%{
/*
 * Copyright © 2010 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <inttypes.h>

#include "glcpp.h"
#include "main/core.h" /* for struct gl_extensions */
#include "main/mtypes.h" /* for gl_api enum */

static void
yyerror(YYLTYPE *locp, glcpp_parser_t *parser, const char *error);

static void
_define_object_macro(glcpp_parser_t *parser,
                     YYLTYPE *loc,
                     const char *macro,
                     token_list_t *replacements);

static void
_define_function_macro(glcpp_parser_t *parser,
                       YYLTYPE *loc,
                       const char *macro,
                       string_list_t *parameters,
                       token_list_t *replacements);

static string_list_t *
_string_list_create(void *ctx);

static void
_string_list_append_item(string_list_t *list, const char *str);

static int
_string_list_contains(string_list_t *list, const char *member, int *index);

static const char *
_string_list_has_duplicate(string_list_t *list);

static int
_string_list_length(string_list_t *list);

static int
_string_list_equal(string_list_t *a, string_list_t *b);

static argument_list_t *
_argument_list_create(void *ctx);

static void
_argument_list_append(argument_list_t *list, token_list_t *argument);

static int
_argument_list_length(argument_list_t *list);

static token_list_t *
_argument_list_member_at(argument_list_t *list, int index);

/* Note: This function ralloc_steal()s the str pointer. */
static token_t *
_token_create_str(void *ctx, int type, char *str);

static token_t *
_token_create_ival(void *ctx, int type, int ival);

static token_list_t *
_token_list_create(void *ctx);

static void
_token_list_append(token_list_t *list, token_t *token);

static void
_token_list_append_list(token_list_t *list, token_list_t *tail);

static int
_token_list_equal_ignoring_space(token_list_t *a, token_list_t *b);

static void
_parser_active_list_push(glcpp_parser_t *parser, const char *identifier,
                         token_node_t *marker);

static void
_parser_active_list_pop(glcpp_parser_t *parser);

static int
_parser_active_list_contains(glcpp_parser_t *parser, const char *identifier);

typedef enum {
   EXPANSION_MODE_IGNORE_DEFINED,
   EXPANSION_MODE_EVALUATE_DEFINED
} expansion_mode_t;

/* Expand list, and begin lexing from the result (after first
 * prefixing a token of type 'head_token_type').
 */
static void
_glcpp_parser_expand_and_lex_from(glcpp_parser_t *parser, int head_token_type,
                                  token_list_t *list, expansion_mode_t mode);

/* Perform macro expansion in-place on the given list. */
static void
_glcpp_parser_expand_token_list(glcpp_parser_t *parser, token_list_t *list,
                                expansion_mode_t mode);

static void
_glcpp_parser_print_expanded_token_list(glcpp_parser_t *parser,
                                        token_list_t *list);

static void
_glcpp_parser_skip_stack_push_if(glcpp_parser_t *parser, YYLTYPE *loc,
                                 int condition);

static void
_glcpp_parser_skip_stack_change_if(glcpp_parser_t *parser, YYLTYPE *loc,
                                   const char *type, int condition);

static void
_glcpp_parser_skip_stack_pop(glcpp_parser_t *parser, YYLTYPE *loc);

static void
_glcpp_parser_handle_version_declaration(glcpp_parser_t *parser, intmax_t version,
                                         const char *ident, bool explicitly_set);

static int
glcpp_parser_lex(YYSTYPE *yylval, YYLTYPE *yylloc, glcpp_parser_t *parser);

static void
glcpp_parser_lex_from(glcpp_parser_t *parser, token_list_t *list);

static void
add_builtin_define(glcpp_parser_t *parser, const char *name, int value);

%}

%pure-parser
%error-verbose

%locations
%initial-action {
   @$.first_line = 1;
   @$.first_column = 1;
   @$.last_line = 1;
   @$.last_column = 1;
   @$.source = 0;
}

%parse-param {glcpp_parser_t *parser}
%lex-param {glcpp_parser_t *parser}

%expect 0

        /* We use HASH_TOKEN, DEFINE_TOKEN and VERSION_TOKEN (as opposed to
         * HASH, DEFINE, and VERSION) to avoid conflicts with other symbols,
         * (such as the <HASH> and <DEFINE> start conditions in the lexer). */
%token DEFINED ELIF_EXPANDED HASH_TOKEN DEFINE_TOKEN FUNC_IDENTIFIER OBJ_IDENTIFIER ELIF ELSE ENDIF ERROR_TOKEN IF IFDEF IFNDEF LINE PRAGMA UNDEF VERSION_TOKEN GARBAGE IDENTIFIER IF_EXPANDED INTEGER INTEGER_STRING LINE_EXPANDED NEWLINE OTHER PLACEHOLDER SPACE PLUS_PLUS MINUS_MINUS
%token PASTE
%type <ival> INTEGER operator SPACE integer_constant
%type <expression_value> expression
%type <str> IDENTIFIER FUNC_IDENTIFIER OBJ_IDENTIFIER INTEGER_STRING OTHER ERROR_TOKEN PRAGMA
%type <string_list> identifier_list
%type <token> preprocessing_token
%type <token_list> pp_tokens replacement_list text_line
%left OR
%left AND
%left '|'
%left '^'
%left '&'
%left EQUAL NOT_EQUAL
%left '<' '>' LESS_OR_EQUAL GREATER_OR_EQUAL
%left LEFT_SHIFT RIGHT_SHIFT
%left '+' '-'
%left '*' '/' '%'
%right UNARY

