_LONG:     type->atomic.akind = ATOMIC_TYPE_ULONG;     break;
-               case ATOMIC_TYPE_LONGLONG: type->atomic.akind = ATOMIC_TYPE_ULONGLONG; break;
+               case ATOMIC_TYPE_INT:      return type_int;
+               case ATOMIC_TYPE_LONG:     return type_long;
+               case ATOMIC_TYPE_LONGLONG: return type_long_long;
 
                default: panic("invalid atomic type");
        }
-
-       type_t* const result = typehash_insert(type);
-       if (result != type)
-               free_type(type);
-
-       return result;
 }
 
 /**
@@ -6712,7 +7278,8 @@ static void semantic_binexpr_arithmetic(binary_expression_t *expression)
        if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
                /* TODO: improve error message */
                if (is_type_valid(type_left) && is_type_valid(type_right)) {
-                       errorf(HERE, "operation needs arithmetic types");
+                       errorf(&expression->base.source_position,
+                              "operation needs arithmetic types");
                }
                return;
        }
@@ -6735,7 +7302,8 @@ static void semantic_shift_op(binary_expression_t *expression)
        if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
                /* TODO: improve error message */
                if (is_type_valid(type_left) && is_type_valid(type_right)) {
-                       errorf(HERE, "operation needs integer types");
+                       errorf(&expression->base.source_position,
+                              "operands of shift operation must have integer types");
                }
                return;
        }
@@ -6781,12 +7349,13 @@ static void semantic_add(binary_expression_t *expression)
 
 static void semantic_sub(binary_expression_t *expression)
 {
-       expression_t *const left            = expression->left;
-       expression_t *const right           = expression->right;
-       type_t       *const orig_type_left  = left->base.type;
-       type_t       *const orig_type_right = right->base.type;
-       type_t       *const type_left       = skip_typeref(orig_type_left);
-       type_t       *const type_right      = skip_typeref(orig_type_right);
+       expression_t            *const left            = expression->left;
+       expression_t            *const right           = expression->right;
+       type_t                  *const orig_type_left  = left->base.type;
+       type_t                  *const orig_type_right = right->base.type;
+       type_t                  *const type_left       = skip_typeref(orig_type_left);
+       type_t                  *const type_right      = skip_typeref(orig_type_right);
+       source_position_t const *const pos             = &expression->base.source_position;
 
        /* ยง 5.6.5 */
        if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
@@ -6803,22 +7372,20 @@ static void semantic_sub(binary_expression_t *expression)
                type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
                type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
                if (!types_compatible(unqual_left, unqual_right)) {
-                       errorf(&expression->base.source_position,
+                       errorf(pos,
                               "subtracting pointers to incompatible types '%T' and '%T'",
                               orig_type_left, orig_type_right);
                } else if (!is_type_object(unqual_left)) {
                        if (is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
-                               warningf(&expression->base.source_position,
-                                        "subtracting pointers to void");
+                               warningf(pos, "subtracting pointers to void");
                        } else {
-                               errorf(&expression->base.source_position,
-                                      "subtracting pointers to non-object types '%T'",
+                               errorf(pos, "subtracting pointers to non-object types '%T'",
                                       orig_type_left);
                        }
                }
                expression->base.type = type_ptrdiff_t;
        } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
-               errorf(HERE, "invalid operands of types '%T' and '%T' to binary '-'",
+               errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
                       orig_type_left, orig_type_right);
        }
 }
@@ -6979,7 +7546,8 @@ static void semantic_arithmetic_assign(binary_expression_t *expression)
        if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
                /* TODO: improve error message */
                if (is_type_valid(type_left) && is_type_valid(type_right)) {
-                       errorf(HERE, "operation needs arithmetic types");
+                       errorf(&expression->base.source_position,
+                              "operation needs arithmetic types");
                }
                return;
        }
@@ -7018,7 +7586,9 @@ static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
                                         type_left, orig_type_left);
                expression->base.type = type_left;
        } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
-               errorf(HERE, "incompatible types '%T' and '%T' in assignment", orig_type_left, orig_type_right);
+               errorf(&expression->base.source_position,
+                      "incompatible types '%T' and '%T' in assignment",
+                      orig_type_left, orig_type_right);
        }
 }
 
