Accept -Wno-all, -Wno-extra and -Wno-unused like GCC.
[cparser] / lexer.c
diff --git a/lexer.c b/lexer.c
index be7360c..7c61082 100644 (file)
--- a/lexer.c
+++ b/lexer.c
@@ -1,52 +1,70 @@
 #include <config.h>
 
-#include "lexer_t.h"
+#include "diagnostic.h"
+#include "lexer.h"
 #include "token_t.h"
 #include "symbol_table_t.h"
 #include "adt/error.h"
+#include "adt/strset.h"
+#include "adt/util.h"
+#include "types.h"
+#include "type_t.h"
+#include "target_architecture.h"
+#include "parser.h"
+#include "warning.h"
 
 #include <assert.h>
 #include <errno.h>
 #include <string.h>
+#include <stdbool.h>
 #include <ctype.h>
 
 //#define DEBUG_CHARS
 #define MAX_PUTBACK 3
 
-static int               c;
-source_position_t source_position;
-static FILE             *input;
-static char              buf[1027];
-static const char       *bufend;
-static const char       *bufpos;
-static strset_t          stringset;
-//static FILE            **input_stack;
-//static char            **buf_stack;
+#ifdef _WIN32
+/* No strtold on windows and no replacement yet */
+#define strtold(s, e) strtod(s, e)
+#endif
+
+#if defined HAS_SIGNED_CHAR
+typedef signed char char_type;
+#elif defined HAS_UNSIGNED_CHAR
+typedef unsigned char char_type;
+#else
+#      error signedness of char not determined
+#endif
+
+static int         c;
+token_t            lexer_token;
+symbol_t          *symbol_L;
+static FILE       *input;
+static char        buf[1024 + MAX_PUTBACK];
+static const char *bufend;
+static const char *bufpos;
+static strset_t    stringset;
 
-static
-void error_prefix_at(const char *input_name, unsigned linenr)
+static void error_prefix_at(const char *input_name, unsigned linenr)
 {
-       fprintf(stderr, "%s:%d: Error: ", input_name, linenr);
+       fprintf(stderr, "%s:%u: Error: ", input_name, linenr);
 }
 
-static
-void error_prefix()
+static void error_prefix(void)
 {
-       error_prefix_at(source_position.input_name, source_position.linenr);
+       error_prefix_at(lexer_token.source_position.input_name,
+                       lexer_token.source_position.linenr);
 }
 
-static
-void parse_error(const char *msg)
+static void parse_error(const char *msg)
 {
        error_prefix();
        fprintf(stderr, "%s\n", msg);
 }
 
-static inline
-void next_char()
+static inline void next_real_char(void)
 {
-       bufpos++;
-       if(bufpos >= bufend) {
+       assert(bufpos <= bufend);
+       if (bufpos >= bufend) {
                size_t s = fread(buf + MAX_PUTBACK, 1, sizeof(buf) - MAX_PUTBACK,
                                 input);
                if(s == 0) {
@@ -56,315 +74,644 @@ void next_char()
                bufpos = buf + MAX_PUTBACK;
                bufend = buf + MAX_PUTBACK + s;
        }
-       c = *(bufpos);
-#ifdef DEBUG_CHARS
-       printf("nchar '%c'\n", c);
-#endif
+       c = *bufpos++;
 }
 
-static inline
-void put_back(int pc)
+static inline void put_back(int pc)
 {
-       char *p = (char*) bufpos - 1;
-       bufpos--;
-       assert(p >= buf);
-       *p = pc;
+       assert(bufpos > buf);
+       *(--bufpos - buf + buf) = (char) pc;
 
 #ifdef DEBUG_CHARS
        printf("putback '%c'\n", pc);
 #endif
 }
 
+static inline void next_char(void);
 
-static
-int replace_trigraph(void)
+#define MATCH_NEWLINE(code)                   \
+       case '\r':                                \
+               next_char();                          \
+               if(c == '\n') {                       \
+                       next_char();                      \
+               }                                     \
+               lexer_token.source_position.linenr++; \
+               code                                  \
+       case '\n':                                \
+               next_char();                          \
+               lexer_token.source_position.linenr++; \
+               code
+
+#define eat(c_type)  do { assert(c == c_type); next_char(); } while(0)
+
+static void maybe_concat_lines(void)
 {
-#define MATCH_TRIGRAPH(ch,replacement)           \
-       case ch:                                     \
-               c = replacement;                         \
-               return 1;
+       eat('\\');
 
        switch(c) {
-       MATCH_TRIGRAPH('=', '#')
-       MATCH_TRIGRAPH('(', '[')
-       MATCH_TRIGRAPH('/', '\\')
-       MATCH_TRIGRAPH(')', ']')
-       MATCH_TRIGRAPH('\'', '^')
-       MATCH_TRIGRAPH('<', '{')
-       MATCH_TRIGRAPH('!', '|')
-       MATCH_TRIGRAPH('>', '}')
-       MATCH_TRIGRAPH('-', '~')
+       MATCH_NEWLINE(return;)
+
        default:
                break;
        }
 