%debug

%%

input:
	/* empty */
|	input line
;

line:
	control_line
|	SPACE control_line
|	text_line {
		_glcpp_parser_print_expanded_token_list (parser, $1);
		ralloc_asprintf_rewrite_tail (&parser->output, &parser->output_length, "\n");
		ralloc_free ($1);
	}
|	expanded_line
;

expanded_line:
	IF_EXPANDED expression NEWLINE {
		if (parser->is_gles && $2.undefined_macro)
			glcpp_error(& @1, parser, "undefined macro %s in expression (illegal in GLES)", $2.undefined_macro);
		_glcpp_parser_skip_stack_push_if (parser, & @1, $2.value);
	}
|	ELIF_EXPANDED expression NEWLINE {
		if (parser->is_gles && $2.undefined_macro)
			glcpp_error(& @1, parser, "undefined macro %s in expression (illegal in GLES)", $2.undefined_macro);
		_glcpp_parser_skip_stack_change_if (parser, & @1, "elif", $2.value);
	}
|	LINE_EXPANDED integer_constant NEWLINE {
		parser->has_new_line_number = 1;
		parser->new_line_number = $2;
		ralloc_asprintf_rewrite_tail (&parser->output,
					      &parser->output_length,
					      "#line %" PRIiMAX "\n",
					      $2);
	}
|	LINE_EXPANDED integer_constant integer_constant NEWLINE {
		parser->has_new_line_number = 1;
		parser->new_line_number = $2;
		parser->has_new_source_number = 1;
		parser->new_source_number = $3;
		ralloc_asprintf_rewrite_tail (&parser->output,
					      &parser->output_length,
					      "#line %" PRIiMAX " %" PRIiMAX "\n",
					      $2, $3);
	}
;

define:
	OBJ_IDENTIFIER replacement_list NEWLINE {
		_define_object_macro (parser, & @1, $1, $2);
	}
|	FUNC_IDENTIFIER '(' ')' replacement_list NEWLINE {
		_define_function_macro (parser, & @1, $1, NULL, $4);
	}
|	FUNC_IDENTIFIER '(' identifier_list ')' replacement_list NEWLINE {
		_define_function_macro (parser, & @1, $1, $3, $5);
	}
;

control_line:
	control_line_success {
		ralloc_asprintf_rewrite_tail (&parser->output, &parser->output_length, "\n");
	}
|	control_line_error
|	HASH_TOKEN LINE pp_tokens NEWLINE {

		if (parser->skip_stack == NULL ||
		    parser->skip_stack->type == SKIP_NO_SKIP)
		{
			_glcpp_parser_expand_and_lex_from (parser,
							   LINE_EXPANDED, $3,
							   EXPANSION_MODE_IGNORE_DEFINED);
		}
	}
;

control_line_success:
	HASH_TOKEN DEFINE_TOKEN define
|	HASH_TOKEN UNDEF IDENTIFIER NEWLINE {
		macro_t *macro;
		if (strcmp("__LINE__", $3) == 0
		    || strcmp("__FILE__", $3) == 0
		    || strcmp("__VERSION__", $3) == 0
		    || strncmp("GL_", $3, 3) == 0)
			glcpp_error(& @1, parser, "Built-in (pre-defined)"
				    " macro names cannot be undefined.");

		macro = hash_table_find (parser->defines, $3);
		if (macro) {
			hash_table_remove (parser->defines, $3);
			ralloc_free (macro);
		}
		ralloc_free ($3);
	}
|	HASH_TOKEN IF pp_tokens NEWLINE {
		/* Be careful to only evaluate the 'if' expression if
		 * we are not skipping. When we are skipping, we
		 * simply push a new 0-valued 'if' onto the skip
		 * stack.
		 *
		 * This avoids generating diagnostics for invalid
		 * expressions that are being skipped. */
		if (parser->skip_stack == NULL ||
		    parser->skip_stack->type == SKIP_NO_SKIP)
		{
			_glcpp_parser_expand_and_lex_from (parser,
							   IF_EXPANDED, $3,
							   EXPANSION_MODE_EVALUATE_DEFINED);
		}	
		else
		{
			_glcpp_parser_skip_stack_push_if (parser, & @1, 0);
			parser->skip_stack->type = SKIP_TO_ENDIF;
		}
	}
|	HASH_TOKEN IF NEWLINE {
		/* #if without an expression is only an error if we
		 *  are not skipping */
		if (parser->skip_stack == NULL ||
		    parser->skip_stack->type == SKIP_NO_SKIP)
		{
			glcpp_error(& @1, parser, "#if with no expression");
		}	
		_glcpp_parser_skip_stack_push_if (parser, & @1, 0);
	}
|	HASH_TOKEN IFDEF IDENTIFIER junk NEWLINE {
		macro_t *macro = hash_table_find (parser->defines, $3);
		ralloc_free ($3);
		_glcpp_parser_skip_stack_push_if (parser, & @1, macro != NULL);
	}
|	HASH_TOKEN IFNDEF IDENTIFIER junk NEWLINE {
		macro_t *macro = hash_table_find (parser->defines, $3);
		ralloc_free ($3);
		_glcpp_parser_skip_stack_push_if (parser, & @3, macro == NULL);
	}
|	HASH_TOKEN ELIF pp_tokens NEWLINE {
		/* Be careful to only evaluate the 'elif' expression
		 * if we are not skipping. When we are skipping, we
		 * simply change to a 0-valued 'elif' on the skip
		 * stack.
		 *
		 * This avoids generating diagnostics for invalid
		 * expressions that are being skipped. */
		if (parser->skip_stack &&
		    parser->skip_stack->type == SKIP_TO_ELSE)
		{
			_glcpp_parser_expand_and_lex_from (parser,
							   ELIF_EXPANDED, $3,
							   EXPANSION_MODE_EVALUATE_DEFINED);
		}
		else if (parser->skip_stack &&
		    parser->skip_stack->has_else)
		{
			glcpp_error(& @1, parser, "#elif after #else");
		}
		else
		{
			_glcpp_parser_skip_stack_change_if (parser, & @1,
							    "elif", 0);
		}
	}
|	HASH_TOKEN ELIF NEWLINE {
		/* #elif without an expression is an error unless we
		 * are skipping. */
		if (parser->skip_stack &&
		    parser->skip_stack->type == SKIP_TO_ELSE)
		{
			glcpp_error(& @1, parser, "#elif with no expression");
		}
		else if (parser->skip_stack &&
		    parser->skip_stack->has_else)
		{
			glcpp_error(& @1, parser, "#elif after #else");
		}
		else
		{
			_glcpp_parser_skip_stack_change_if (parser, & @1,
							    "elif", 0);
			glcpp_warning(& @1, parser, "ignoring illegal #elif without expression");
		}
	}
|	HASH_TOKEN ELSE { parser->lexing_directive = 1; } NEWLINE {
		if (parser->skip_stack &&
		    parser->skip_stack->has_else)
		{
			glcpp_error(& @1, parser, "multiple #else");
		}
		else
		{
			_glcpp_parser_skip_stack_change_if (parser, & @1, "else", 1);
			if (parser->skip_stack)
				parser->skip_stack->has_else = true;
		}
	}
|	HASH_TOKEN ENDIF {
		_glcpp_parser_skip_stack_pop (parser, & @1);
	} NEWLINE
|	HASH_TOKEN VERSION_TOKEN integer_constant NEWLINE {
		if (parser->version != 0) {
			glcpp_error(& @1, parser, "#version must appear on the first line");
		}
		_glcpp_parser_handle_version_declaration(parser, $3, NULL, true);
	}
|	HASH_TOKEN VERSION_TOKEN integer_constant IDENTIFIER NEWLINE {
		if (parser->version != 0) {
			glcpp_error(& @1, parser, "#version must appear on the first line");
		}
		_glcpp_parser_handle_version_declaration(parser, $3, $4, true);
	}
|	HASH_TOKEN NEWLINE {
		glcpp_parser_resolve_implicit_version(parser);
	}
|	HASH_TOKEN PRAGMA NEWLINE {
		ralloc_asprintf_rewrite_tail (&parser->output, &parser->output_length, "#%s", $2);
	}
;

