Accept -Wno-all, -Wno-extra and -Wno-unused like GCC.
[cparser] / lexer.c
diff --git a/lexer.c b/lexer.c
index f23cb11..7c61082 100644 (file)
--- a/lexer.c
+++ b/lexer.c
@@ -1,54 +1,70 @@
 #include <config.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
 
+#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 FILE      **input_stack;
-//static char      **buf_stack;
 
-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:%u: Error: ", input_name, linenr);
 }
 
-static
-void error_prefix(void)
+static void error_prefix(void)
 {
        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(void)
+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) {
@@ -58,83 +74,95 @@ void next_char(void)
                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;
+       put_back(c);
+       c = '\\';
 }
 
-#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();                       \
-               lexer_token.source_position.linenr++;  \
-               newline_code;                          \
-       } else if(c == '\n') {                     \
-               next_char();                           \
-               lexer_token.source_position.linenr++;  \
-               newline_code;                          \
+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':         \
@@ -202,47 +230,27 @@ int replace_trigraph(void)
        case '8':         \
        case '9':
 
-static
-void parse_symbol(void)
+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;
-
                DIGITS
                SYMBOL_CHARS
-                       obstack_1grow(&symbol_obstack, c);
+                       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');
 
@@ -257,128 +265,352 @@ end_symbol:
        }
 }
 
-static
-void parse_number_hex(void)
+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");
-               lexer_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;
-       while(1) {
-               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 {
-                       lexer_token.type     = T_INTEGER;
-                       lexer_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;
                }
-               next_char();
+
+               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_number_oct(void)
+static void parse_floating_suffix(void)
 {
-       assert(c == 'o' || c == 'O');
-       next_char();
+       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;
+       }
+}
 
-       int value = 0;
-       while(1) {
-               if ('0' <= c && c <= '7') {
-                       value = 8 * value + c - '0';
-               } else {
-                       lexer_token.type       = T_INTEGER;
-                       lexer_token.v.intvalue = value;
-                       return;
+/**
+ * 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;
+                       }
                }
-               next_char();
+               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_dec(int first_char)
+static void parse_number_hex(void)
 {
-       int value = 0;
-       if(first_char > 0) {
-               assert(first_char >= '0' && first_char <= '9');
-               value = first_char - '0';
+       assert(c == 'x' || c == 'X');
+       next_char();
+
+       while(isxdigit(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 {
-                       lexer_token.type       = T_INTEGER;
-                       lexer_token.v.intvalue = value;
-                       return;
-               }
+       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(void)
+static inline bool is_octal_digit(int chr)
 {
-       // TODO check for overflow
-       // TODO check for various invalid inputs sequences
+       return '0' <= chr && chr <= '7';
+}
 
-       if (c == '0') {
+static void parse_number_oct(void)
+{
+       while(is_octal_digit(c)) {
+               obstack_1grow(&symbol_obstack, (char) c);
                next_char();
-               switch (c) {
-                       case 'X':
-                       case 'x': parse_number_hex(); break;
-                       case 'o':
-                       case 'O': parse_number_oct(); break;
-                       default:  parse_number_dec('0');
-               }
-       } else {
-               parse_number_dec(0);
        }
-       if(c == 'U' || c == 'U') {
-               /* TODO do something with the suffixes... */
+       obstack_1grow(&symbol_obstack, '\0');
+       char *string = obstack_finish(&symbol_obstack);
+
+       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 == 'L' || c == 'l') {
+       }
+
+       if(c == '.') {
+               obstack_1grow(&symbol_obstack, '.');
+               next_char();
+
+               while(isdigit(c)) {
+                       obstack_1grow(&symbol_obstack, (char) c);
                        next_char();
-                       if(c == 'L' || c == 'l') {
-                               next_char();
-                       }
                }
-       } else if(c == 'l' || c == 'L') {
+               is_float = true;
+       }
+       if(c == 'e' || c == 'E') {
+               obstack_1grow(&symbol_obstack, 'e');
                next_char();
-               if(c == 'l' || c == 'L') {
+
+               if(c == '-' || c == '+') {
+                       obstack_1grow(&symbol_obstack, (char) c);
                        next_char();
-                       if(c == 'u' || c == 'U') {
-                               next_char();
-                       }
-               } else if(c == 'u' || c == 'U') {
+               }
+
+               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 int parse_octal_sequence(void)
+static void parse_number(void)
 {
-       int value = 0;
-       while(1) {
-               if(c < '0' || c > '7')
-                       break;
-               value = 8 * value + c - '0';
+       if (c == '0') {
                next_char();
+               switch (c) {
+                       case 'X':
+                       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();
        }
+}
 
-       return value;
+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)
@@ -397,102 +629,82 @@ static int parse_hex_sequence(void)
                next_char();
        }
 
-       return value;
+       return (char_type)value;
 }
 
 static int parse_escape_sequence(void)
 {
-       while(1) {
-               int ec = c;
-               next_char();
+       eat('\\');
 