-       return 0;
-}
-
-#define SKIP_TRIGRAPHS(custom_putback, no_trigraph_code) \
-       case '?':                                  \
-               next_char();                           \
-               if(c != '?') {                         \
-                       custom_putback;                    \
-                       put_back(c);                       \
-                       c = '?';                           \
-                       no_trigraph_code;                  \
-               }                                      \
-               next_char();                           \
-               if(replace_trigraph()) {               \
-                       break;                             \
-               }                                      \
-               custom_putback;                        \
-               put_back('?');                         \
-               put_back(c);                           \
-               c = '?';                               \
-               no_trigraph_code;
-
-#define EAT_NEWLINE(newline_code)              \
-       if(c == '\r') {                            \
-               next_char();                           \
-               if(c == '\n')                          \
-                       next_char();                       \
-               source_position.linenr++;              \
-               newline_code;                          \
-       } else if(c == '\n') {                     \
-               next_char();                           \
-               source_position.linenr++;              \
-               newline_code;                          \
-       }
-
-static
-void parse_symbol(token_t *token)
+       put_back(c);
+       c = '\\';
+}
+
+static inline void next_char(void)
+{
+       next_real_char();
+
+       /* filter trigraphs */
+       if(UNLIKELY(c == '\\')) {
+               maybe_concat_lines();
+               goto end_of_next_char;
+       }
+
+       if(LIKELY(c != '?'))
+               goto end_of_next_char;
+
+       next_real_char();
+       if(LIKELY(c != '?')) {
+               put_back(c);
+               c = '?';
+               goto end_of_next_char;
+       }
+
+       next_real_char();
+       switch(c) {
+       case '=': c = '#'; break;
+       case '(': c = '['; break;
+       case '/': c = '\\'; maybe_concat_lines(); break;
+       case ')': c = ']'; break;
+       case '\'': c = '^'; break;
+       case '<': c = '{'; break;
+       case '!': c = '|'; break;
+       case '>': c = '}'; break;
+       case '-': c = '~'; break;
+       default:
+               put_back(c);
+               put_back('?');
+               c = '?';
+               break;
+       }
+
+end_of_next_char:;
+#ifdef DEBUG_CHARS
+       printf("nchar '%c'\n", c);
+#endif
+}
+
+#define SYMBOL_CHARS  \
+       case 'a':         \
+       case 'b':         \
+       case 'c':         \
+       case 'd':         \
+       case 'e':         \
+       case 'f':         \
+       case 'g':         \
+       case 'h':         \
+       case 'i':         \
+       case 'j':         \
+       case 'k':         \
+       case 'l':         \
+       case 'm':         \
+       case 'n':         \
+       case 'o':         \
+       case 'p':         \
+       case 'q':         \
+       case 'r':         \
+       case 's':         \
+       case 't':         \
+       case 'u':         \
+       case 'v':         \
+       case 'w':         \
+       case 'x':         \
+       case 'y':         \
+       case 'z':         \
+       case 'A':         \
+       case 'B':         \
+       case 'C':         \
+       case 'D':         \
+       case 'E':         \
+       case 'F':         \
+       case 'G':         \
+       case 'H':         \
+       case 'I':         \
+       case 'J':         \
+       case 'K':         \
+       case 'L':         \
+       case 'M':         \
+       case 'N':         \
+       case 'O':         \
+       case 'P':         \
+       case 'Q':         \
+       case 'R':         \
+       case 'S':         \
+       case 'T':         \
+       case 'U':         \
+       case 'V':         \
+       case 'W':         \
+       case 'X':         \
+       case 'Y':         \
+       case 'Z':         \
+       case '_':
+
+#define DIGITS        \
+       case '0':         \
+       case '1':         \
+       case '2':         \
+       case '3':         \
+       case '4':         \
+       case '5':         \
+       case '6':         \
+       case '7':         \
+       case '8':         \
+       case '9':
+
+static void parse_symbol(void)
 {
        symbol_t *symbol;
        char     *string;
 
-       obstack_1grow(&symbol_obstack, c);
+       obstack_1grow(&symbol_obstack, (char) c);
        next_char();
 
        while(1) {
                switch(c) {
-               case '\\':
-                       next_char();
-                       EAT_NEWLINE(break;)
-                       goto end_symbol;
-
-               case 'A' ... 'Z':
-               case 'a' ... 'z':
-               case '_':
-                       obstack_1grow(&symbol_obstack, c);
+               DIGITS
+               SYMBOL_CHARS
+                       obstack_1grow(&symbol_obstack, (char) c);
                        next_char();
                        break;
 
-               case '?':
-                       next_char();
-                       if(c != '?') {
-                               put_back(c);
-                               c = '?';
-                               goto end_symbol;
-                       }
-                       next_char();
-                       if(replace_trigraph())
-                               break;
-                       put_back('?');
-                       put_back(c);
-                       c = '?';
-                       goto end_symbol;
-
                default:
                        goto end_symbol;
                }
        }
+
 end_symbol:
        obstack_1grow(&symbol_obstack, '\0');
 
        string = obstack_finish(&symbol_obstack);
        symbol = symbol_table_insert(string);
 
-#if 0
-       if(symbol->ID > 0) {
-               token->type = symbol->ID;
-       } else {
-               token->type = T_IDENTIFIER;
-       }
-#endif
-       token->type     = T_IDENTIFIER;
-       token->v.symbol = symbol;
+       lexer_token.type     = symbol->ID;
+       lexer_token.v.symbol = symbol;
 
        if(symbol->string != string) {
                obstack_free(&symbol_obstack, string);
        }
 }
 
-static
-void parse_number_hex(token_t *token)
+static void parse_integer_suffix(bool is_oct_hex)
 {
-       assert(c == 'x' || c == 'X');
-       next_char();
+       bool is_unsigned  = false;
+       bool min_long     = false;
+       bool min_longlong = false;
 
-       if (!isdigit(c) &&
-               !('A' <= c && c <= 'F') &&
-               !('a' <= c && c <= 'f')) {
-               parse_error("premature end of hex number literal");
-               token->type = T_ERROR;
-               return;
+       if(c == 'U' || c == 'u') {
+               is_unsigned = true;
+               next_char();
+               if(c == 'L' || c == 'l') {
+                       min_long = true;
+                       next_char();
+                       if(c == 'L' || c == 'l') {
+                               min_longlong = true;
+                               next_char();
+                       }
+               }
+       } else if(c == 'l' || c == 'L') {
+               min_long = true;
+               next_char();
+               if(c == 'l' || c == 'L') {
+                       min_longlong = true;
+                       next_char();
+                       if(c == 'u' || c == 'U') {
+                               is_unsigned = true;
+                               next_char();
+                       }
+               } else if(c == 'u' || c == 'U') {
+                       is_unsigned = true;
+                       next_char();
+                       lexer_token.datatype = type_unsigned_long;
+               }
        }
 
