- implemented most cases of -W traditional (preprocessor missing)
[cparser] / lexer.c
diff --git a/lexer.c b/lexer.c
index 4b86a38..779f4b3 100644 (file)
--- a/lexer.c
+++ b/lexer.c
@@ -1,7 +1,27 @@
+/*
+ * This file is part of cparser.
+ * Copyright (C) 2007-2008 Matthias Braun <matze@braunis.de>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
 #include <config.h>
 
 #include "diagnostic.h"
 #include "lexer.h"
+#include "symbol_t.h"
 #include "token_t.h"
 #include "symbol_table_t.h"
 #include "adt/error.h"
 #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;
@@ -44,6 +56,7 @@ static char        buf[1024 + MAX_PUTBACK];
 static const char *bufend;
 static const char *bufpos;
 static strset_t    stringset;
+bool               allow_dollar_in_symbol = true;
 
 /**
  * Prints a parse error message at the current token.
@@ -52,13 +65,28 @@ static strset_t    stringset;
  */
 static void parse_error(const char *msg)
 {
-       errorf(lexer_token.source_position,  "%s", msg);
+       errorf(&lexer_token.source_position, "%s", msg);
+}
+
+/**
+ * Prints an internal error message at the current token.
+ *
+ * @param msg   the error message
+ */
+static NORETURN internal_error(const char *msg)
+{
+       internal_errorf(&lexer_token.source_position, "%s", msg);
 }
 
 static inline void next_real_char(void)
 {
        assert(bufpos <= bufend);
        if (bufpos >= bufend) {
+               if (input == NULL) {
+                       c = EOF;
+                       return;
+               }
+
                size_t s = fread(buf + MAX_PUTBACK, 1, sizeof(buf) - MAX_PUTBACK,
                                 input);
                if(s == 0) {
@@ -167,6 +195,7 @@ end_of_next_char:;
 }
 
 #define SYMBOL_CHARS  \
+       case '$': if (!allow_dollar_in_symbol) goto dollar_sign; \
        case 'a':         \
        case 'b':         \
        case 'c':         \
@@ -254,6 +283,7 @@ static void parse_symbol(void)
                        break;
 
                default:
+dollar_sign:
                        goto end_symbol;
                }
        }
@@ -274,60 +304,78 @@ end_symbol:
 
 static void parse_integer_suffix(bool is_oct_hex)
 {
-       bool is_unsigned  = false;
-       bool min_long     = false;
-       bool min_longlong = false;
-
-       if(c == 'U' || c == 'u') {
-               is_unsigned = true;
+       bool is_unsigned     = false;
+       bool min_long        = false;
+       bool min_longlong    = false;
+       bool not_traditional = false;
+       int  pos             = 0;
+       char suffix[4];
+
+       if (c == 'U' || c == 'u') {
+               not_traditional = true;
+               suffix[pos++]   = toupper(c);
+               is_unsigned     = true;
                next_char();
-               if(c == 'L' || c == 'l') {
+               if (c == 'L' || c == 'l') {
+                       suffix[pos++] = toupper(c);
                        min_long = true;
                        next_char();
-                       if(c == 'L' || c == 'l') {
+                       if (c == 'L' || c == 'l') {
+                               suffix[pos++] = toupper(c);
                                min_longlong = true;
                                next_char();
                        }
                }
-       } else if(c == 'l' || c == 'L') {
+       } else if (c == 'l' || c == 'L') {
+               suffix[pos++] = toupper(c);
                min_long = true;
                next_char();
-               if(c == 'l' || c == 'L') {
-                       min_longlong = true;
+               if (c == 'l' || c == 'L') {
+                       not_traditional = true;
+                       suffix[pos++]   = toupper(c);
+                       min_longlong    = true;
                        next_char();
-                       if(c == 'u' || c == 'U') {
-                               is_unsigned = true;
+                       if (c == 'u' || c == 'U') {
+                               suffix[pos++] = toupper(c);
+                               is_unsigned   = true;
                                next_char();
                        }
-               } else if(c == 'u' || c == 'U') {
-                       is_unsigned = true;
+               } else if (c == 'u' || c == 'U') {
+                       not_traditional = true;
+                       suffix[pos++]   = toupper(c);
+                       is_unsigned     = true;
                        next_char();
                        lexer_token.datatype = type_unsigned_long;
                }
        }
 