-               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':
-                       return parse_hex_sequence();
-               case '0':
-               case '1':
-               case '2':
-               case '3':
-               case '4':
-               case '5':
-               case '6':
-               case '7':
-                       return parse_octal_sequence();
-               case '?':
-                       if(c != '?') {
-                               return '?';
-                       }
-                       /* might be a trigraph */
-                       next_char();
-                       if(replace_trigraph()) {
-                               break;
-                       }
-                       put_back(c);
-                       c = '?';
-                       return '?';
+       int ec = c;
+       next_char();
 
-               case EOF:
-                       parse_error("reached end of file while parsing escape sequence");
-                       return EOF;
-               default:
-                       parse_error("unknown escape sequence");
-                       return EOF;
-               }
+       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;
        }
 }
 
-const char *concat_strings(const char *s1, const char *s2)
+string_t concat_strings(const string_t *const s1, const string_t *const s2)
 {
-       size_t  len1   = strlen(s1);
-       size_t  len2   = strlen(s2);
+       const size_t len1 = s1->size - 1;
+       const size_t len2 = s2->size - 1;
 
-       char   *concat = obstack_alloc(&symbol_obstack, len1 + len2 + 1);
-       memcpy(concat, s1, len1);
-       memcpy(concat + len1, s2, len2 + 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)
+static void parse_string_literal(void)
 {
-       unsigned    start_linenr = lexer_token.source_position.linenr;
-       char       *string;
-       const char *result;
+       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:
@@ -507,7 +719,7 @@ void parse_string_literal(void)
                        goto end_of_string;
 
                default:
-                       obstack_1grow(&symbol_obstack, c);
+                       obstack_1grow(&symbol_obstack, (char) c);
                        next_char();
                        break;
                }
@@ -519,49 +731,136 @@ 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
 
-       lexer_token.type     = T_STRING_LITERAL;
-       lexer_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();                      \
-               }                                     \
-               lexer_token.source_position.linenr++; \
-               code;                                 \
-       case '\n':                                \
-               next_char();                          \
-               lexer_token.source_position.linenr++; \
-               code;
-
-static
-void parse_character_constant(void)
+static void parse_wide_character_constant(void)
 {
-       assert(c == '\'');
-       next_char();
+       eat('\'');
 
        int found_char = 0;
        while(1) {
                switch(c) {
-               SKIP_TRIGRAPHS(,
-                       next_char();
-                       found_char = '?';
+               case '\\':
+                       found_char = parse_escape_sequence();
+                       break;
+
+               MATCH_NEWLINE(
+                       parse_error("newline while parsing character constant");
                        break;
                )
 
-               case '\\':
+               case '\'':
                        next_char();
-                       EAT_NEWLINE(break;)
+                       goto end_of_wide_char_constant;
+
+               case EOF:
+                       parse_error("EOF while parsing character constant");
+                       lexer_token.type = T_ERROR;
+                       return;
+
+               default:
+                       if(found_char != 0) {
+                               parse_error("more than 1 characters in character "
+                                           "constant");
+                               goto end_of_wide_char_constant;
+                       } else {
+                               found_char = c;
+                               next_char();
+                       }
+                       break;
+               }
+       }
+
+end_of_wide_char_constant:
+       lexer_token.type       = T_INTEGER;
+       lexer_token.v.intvalue = found_char;
+       lexer_token.datatype   = type_wchar_t;
+}
+
+static void parse_wide_string_literal(void)
+{
+       const unsigned start_linenr = lexer_token.source_position.linenr;
+
+       assert(c == '"');
+       next_char();
+
+       while(1) {
+               switch(c) {
+                       case '\\': {
+                               wchar_rep_t tc = parse_escape_sequence();
+                               obstack_grow(&symbol_obstack, &tc, sizeof(tc));
+                               break;
+                       }
+
+                       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;
+                       }
+               }
+       }
+
+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 '\\':
                        found_char = parse_escape_sequence();
                        break;
 
@@ -595,94 +894,47 @@ void parse_character_constant(void)
 end_of_char_constant:
        lexer_token.type       = T_INTEGER;
        lexer_token.v.intvalue = found_char;
+       lexer_token.datatype   = type_int;
 }
 
-static
-void skip_multiline_comment(void)
+static void skip_multiline_comment(void)
 {
        unsigned start_linenr = lexer_token.source_position.linenr;
-       int had_star = 0;
 
        while(1) {
                switch(c) {
                case '*':
                        next_char();
-                       had_star = 1;
-                       break;
-
-               case '/':
-                       next_char();
-                       if(had_star) {
+                       if(c == '/') {
+                               next_char();
                                return;
                        }
-                       had_star = 0;
-                       break;
-
-               case '\\':
-                       next_char();
-                       EAT_NEWLINE(break;)
-                       had_star = 0;
-                       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 */
                        break;
 
-               MATCH_NEWLINE(had_star = 0; break;)
+               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:
-                       had_star = 0;
                        next_char();
                        break;
                }
        }
 }
 