-       int value = 0;
-       for(;;) {
-               if (isdigit(c)) {
-                       value = 16 * value + c - '0';
-               } else if ('A' <= c && c <= 'F') {
-                       value = 16 * value + c - 'A' + 10;
-               } else if ('a' <= c && c <= 'f') {
-                       value = 16 * value + c - 'a' + 10;
-               } else {
-                       token->type     = T_INTEGER;
-                       token->v.intvalue = value;
+       if(!is_unsigned) {
+               long long v = lexer_token.v.intvalue;
+               if(!min_long) {
+                       if(v >= TARGET_INT_MIN && v <= TARGET_INT_MAX) {
+                               lexer_token.datatype = type_int;
+                               return;
+                       } else if(is_oct_hex && v >= 0 && v <= TARGET_UINT_MAX) {
+                               lexer_token.datatype = type_unsigned_int;
+                               return;
+                       }
+               }
+               if(!min_longlong) {
+                       if(v >= TARGET_LONG_MIN && v <= TARGET_LONG_MAX) {
+                               lexer_token.datatype = type_long;
+                               return;
+                       } else if(is_oct_hex && v >= 0 && v <= TARGET_ULONG_MAX) {
+                               lexer_token.datatype = type_unsigned_long;
+                               return;
+                       }
+               }
+               unsigned long long uv = (unsigned long long) v;
+               if(is_oct_hex && uv > (unsigned long long) TARGET_LONGLONG_MAX) {
+                       lexer_token.datatype = type_unsigned_long_long;
+                       return;
+               }
+
+               lexer_token.datatype = type_long_long;
+       } else {
+               unsigned long long v = (unsigned long long) lexer_token.v.intvalue;
+               if(!min_long && v <= TARGET_UINT_MAX) {
+                       lexer_token.datatype = type_unsigned_int;
                        return;
                }
+               if(!min_longlong && v <= TARGET_ULONG_MAX) {
+                       lexer_token.datatype = type_unsigned_long;
+                       return;
+               }
+               lexer_token.datatype = type_unsigned_long_long;
+       }
+}
+
+static void parse_floating_suffix(void)
+{
+       switch(c) {
+       /* TODO: do something usefull with the suffixes... */
+       case 'f':
+       case 'F':
                next_char();
+               lexer_token.datatype = type_float;
+               break;
+       case 'l':
+       case 'L':
+               next_char();
+               lexer_token.datatype = type_long_double;
+               break;
+       default:
+               lexer_token.datatype = type_double;
+               break;
+       }
+}
+
+/**
+ * A replacement for strtoull. Only those parts needed for
+ * our parser are implemented.
+ */
+static unsigned long long parse_int_string(const char *s, const char **endptr, int base) {
+       unsigned long long v = 0;
+
+       switch (base) {
+       case 16:
+               for (;; ++s) {
+                       /* check for overrun */
+                       if (v >= 0x1000000000000000ULL)
+                               break;
+                       switch (tolower(*s)) {
+                       case '0': v <<= 4; break;
+                       case '1': v <<= 4; v |= 0x1; break;
+                       case '2': v <<= 4; v |= 0x2; break;
+                       case '3': v <<= 4; v |= 0x3; break;
+                       case '4': v <<= 4; v |= 0x4; break;
+                       case '5': v <<= 4; v |= 0x5; break;
+                       case '6': v <<= 4; v |= 0x6; break;
+                       case '7': v <<= 4; v |= 0x7; break;
+                       case '8': v <<= 4; v |= 0x8; break;
+                       case '9': v <<= 4; v |= 0x9; break;
+                       case 'a': v <<= 4; v |= 0xa; break;
+                       case 'b': v <<= 4; v |= 0xb; break;
+                       case 'c': v <<= 4; v |= 0xc; break;
+                       case 'd': v <<= 4; v |= 0xd; break;
+                       case 'e': v <<= 4; v |= 0xe; break;
+                       case 'f': v <<= 4; v |= 0xf; break;
+                       default:
+                               goto end;
+                       }
+               }
+               break;
+       case 8:
+               for (;; ++s) {
+                       /* check for overrun */
+                       if (v >= 0x2000000000000000ULL)
+                               break;
+                       switch (tolower(*s)) {
+                       case '0': v <<= 3; break;
+                       case '1': v <<= 3; v |= 1; break;
+                       case '2': v <<= 3; v |= 2; break;
+                       case '3': v <<= 3; v |= 3; break;
+                       case '4': v <<= 3; v |= 4; break;
+                       case '5': v <<= 3; v |= 5; break;
+                       case '6': v <<= 3; v |= 6; break;
+                       case '7': v <<= 3; v |= 7; break;
+                       default:
+                               goto end;
+                       }
+               }
+               break;
+       case 10:
+               for (;; ++s) {
+                       /* check for overrun */
+                       if (v > 0x1999999999999999ULL)
+                               break;
+                       switch (tolower(*s)) {
+                       case '0': v *= 10; break;
+                       case '1': v *= 10; v += 1; break;
+                       case '2': v *= 10; v += 2; break;
+                       case '3': v *= 10; v += 3; break;
+                       case '4': v *= 10; v += 4; break;
+                       case '5': v *= 10; v += 5; break;
+                       case '6': v *= 10; v += 6; break;
+                       case '7': v *= 10; v += 7; break;
+                       case '8': v *= 10; v += 8; break;
+                       case '9': v *= 10; v += 9; break;
+                       default:
+                               goto end;
+                       }
+               }
+               break;
+       default:
+               assert(0);
+               break;
        }
+end:
+       *endptr = s;
+       return v;
 }
 
-static
-void parse_number_oct(token_t *token)
+static void parse_number_hex(void)
 {
-       assert(c == 'o' || c == 'O');
+       assert(c == 'x' || c == 'X');
        next_char();
 
-       int value = 0;
-       for(;;) {
-               if ('0' <= c && c <= '7') {
-                       value = 8 * value + c - '0';
-               } else {
-                       token->type     = T_INTEGER;
-                       token->v.intvalue = value;
-                       return;
-               }
+       while(isxdigit(c)) {
+               obstack_1grow(&symbol_obstack, (char) c);
+               next_char();
+       }
+       obstack_1grow(&symbol_obstack, '\0');
+       char *string = obstack_finish(&symbol_obstack);
+
+       if(c == '.' || c == 'p' || c == 'P') {
                next_char();
+               panic("Hex floating point numbers not implemented yet");
        }
+       if(*string == '\0') {
+               parse_error("invalid hex number");
+               lexer_token.type = T_ERROR;
+       }
+
+       const char *endptr;
+       lexer_token.type       = T_INTEGER;
+       lexer_token.v.intvalue = parse_int_string(string, &endptr, 16);
+       if(*endptr != '\0') {
+               parse_error("hex number literal too long");
+       }
+
+       obstack_free(&symbol_obstack, string);
+       parse_integer_suffix(true);
 }
 