-       if(!is_unsigned) {
+       if (warning.traditional && not_traditional) {
+               suffix[pos] = '\0';
+               warningf(&lexer_token.source_position,
+                       "traditional C rejects the '%s' suffix", suffix);
+       }
+       if (!is_unsigned) {
                long long v = lexer_token.v.intvalue;
-               if(!min_long) {
-                       if(v >= TARGET_INT_MIN && v <= TARGET_INT_MAX) {
+               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) {
+                       } 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) {
+               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) {
+                       } else if (is_oct_hex && v >= 0 && (unsigned long long)v <= (unsigned long long)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) {
+               if (is_oct_hex && uv > (unsigned long long) TARGET_LONGLONG_MAX) {
                        lexer_token.datatype = type_unsigned_long_long;
                        return;
                }
@@ -335,11 +383,11 @@ static void parse_integer_suffix(bool is_oct_hex)
                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) {
+               if (!min_long && v <= TARGET_UINT_MAX) {
                        lexer_token.datatype = type_unsigned_int;
                        return;
                }
-               if(!min_longlong && v <= TARGET_ULONG_MAX) {
+               if (!min_longlong && v <= TARGET_ULONG_MAX) {
                        lexer_token.datatype = type_unsigned_long;
                        return;
                }
@@ -353,11 +401,19 @@ static void parse_floating_suffix(void)
        /* TODO: do something useful with the suffixes... */
        case 'f':
        case 'F':
+               if (warning.traditional) {
+                       warningf(&lexer_token.source_position,
+                               "traditional C rejects the 'F' suffix");
+               }
                next_char();
                lexer_token.datatype = type_float;
                break;
        case 'l':
        case 'L':
+               if (warning.traditional) {
+                       warningf(&lexer_token.source_position,
+                               "traditional C rejects the 'F' suffix");
+               }
                next_char();
                lexer_token.datatype = type_long_double;
                break;
@@ -457,34 +513,74 @@ end:
  */
 static void parse_number_hex(void)
 {
+       bool is_float = false;
        assert(c == 'x' || c == 'X');
        next_char();
 
+       obstack_1grow(&symbol_obstack, '0');
+       obstack_1grow(&symbol_obstack, 'x');
+
        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') {
+       if (c == '.') {
+               obstack_1grow(&symbol_obstack, (char) c);
                next_char();
-               panic("Hex floating point numbers not implemented yet");
+
+               while (isxdigit(c)) {
+                       obstack_1grow(&symbol_obstack, (char) c);
+                       next_char();
+               }
+               is_float = true;
        }
+       if (c == 'p' || c == 'P') {
+               obstack_1grow(&symbol_obstack, (char) c);
+               next_char();
+
+               if (c == '-' || c == '+') {
+                       obstack_1grow(&symbol_obstack, (char) c);
+                       next_char();
+               }
+
+               while (isxdigit(c)) {
+                       obstack_1grow(&symbol_obstack, (char) c);
+                       next_char();
+               }
+               is_float = true;
+       }
+
+       obstack_1grow(&symbol_obstack, '\0');
+       char *string = obstack_finish(&symbol_obstack);
        if(*string == '\0') {
                parse_error("invalid hex number");
                lexer_token.type = T_ERROR;
+               obstack_free(&symbol_obstack, string);
+               return;
        }
 
