some refactoring in preparation for a preprocessor
[cparser] / lexer.c
diff --git a/lexer.c b/lexer.c
index 66401d5..3ba2c37 100644 (file)
--- a/lexer.c
+++ b/lexer.c
@@ -1,6 +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"
@@ -10,6 +31,8 @@
 #include "type_t.h"
 #include "target_architecture.h"
 #include "parser.h"
+#include "warning.h"
+#include "lang_features.h"
 
 #include <assert.h>
 #include <errno.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;
@@ -42,27 +57,20 @@ static const char *bufend;
 static const char *bufpos;
 static strset_t    stringset;
 
-static void error_prefix_at(const char *input_name, unsigned linenr)
-{
-       fprintf(stderr, "%s:%u: Error: ", input_name, linenr);
-}
-
-static void error_prefix(void)
-{
-       error_prefix_at(lexer_token.source_position.input_name,
-                       lexer_token.source_position.linenr);
-}
-
+/**
+ * Prints a parse error message at the current token.
+ *
+ * @param msg   the error message
+ */
 static void parse_error(const char *msg)
 {
-       error_prefix();
-       fprintf(stderr, "%s\n", msg);
+       errorf(lexer_token.source_position,  "%s", msg);
 }
 
 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) {
@@ -72,20 +80,18 @@ static inline void next_real_char(void)
                bufpos = buf + MAX_PUTBACK;
                bufend = buf + MAX_PUTBACK + s;
        }
-       c = *(bufpos);
+       c = *bufpos++;
 }
 
+/**
+ * Put a character back into the buffer.
+ *
+ * @param pc  the character to put back
+ */
 static inline void put_back(int pc)
 {
-       assert(bufpos >= buf);
-       //assert(bufpos < buf+MAX_PUTBACK || *bufpos == pc);
-
-       char *p = buf + (bufpos - buf);
-       *p = (char) pc;
-
-       /* going backwards in the buffer is legal as long as it's not more often
-        * than MAX_PUTBACK */
-       bufpos--;
+       assert(bufpos > buf);
+       *(--bufpos - buf + buf) = (char) pc;
 
 #ifdef DEBUG_CHARS
        printf("putback '%c'\n", pc);
@@ -101,11 +107,11 @@ static inline void next_char(void);
                        next_char();                      \
                }                                     \
                lexer_token.source_position.linenr++; \
-               code;                                 \
+               code                                  \
        case '\n':                                \
                next_char();                          \
                lexer_token.source_position.linenr++; \
-               code;
+               code
 
 #define eat(c_type)  do { assert(c == c_type); next_char(); } while(0)
 
@@ -124,6 +130,10 @@ static void maybe_concat_lines(void)
        c = '\\';
 }
 
+/**
+ * Set c to the next input character, ie.
+ * after expanding trigraphs.
+ */
 static inline void next_char(void)
 {
        next_real_char();
@@ -156,8 +166,8 @@ static inline void next_char(void)
        case '>': c = '}'; break;
        case '-': c = '~'; break;
        default:
-               put_back('?');
                put_back(c);
+               put_back('?');
                c = '?';
                break;
        }
@@ -235,6 +245,10 @@ end_of_next_char:;
        case '8':         \
        case '9':
 
+/**
+ * Read a symbol from the input and build
+ * the lexer_token.
+ */
 static void parse_symbol(void)
 {
        symbol_t *symbol;
@@ -348,7 +362,7 @@ static void parse_integer_suffix(bool is_oct_hex)
 static void parse_floating_suffix(void)
 {
        switch(c) {
-       /* TODO: do something usefull with the suffixes... */
+       /* TODO: do something useful with the suffixes... */
        case 'f':
        case 'F':
                next_char();
@@ -449,6 +463,10 @@ end:
        return v;
 }
 