@@ -7037,7 +7607,8 @@ static void semantic_logical_op(binary_expression_t *expression)
        if (!is_type_scalar(type_left) || !is_type_scalar(type_right)) {
                /* TODO: improve error message */
                if (is_type_valid(type_left) && is_type_valid(type_right)) {
-                       errorf(HERE, "operation needs scalar types");
+                       errorf(&expression->base.source_position,
+                              "operation needs scalar types");
                }
                return;
        }
@@ -7214,14 +7785,13 @@ static void semantic_comma(binary_expression_t *expression)
 static expression_t *parse_##binexpression_type(unsigned precedence,      \
                                                 expression_t *left)       \
 {                                                                         \
+       expression_t *binexpr = allocate_expression_zero(binexpression_type); \
+       binexpr->base.source_position = *HERE;                                \
+       binexpr->binary.left          = left;                                 \
        eat(token_type);                                                      \
-       source_position_t pos = *HERE;                                        \
                                                                           \
        expression_t *right = parse_sub_expression(precedence + lr);          \
                                                                           \
-       expression_t *binexpr = allocate_expression_zero(binexpression_type); \
-       binexpr->base.source_position = pos;                                  \
-       binexpr->binary.left  = left;                                         \
        binexpr->binary.right = right;                                        \
        sfunc(&binexpr->binary);                                              \
                                                                           \
@@ -7639,59 +8209,83 @@ static statement_t *parse_case_statement(void)
 {
        eat(T_case);
 
-       statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
+       statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
+       source_position_t *const pos       = &statement->base.source_position;
 
-       statement->base.source_position  = token.source_position;
+       *pos                             = token.source_position;
        statement->case_label.expression = parse_expression();
+       if (! is_constant_expression(statement->case_label.expression)) {
+               errorf(pos, "case label does not reduce to an integer constant");
+               statement->case_label.is_bad = true;
+       } else {
+               long const val = fold_constant(statement->case_label.expression);
+               statement->case_label.first_case = val;
+               statement->case_label.last_case  = val;
+       }
 
        if (c_mode & _GNUC) {
                if (token.type == T_DOTDOTDOT) {
                        next_token();
                        statement->case_label.end_range = parse_expression();
+                       if (! is_constant_expression(statement->case_label.end_range)) {
+                               errorf(pos, "case range does not reduce to an integer constant");
+                               statement->case_label.is_bad = true;
+                       } else {
+                               long const val = fold_constant(statement->case_label.end_range);
+                               statement->case_label.last_case = val;
+
+                               if (val < statement->case_label.first_case) {
+                                       statement->case_label.is_empty = true;
+                                       warningf(pos, "empty range specified");
+                               }
+                       }
                }
        }
 
+       PUSH_PARENT(statement);
+
        expect(':');
 
-       if (! is_constant_expression(statement->case_label.expression)) {
-               errorf(&statement->base.source_position,
-                      "case label does not reduce to an integer constant");
-       } else {
-               /* TODO: check if the case label is already known */
-               if (current_switch != NULL) {
-                       /* link all cases into the switch statement */
-                       if (current_switch->last_case == NULL) {
-                               current_switch->first_case =
-                               current_switch->last_case  = &statement->case_label;
-                       } else {
-                               current_switch->last_case->next = &statement->case_label;
+       if (current_switch != NULL) {
+               if (! statement->case_label.is_bad) {
+                       /* Check for duplicate case values */
+                       case_label_statement_t *c = &statement->case_label;
+                       for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
+                               if (l->is_bad || l->is_empty)
+                                       continue;
+
+                               if (c->last_case < l->first_case || c->first_case > l->last_case)
+                                       continue;
+
+                               errorf(pos, "duplicate case value (previously used %P)",
+                                      &l->base.source_position);
+                               break;
                        }
+               }
+               /* link all cases into the switch statement */
+               if (current_switch->last_case == NULL) {
+                       current_switch->first_case      = &statement->case_label;
                } else {
-                       errorf(&statement->base.source_position,
-                              "case label not within a switch statement");
+                       current_switch->last_case->next = &statement->case_label;
                }
+               current_switch->last_case = &statement->case_label;
+       } else {
+               errorf(pos, "case label not within a switch statement");
        }
-       statement->case_label.statement = parse_statement();
 
+       statement_t *const inner_stmt = parse_statement();
+       statement->case_label.statement = inner_stmt;
+       if (inner_stmt->kind == STATEMENT_DECLARATION) {
+               errorf(&inner_stmt->base.source_position, "declaration after case label");
+       }
+
+       POP_PARENT;
        return statement;
 end_error:
+       POP_PARENT;
        return create_invalid_statement();
 }
 