-       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");
+       if (is_float) {
+               char *endptr;
+               lexer_token.type         = T_FLOATINGPOINT;
+               lexer_token.v.floatvalue = strtold(string, &endptr);
+
+               if(*endptr != '\0') {
+                       parse_error("invalid hex float literal");
+               }
+
+               parse_floating_suffix();
+       } else {
+               const char *endptr;
+               lexer_token.type       = T_INTEGER;
+               lexer_token.v.intvalue = parse_int_string(string + 2, &endptr, 16);
+               if(*endptr != '\0') {
+                       parse_error("hex number literal too long");
+               }
+               parse_integer_suffix(true);
        }
 
        obstack_free(&symbol_obstack, string);
-       parse_integer_suffix(true);
 }
 
 /**
@@ -539,23 +635,23 @@ static void parse_number_oct(void)
 static void parse_number_dec(void)
 {
        bool is_float = false;
-       while(isdigit(c)) {
+       while (isdigit(c)) {
                obstack_1grow(&symbol_obstack, (char) c);
                next_char();
        }
 
-       if(c == '.') {
+       if (c == '.') {
                obstack_1grow(&symbol_obstack, '.');
                next_char();
 
-               while(isdigit(c)) {
+               while (isdigit(c)) {
                        obstack_1grow(&symbol_obstack, (char) c);
                        next_char();
                }
                is_float = true;
        }
        if(c == 'e' || c == 'E') {
-               obstack_1grow(&symbol_obstack, 'e');
+               obstack_1grow(&symbol_obstack, (char) c);
                next_char();
 
                if(c == '-' || c == '+') {
@@ -667,7 +763,7 @@ static int digit_value(int digit) {
        case 'f':
        case 'F': return 15;
        default:
-               panic("wrong character given");
+               internal_error("wrong character given");
        }
 }
 
@@ -686,7 +782,12 @@ static int parse_octal_sequence(const int first_digit)
        if (!is_octal_digit(c)) return value;
        value = 8 * value + digit_value(c);
        next_char();
-       return (char_type)value;
+
+       if(char_is_signed) {
+               return (signed char) value;
+       } else {
+               return (unsigned char) value;
+       }
 }
 
 /**
@@ -700,7 +801,11 @@ static int parse_hex_sequence(void)
                next_char();
        }
 
-       return (char_type)value;
+       if(char_is_signed) {
+               return (signed char) value;
+       } else {
+               return (unsigned char) value;
+       }
 }
 
 /**
@@ -713,7 +818,7 @@ static int parse_escape_sequence(void)
        int ec = c;
        next_char();
 
-       switch(ec) {
+       switch (ec) {
        case '"':  return '"';
        case '\'': return '\'';
        case '\\': return '\\';
@@ -739,6 +844,10 @@ static int parse_escape_sequence(void)
        case EOF:
                parse_error("reached end of file while parsing escape sequence");
                return EOF;
+       case 'e':
+               if (c_mode & _GNUC)
+                       return 27;   /* hopefully 27 is ALWAYS the code for ESACAPE */
+               /*fallthrough*/
        default:
                parse_error("unknown escape sequence");
                return EOF;
@@ -757,6 +866,10 @@ string_t concat_strings(const string_t *const s1, const string_t *const s2)
        memcpy(concat, s1->begin, len1);
        memcpy(concat + len1, s2->begin, len2 + 1);
 
+       if (warning.traditional) {
+               warningf(&lexer_token.source_position,
+                       "traditional C rejects string constant concatenation");
+       }
 #if 0 /* TODO hash */
        const char *result = strset_insert(&stringset, concat);
        if(result != concat) {
@@ -783,6 +896,10 @@ wide_string_t concat_string_wide_string(const string_t *const s1, const wide_str
                concat[i] = src[i];
        }
        memcpy(concat + len1, s2->begin, (len2 + 1) * sizeof(*concat));
+       if (warning.traditional) {
+               warningf(&lexer_token.source_position,
+                       "traditional C rejects string constant concatenation");
+       }
 
        return (wide_string_t){ concat, len1 + len2 + 1 };
 }
@@ -798,6 +915,10 @@ wide_string_t concat_wide_strings(const wide_string_t *const s1, const wide_stri
        wchar_rep_t *const concat = obstack_alloc(&symbol_obstack, (len1 + len2 + 1) * sizeof(*concat));
        memcpy(concat,        s1->begin, len1       * sizeof(*concat));
        memcpy(concat + len1, s2->begin, (len2 + 1) * sizeof(*concat));
+       if (warning.traditional) {
+               warningf(&lexer_token.source_position,
+                       "traditional C rejects string constant concatenation");
+       }
 