-static
-void parse_number_dec(token_t *token, int first_char)
+static inline bool is_octal_digit(int chr)
 {
-       int value = 0;
-       if(first_char > 0) {
-               assert(first_char >= '0' && first_char <= '9');
-               value = first_char - '0';
+       return '0' <= chr && chr <= '7';
+}
+
+static void parse_number_oct(void)
+{
+       while(is_octal_digit(c)) {
+               obstack_1grow(&symbol_obstack, (char) c);
+               next_char();
        }
+       obstack_1grow(&symbol_obstack, '\0');
+       char *string = obstack_finish(&symbol_obstack);
 
-       for(;;) {
-               if (isdigit(c)) {
-                       value = 10 * value + c - '0';
-               } else {
-                       token->type     = T_INTEGER;
-                       token->v.intvalue = value;
-                       return;
+       const char *endptr;
+       lexer_token.type       = T_INTEGER;
+       lexer_token.v.intvalue = parse_int_string(string, &endptr, 8);
+       if(*endptr != '\0') {
+               parse_error("octal number literal too long");
+       }
+
+       obstack_free(&symbol_obstack, string);
+       parse_integer_suffix(true);
+}
+
+static void parse_number_dec(void)
+{
+       bool is_float = false;
+       while(isdigit(c)) {
+               obstack_1grow(&symbol_obstack, (char) c);
+               next_char();
+       }
+
+       if(c == '.') {
+               obstack_1grow(&symbol_obstack, '.');
+               next_char();
+
+               while(isdigit(c)) {
+                       obstack_1grow(&symbol_obstack, (char) c);
+                       next_char();
                }
+               is_float = true;
+       }
+       if(c == 'e' || c == 'E') {
+               obstack_1grow(&symbol_obstack, 'e');
                next_char();
+
+               if(c == '-' || c == '+') {
+                       obstack_1grow(&symbol_obstack, (char) c);
+                       next_char();
+               }
+
+               while(isdigit(c)) {
+                       obstack_1grow(&symbol_obstack, (char) c);
+                       next_char();
+               }
+               is_float = true;
+       }
+
+       obstack_1grow(&symbol_obstack, '\0');
+       char *string = obstack_finish(&symbol_obstack);
+
+       if(is_float) {
+               char *endptr;
+               lexer_token.type         = T_FLOATINGPOINT;
+               lexer_token.v.floatvalue = strtold(string, &endptr);
+
+               if(*endptr != '\0') {
+                       parse_error("invalid number literal");
+               }
+
+               parse_floating_suffix();
+       } else {
+               const char *endptr;
+               lexer_token.type       = T_INTEGER;
+               lexer_token.v.intvalue = parse_int_string(string, &endptr, 10);
+
+               if(*endptr != '\0') {
+                       parse_error("invalid number literal");
+               }
+
+               parse_integer_suffix(false);
        }
+       obstack_free(&symbol_obstack, string);
 }
 
-static
-void parse_number(token_t *token)
+static void parse_number(void)
 {
-       // TODO check for overflow
-       // TODO check for various invalid inputs sequences
-
        if (c == '0') {
                next_char();
                switch (c) {
                        case 'X':
-                       case 'x': parse_number_hex(token); break;
-                       case 'o':
-                       case 'O': parse_number_oct(token); break;
-                       default:  parse_number_dec(token, '0');
+                       case 'x':
+                               parse_number_hex();
+                               break;
+                       case '0':
+                       case '1':
+                       case '2':
+                       case '3':
+                       case '4':
+                       case '5':
+                       case '6':
+                       case '7':
+                               parse_number_oct();
+                               break;
+                       case '8':
+                       case '9':
+                               next_char();
+                               parse_error("invalid octal number");
+                               lexer_token.type = T_ERROR;
+                               return;
+                       case '.':
+                       case 'e':
+                       case 'E':
+                       default:
+                               obstack_1grow(&symbol_obstack, '0');
+                               parse_number_dec();
+                               return;
                }
        } else {
-               parse_number_dec(token, 0);
+               parse_number_dec();
        }
 }
 
-static
-int parse_escape_sequence()
+static int parse_octal_sequence(const int first_digit)
+{
+       assert(is_octal_digit(first_digit));
+       int value = first_digit - '0';
+       if (!is_octal_digit(c)) return value;
+       value = 8 * value + c - '0';
+       next_char();
+       if (!is_octal_digit(c)) return value;
+       value = 8 * value + c - '0';
+       next_char();
+       return (char_type)value;
+}
+
+static int parse_hex_sequence(void)
 {
+       int value = 0;
        while(1) {
-               int ec = c;
+               if (c >= '0' && c <= '9') {
+                       value = 16 * value + c - '0';
+               } else if ('A' <= c && c <= 'F') {
+                       value = 16 * value + c - 'A' + 10;
+               } else if ('a' <= c && c <= 'f') {
+                       value = 16 * value + c - 'a' + 10;
+               } else {
+                       break;
+               }
                next_char();
+       }
 
-               switch(ec) {
-               case '"': return '"';
-               case '\'': return'\'';
-               case '\\':
-                       EAT_NEWLINE(break;)
-                       return '\\';
-               case 'a': return '\a';
-               case 'b': return '\b';
-               case 'f': return '\f';
-               case 'n': return '\n';
-               case 'r': return '\r';
-               case 't': return '\t';
-               case 'v': return '\v';
-               case 'x': /* TODO parse hex number ... */
-                       parse_error("hex escape sequences not implemented yet");
-                       return EOF;
-               case 0 ... 8: /* TODO parse octal number ... */
-                       parse_error("octal escape sequences not implemented yet");
-                       return EOF;
-               case '?':
-                       if(c != '?') {
-                               return '?';
-                       }
-                       /* might be a trigraph */
-                       next_char();
-                       if(replace_trigraph()) {
-                               break;
-                       }
-                       put_back(c);
-                       c = '?';
-                       return '?';
+       return (char_type)value;
+}
 