+/**
+ * Parses a hex number including hex floats and set the
+ * lexer_token.
+ */
 static void parse_number_hex(void)
 {
        assert(c == 'x' || c == 'X');
@@ -481,11 +499,31 @@ static void parse_number_hex(void)
        parse_integer_suffix(true);
 }
 
+/**
+ * Returns true if the given char is a octal digit.
+ *
+ * @param char  the character to check
+ */
 static inline bool is_octal_digit(int chr)
 {
-       return '0' <= chr && chr <= '7';
+       switch(chr) {
+       case '0':
+       case '1':
+       case '2':
+       case '3':
+       case '4':
+       case '5':
+       case '6':
+       case '7':
+               return true;
+       default:
+               return false;
+       }
 }
 
+/**
+ * Parses a octal number and set the lexer_token.
+ */
 static void parse_number_oct(void)
 {
        while(is_octal_digit(c)) {
@@ -506,6 +544,10 @@ static void parse_number_oct(void)
        parse_integer_suffix(true);
 }
 
+/**
+ * Parses a decimal including float number and set the
+ * lexer_token.
+ */
 static void parse_number_dec(void)
 {
        bool is_float = false;
@@ -567,6 +609,9 @@ static void parse_number_dec(void)
        obstack_free(&symbol_obstack, string);
 }
 
+/**
+ * Parses a number and sets the lexer_token.
+ */
 static void parse_number(void)
 {
        if (c == '0') {
@@ -605,38 +650,83 @@ static void parse_number(void)
        }
 }
 
+/**
+ * Returns the value of a digit.
+ * The only portable way to do it ...
+ */
+static int digit_value(int digit) {
+       switch (digit) {
+       case '0': return 0;
+       case '1': return 1;
+       case '2': return 2;
+       case '3': return 3;
+       case '4': return 4;
+       case '5': return 5;
+       case '6': return 6;
+       case '7': return 7;
+       case '8': return 8;
+       case '9': return 9;
+       case 'a':
+       case 'A': return 10;
+       case 'b':
+       case 'B': return 11;
+       case 'c':
+       case 'C': return 12;
+       case 'd':
+       case 'D': return 13;
+       case 'e':
+       case 'E': return 14;
+       case 'f':
+       case 'F': return 15;
+       default:
+               panic("wrong character given");
+       }
+}
+
+/**
+ * Parses an octal character sequence.
+ *
+ * @param first_digit  the already read first digit
+ */
 static int parse_octal_sequence(const int first_digit)
 {
        assert(is_octal_digit(first_digit));
-       int value = first_digit - '0';
+       int value = digit_value(first_digit);
        if (!is_octal_digit(c)) return value;
-       value = 8 * value + c - '0';
+       value = 8 * value + digit_value(c);
        next_char();
        if (!is_octal_digit(c)) return value;
-       value = 8 * value + c - '0';
+       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;
+       }
 }
 
+/**
+ * Parses a hex character sequence.
+ */
 static int parse_hex_sequence(void)
 {
        int value = 0;
-       while(1) {
-               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;
-               }
+       while(isxdigit(c)) {
+               value = 16 * value + digit_value(c);
                next_char();
        }
 
-       return (char_type)value;
+       if(char_is_signed) {
+               return (signed char) value;
+       } else {
+               return (unsigned char) value;
+       }
 }
 
+/**
+ * Parse an escape sequence.
+ */
 static int parse_escape_sequence(void)
 {
        eat('\\');
@@ -676,31 +766,89 @@ static int parse_escape_sequence(void)
        }
 }
 
-const char *concat_strings(const char *s1, const char *s2)
+/**
+ * Concatenate two strings.
+ */
+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
 }
 