        return (wide_string_t){ concat, len1 + len2 + 1 };
 }
@@ -816,6 +937,10 @@ wide_string_t concat_wide_string_string(const wide_string_t *const s1, const str
        for (size_t i = 0; i != len2 + 1; ++i) {
                concat[i] = src[i];
        }
+       if (warning.traditional) {
+               warningf(&lexer_token.source_position,
+                       "traditional C rejects string constant concatenation");
+       }
 
        return (wide_string_t){ concat, len1 + len2 + 1 };
 }
@@ -841,7 +966,7 @@ static void parse_string_literal(void)
                        source_position_t source_position;
                        source_position.input_name = lexer_token.source_position.input_name;
                        source_position.linenr     = start_linenr;
-                       errorf(source_position, "string has no end");
+                       errorf(&source_position, "string has no end");
                        lexer_token.type = T_ERROR;
                        return;
                }
@@ -886,14 +1011,17 @@ end_of_string:
  */
 static void parse_wide_character_constant(void)
 {
+       const unsigned start_linenr = lexer_token.source_position.linenr;
+
        eat('\'');
 
-       int found_char = 0;
        while(1) {
                switch(c) {
-               case '\\':
-                       found_char = parse_escape_sequence();
+               case '\\': {
+                       wchar_rep_t tc = parse_escape_sequence();
+                       obstack_grow(&symbol_obstack, &tc, sizeof(tc));
                        break;
+               }
 
                MATCH_NEWLINE(
                        parse_error("newline while parsing character constant");
@@ -904,28 +1032,34 @@ static void parse_wide_character_constant(void)
                        next_char();
                        goto end_of_wide_char_constant;
 
-               case EOF:
-                       parse_error("EOF while parsing character constant");
+               case EOF: {
+                       source_position_t source_position = lexer_token.source_position;
+                       source_position.linenr = start_linenr;
+                       errorf(&source_position, "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();
-                       }
+               default: {
+                       wchar_rep_t tc = (wchar_rep_t) c;
+                       obstack_grow(&symbol_obstack, &tc, sizeof(tc));
+                       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;
+end_of_wide_char_constant:;
+       size_t             size   = (size_t) obstack_object_size(&symbol_obstack);
+       assert(size % sizeof(wchar_rep_t) == 0);
+       size /= sizeof(wchar_rep_t);
+
+       const wchar_rep_t *string = obstack_finish(&symbol_obstack);
+
+       lexer_token.type                = T_WIDE_CHARACTER_CONSTANT;
+       lexer_token.v.wide_string.begin = string;
+       lexer_token.v.wide_string.size  = size;
+       lexer_token.datatype            = type_wchar_t;
 }
 
 /**
@@ -950,7 +1084,7 @@ static void parse_wide_string_literal(void)
                        source_position_t source_position;
                        source_position.input_name = lexer_token.source_position.input_name;
                        source_position.linenr     = start_linenr;
-                       errorf(source_position, "string has no end");
+                       errorf(&source_position, "string has no end");
                        lexer_token.type = T_ERROR;
                        return;
                }
@@ -1002,32 +1136,32 @@ static void parse_character_constant(void)
 
        eat('\'');
 
-       int tc;
        while(1) {
                switch(c) {
-               case '\\':
-                       tc = parse_escape_sequence();
+               case '\\': {
+                       int tc = parse_escape_sequence();
                        obstack_1grow(&symbol_obstack, (char) tc);
                        break;
+               }
 
                MATCH_NEWLINE(
                        parse_error("newline while parsing character constant");
                        break;
                )
 
+               case '\'':
+                       next_char();
+                       goto end_of_char_constant;
+
                case EOF: {
                        source_position_t source_position;
                        source_position.input_name = lexer_token.source_position.input_name;
                        source_position.linenr     = start_linenr;
-                       errorf(source_position, "EOF while parsing character constant");
+                       errorf(&source_position, "EOF while parsing character constant");
                        lexer_token.type = T_ERROR;
                        return;
                }
 