control_line_error:
	HASH_TOKEN ERROR_TOKEN NEWLINE {
		glcpp_error(& @1, parser, "#%s", $2);
	}
|	HASH_TOKEN DEFINE_TOKEN NEWLINE {
		glcpp_error (& @1, parser, "#define without macro name");
	}
|	HASH_TOKEN GARBAGE pp_tokens NEWLINE  {
		glcpp_error (& @1, parser, "Illegal non-directive after #");
	}
;

integer_constant:
	INTEGER_STRING {
		if (strlen ($1) >= 3 && strncmp ($1, "0x", 2) == 0) {
			$$ = strtoll ($1 + 2, NULL, 16);
		} else if ($1[0] == '0') {
			$$ = strtoll ($1, NULL, 8);
		} else {
			$$ = strtoll ($1, NULL, 10);
		}
	}
|	INTEGER {
		$$ = $1;
	}

expression:
	integer_constant {
		$$.value = $1;
		$$.undefined_macro = NULL;
	}
|	IDENTIFIER {
		$$.value = 0;
		if (parser->is_gles)
			$$.undefined_macro = ralloc_strdup (parser, $1);
		else
			$$.undefined_macro = NULL;
	}
|	expression OR expression {
		$$.value = $1.value || $3.value;

		/* Short-circuit: Only flag undefined from right side
		 * if left side evaluates to false.
		 */
		if ($1.undefined_macro)
			$$.undefined_macro = $1.undefined_macro;
                else if (! $1.value)
			$$.undefined_macro = $3.undefined_macro;
	}
|	expression AND expression {
		$$.value = $1.value && $3.value;

		/* Short-circuit: Only flag undefined from right-side
		 * if left side evaluates to true.
		 */
		if ($1.undefined_macro)
			$$.undefined_macro = $1.undefined_macro;
                else if ($1.value)
			$$.undefined_macro = $3.undefined_macro;
	}
|	expression '|' expression {
		$$.value = $1.value | $3.value;
		if ($1.undefined_macro)
			$$.undefined_macro = $1.undefined_macro;
                else
			$$.undefined_macro = $3.undefined_macro;
	}
|	expression '^' expression {
		$$.value = $1.value ^ $3.value;
		if ($1.undefined_macro)
			$$.undefined_macro = $1.undefined_macro;
                else
			$$.undefined_macro = $3.undefined_macro;
	}
|	expression '&' expression {
		$$.value = $1.value & $3.value;
		if ($1.undefined_macro)
			$$.undefined_macro = $1.undefined_macro;
                else
			$$.undefined_macro = $3.undefined_macro;
	}
|	expression NOT_EQUAL expression {
		$$.value = $1.value != $3.value;
		if ($1.undefined_macro)
			$$.undefined_macro = $1.undefined_macro;
                else
			$$.undefined_macro = $3.undefined_macro;
	}
|	expression EQUAL expression {
		$$.value = $1.value == $3.value;
		if ($1.undefined_macro)
			$$.undefined_macro = $1.undefined_macro;
                else
			$$.undefined_macro = $3.undefined_macro;
	}
|	expression GREATER_OR_EQUAL expression {
		$$.value = $1.value >= $3.value;
		if ($1.undefined_macro)
			$$.undefined_macro = $1.undefined_macro;
                else
			$$.undefined_macro = $3.undefined_macro;
	}
|	expression LESS_OR_EQUAL expression {
		$$.value = $1.value <= $3.value;
		if ($1.undefined_macro)
			$$.undefined_macro = $1.undefined_macro;
                else
			$$.undefined_macro = $3.undefined_macro;
	}
|	expression '>' expression {
		$$.value = $1.value > $3.value;
		if ($1.undefined_macro)
			$$.undefined_macro = $1.undefined_macro;
                else
			$$.undefined_macro = $3.undefined_macro;
	}
|	expression '<' expression {
		$$.value = $1.value < $3.value;
		if ($1.undefined_macro)
			$$.undefined_macro = $1.undefined_macro;
                else
			$$.undefined_macro = $3.undefined_macro;
	}
|	expression RIGHT_SHIFT expression {
		$$.value = $1.value >> $3.value;
		if ($1.undefined_macro)
			$$.undefined_macro = $1.undefined_macro;
                else
			$$.undefined_macro = $3.undefined_macro;
	}
|	expression LEFT_SHIFT expression {
		$$.value = $1.value << $3.value;
		if ($1.undefined_macro)
			$$.undefined_macro = $1.undefined_macro;
                else
			$$.undefined_macro = $3.undefined_macro;
	}
|	expression '-' expression {
		$$.value = $1.value - $3.value;
		if ($1.undefined_macro)
			$$.undefined_macro = $1.undefined_macro;
                else
			$$.undefined_macro = $3.undefined_macro;
	}
|	expression '+' expression {
		$$.value = $1.value + $3.value;
		if ($1.undefined_macro)
			$$.undefined_macro = $1.undefined_macro;
                else
			$$.undefined_macro = $3.undefined_macro;
	}
|	expression '%' expression {
		if ($3.value == 0) {
			yyerror (& @1, parser,
				 "zero modulus in preprocessor directive");
		} else {
			$$.value = $1.value % $3.value;
		}
		if ($1.undefined_macro)
			$$.undefined_macro = $1.undefined_macro;
                else
			$$.undefined_macro = $3.undefined_macro;
	}
|	expression '/' expression {
		if ($3.value == 0) {
			yyerror (& @1, parser,
				 "division by 0 in preprocessor directive");
		} else {
			$$.value = $1.value / $3.value;
		}
		if ($1.undefined_macro)
			$$.undefined_macro = $1.undefined_macro;
                else
			$$.undefined_macro = $3.undefined_macro;
	}
|	expression '*' expression {
		$$.value = $1.value * $3.value;
		if ($1.undefined_macro)
			$$.undefined_macro = $1.undefined_macro;
                else
			$$.undefined_macro = $3.undefined_macro;
	}
|	'!' expression %prec UNARY {
		$$.value = ! $2.value;
		$$.undefined_macro = $2.undefined_macro;
	}
|	'~' expression %prec UNARY {
		$$.value = ~ $2.value;
		$$.undefined_macro = $2.undefined_macro;
	}
|	'-' expression %prec UNARY {
		$$.value = - $2.value;
		$$.undefined_macro = $2.undefined_macro;
	}
|	'+' expression %prec UNARY {
		$$.value = + $2.value;
		$$.undefined_macro = $2.undefined_macro;
	}
|	'(' expression ')' {
		$$ = $2;
	}
;