+/**
+ * Concatenate a string and a wide string.
+ */
+wide_string_t concat_string_wide_string(const string_t *const s1, const wide_string_t *const s2)
+{
+       const size_t len1 = s1->size - 1;
+       const size_t len2 = s2->size - 1;
+
+       wchar_rep_t *const concat = obstack_alloc(&symbol_obstack, (len1 + len2 + 1) * sizeof(*concat));
+       const char *const src = s1->begin;
+       for (size_t i = 0; i != len1; ++i) {
+               concat[i] = src[i];
+       }
+       memcpy(concat + len1, s2->begin, (len2 + 1) * sizeof(*concat));
+
+       return (wide_string_t){ concat, len1 + len2 + 1 };
+}
+
+/**
+ * Concatenate two wide strings.
+ */
+wide_string_t concat_wide_strings(const wide_string_t *const s1, const wide_string_t *const s2)
+{
+       const size_t len1 = s1->size - 1;
+       const size_t len2 = s2->size - 1;
+
+       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));
+
+       return (wide_string_t){ concat, len1 + len2 + 1 };
+}
+
+/**
+ * Concatenate a wide string and a string.
+ */
+wide_string_t concat_wide_string_string(const wide_string_t *const s1, const string_t *const s2)
+{
+       const size_t len1 = s1->size - 1;
+       const size_t len2 = s2->size - 1;
+
+       wchar_rep_t *const concat = obstack_alloc(&symbol_obstack, (len1 + len2 + 1) * sizeof(*concat));
+       memcpy(concat, s1->begin, len1 * sizeof(*concat));
+       const char *const src = s2->begin;
+       for (size_t i = 0; i != len2 + 1; ++i) {
+               concat[i] = src[i];
+       }
+
+       return (wide_string_t){ concat, len1 + len2 + 1 };
+}
+
+/**
+ * Parse a string literal and set lexer_token.
+ */
 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();
+       eat('"');
 
        int tc;
        while(1) {
@@ -710,12 +858,14 @@ static void parse_string_literal(void)
                        obstack_1grow(&symbol_obstack, (char) tc);
                        break;
 
-               case EOF:
-                       error_prefix_at(lexer_token.source_position.input_name,
-                                       start_linenr);
-                       fprintf(stderr, "string has no end\n");
+               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, "string has no end");
                        lexer_token.type = T_ERROR;
                        return;
+               }
 
                case '"':
                        next_char();
@@ -734,28 +884,40 @@ 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;
 }
 
+/**
+ * Parse a wide character constant and set lexer_token.
+ */
 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");
@@ -766,30 +928,36 @@ 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);
+       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;
 }
 
+/**
+ * Parse a wide string literal and set lexer_token.
+ */
 static void parse_wide_string_literal(void)
 {
        const unsigned start_linenr = lexer_token.source_position.linenr;
@@ -799,29 +967,31 @@ static void parse_wide_string_literal(void)
 
        while(1) {
                switch(c) {
-                       case '\\': {
-                               wchar_rep_t tc = parse_escape_sequence();
-                               obstack_grow(&symbol_obstack, &tc, sizeof(tc));
-                               break;
-                       }
+               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 EOF: {
+                       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");
+                       lexer_token.type = T_ERROR;
+                       return;
+               }
 
-                       case '"':
-                               next_char();
-                               goto end_of_string;
+               case '"':
+                       next_char();
+                       goto end_of_string;
 
-                       default: {
-                               wchar_rep_t tc = c;
-                               obstack_grow(&symbol_obstack, &tc, sizeof(tc));
-                               next_char();
-                               break;
-                       }
+               default: {
+                       wchar_rep_t tc = c;
+                       obstack_grow(&symbol_obstack, &tc, sizeof(tc));
+                       next_char();
+                       break;
+               }
                }
        }
 
@@ -850,16 +1020,22 @@ end_of_string:;
        lexer_token.v.wide_string.size  = size;
 }
 
+/**
+ * Parse a character constant and set lexer_token.
+ */
 static void parse_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 '\\': {
+                       int tc = parse_escape_sequence();
+                       obstack_1grow(&symbol_obstack, (char) tc);
                        break;
+               }
 