-static
-void skip_line_comment(void)
+static void skip_line_comment(void)
 {
        while(1) {
                switch(c) {
-               case '?':
-                       next_char();
-                       if(c != '?')
-                               break;
-                       next_char();
-                       if(replace_trigraph())
-                               break;
-                       put_back('?');
-                       /* we don't put back the 2nd ? as the comment text is discarded
-                        * anyway */
-                       break;
-
-               case '\\':
-                       next_char();
-                       if(c == '\n') {
-                               next_char();
-                               lexer_token.source_position.linenr++;
-                       }
-                       break;
-
                case EOF:
-               case '\r':
+                       return;
+
                case '\n':
+               case '\r':
                        return;
 
                default:
@@ -694,23 +946,20 @@ void skip_line_comment(void)
 
 static token_t pp_token;
 
-static inline
-void next_pp_token(void)
+static inline void next_pp_token(void)
 {
        lexer_next_preprocessing_token();
        pp_token = lexer_token;
 }
 
-static
-void eat_until_newline(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)
+static void error_directive(void)
 {
        error_prefix();
        fprintf(stderr, "#error directive: \n");
@@ -718,8 +967,7 @@ void error_directive(void)
        /* parse pp-tokens until new-line */
 }
 
-static
-void define_directive(void)
+static void define_directive(void)
 {
        lexer_next_preprocessing_token();
        if(lexer_token.type != T_IDENTIFIER) {
@@ -728,8 +976,7 @@ void define_directive(void)
        }
 }
 
-static
-void ifdef_directive(int is_ifndef)
+static void ifdef_directive(int is_ifndef)
 {
        (void) is_ifndef;
        lexer_next_preprocessing_token();
@@ -737,31 +984,28 @@ void ifdef_directive(int is_ifndef)
        //extect_newline();
 }
 
-static
-void endif_directive(void)
+static void endif_directive(void)
 {
        //expect_newline();
 }
 
-static
-void parse_line_directive(void)
+static void parse_line_directive(void)
 {
        if(pp_token.type != T_INTEGER) {
                parse_error("expected integer");
        } else {
-               lexer_token.source_position.linenr = pp_token.v.intvalue - 1;
+               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;
+               lexer_token.source_position.input_name = pp_token.v.string.begin;
                next_pp_token();
        }
 
        eat_until_newline();
 }
 
-static
-void parse_preprocessor_identifier(void)
+static void parse_preprocessor_identifier(void)
 {
        assert(pp_token.type == T_IDENTIFIER);
        symbol_t *symbol = pp_token.v.symbol;
@@ -794,12 +1038,15 @@ void parse_preprocessor_identifier(void)
                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()
+static void parse_preprocessor_directive(void)
 {
        next_pp_token();
 
@@ -829,14 +1076,6 @@ void parse_preprocessor_directive()
                                        return;
 
 #define ELSE_CODE(code)                                    \
-                               SKIP_TRIGRAPHS(,                           \
-                                       code;                                  \
-                               )                                          \
-                                                                                                                  \
-                               case '\\':                                 \
-                                       next_char();                           \
-                                       EAT_NEWLINE(break;)                    \
-                                       /* fallthrough */                      \
                                default:                                   \
                                        code;                                  \
                                }                                          \
@@ -865,6 +1104,15 @@ void lexer_next_preprocessing_token(void)
 
                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();
+                               }
+                       }
                        return;
 
                DIGITS
@@ -879,20 +1127,23 @@ void lexer_next_preprocessing_token(void)
                        parse_character_constant();
                        return;
 
-               case '\\':
-                       next_char();
-                       if(c == '\n') {
-                               next_char();
-                               lexer_token.source_position.linenr++;
-                               break;
-                       } else {
-                               parse_error("unexpected '\\' found");
-                               lexer_token.type = T_ERROR;
-                       }
-                       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)
@@ -999,22 +1250,6 @@ void lexer_next_preprocessing_token(void)
                        ELSE('#')
 
                case '?':
-                       next_char();
-                       /* just a simple ? */
-                       if(c != '?') {
-                               lexer_token.type = '?';
-                               return;
-                       }
-                       /* might be a trigraph */
-                       next_char();
-                       if(replace_trigraph()) {
-                               break;
-                       }
-                       put_back(c);
-                       c = '?';
-                       lexer_token.type = '?';
-                       return;
-
                case '[':
                case ']':
                case '(':
@@ -1024,6 +1259,7 @@ void lexer_next_preprocessing_token(void)
                case '~':
                case ';':
                case ',':
+               case '\\':
                        lexer_token.type = c;
                        next_char();
                        return;
@@ -1070,8 +1306,12 @@ void lexer_open_stream(FILE *stream, const char *input_name)
        lexer_token.source_position.linenr     = 0;
        lexer_token.source_position.input_name = input_name;
 
-       /* we place a virtual '\n' at the beginning so the lexer knows we're at the
-        * beginning of a line */
+       symbol_L = symbol_table_insert("L");
+       bufpos = NULL;
+       bufend = NULL;
+
+       /* place a virtual \n at the beginning so the lexer knows that we're
+        * at the beginning of a line */
        c = '\n';
 }
 
@@ -1083,7 +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,
+       fprintf(stdout, "%s:%u\n", source_position.input_name,
                source_position.linenr);
        fflush(stdout);
 }