identifier_list:
	IDENTIFIER {
		$$ = _string_list_create (parser);
		_string_list_append_item ($$, $1);
		ralloc_steal ($$, $1);
	}
|	identifier_list ',' IDENTIFIER {
		$$ = $1;	
		_string_list_append_item ($$, $3);
		ralloc_steal ($$, $3);
	}
;

text_line:
	NEWLINE { $$ = NULL; }
|	pp_tokens NEWLINE
;

replacement_list:
	/* empty */ { $$ = NULL; }
|	pp_tokens
;

junk:
	/* empty */
|	pp_tokens {
		glcpp_error(&@1, parser, "extra tokens at end of directive");
	}
;

pp_tokens:
	preprocessing_token {
		parser->space_tokens = 1;
		$$ = _token_list_create (parser);
		_token_list_append ($$, $1);
	}
|	pp_tokens preprocessing_token {
		$$ = $1;
		_token_list_append ($$, $2);
	}
;

preprocessing_token:
	IDENTIFIER {
		$$ = _token_create_str (parser, IDENTIFIER, $1);
		$$->location = yylloc;
	}
|	INTEGER_STRING {
		$$ = _token_create_str (parser, INTEGER_STRING, $1);
		$$->location = yylloc;
	}
|	operator {
		$$ = _token_create_ival (parser, $1, $1);
		$$->location = yylloc;
	}
|	DEFINED {
		$$ = _token_create_ival (parser, DEFINED, DEFINED);
		$$->location = yylloc;
	}
|	OTHER {
		$$ = _token_create_str (parser, OTHER, $1);
		$$->location = yylloc;
	}
|	SPACE {
		$$ = _token_create_ival (parser, SPACE, SPACE);
		$$->location = yylloc;
	}
;

operator:
	'['			{ $$ = '['; }
|	']'			{ $$ = ']'; }
|	'('			{ $$ = '('; }
|	')'			{ $$ = ')'; }
|	'{'			{ $$ = '{'; }
|	'}'			{ $$ = '}'; }
|	'.'			{ $$ = '.'; }
|	'&'			{ $$ = '&'; }
|	'*'			{ $$ = '*'; }
|	'+'			{ $$ = '+'; }
|	'-'			{ $$ = '-'; }
|	'~'			{ $$ = '~'; }
|	'!'			{ $$ = '!'; }
|	'/'			{ $$ = '/'; }
|	'%'			{ $$ = '%'; }
|	LEFT_SHIFT		{ $$ = LEFT_SHIFT; }
|	RIGHT_SHIFT		{ $$ = RIGHT_SHIFT; }
|	'<'			{ $$ = '<'; }
|	'>'			{ $$ = '>'; }
|	LESS_OR_EQUAL		{ $$ = LESS_OR_EQUAL; }
|	GREATER_OR_EQUAL	{ $$ = GREATER_OR_EQUAL; }
|	EQUAL			{ $$ = EQUAL; }
|	NOT_EQUAL		{ $$ = NOT_EQUAL; }
|	'^'			{ $$ = '^'; }
|	'|'			{ $$ = '|'; }
|	AND			{ $$ = AND; }
|	OR			{ $$ = OR; }
|	';'			{ $$ = ';'; }
|	','			{ $$ = ','; }
|	'='			{ $$ = '='; }
|	PASTE			{ $$ = PASTE; }
|	PLUS_PLUS		{ $$ = PLUS_PLUS; }
|	MINUS_MINUS		{ $$ = MINUS_MINUS; }
;

%%

string_list_t *
_string_list_create(void *ctx)
{
   string_list_t *list;

   list = ralloc (ctx, string_list_t);
   list->head = NULL;
   list->tail = NULL;

   return list;
}

void
_string_list_append_item(string_list_t *list, const char *str)
{
   string_node_t *node;

   node = ralloc (list, string_node_t);
   node->str = ralloc_strdup (node, str);

   node->next = NULL;

   if (list->head == NULL) {
      list->head = node;
   } else {
      list->tail->next = node;
   }

   list->tail = node;
}

int
_string_list_contains(string_list_t *list, const char *member, int *index)
{
   string_node_t *node;
   int i;

   if (list == NULL)
      return 0;

   for (i = 0, node = list->head; node; i++, node = node->next) {
      if (strcmp (node->str, member) == 0) {
         if (index)
            *index = i;
         return 1;
      }
   }

   return 0;
}

/* Return duplicate string in list (if any), NULL otherwise. */
const char *
_string_list_has_duplicate(string_list_t *list)
{
   string_node_t *node, *dup;

   if (list == NULL)
      return NULL;

   for (node = list->head; node; node = node->next) {
      for (dup = node->next; dup; dup = dup->next) {
         if (strcmp (node->str, dup->str) == 0)
            return node->str;
      }
   }

   return NULL;
}

int
_string_list_length(string_list_t *list)
{
   int length = 0;
   string_node_t *node;

   if (list == NULL)
      return 0;

   for (node = list->head; node; node = node->next)
      length++;

   return length;
}

int
_string_list_equal(string_list_t *a, string_list_t *b)
{
   string_node_t *node_a, *node_b;

   if (a == NULL && b == NULL)
      return 1;

   if (a == NULL || b == NULL)
      return 0;

   for (node_a = a->head, node_b = b->head;
        node_a && node_b;
        node_a = node_a->next, node_b = node_b->next)
   {
      if (strcmp (node_a->str, node_b->str))
         return 0;
   }