                MATCH_NEWLINE(
                        parse_error("newline while parsing character constant");
@@ -870,36 +1046,48 @@ static void parse_character_constant(void)
                        next_char();
                        goto end_of_char_constant;
 
-               case EOF:
-                       parse_error("EOF while parsing character 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");
                        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;
-                       } else {
-                               found_char = c;
-                               next_char();
-                       }
+                       obstack_1grow(&symbol_obstack, (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;
+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_CHARACTER_CONSTANT;
+       lexer_token.v.string.begin = string;
+       lexer_token.v.string.size  = size;
+       lexer_token.datatype       = type_int;
 }
 
+/**
+ * Skip a multiline comment.
+ */
 static void skip_multiline_comment(void)
 {
        unsigned start_linenr = lexer_token.source_position.linenr;
 
        while(1) {
                switch(c) {
+               case '/':
+                       next_char();
+                       if (c == '*') {
+                               /* TODO: nested comment, warn here */
+                       }
+                       break;
                case '*':
                        next_char();
                        if(c == '/') {
@@ -910,11 +1098,13 @@ static void skip_multiline_comment(void)
 
                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");
+               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, "at end of file while looking for comment end");
                        return;
+               }
 
                default:
                        next_char();
@@ -923,6 +1113,9 @@ static void skip_multiline_comment(void)
        }
 }
 
+/**
+ * Skip a single line comment.
+ */
 static void skip_line_comment(void)
 {
        while(1) {
@@ -941,14 +1134,21 @@ static void skip_line_comment(void)
        }
 }
 
+/** The current preprocessor token. */
 static token_t pp_token;
 
+/**
+ * Read the next preprocessor token.
+ */
 static inline void next_pp_token(void)
 {
        lexer_next_preprocessing_token();
        pp_token = lexer_token;
 }
 
+/**
+ * Eat all preprocessor tokens until newline.
+ */
 static void eat_until_newline(void)
 {
        while(pp_token.type != '\n' && pp_token.type != T_EOF) {
@@ -956,14 +1156,9 @@ static void eat_until_newline(void)
        }
 }
 
-static void error_directive(void)
-{
-       error_prefix();
-       fprintf(stderr, "#error directive: \n");
-
-       /* parse pp-tokens until new-line */
-}
-
+/**
+ * Handle the define directive.
+ */
 static void define_directive(void)
 {
        lexer_next_preprocessing_token();
@@ -973,6 +1168,9 @@ static void define_directive(void)
        }
 }
 
+/**
+ * Handle the ifdef directive.
+ */
 static void ifdef_directive(int is_ifndef)
 {
        (void) is_ifndef;
@@ -981,11 +1179,17 @@ static void ifdef_directive(int is_ifndef)
        //extect_newline();
 }
 
+/**
+ * Handle the endif directive.
+ */
 static void endif_directive(void)
 {
        //expect_newline();
 }
 
+/**
+ * Parse the line directive.
+ */
 static void parse_line_directive(void)
 {
        if(pp_token.type != T_INTEGER) {
@@ -995,13 +1199,94 @@ static void parse_line_directive(void)
                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();
 }
 