-               case '\'':
-                       next_char();
-                       goto end_of_char_constant;
-
                default:
                        obstack_1grow(&symbol_obstack, (char) c);
                        next_char();
@@ -1040,7 +1174,7 @@ end_of_char_constant:;
        const size_t      size   = (size_t)obstack_object_size(&symbol_obstack);
        const char *const string = obstack_finish(&symbol_obstack);
 
-       lexer_token.type           = T_CHARS;
+       lexer_token.type           = T_CHARACTER_CONSTANT;
        lexer_token.v.string.begin = string;
        lexer_token.v.string.size  = size;
        lexer_token.datatype       = type_int;
@@ -1058,7 +1192,10 @@ static void skip_multiline_comment(void)
                case '/':
                        next_char();
                        if (c == '*') {
-                               /* TODO: nested comment, warn here */
+                               /* nested comment, warn here */
+                               if (warning.comment) {
+                                       warningf(&lexer_token.source_position, "'/*' within comment");
+                               }
                        }
                        break;
                case '*':
@@ -1075,7 +1212,7 @@ static void skip_multiline_comment(void)
                        source_position_t source_position;
                        source_position.input_name = lexer_token.source_position.input_name;
                        source_position.linenr     = start_linenr;
-                       errorf(source_position, "at end of file while looking for comment end");
+                       errorf(&source_position, "at end of file while looking for comment end");
                        return;
                }
 
@@ -1100,6 +1237,15 @@ static void skip_line_comment(void)
                case '\r':
                        return;
 
+               case '\\':
+                       next_char();
+                       if (c == '\n' || c == '\r') {
+                               if (warning.comment)
+                                       warningf(&lexer_token.source_position, "multi-line comment");
+                               return;
+                       }
+                       break;
+
                default:
                        next_char();
                        break;
@@ -1182,7 +1328,7 @@ static void parse_line_directive(void)
 /**
  * STDC pragmas.
  */
-typedef enum {
+typedef enum stdc_pragma_kind_t {
        STDC_UNKNOWN,
        STDC_FP_CONTRACT,
        STDC_FENV_ACCESS,
@@ -1192,7 +1338,7 @@ typedef enum {
 /**
  * STDC pragma values.
  */
-typedef enum {
+typedef enum stdc_pragma_value_kind_t {
        STDC_VALUE_UNKNOWN,
        STDC_VALUE_ON,
        STDC_VALUE_OFF,
@@ -1244,7 +1390,7 @@ static void parse_pragma(void) {
                                if (value != STDC_VALUE_UNKNOWN) {
                                        unknown_pragma = false;
                                } else {
-                                       errorf(pp_token.source_position, "bad STDC pragma argument");
+                                       errorf(&pp_token.source_position, "bad STDC pragma argument");
                                }
                        }
                }
@@ -1253,7 +1399,7 @@ static void parse_pragma(void) {
        }
        eat_until_newline();
        if (unknown_pragma && warning.unknown_pragmas) {
-               warningf(pp_token.source_position, "encountered unknown #pragma");
+               warningf(&pp_token.source_position, "encountered unknown #pragma");
        }
 }
 
@@ -1314,7 +1460,7 @@ static void parse_preprocessor_directive(void)
                parse_line_directive();
                break;
        case '\n':
-               /* NULL directive, see § 6.10.7 */
+               /* NULL directive, see Â§ 6.10.7 */
                break;
        default:
                parse_error("invalid preprocessor directive");
@@ -1336,7 +1482,7 @@ static void parse_preprocessor_directive(void)
 