-               case EOF:
-                       parse_error("reached end of file while parsing escape sequence");
-                       return EOF;
-               default:
-                       parse_error("unknown escape sequence");
-                       return EOF;
-               }
+static int parse_escape_sequence(void)
+{
+       eat('\\');
+
+       int ec = c;
+       next_char();
+
+       switch(ec) {
+       case '"':  return '"';
+       case '\'': return '\'';
+       case '\\': return '\\';
+       case '?': return '\?';
+       case 'a': return '\a';
+       case 'b': return '\b';
+       case 'f': return '\f';
+       case 'n': return '\n';
+       case 'r': return '\r';
+       case 't': return '\t';
+       case 'v': return '\v';
+       case 'x':
+               return parse_hex_sequence();
+       case '0':
+       case '1':
+       case '2':
+       case '3':
+       case '4':
+       case '5':
+       case '6':
+       case '7':
+               return parse_octal_sequence(ec);
+       case EOF:
+               parse_error("reached end of file while parsing escape sequence");
+               return EOF;
+       default:
+               parse_error("unknown escape sequence");
+               return EOF;
        }
 }
 
-static
-void parse_string_literal(token_t *token)
+string_t concat_strings(const string_t *const s1, const string_t *const s2)
 {
-       unsigned    start_linenr = source_position.linenr;
-       char       *string;
-       const char *result;
+       const size_t len1 = s1->size - 1;
+       const size_t len2 = s2->size - 1;
+
+       char *const concat = obstack_alloc(&symbol_obstack, len1 + len2 + 1);
+       memcpy(concat, s1->begin, len1);
+       memcpy(concat + len1, s2->begin, len2 + 1);
+
+#if 0 /* TODO hash */
+       const char *result = strset_insert(&stringset, concat);
+       if(result != concat) {
+               obstack_free(&symbol_obstack, concat);
+       }
+
+       return result;
+#else
+       return (string_t){ concat, len1 + len2 + 1 };
+#endif
+}
+
+static void parse_string_literal(void)
+{
+       const unsigned start_linenr = lexer_token.source_position.linenr;
 
        assert(c == '"');
        next_char();
 
+       int tc;
        while(1) {
                switch(c) {
-               SKIP_TRIGRAPHS(,
-                       obstack_1grow(&symbol_obstack, '?');
-                       next_char();
-                       break;
-               )
-
                case '\\':
-                       next_char();
-                       EAT_NEWLINE(break;)
-                       int ec = parse_escape_sequence();
-                       obstack_1grow(&symbol_obstack, ec);
+                       tc = parse_escape_sequence();
+                       obstack_1grow(&symbol_obstack, (char) tc);
                        break;
 
                case EOF:
-                       error_prefix_at(source_position.input_name, start_linenr);
+                       error_prefix_at(lexer_token.source_position.input_name,
+                                       start_linenr);
                        fprintf(stderr, "string has no end\n");
-                       token->type = T_ERROR;
+                       lexer_token.type = T_ERROR;
                        return;
 
                case '"':
@@ -372,7 +719,7 @@ void parse_string_literal(token_t *token)
                        goto end_of_string;
 
                default:
-                       obstack_1grow(&symbol_obstack, c);
+                       obstack_1grow(&symbol_obstack, (char) c);
                        next_char();
                        break;
                }
@@ -384,49 +731,33 @@ end_of_string:
 
        /* add finishing 0 to the string */
        obstack_1grow(&symbol_obstack, '\0');
-       string = obstack_finish(&symbol_obstack);
+       const size_t      size   = (size_t)obstack_object_size(&symbol_obstack);
+       const char *const string = obstack_finish(&symbol_obstack);
 
+#if 0 /* TODO hash */
        /* check if there is already a copy of the string */
        result = strset_insert(&stringset, string);
        if(result != string) {
                obstack_free(&symbol_obstack, string);
        }
+#else
+       const char *const result = string;
+#endif
 
-       token->type     = T_STRING_LITERAL;
-       token->v.string = result;
+       lexer_token.type           = T_STRING_LITERAL;
+       lexer_token.v.string.begin = result;
+       lexer_token.v.string.size  = size;
 }
 
-#define MATCH_NEWLINE(code)                 \
-       case '\r':                              \
-               next_char();                        \
-               if(c == '\n') {                     \
-                       next_char();                    \
-               }                                   \
-               source_position.linenr++;           \
-               code;                               \
-       case '\n':                              \
-               next_char();                        \
-               source_position.linenr++;           \
-               code;
-
-static
-void parse_character_constant(token_t *token)
+static void parse_wide_character_constant(void)
 {
-       assert(c == '\'');
-       next_char();
+       eat('\'');
 
        int found_char = 0;
        while(1) {
                switch(c) {
-               SKIP_TRIGRAPHS(,
-                       found_char = '?';
-                       break;
-               )
-
                case '\\':
-                       next_char();
-                       EAT_NEWLINE(break;)
-                       found_char = '\\';
+                       found_char = parse_escape_sequence();
                        break;
 
                MATCH_NEWLINE(
@@ -436,18 +767,18 @@ void parse_character_constant(token_t *token)
 
                case '\'':
                        next_char();
-                       goto end_of_char_constant;
+                       goto end_of_wide_char_constant;
 
                case EOF:
                        parse_error("EOF while parsing character constant");
-                       token->type = T_ERROR;
+                       lexer_token.type = T_ERROR;
                        return;
 
                default:
                        if(found_char != 0) {
                                parse_error("more than 1 characters in character "
                                            "constant");
-                               goto end_of_char_constant;
+                               goto end_of_wide_char_constant;
                        } else {
                                found_char = c;
                                next_char();
@@ -456,96 +787,154 @@ void parse_character_constant(token_t *token)
                }
        }
 
-end_of_char_constant:
-       token->type       = T_INTEGER;
-       token->v.intvalue = found_char;
+end_of_wide_char_constant:
+       lexer_token.type       = T_INTEGER;
+       lexer_token.v.intvalue = found_char;
+       lexer_token.datatype   = type_wchar_t;
 }
 