+/**
+ * STDC pragmas.
+ */
+typedef enum {
+       STDC_UNKNOWN,
+       STDC_FP_CONTRACT,
+       STDC_FENV_ACCESS,
+       STDC_CX_LIMITED_RANGE
+} stdc_pragma_kind_t;
+
+/**
+ * STDC pragma values.
+ */
+typedef enum {
+       STDC_VALUE_UNKNOWN,
+       STDC_VALUE_ON,
+       STDC_VALUE_OFF,
+       STDC_VALUE_DEFAULT
+} stdc_pragma_value_kind_t;
+
+/**
+ * Parse a pragma directive.
+ */
+static void parse_pragma(void) {
+       bool unknown_pragma = true;
+
+       next_pp_token();
+       if (pp_token.v.symbol->pp_ID == TP_STDC) {
+               stdc_pragma_kind_t kind = STDC_UNKNOWN;
+               /* a STDC pragma */
+               if (c_mode & _C99) {
+                       next_pp_token();
+
+                       switch (pp_token.v.symbol->pp_ID) {
+                       case TP_FP_CONTRACT:
+                               kind = STDC_FP_CONTRACT;
+                               break;
+                       case TP_FENV_ACCESS:
+                               kind = STDC_FENV_ACCESS;
+                               break;
+                       case TP_CX_LIMITED_RANGE:
+                               kind = STDC_CX_LIMITED_RANGE;
+                               break;
+                       default:
+                               break;
+                       }
+                       if (kind != STDC_UNKNOWN) {
+                               stdc_pragma_value_kind_t value = STDC_VALUE_UNKNOWN;
+                               next_pp_token();
+                               switch (pp_token.v.symbol->pp_ID) {
+                               case TP_ON:
+                                       value = STDC_VALUE_ON;
+                                       break;
+                               case TP_OFF:
+                                       value = STDC_VALUE_OFF;
+                                       break;
+                               case TP_DEFAULT:
+                                       value = STDC_VALUE_DEFAULT;
+                                       break;
+                               default:
+                                       break;
+                               }
+                               if (value != STDC_VALUE_UNKNOWN) {
+                                       unknown_pragma = false;
+                               } else {
+                                       errorf(pp_token.source_position, "bad STDC pragma argument");
+                               }
+                       }
+               }
+       } else {
+               unknown_pragma = true;
+       }
+       eat_until_newline();
+       if (unknown_pragma && warning.unknown_pragmas) {
+               warningf(pp_token.source_position, "encountered unknown #pragma");
+       }
+}
+
+/**
+ * Parse a preprocessor non-null directive.
+ */
 static void parse_preprocessor_identifier(void)
 {
        assert(pp_token.type == T_IDENTIFIER);
@@ -1032,13 +1317,18 @@ static void parse_preprocessor_identifier(void)
        case TP_elif:
        case TP_undef:
        case TP_error:
-               error_directive();
+               /* TODO; output the rest of the line */
+               parse_error("#error directive: ");
                break;
        case TP_pragma:
+               parse_pragma();
                break;
        }
 }
 
+/**
+ * Parse a preprocessor directive.
+ */
 static void parse_preprocessor_directive(void)
 {
        next_pp_token();
@@ -1050,6 +1340,9 @@ static void parse_preprocessor_directive(void)
        case T_INTEGER:
                parse_line_directive();
                break;
+       case '\n':
+               /* NULL directive, see ยง 6.10.7 */
+               break;
        default:
                parse_error("invalid preprocessor directive");
                eat_until_newline();
@@ -1122,6 +1415,21 @@ 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':
+                                       put_back(c);
+                                       c = '.';
+                                       parse_number_dec();
+                                       return;
+
                                case '.':
                                        MAYBE_PROLOG
                                        MAYBE('.', T_DOTDOTDOT)
@@ -1172,25 +1480,25 @@ 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
@@ -1216,7 +1524,7 @@ void lexer_next_preprocessing_token(void)
                        ELSE('|')
                case ':':
                        MAYBE_PROLOG
-                       MAYBE('>', T_COLONGREATER)
+                       MAYBE('>', ']')
                        ELSE(':')
                case '=':
                        MAYBE_PROLOG
@@ -1248,8 +1556,7 @@ void lexer_next_preprocessing_token(void)
 
                default:
                        next_char();
-                       error_prefix();
-                       fprintf(stderr, "unknown character '%c' found\n", c);
+                       errorf(lexer_token.source_position, "unknown character '%c' found\n", c);
                        lexer_token.type = T_ERROR;
                        return;
                }
@@ -1285,6 +1592,8 @@ void lexer_open_stream(FILE *stream, const char *input_name)
        lexer_token.source_position.input_name = input_name;
 
        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 */