-/**
- * Finds an existing default label of a switch statement.
- */
-static case_label_statement_t *
-find_default_label(const switch_statement_t *statement)
-{
-       case_label_statement_t *label = statement->first_case;
-       for ( ; label != NULL; label = label->next) {
-               if (label->expression == NULL)
-                       return label;
-       }
-       return NULL;
-}
-
 /**
  * Parse a default statement.
  */
@@ -7700,32 +8294,42 @@ static statement_t *parse_default_statement(void)
        eat(T_default);
 
        statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
-
        statement->base.source_position = token.source_position;
 
+       PUSH_PARENT(statement);
+
        expect(':');
        if (current_switch != NULL) {
-               const case_label_statement_t *def_label = find_default_label(current_switch);
+               const case_label_statement_t *def_label = current_switch->default_label;
                if (def_label != NULL) {
                        errorf(HERE, "multiple default labels in one switch (previous declared %P)",
                               &def_label->base.source_position);
                } else {
+                       current_switch->default_label = &statement->case_label;
+
                        /* link all cases into the switch statement */
                        if (current_switch->last_case == NULL) {
-                               current_switch->first_case =
-                                       current_switch->last_case  = &statement->case_label;
+                               current_switch->first_case      = &statement->case_label;
                        } else {
                                current_switch->last_case->next = &statement->case_label;
                        }
+                       current_switch->last_case = &statement->case_label;
                }
        } else {
                errorf(&statement->base.source_position,
                        "'default' label not within a switch statement");
        }
-       statement->case_label.statement = parse_statement();
 
+       statement_t *const inner_stmt = parse_statement();
+       statement->case_label.statement = inner_stmt;
+       if (inner_stmt->kind == STATEMENT_DECLARATION) {
+               errorf(&inner_stmt->base.source_position, "declaration after default label");
+       }
+
+       POP_PARENT;
        return statement;
 end_error:
+       POP_PARENT;
        return create_invalid_statement();
 }
 
@@ -7766,6 +8370,12 @@ static statement_t *parse_label_statement(void)
 
        declaration_t *label = get_label(symbol);
 
+       statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
+       statement->base.source_position = token.source_position;
+       statement->label.label          = label;
+
+       PUSH_PARENT(statement);
+
        /* if source position is already set then the label is defined twice,
         * otherwise it was just mentioned in a goto so far */
        if (label->source_position.input_name != NULL) {
@@ -7773,13 +8383,9 @@ static statement_t *parse_label_statement(void)
                       symbol, &label->source_position);
        } else {
                label->source_position = token.source_position;
+               label->init.statement  = statement;
        }
 
-       statement_t *statement = allocate_statement_zero(STATEMENT_LABEL);
-
-       statement->base.source_position = token.source_position;
-       statement->label.label          = label;
-
        eat(':');
 
        if (token.type == '}') {
@@ -7798,7 +8404,11 @@ static statement_t *parse_label_statement(void)
                statement->label.statement = create_empty_statement();
                next_token();
        } else {
-               statement->label.statement = parse_statement();
+               statement_t *const inner_stmt = parse_statement();
+               statement->label.statement = inner_stmt;
+               if (inner_stmt->kind == STATEMENT_DECLARATION) {
+                       errorf(&inner_stmt->base.source_position, "declaration after label");
+               }
        }
 
        /* remember the labels in a list for later checking */
@@ -7809,6 +8419,7 @@ static statement_t *parse_label_statement(void)
        }
        label_last = &statement->label;
 
+       POP_PARENT;
        return statement;
 }
 
@@ -7822,6 +8433,8 @@ static statement_t *parse_if(void)
        statement_t *statement          = allocate_statement_zero(STATEMENT_IF);
        statement->base.source_position = token.source_position;
 
+       PUSH_PARENT(statement);
+
        expect('(');
        add_anchor_token(')');
        statement->ifs.condition = parse_expression();
@@ -7837,11 +8450,53 @@ static statement_t *parse_if(void)
                statement->ifs.false_statement = parse_statement();
        }
 
+       POP_PARENT;
        return statement;
 end_error:
+       POP_PARENT;
        return create_invalid_statement();
 }
 