   /* Catch the case of lists being different lengths, (which
    * would cause the loop above to terminate after the shorter
    * list). */
   return node_a == node_b;
}

argument_list_t *
_argument_list_create(void *ctx)
{
   argument_list_t *list;

   list = ralloc (ctx, argument_list_t);
   list->head = NULL;
   list->tail = NULL;

   return list;
}

void
_argument_list_append(argument_list_t *list, token_list_t *argument)
{
   argument_node_t *node;

   node = ralloc (list, argument_node_t);
   node->argument = argument;

   node->next = NULL;

   if (list->head == NULL) {
      list->head = node;
   } else {
      list->tail->next = node;
   }

   list->tail = node;
}

int
_argument_list_length(argument_list_t *list)
{
   int length = 0;
   argument_node_t *node;

   if (list == NULL)
      return 0;

   for (node = list->head; node; node = node->next)
      length++;

   return length;
}

token_list_t *
_argument_list_member_at(argument_list_t *list, int index)
{
   argument_node_t *node;
   int i;

   if (list == NULL)
      return NULL;

   node = list->head;
   for (i = 0; i < index; i++) {
      node = node->next;
      if (node == NULL)
         break;
   }

   if (node)
      return node->argument;

   return NULL;
}

/* Note: This function ralloc_steal()s the str pointer. */
token_t *
_token_create_str(void *ctx, int type, char *str)
{
   token_t *token;

   token = ralloc (ctx, token_t);
   token->type = type;
   token->value.str = str;

   ralloc_steal (token, str);

   return token;
}

token_t *
_token_create_ival(void *ctx, int type, int ival)
{
   token_t *token;

   token = ralloc (ctx, token_t);
   token->type = type;
   token->value.ival = ival;

   return token;
}

token_list_t *
_token_list_create(void *ctx)
{
   token_list_t *list;

   list = ralloc (ctx, token_list_t);
   list->head = NULL;
   list->tail = NULL;
   list->non_space_tail = NULL;

   return list;
}

void
_token_list_append(token_list_t *list, token_t *token)
{
   token_node_t *node;

   node = ralloc (list, token_node_t);
   node->token = token;
   node->next = NULL;

   if (list->head == NULL) {
      list->head = node;
   } else {
      list->tail->next = node;
   }

   list->tail = node;
   if (token->type != SPACE)
      list->non_space_tail = node;
}

void
_token_list_append_list(token_list_t *list, token_list_t *tail)
{
   if (tail == NULL || tail->head == NULL)
      return;

   if (list->head == NULL) {
      list->head = tail->head;
   } else {
      list->tail->next = tail->head;
   }

   list->tail = tail->tail;
   list->non_space_tail = tail->non_space_tail;
}

static token_list_t *
_token_list_copy(void *ctx, token_list_t *other)
{
   token_list_t *copy;
   token_node_t *node;

   if (other == NULL)
      return NULL;

   copy = _token_list_create (ctx);
   for (node = other->head; node; node = node->next) {
      token_t *new_token = ralloc (copy, token_t);
      *new_token = *node->token;
      _token_list_append (copy, new_token);
   }

   return copy;
}

static void
_token_list_trim_trailing_space(token_list_t *list)
{
   token_node_t *tail, *next;

   if (list->non_space_tail) {
      tail = list->non_space_tail->next;
      list->non_space_tail->next = NULL;
      list->tail = list->non_space_tail;

      while (tail) {
         next = tail->next;
         ralloc_free (tail);
         tail = next;
      }
   }
}

static int
_token_list_is_empty_ignoring_space(token_list_t *l)
{
   token_node_t *n;

   if (l == NULL)
      return 1;

   n = l->head;
   while (n != NULL && n->token->type == SPACE)
      n = n->next;

   return n == NULL;
}

int
_token_list_equal_ignoring_space(token_list_t *a, token_list_t *b)
{
   token_node_t *node_a, *node_b;

   if (a == NULL || b == NULL) {
      int a_empty = _token_list_is_empty_ignoring_space(a);
      int b_empty = _token_list_is_empty_ignoring_space(b);
      return a_empty == b_empty;
   }

   node_a = a->head;
   node_b = b->head;

   while (1)
   {
      if (node_a == NULL && node_b == NULL)
         break;

      if (node_a == NULL || node_b == NULL)
         return 0;
      /* Make sure whitespace appears in the same places in both.
       * It need not be exactly the same amount of whitespace,
       * though.
       */
      if (node_a->token->type == SPACE && node_b->token->type == SPACE) {
         while (node_a && node_a->token->type == SPACE)
            node_a = node_a->next;
         while (node_b && node_b->token->type == SPACE)
            node_b = node_b->next;
         continue;
      }

      if (node_a->token->type != node_b->token->type)
         return 0;

      switch (node_a->token->type) {
      case INTEGER:
         if (node_a->token->value.ival !=  node_b->token->value.ival) {
            return 0;
         }
         break;
      case IDENTIFIER:
      case INTEGER_STRING:
      case OTHER:
         if (strcmp(node_a->token->value.str, node_b->token->value.str)) {
            return 0;
         }
         break;
      }

      node_a = node_a->next;
      node_b = node_b->next;
   }

   return 1;
}

static void
_token_print(char **out, size_t *len, token_t *token)
{
   if (token->type < 256) {
      ralloc_asprintf_rewrite_tail (out, len, "%c", token->type);
      return;
   }

   switch (token->type) {
   case INTEGER:
      ralloc_asprintf_rewrite_tail (out, len, "%" PRIiMAX, token->value.ival);
      break;
   case IDENTIFIER:
   case INTEGER_STRING:
   case OTHER:
      ralloc_asprintf_rewrite_tail (out, len, "%s", token->value.str);
      break;
   case SPACE:
      ralloc_asprintf_rewrite_tail (out, len, " ");
      break;
   case LEFT_SHIFT:
      ralloc_asprintf_rewrite_tail (out, len, "<<");
      break;
   case RIGHT_SHIFT:
      ralloc_asprintf_rewrite_tail (out, len, ">>");
      break;
   case LESS_OR_EQUAL:
      ralloc_asprintf_rewrite_tail (out, len, "<=");
      break;
   case GREATER_OR_EQUAL:
      ralloc_asprintf_rewrite_tail (out, len, ">=");
      break;
   case EQUAL:
      ralloc_asprintf_rewrite_tail (out, len, "==");
      break;
   case NOT_EQUAL:
      ralloc_asprintf_rewrite_tail (out, len, "!=");
      break;
   case AND:
      ralloc_asprintf_rewrite_tail (out, len, "&&");
      break;
   case OR:
      ralloc_asprintf_rewrite_tail (out, len, "||");
      break;
   case PASTE:
      ralloc_asprintf_rewrite_tail (out, len, "##");
      break;
   case PLUS_PLUS:
      ralloc_asprintf_rewrite_tail (out, len, "++");
      break;
   case MINUS_MINUS:
      ralloc_asprintf_rewrite_tail (out, len, "--");
      break;
   case DEFINED:
      ralloc_asprintf_rewrite_tail (out, len, "defined");
      break;
   case PLACEHOLDER:
      /* Nothing to print. */
      break;
   default:
      assert(!"Error: Don't know how to print token.");