-static
-void skip_multiline_comment(void)
+static void parse_wide_string_literal(void)
 {
-       unsigned start_linenr = source_position.linenr;
-       int had_star = 0;
+       const unsigned start_linenr = lexer_token.source_position.linenr;
+
+       assert(c == '"');
+       next_char();
 
        while(1) {
                switch(c) {
-               case '*':
-                       next_char();
-                       had_star = 1;
-                       break;
+                       case '\\': {
+                               wchar_rep_t tc = parse_escape_sequence();
+                               obstack_grow(&symbol_obstack, &tc, sizeof(tc));
+                               break;
+                       }
 
-               case '/':
-                       next_char();
-                       if(had_star) {
+                       case EOF:
+                               error_prefix_at(lexer_token.source_position.input_name,
+                                               start_linenr);
+                               fprintf(stderr, "string has no end\n");
+                               lexer_token.type = T_ERROR;
                                return;
+
+                       case '"':
+                               next_char();
+                               goto end_of_string;
+
+                       default: {
+                               wchar_rep_t tc = c;
+                               obstack_grow(&symbol_obstack, &tc, sizeof(tc));
+                               next_char();
+                               break;
                        }
-                       had_star = 0;
-                       break;
+               }
+       }
+
+end_of_string:;
+
+       /* TODO: concatenate multiple strings separated by whitespace... */
 
+       /* add finishing 0 to the string */
+       wchar_rep_t nul = L'\0';
+       obstack_grow(&symbol_obstack, &nul, sizeof(nul));
+       const size_t             size   = (size_t)obstack_object_size(&symbol_obstack) / sizeof(wchar_rep_t);
+       const wchar_rep_t *const string = obstack_finish(&symbol_obstack);
+
+#if 0 /* TODO hash */
+       /* check if there is already a copy of the string */
+       const wchar_rep_t *const result = strset_insert(&stringset, string);
+       if(result != string) {
+               obstack_free(&symbol_obstack, string);
+       }
+#else
+       const wchar_rep_t *const result = string;
+#endif
+
+       lexer_token.type                = T_WIDE_STRING_LITERAL;
+       lexer_token.v.wide_string.begin = result;
+       lexer_token.v.wide_string.size  = size;
+}
+
+static void parse_character_constant(void)
+{
+       eat('\'');
+
+       int found_char = 0;
+       while(1) {
+               switch(c) {
                case '\\':
-                       next_char();
-                       EAT_NEWLINE(break;)
-                       had_star = 0;
+                       found_char = parse_escape_sequence();
                        break;
 
-               case '?':
-                       next_char();
-                       if(c != '?') {
-                               had_star = 0;
-                               break;
-                       }
-                       next_char();
-                       if(replace_trigraph())
-                               break;
-                       put_back(c);
-                       c = '?';
-                       had_star = 0;
-                       /* we don't put back the 2nd ? as the comment text is discarded
-                        * anyway */
+               MATCH_NEWLINE(
+                       parse_error("newline while parsing character constant");
                        break;
+               )
 
-               MATCH_NEWLINE(had_star = 0; break;)
+               case '\'':
+                       next_char();
+                       goto end_of_char_constant;
 
                case EOF:
-                       error_prefix_at(source_position.input_name, start_linenr);
-                       fprintf(stderr, "at end of file while looking for comment end\n");
+                       parse_error("EOF while parsing character constant");
+                       lexer_token.type = T_ERROR;
                        return;
+
                default:
-                       had_star = 0;
-                       next_char();
+                       if(found_char != 0) {
+                               parse_error("more than 1 characters in character "
+                                           "constant");
+                               goto end_of_char_constant;
+                       } else {
+                               found_char = c;
+                               next_char();
+                       }
                        break;
                }
        }
+
+end_of_char_constant:
+       lexer_token.type       = T_INTEGER;
+       lexer_token.v.intvalue = found_char;
+       lexer_token.datatype   = type_int;
 }
 
-static
-void skip_line_comment(void)
+static void skip_multiline_comment(void)
 {
+       unsigned start_linenr = lexer_token.source_position.linenr;
+
        while(1) {
                switch(c) {
-               case '?':
-                       next_char();
-                       if(c != '?')
-                               break;
+               case '*':
                        next_char();
-                       if(replace_trigraph())
-                               break;
-                       put_back('?');
-                       /* we don't put back the 2nd ? as the comment text is discarded
-                        * anyway */
+                       if(c == '/') {
+                               next_char();
+                               return;
+                       }
                        break;
 
-               case '\\':
+               MATCH_NEWLINE(break;)
+
+               case EOF:
+                       error_prefix_at(lexer_token.source_position.input_name,
+                                       start_linenr);
+                       fprintf(stderr, "at end of file while looking for comment end\n");
+                       return;
+
+               default:
                        next_char();
-                       if(c == '\n') {
-                               next_char();
-                               source_position.linenr++;
-                       }
                        break;
+               }
+       }
+}
 
+static void skip_line_comment(void)
+{
+       while(1) {
+               switch(c) {
                case EOF:
-               case '\r':
+                       return;
+
                case '\n':
+               case '\r':
                        return;
 
                default:
@@ -555,17 +944,22 @@ void skip_line_comment(void)
        }
 }
 
-static
-void lexer_next_preprocessing_token(token_t *token);
+static token_t pp_token;
 
-static
-void eat_until_newline(void)
+static inline void next_pp_token(void)
 {
-       /* TODO */
+       lexer_next_preprocessing_token();
+       pp_token = lexer_token;
 }
 
-static
-void error_directive(void)
+static void eat_until_newline(void)
+{
+       while(pp_token.type != '\n' && pp_token.type != T_EOF) {
+               next_pp_token();
+       }
+}
+
+static void error_directive(void)
 {
        error_prefix();
        fprintf(stderr, "#error directive: \n");
@@ -573,37 +967,49 @@ void error_directive(void)
        /* parse pp-tokens until new-line */
 }
 