+/**
+ * Check that all enums are handled in a switch.
+ *
+ * @param statement  the switch statement to check
+ */
+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;
+       const enum_type_t *enumt = &type->enumt;
+
+       /* if we have a default, no warnings */
+       if (statement->default_label != NULL)
+               return;
+
+       /* FIXME: calculation of value should be done while parsing */
+       const declaration_t *declaration;
+       long last_value = -1;
+       for (declaration = enumt->declaration->next;
+            declaration != NULL && declaration->storage_class == STORAGE_CLASS_ENUM_ENTRY;
+                declaration = declaration->next) {
+               const expression_t *expression = declaration->init.enum_value;
+               long                value      = expression != NULL ? fold_constant(expression) : last_value + 1;
+               bool                found      = false;
+               for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
+                       if (l->expression == NULL)
+                               continue;
+                       if (l->first_case <= value && value <= l->last_case) {
+                               found = true;
+                               break;
+                       }
+               }
+               if (! found) {
+                       warningf(&statement->base.source_position,
+                               "enumeration value '%Y' not handled in switch", declaration->symbol);
+               }
+               last_value = value;
+       }
+}
+
 /**
  * Parse a switch statement.
  */
@@ -7852,7 +8507,10 @@ static statement_t *parse_switch(void)
        statement_t *statement          = allocate_statement_zero(STATEMENT_SWITCH);
        statement->base.source_position = token.source_position;
 
+       PUSH_PARENT(statement);
+
        expect('(');
+       add_anchor_token(')');
        expression_t *const expr = parse_expression();
        type_t       *      type = skip_typeref(expr->base.type);
        if (is_type_integer(type)) {
@@ -7864,6 +8522,7 @@ static statement_t *parse_switch(void)
        }
        statement->switchs.expression = create_implicit_cast(expr, type);
        expect(')');
+       rem_anchor_token(')');
 
        switch_statement_t *rem = current_switch;
        current_switch          = &statement->switchs;
@@ -7871,12 +8530,16 @@ static statement_t *parse_switch(void)
        current_switch          = rem;
 
        if (warning.switch_default &&
-          find_default_label(&statement->switchs) == NULL) {
+           statement->switchs.default_label == NULL) {
                warningf(&statement->base.source_position, "switch has no default case");
        }
+       if (warning.switch_enum)
+               check_enum_cases(&statement->switchs);
 
+       POP_PARENT;
        return statement;
 end_error:
+       POP_PARENT;
        return create_invalid_statement();
 }
 
@@ -7901,6 +8564,8 @@ static statement_t *parse_while(void)
        statement_t *statement          = allocate_statement_zero(STATEMENT_WHILE);
        statement->base.source_position = token.source_position;
 
+       PUSH_PARENT(statement);
+
        expect('(');
        add_anchor_token(')');
        statement->whiles.condition = parse_expression();
@@ -7909,8 +8574,10 @@ static statement_t *parse_while(void)
 
        statement->whiles.body = parse_loop_body(statement);
 
+       POP_PARENT;
        return statement;
 end_error:
+       POP_PARENT;
        return create_invalid_statement();
 }
 
@@ -7922,9 +8589,10 @@ static statement_t *parse_do(void)
        eat(T_do);
 
        statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
-
        statement->base.source_position = token.source_position;
 
+       PUSH_PARENT(statement)
+
        add_anchor_token(T_while);
        statement->do_while.body = parse_loop_body(statement);
        rem_anchor_token(T_while);
@@ -7937,8 +8605,10 @@ static statement_t *parse_do(void)
        expect(')');
        expect(';');
 
+       POP_PARENT;
        return statement;
 end_error:
+       POP_PARENT;
        return create_invalid_statement();
 }
 
@@ -7952,6 +8622,8 @@ static statement_t *parse_for(void)
        statement_t *statement          = allocate_statement_zero(STATEMENT_FOR);
        statement->base.source_position = token.source_position;
 
+       PUSH_PARENT(statement);
+
        int      top        = environment_top();
        scope_t *last_scope = scope;
        set_scope(&statement->fors.scope);
@@ -7999,9 +8671,11 @@ static statement_t *parse_for(void)
        set_scope(last_scope);
        environment_pop_to(top);
 
+       POP_PARENT;
        return statement;
 
 end_error:
+       POP_PARENT;
        rem_anchor_token(')');
        assert(scope == &statement->fors.scope);
        set_scope(last_scope);
@@ -8321,8 +8995,9 @@ static statement_t *parse_empty_statement(void)
        if (warning.empty_statement) {
                warningf(HERE, "statement is empty");
        }
+       statement_t *const statement = create_empty_statement();
        eat(';');
-       return create_empty_statement();
+       return statement;
 }
 
 /**
@@ -8413,9 +9088,10 @@ static statement_t *parse_statement(void)
 static statement_t *parse_compound_statement(bool inside_expression_statement)
 {
        statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
-
        statement->base.source_position = token.source_position;
 
+       PUSH_PARENT(statement);
+
        eat('{');
        add_anchor_token('}');
 