      break;
   }
}

/* Return a new token (ralloc()ed off of 'token') formed by pasting
 * 'token' and 'other'. Note that this function may return 'token' or
 * 'other' directly rather than allocating anything new.
 *
 * Caution: Only very cursory error-checking is performed to see if
 * the final result is a valid single token. */
static token_t *
_token_paste(glcpp_parser_t *parser, token_t *token, token_t *other)
{
   token_t *combined = NULL;

   /* Pasting a placeholder onto anything makes no change. */
   if (other->type == PLACEHOLDER)
      return token;

   /* When 'token' is a placeholder, just return 'other'. */
   if (token->type == PLACEHOLDER)
      return other;

   /* A very few single-character punctuators can be combined
    * with another to form a multi-character punctuator. */
   switch (token->type) {
   case '<':
      if (other->type == '<')
         combined = _token_create_ival (token, LEFT_SHIFT, LEFT_SHIFT);
      else if (other->type == '=')
         combined = _token_create_ival (token, LESS_OR_EQUAL, LESS_OR_EQUAL);
      break;
   case '>':
      if (other->type == '>')
         combined = _token_create_ival (token, RIGHT_SHIFT, RIGHT_SHIFT);
      else if (other->type == '=')
         combined = _token_create_ival (token, GREATER_OR_EQUAL, GREATER_OR_EQUAL);
      break;
   case '=':
      if (other->type == '=')
         combined = _token_create_ival (token, EQUAL, EQUAL);
      break;
   case '!':
      if (other->type == '=')
         combined = _token_create_ival (token, NOT_EQUAL, NOT_EQUAL);
      break;
   case '&':
      if (other->type == '&')
         combined = _token_create_ival (token, AND, AND);
      break;
   case '|':
      if (other->type == '|')
         combined = _token_create_ival (token, OR, OR);
      break;
   }

   if (combined != NULL) {
      /* Inherit the location from the first token */
      combined->location = token->location;
      return combined;
   }

   /* Two string-valued (or integer) tokens can usually just be
    * mashed together. (We also handle a string followed by an
    * integer here as well.)
    *
    * There are some exceptions here. Notably, if the first token
    * is an integer (or a string representing an integer), then
    * the second token must also be an integer or must be a
    * string representing an integer that begins with a digit.
    */
   if ((token->type == IDENTIFIER || token->type == OTHER || token->type == INTEGER_STRING || token->type == INTEGER) &&
       (other->type == IDENTIFIER || other->type == OTHER || other->type == INTEGER_STRING || other->type == INTEGER))
   {
      char *str;
      int combined_type;

      /* Check that pasting onto an integer doesn't create a
       * non-integer, (that is, only digits can be
       * pasted. */
      if (token->type == INTEGER_STRING || token->type == INTEGER) {
         switch (other->type) {
         case INTEGER_STRING:
            if (other->value.str[0] < '0' || other->value.str[0] > '9')
               goto FAIL;
            break;
         case INTEGER:
            if (other->value.ival < 0)
               goto FAIL;
            break;
         default:
            goto FAIL;
         }
      }

      if (token->type == INTEGER)
         str = ralloc_asprintf (token, "%" PRIiMAX, token->value.ival);
      else
         str = ralloc_strdup (token, token->value.str);

      if (other->type == INTEGER)
         ralloc_asprintf_append (&str, "%" PRIiMAX, other->value.ival);
      else
         ralloc_strcat (&str, other->value.str);

      /* New token is same type as original token, unless we
       * started with an integer, in which case we will be
       * creating an integer-string. */
      combined_type = token->type;
      if (combined_type == INTEGER)
         combined_type = INTEGER_STRING;

      combined = _token_create_str (token, combined_type, str);
      combined->location = token->location;
      return combined;
   }

    FAIL:
   glcpp_error (&token->location, parser, "");
   ralloc_asprintf_rewrite_tail (&parser->info_log, &parser->info_log_length, "Pasting \"");
   _token_print (&parser->info_log, &parser->info_log_length, token);
   ralloc_asprintf_rewrite_tail (&parser->info_log, &parser->info_log_length, "\" and \"");
   _token_print (&parser->info_log, &parser->info_log_length, other);
   ralloc_asprintf_rewrite_tail (&parser->info_log, &parser->info_log_length, "\" does not give a valid preprocessing token.\n");

   return token;
}

static void
_token_list_print(glcpp_parser_t *parser, token_list_t *list)
{
   token_node_t *node;

   if (list == NULL)
      return;

   for (node = list->head; node; node = node->next)
      _token_print (&parser->output, &parser->output_length, node->token);
}

void
yyerror(YYLTYPE *locp, glcpp_parser_t *parser, const char *error)
{
   glcpp_error(locp, parser, "%s", error);
}

static void
add_builtin_define(glcpp_parser_t *parser, const char *name, int value)
{
   token_t *tok;
   token_list_t *list;

   tok = _token_create_ival (parser, INTEGER, value);

   list = _token_list_create(parser);
   _token_list_append(list, tok);
   _define_object_macro(parser, NULL, name, list);
}

glcpp_parser_t *
glcpp_parser_create(glcpp_extension_iterator extensions, void *state, gl_api api)
{
   glcpp_parser_t *parser;

   parser = ralloc (NULL, glcpp_parser_t);