-static
-void define_directive(void)
+static void define_directive(void)
 {
-       token_t temptoken;
-
-       lexer_next_preprocessing_token(&temptoken);
-       if(temptoken.type != T_IDENTIFIER) {
+       lexer_next_preprocessing_token();
+       if(lexer_token.type != T_IDENTIFIER) {
                parse_error("expected identifier after #define\n");
                eat_until_newline();
        }
 }
 
-static
-void ifdef_directive(int is_ifndef)
+static void ifdef_directive(int is_ifndef)
 {
        (void) is_ifndef;
-       token_t temptoken;
-       lexer_next_preprocessing_token(&temptoken);
+       lexer_next_preprocessing_token();
        //expect_identifier();
        //extect_newline();
 }
 
-static
-void endif_directive(void)
+static void endif_directive(void)
 {
        //expect_newline();
 }
 
-static
-void found_preprocessor_identifier(symbol_t *symbol)
+static void parse_line_directive(void)
+{
+       if(pp_token.type != T_INTEGER) {
+               parse_error("expected integer");
+       } else {
+               lexer_token.source_position.linenr = (unsigned int)(pp_token.v.intvalue - 1);
+               next_pp_token();
+       }
+       if(pp_token.type == T_STRING_LITERAL) {
+               lexer_token.source_position.input_name = pp_token.v.string.begin;
+               next_pp_token();
+       }
+
+       eat_until_newline();
+}
+
+static void parse_preprocessor_identifier(void)
 {
+       assert(pp_token.type == T_IDENTIFIER);
+       symbol_t *symbol = pp_token.v.symbol;
+
        switch(symbol->pp_ID) {
        case TP_include:
                printf("include - enable header name parsing!\n");
@@ -620,29 +1026,40 @@ void found_preprocessor_identifier(symbol_t *symbol)
        case TP_endif:
                endif_directive();
                break;
+       case TP_line:
+               next_pp_token();
+               parse_line_directive();
+               break;
        case TP_if:
        case TP_else:
        case TP_elif:
        case TP_undef:
-       case TP_line:
        case TP_error:
                error_directive();
                break;
        case TP_pragma:
+               if (warning.unknown_pragmas) {
+                       warningf(lexer_token.source_position, "encountered unknown #pragma");
+               }
+               eat_until_newline();
                break;
        }
 }
 
-static
-void parse_preprocessor_directive(token_t *result_token)
+static void parse_preprocessor_directive(void)
 {
-       token_t temptoken;
+       next_pp_token();
 
-       (void) result_token;
-       lexer_next_preprocessing_token(&temptoken);
-       switch(temptoken.type) {
+       switch(pp_token.type) {
        case T_IDENTIFIER:
-               found_preprocessor_identifier(temptoken.v.symbol);
+               parse_preprocessor_identifier();
+               break;
+       case T_INTEGER:
+               parse_line_directive();
+               break;
+       default:
+               parse_error("invalid preprocessor directive");
+               eat_until_newline();
                break;
        }
 }
@@ -655,18 +1072,10 @@ void parse_preprocessor_directive(token_t *result_token)
 #define MAYBE(ch, set_type)                                \
                                case ch:                                   \
                                        next_char();                           \
-                                       token->type = set_type;                \
+                                       lexer_token.type = set_type;           \
                                        return;
 
 #define ELSE_CODE(code)                                    \
-                               SKIP_TRIGRAPHS(,                           \
-                                       code;                                  \
-                               )                                          \
-                                                                                                                  \
-                               case '\\':                                 \
-                                       next_char();                           \
-                                       EAT_NEWLINE(break;)                    \
-                                       /* fallthrough */                      \
                                default:                                   \
                                        code;                                  \
                                }                                          \
@@ -675,12 +1084,11 @@ void parse_preprocessor_directive(token_t *result_token)
 
 #define ELSE(set_type)                                     \
                ELSE_CODE(                                         \
-                       token->type = set_type;                        \
+                       lexer_token.type = set_type;                   \
                        return;                                        \
                )
 
-static
-void eat_whitespace()
+void lexer_next_preprocessing_token(void)
 {
        while(1) {
                switch(c) {
@@ -689,124 +1097,60 @@ void eat_whitespace()
                        next_char();
                        break;
 
-               case '\r':
-               case '\n':
-                       return;
-
-               case '\\':
-                       next_char();
-                       if(c == '\n') {
-                               next_char();
-                               source_position.linenr++;
-                               break;
-                       }
-
-                       put_back(c);
-                       c = '\\';
-                       return;
-
-               SKIP_TRIGRAPHS(,
+               MATCH_NEWLINE(
+                       lexer_token.type = '\n';
                        return;
                )
 
-               case '/':
-                       next_char();
-                       while(1) {
-                               switch(c) {
-                               case '*':
-                                       next_char();
-                                       skip_multiline_comment();
-                                       eat_whitespace();
-                                       return;
-                               case '/':
-                                       next_char();
-                                       skip_line_comment();
-                                       eat_whitespace();
-                                       return;
-
-                               SKIP_TRIGRAPHS(
-                                               put_back('?');
-                                       ,
-                                               c = '/';
-                                               return;
-                               )
-
-                               case '\\':
-                                       next_char();
-                                       EAT_NEWLINE(break;)
-                                       /* fallthrough */
-                               default:
-                                       return;
+               SYMBOL_CHARS
+                       parse_symbol();
+                       /* might be a wide string ( L"string" ) */
+                       if(lexer_token.type == T_IDENTIFIER &&
+                           lexer_token.v.symbol == symbol_L) {
+                           if(c == '"') {
+                                       parse_wide_string_literal();
+                               } else if(c == '\'') {
+                                       parse_wide_character_constant();
                                }
                        }
-                       break;
-
-               default:
-                       return;
-               }
-       }
-}
-
-static
-void lexer_next_preprocessing_token(token_t *token)
-{
-       while(1) {
-               switch(c) {
-               case ' ':
-               case '\t':
-                       next_char();
-                       break;
-
-               MATCH_NEWLINE(
-                       eat_whitespace();
-                       if(c == '#') {
-                               next_char();
-                               parse_preprocessor_directive(token);
-                               return;
-                       }
-                       token->type = '\n';
-                       return;
-               )
-
-               case 'A' ... 'Z':
-               case 'a' ... 'z':
-               case '_':
-                       parse_symbol(token);
                        return;
 