@@ -8423,8 +9099,8 @@ static statement_t *parse_compound_statement(bool inside_expression_statement)
        scope_t *last_scope = scope;
        set_scope(&statement->compound.scope);
 
-       statement_t *last_statement = NULL;
-
+       statement_t **anchor            = &statement->compound.statements;
+       bool          only_decls_so_far = true;
        while (token.type != '}' && token.type != T_EOF) {
                statement_t *sub_statement = intern_parse_statement();
                if (is_invalid_statement(sub_statement)) {
@@ -8434,16 +9110,21 @@ static statement_t *parse_compound_statement(bool inside_expression_statement)
                        continue;
                }
 
-               if (last_statement != NULL) {
-                       last_statement->base.next = sub_statement;
-               } else {
-                       statement->compound.statements = sub_statement;
+               if (warning.declaration_after_statement) {
+                       if (sub_statement->kind != STATEMENT_DECLARATION) {
+                               only_decls_so_far = false;
+                       } else if (!only_decls_so_far) {
+                               warningf(&sub_statement->base.source_position,
+                                        "ISO C90 forbids mixed declarations and code");
+                       }
                }
 
+               *anchor = sub_statement;
+
                while (sub_statement->base.next != NULL)
                        sub_statement = sub_statement->base.next;
 
-               last_statement = sub_statement;
+               anchor = &sub_statement->base.next;
        }
 
        if (token.type == '}') {
@@ -8478,6 +9159,7 @@ end_error:
        set_scope(last_scope);
        environment_pop_to(top);
 
+       POP_PARENT;
        return statement;
 }
 
@@ -8492,13 +9174,20 @@ static void initialize_builtin_types(void)
        type_ptrdiff_t   = make_global_typedef("__PTRDIFF_TYPE__",  type_long);
        type_uintmax_t   = make_global_typedef("__uintmax_t__",     type_unsigned_long_long);
        type_uptrdiff_t  = make_global_typedef("__UPTRDIFF_TYPE__", type_unsigned_long);
-       type_wchar_t     = make_global_typedef("__WCHAR_TYPE__",    type_int);
+       type_wchar_t     = make_global_typedef("__WCHAR_TYPE__",    opt_short_wchar_t ? type_unsigned_short : type_int);
        type_wint_t      = make_global_typedef("__WINT_TYPE__",     type_int);
 
        type_intmax_t_ptr  = make_pointer_type(type_intmax_t,  TYPE_QUALIFIER_NONE);
        type_ptrdiff_t_ptr = make_pointer_type(type_ptrdiff_t, TYPE_QUALIFIER_NONE);
        type_ssize_t_ptr   = make_pointer_type(type_ssize_t,   TYPE_QUALIFIER_NONE);
        type_wchar_t_ptr   = make_pointer_type(type_wchar_t,   TYPE_QUALIFIER_NONE);
+
+       /* const version of wchar_t */
+       type_const_wchar_t = allocate_type_zero(TYPE_TYPEDEF, &builtin_source_position);
+       type_const_wchar_t->typedeft.declaration  = type_wchar_t->typedeft.declaration;
+       type_const_wchar_t->base.qualifiers      |= TYPE_QUALIFIER_CONST;
+
+       type_const_wchar_t_ptr = make_pointer_type(type_const_wchar_t, TYPE_QUALIFIER_NONE);
 }
 
 /**
@@ -8557,22 +9246,32 @@ end_error:;
  */
 static void parse_translation_unit(void)
 {
-       while (token.type != T_EOF) {
-               switch (token.type) {
-                       case ';':
-                               /* TODO error in strict mode */
-                               warningf(HERE, "stray ';' outside of function");
-                               next_token();
-                               break;
+       for (;;) switch (token.type) {
+               DECLARATION_START
+               case T_IDENTIFIER:
+               case T___extension__:
+                       parse_external_declaration();
+                       break;
 
-                       case T_asm:
-                               parse_global_asm();
-                               break;
+               case T_asm:
+                       parse_global_asm();
+                       break;
 
-                       default:
-                               parse_external_declaration();
-                               break;
-               }
+               case T_EOF:
+                       return;
+
+               case ';':
+                       /* TODO error in strict mode */
+                       warningf(HERE, "stray ';' outside of function");
+                       next_token();
+                       break;
+
+               default:
+                       errorf(HERE, "stray %K outside of function", &token);
+                       if (token.type == '(' || token.type == '{' || token.type == '[')
+                               eat_until_matching_token(token.type);
+                       next_token();
+                       break;
        }
 }