 #define ELSE_CODE(code)                                    \
                                default:                                   \
-                                       code;                                  \
+                                       code                                   \
                                }                                          \
                        } /* end of while(1) */                        \
                        break;
@@ -1388,16 +1534,7 @@ void lexer_next_preprocessing_token(void)
 
                case '.':
                        MAYBE_PROLOG
-                               case '0':
-                               case '1':
-                               case '2':
-                               case '3':
-                               case '4':
-                               case '5':
-                               case '6':
-                               case '7':
-                               case '8':
-                               case '9':
+                               DIGITS
                                        put_back(c);
                                        c = '.';
                                        parse_number_dec();
@@ -1453,25 +1590,25 @@ void lexer_next_preprocessing_token(void)
                        ELSE('/')
                case '%':
                        MAYBE_PROLOG
-                       MAYBE('>', T_PERCENTGREATER)
+                       MAYBE('>', '}')
                        MAYBE('=', T_PERCENTEQUAL)
                                case ':':
                                        MAYBE_PROLOG
                                                case '%':
                                                        MAYBE_PROLOG
-                                                       MAYBE(':', T_PERCENTCOLONPERCENTCOLON)
+                                                       MAYBE(':', T_HASHHASH)
                                                        ELSE_CODE(
                                                                put_back(c);
                                                                c = '%';
-                                                               lexer_token.type = T_PERCENTCOLON;
+                                                               lexer_token.type = '#';
                                                                return;
                                                        )
-                                       ELSE(T_PERCENTCOLON)
+                                       ELSE('#')
                        ELSE('%')
                case '<':
                        MAYBE_PROLOG
-                       MAYBE(':', T_LESSCOLON)
-                       MAYBE('%', T_LESSPERCENT)
+                       MAYBE(':', '[')
+                       MAYBE('%', '{')
                        MAYBE('=', T_LESSEQUAL)
                                case '<':
                                        MAYBE_PROLOG
@@ -1497,7 +1634,7 @@ void lexer_next_preprocessing_token(void)
                        ELSE('|')
                case ':':
                        MAYBE_PROLOG
-                       MAYBE('>', T_COLONGREATER)
+                       MAYBE('>', ']')
                        ELSE(':')
                case '=':
                        MAYBE_PROLOG
@@ -1528,8 +1665,9 @@ void lexer_next_preprocessing_token(void)
                        return;
 
                default:
+dollar_sign:
+                       errorf(&lexer_token.source_position, "unknown character '%c' found", c);
                        next_char();
-                       errorf(lexer_token.source_position, "unknown character '%c' found\n", c);
                        lexer_token.type = T_ERROR;
                        return;
                }
@@ -1539,15 +1677,13 @@ void lexer_next_preprocessing_token(void)
 void lexer_next_token(void)
 {
        lexer_next_preprocessing_token();
-       if(lexer_token.type != '\n')
-               return;
 
+       while (lexer_token.type == '\n') {
 newline_found:
-       do {
                lexer_next_preprocessing_token();
-       } while(lexer_token.type == '\n');
+       }
 
-       if(lexer_token.type == '#') {
+       if (lexer_token.type == '#') {
                parse_preprocessor_directive();
                goto newline_found;
        }
@@ -1556,6 +1692,7 @@ newline_found:
 void init_lexer(void)
 {
        strset_init(&stringset);
+       symbol_L = symbol_table_insert("L");
 }
 
 void lexer_open_stream(FILE *stream, const char *input_name)
@@ -1564,7 +1701,6 @@ void lexer_open_stream(FILE *stream, const char *input_name)
        lexer_token.source_position.linenr     = 0;
        lexer_token.source_position.input_name = input_name;
 
-       symbol_L = symbol_table_insert("L");
        bufpos = NULL;
        bufend = NULL;
 
@@ -1573,6 +1709,20 @@ void lexer_open_stream(FILE *stream, const char *input_name)
        c = '\n';
 }
 
+void lexer_open_buffer(const char *buffer, size_t len, const char *input_name)
+{
+       input                                  = NULL;
+       lexer_token.source_position.linenr     = 0;
+       lexer_token.source_position.input_name = input_name;
+
+       bufpos = buffer;
+       bufend = buffer + len;
+
+       /* place a virtual \n at the beginning so the lexer knows that we're
+        * at the beginning of a line */
+       c = '\n';
+}
+
 void exit_lexer(void)
 {
        strset_destroy(&stringset);