-               case '0' ... '9':
-                       parse_number(token);
+               DIGITS
+                       parse_number();
                        return;
 
                case '"':
-                       parse_string_literal(token);
+                       parse_string_literal();
                        return;
 
                case '\'':
-                       parse_character_constant(token);
-                       return;
-
-               case '\\':
-                       next_char();
-                       if(c == '\n') {
-                               next_char();
-                               source_position.linenr++;
-                               break;
-                       } else {
-                               parse_error("unexpected '\\' found");
-                               token->type = T_ERROR;
-                       }
+                       parse_character_constant();
                        return;
 
                case '.':
                        MAYBE_PROLOG
+                               case '0':
+                               case '1':
+                               case '2':
+                               case '3':
+                               case '4':
+                               case '5':
+                               case '6':
+                               case '7':
+                               case '8':
+                               case '9':
+                                       put_back(c);
+                                       c = '.';
+                                       parse_number_dec();
+                                       return;
+
                                case '.':
                                        MAYBE_PROLOG
                                        MAYBE('.', T_DOTDOTDOT)
                                        ELSE_CODE(
                                                put_back(c);
                                                c = '.';
-                                               token->type = '.';
+                                               lexer_token.type = '.';
                                                return;
                                        )
                        ELSE('.')
@@ -826,6 +1170,7 @@ void lexer_next_preprocessing_token(token_t *token)
                        ELSE('+')
                case '-':
                        MAYBE_PROLOG
+                       MAYBE('>', T_MINUSGREATER)
                        MAYBE('-', T_MINUSMINUS)
                        MAYBE('=', T_MINUSEQUAL)
                        ELSE('-')
@@ -839,12 +1184,12 @@ void lexer_next_preprocessing_token(token_t *token)
                                case '*':
                                        next_char();
                                        skip_multiline_comment();
-                                       lexer_next_preprocessing_token(token);
+                                       lexer_next_preprocessing_token();
                                        return;
                                case '/':
                                        next_char();
                                        skip_line_comment();
-                                       lexer_next_preprocessing_token(token);
+                                       lexer_next_preprocessing_token();
                                        return;
                        ELSE('/')
                case '%':
@@ -859,7 +1204,7 @@ void lexer_next_preprocessing_token(token_t *token)
                                                        ELSE_CODE(
                                                                put_back(c);
                                                                c = '%';
-                                                               token->type = T_PERCENTCOLON;
+                                                               lexer_token.type = T_PERCENTCOLON;
                                                                return;
                                                        )
                                        ELSE(T_PERCENTCOLON)
@@ -868,6 +1213,7 @@ void lexer_next_preprocessing_token(token_t *token)
                        MAYBE_PROLOG
                        MAYBE(':', T_LESSCOLON)
                        MAYBE('%', T_LESSPERCENT)
+                       MAYBE('=', T_LESSEQUAL)
                                case '<':
                                        MAYBE_PROLOG
                                        MAYBE('=', T_LESSLESSEQUAL)
@@ -875,6 +1221,7 @@ void lexer_next_preprocessing_token(token_t *token)
                        ELSE('<')
                case '>':
                        MAYBE_PROLOG
+                       MAYBE('=', T_GREATEREQUAL)
                                case '>':
                                        MAYBE_PROLOG
                                        MAYBE('=', T_GREATERGREATEREQUAL)
@@ -903,22 +1250,6 @@ void lexer_next_preprocessing_token(token_t *token)
                        ELSE('#')
 
                case '?':
-                       next_char();
-                       /* just a simple ? */
-                       if(c != '?') {
-                               token->type = '?';
-                               return;
-                       }
-                       /* might be a trigraph */
-                       next_char();
-                       if(replace_trigraph()) {
-                               break;
-                       }
-                       put_back(c);
-                       c = '?';
-                       token->type = '?';
-                       return;
-
                case '[':
                case ']':
                case '(':
@@ -928,29 +1259,40 @@ void lexer_next_preprocessing_token(token_t *token)
                case '~':
                case ';':
                case ',':
-                       token->type = c;
+               case '\\':
+                       lexer_token.type = c;
                        next_char();
                        return;
 
                case EOF:
-                       token->type = T_EOF;
+                       lexer_token.type = T_EOF;
                        return;
 
                default:
                        next_char();
                        error_prefix();
                        fprintf(stderr, "unknown character '%c' found\n", c);
-                       token->type = T_ERROR;
+                       lexer_token.type = T_ERROR;
                        return;
                }
        }
 }
 
-void lexer_next_token(token_t *token)
+void lexer_next_token(void)
 {
+       lexer_next_preprocessing_token();
+       if(lexer_token.type != '\n')
+               return;
+
+newline_found:
        do {
-               lexer_next_preprocessing_token(token);
-       } while(token->type == '\n');
+               lexer_next_preprocessing_token();
+       } while(lexer_token.type == '\n');
+
+       if(lexer_token.type == '#') {
+               parse_preprocessor_directive();
+               goto newline_found;
+       }
 }
 
 void init_lexer(void)
@@ -960,12 +1302,16 @@ void init_lexer(void)
 
 void lexer_open_stream(FILE *stream, const char *input_name)
 {
-       input                      = stream;
-       source_position.linenr     = 0;
-       source_position.input_name = input_name;
+       input                                  = stream;
+       lexer_token.source_position.linenr     = 0;
+       lexer_token.source_position.input_name = input_name;
+
+       symbol_L = symbol_table_insert("L");
+       bufpos = NULL;
+       bufend = NULL;
 
-       /* we place a virtual '\n' at the beginning so the lexer knows we're at the
-        * beginning of a line */
+       /* place a virtual \n at the beginning so the lexer knows that we're
+        * at the beginning of a line */
        c = '\n';
 }
 
@@ -977,6 +1323,7 @@ void exit_lexer(void)
 static __attribute__((unused))
 void dbg_pos(const source_position_t source_position)
 {
-       fprintf(stdout, "%s:%d\n", source_position.input_name, source_position.linenr);
+       fprintf(stdout, "%s:%u\n", source_position.input_name,
+               source_position.linenr);
        fflush(stdout);
 }