   glcpp_lex_init_extra (parser, &parser->scanner);
   parser->defines = hash_table_ctor(32, hash_table_string_hash,
                                     hash_table_string_compare);
   parser->active = NULL;
   parser->lexing_directive = 0;
   parser->space_tokens = 1;
   parser->last_token_was_newline = 0;
   parser->last_token_was_space = 0;
   parser->first_non_space_token_this_line = 1;
   parser->newline_as_space = 0;
   parser->in_control_line = 0;
   parser->paren_count = 0;
   parser->commented_newlines = 0;

   parser->skip_stack = NULL;
   parser->skipping = 0;

   parser->lex_from_list = NULL;
   parser->lex_from_node = NULL;

   parser->output = ralloc_strdup(parser, "");
   parser->output_length = 0;
   parser->info_log = ralloc_strdup(parser, "");
   parser->info_log_length = 0;
   parser->error = 0;

   parser->extensions = extensions;
   parser->state = state;
   parser->api = api;
   parser->version = 0;

   parser->has_new_line_number = 0;
   parser->new_line_number = 1;
   parser->has_new_source_number = 0;
   parser->new_source_number = 0;

   return parser;
}

void
glcpp_parser_destroy(glcpp_parser_t *parser)
{
   glcpp_lex_destroy (parser->scanner);
   hash_table_dtor (parser->defines);
   ralloc_free (parser);
}

typedef enum function_status
{
   FUNCTION_STATUS_SUCCESS,
   FUNCTION_NOT_A_FUNCTION,
   FUNCTION_UNBALANCED_PARENTHESES
} function_status_t;

/* Find a set of function-like macro arguments by looking for a
 * balanced set of parentheses.
 *
 * When called, 'node' should be the opening-parenthesis token, (or
 * perhaps preceeding SPACE tokens). Upon successful return *last will
 * be the last consumed node, (corresponding to the closing right
 * parenthesis).
 *
 * Return values:
 *
 *   FUNCTION_STATUS_SUCCESS:
 *
 *      Successfully parsed a set of function arguments.
 *
 *   FUNCTION_NOT_A_FUNCTION:
 *
 *      Macro name not followed by a '('. This is not an error, but
 *      simply that the macro name should be treated as a non-macro.
 *
 *   FUNCTION_UNBALANCED_PARENTHESES
 *
 *      Macro name is not followed by a balanced set of parentheses.
 */
static function_status_t
_arguments_parse(argument_list_t *arguments, token_node_t *node,
                 token_node_t **last)
{
   token_list_t *argument;
   int paren_count;

   node = node->next;

   /* Ignore whitespace before first parenthesis. */
   while (node && node->token->type == SPACE)
      node = node->next;

   if (node == NULL || node->token->type != '(')
      return FUNCTION_NOT_A_FUNCTION;

   node = node->next;

   argument = _token_list_create (arguments);
   _argument_list_append (arguments, argument);

   for (paren_count = 1; node; node = node->next) {
      if (node->token->type == '(') {
         paren_count++;
      } else if (node->token->type == ')') {
         paren_count--;
         if (paren_count == 0)
            break;
      }

      if (node->token->type == ',' && paren_count == 1) {
         _token_list_trim_trailing_space (argument);
         argument = _token_list_create (arguments);
         _argument_list_append (arguments, argument);
      } else {
         if (argument->head == NULL) {
            /* Don't treat initial whitespace as part of the argument. */
            if (node->token->type == SPACE)
               continue;
         }
         _token_list_append (argument, node->token);
      }
   }

   if (paren_count)
      return FUNCTION_UNBALANCED_PARENTHESES;

   *last = node;

   return FUNCTION_STATUS_SUCCESS;
}

static token_list_t *
_token_list_create_with_one_ival(void *ctx, int type, int ival)
{
   token_list_t *list;
   token_t *node;

   list = _token_list_create(ctx);
   node = _token_create_ival(list, type, ival);
   _token_list_append(list, node);

   return list;
}

static token_list_t *
_token_list_create_with_one_space(void *ctx)
{
   return _token_list_create_with_one_ival(ctx, SPACE, SPACE);
}

static token_list_t *
_token_list_create_with_one_integer(void *ctx, int ival)
{
   return _token_list_create_with_one_ival(ctx, INTEGER, ival);
}

/* Evaluate a DEFINED token node (based on subsequent tokens in the list).
 *
 * Note: This function must only be called when "node" is a DEFINED token,
 * (and will abort with an assertion failure otherwise).
 *
 * If "node" is followed, (ignoring any SPACE tokens), by an IDENTIFIER token
 * (optionally preceded and followed by '(' and ')' tokens) then the following
 * occurs:
 *
 *   If the identifier is a defined macro, this function returns 1.
 *
 *   If the identifier is not a defined macro, this function returns 0.
 *
 *   In either case, *last will be updated to the last node in the list
 *   consumed by the evaluation, (either the token of the identifier or the
 *   token of the closing parenthesis).
 *
 * In all other cases, (such as "node is the final node of the list", or
 * "missing closing parenthesis", etc.), this function generates a
 * preprocessor error, returns -1 and *last will not be set.
 */
static int
_glcpp_parser_evaluate_defined(glcpp_parser_t *parser, token_node_t *node,
                               token_node_t **last)
{
   token_node_t *argument, *defined = node;

   assert(node->token->type == DEFINED);

   node = node->next;

   /* Ignore whitespace after DEFINED token. */
   while (node && node->token->type == SPACE)
      node = node->next;

   if (node == NULL)
      goto FAIL;

   if (node->token->type == IDENTIFIER || node->token->type == OTHER) {
      argument = node;
   } else if (node->token->type == '(') {
      node = node->next;

      /* Ignore whitespace after '(' token. */
      while (node && node->token->type == SPACE)
         node = node->next;

      if (node == NULL || (node->token->type != IDENTIFIER &&
                           node->token->type != OTHER)) {
         goto FAIL;
      }

      argument = node;

      node = node->next;

      /* Ignore whitespace after identifier, before ')' token. */
      while (node && node->token->type == SPACE)
         node = node->next;

      if (node == NULL || node->token->type != ')')
         goto FAIL;
   } else {
      goto FAIL;
   }

   *last = node;

   return hash_table_find(parser->defines,
                          argument->token->value.str) ? 1 : 0;

FAIL:
   glcpp_error (&defined->token->location, parser,
                "\"defined\" not followed by an identifier");
   return -1;
}

/* Evaluate all DEFINED nodes in a given list, modifying the list in place.
 */
static void
_glcpp_parser_evaluate_defined_in_list(glcpp_parser_t *parser,
                                       token_list_t *list)
{
   token_node_t *node, *node_prev, *replacement, *last = NULL;
   int value;

   if (list == NULL)
      return;

   node_prev = NULL;
   node = list->head;

   while (node) {

      if (node->token->type != DEFINED)
         goto NEXT;

      value = _glcpp_parser_evaluate_defined (parser, node, &last);
      if (value == -1)
         goto NEXT;

      replacement = ralloc (list, token_node_t);
      replacement->token = _token_create_ival (list, INTEGER, value);

      /* Splice replacement node into list, replacing from "node"
       * through "last". */
      if (node_prev)
         node_prev->next = replacement;
      else
         list->head = replacement;
      replacement->next = last->next;
      if (last == list->tail)
         list->tail = replacement;

      node = replacement;

   NEXT:
      node_prev = node;
      node = node->next;
   }
}

/* Perform macro expansion on 'list', placing the resulting tokens
 * into a new list which is initialized with a first token of type
 * 'head_token_type'. Then begin lexing from the resulting list,
 * (return to the current lexing source when this list is exhausted).
 *
 * See the documentation of _glcpp_parser_expand_token_list for a description
 * of the "mode" parameter.
 */
static void
_glcpp_parser_expand_and_lex_from(glcpp_parser_t *parser, int head_token_type,
                                  token_list_t *list, expansion_mode_t mode)
{
   token_list_t *expanded;
   token_t *token;

   expanded = _token_list_create (parser);
   token = _token_create_ival (parser, head_token_type, head_token_type);
   _token_list_append (expanded, token);
   _glcpp_parser_expand_token_list (parser, list, mode);
   _token_list_append_list (expanded, list);
   glcpp_parser_lex_from (parser, expanded);
}

static void
_glcpp_parser_apply_pastes(glcpp_parser_t *parser, token_list_t *list)
{
   token_node_t *node;

   node = list->head;
   while (node) {
      token_node_t *next_non_space;

      /* Look ahead for a PASTE token, skipping space. */
      next_non_space = node->next;
      while (next_non_space && next_non_space->token->type == SPACE)
         next_non_space = next_non_space->next;

      if (next_non_space == NULL)
         break;

      if (next_non_space->token->type != PASTE) {
         node = next_non_space;
         continue;
      }

      /* Now find the next non-space token after the PASTE. */
      next_non_space = next_non_space->next;
      while (next_non_space && next_non_space->token->type == SPACE)
         next_non_space = next_non_space->next;

      if (next_non_space == NULL) {
         yyerror(&node->token->location, parser, "'##' cannot appear at either end of a macro expansion\n");
         return;
      }

      node->token = _token_paste(parser, node->token, next_non_space->token);
      node->next = next_non_space->next;
      if (next_non_space == list->tail)
         list->tail = node;
   }

   list->non_space_tail = list->tail;
}

/* This is a helper function that's essentially part of the
 * implementation of _glcpp_parser_expand_node. It shouldn't be called
 * except for by that function.
 *
 * Returns NULL if node is a simple token with no expansion, (that is,
 * although 'node' corresponds to an identifier defined as a
 * function-like macro, it is not followed with a parenthesized
 * argument list).
 *
 * Compute the complete expansion of node (which is a function-like
 * macro) and subsequent nodes which are arguments.
 *
 * Returns the token list that results from the expansion and sets
 * *last to the last node in the list that was consumed by the
 * expansion. Specifically, *last will be set as follows: as the
 * token of the closing right parenthesis.
 *
 * See the documentation of _glcpp_parser_expand_token_list for a description
 * of the "mode" parameter.
 */
static token_list_t *
_glcpp_parser_expand_function(glcpp_parser_t *parser, token_node_t *node,
                              token_node_t **last, expansion_mode_t mode)
{
   macro_t *macro;
   const char *identifier;
   argument_list_t *arguments;
   function_status_t status;
   token_list_t *substituted;
   int parameter_index;

   identifier = node->token->value.str;

   macro = hash_table_find(parser->defines, identifier);

   assert(macro->is_function);

   arguments = _argument_list_create(parser);
   status = _arguments_parse(arguments, node, last);

   switch (status) {
   case FUNCTION_STATUS_SUCCESS:
      break;
   case FUNCTION_NOT_A_FUNCTION:
      return NULL;
   case FUNCTION_UNBALANCED_PARENTHESES:
      glcpp_error(&node->token->location, parser, "Macro %s call has unbalanced parentheses\n", identifier);
      return NULL;
   }

   /* Replace a macro defined as empty with a SPACE token. */
   if (macro->replacements == NULL) {
      ralloc_free(arguments);
      return _token_list_create_with_one_space(parser);
   }

   if (!((_argument_list_length (arguments) ==
          _string_list_length (macro->parameters)) ||
         (_string_list_length (macro->parameters) == 0 &&
          _argument_list_length (arguments) == 1 &&
          arguments->head->argument->head == NULL))) {
      glcpp_error(&node->token->location, parser,
                  "Error: macro %s invoked with %d arguments (expected %d)\n",
                  identifier, _argument_list_length (arguments),
                  _string_list_length(macro->parameters));
      return NULL;
   }

   /* Perform argument substitution on the replacement list. */
   substituted = _token_list_create(arguments);

   for (node = macro->replacements->head; node; node = node->next) {
      if (node->token->type == IDENTIFIER &&
          _string_list_contains(macro->parameters, node->token->value.str,
                                &parameter_index)) {
         token_list_t *argument;
         argument = _argument_list_member_at(arguments, parameter_index);
         /* Before substituting, we expand the argument tokens, or append a
          * placeholder token for an empty argument. */
         if (argument->head) {
            token_list_t *expanded_argument;
            expanded_argument = _token_list_copy(parser, argument);
            _glcpp_parser_expand_token_list(parser, expanded_argument, mode);
            _token_list_append_list(substituted, expanded_argument);
         } else {
            token_t *new_token;

            new_token = _token_create_ival(substituted, PLACEHOLDER,
                                           PLACEHOLDER);
            _token_list_append(substituted, new_token);
         }
      } else {
         _token_list_append(substituted, node->token);
      }
   }

   /* After argument substitution, and before further expansion
    * below, implement token pasting. */

   _token_list_trim_trailing_space(substituted);

   _glcpp_parser_apply_pastes(parser, substituted);

   return substituted;
}

/* Compute the complete expansion of node, (and subsequent nodes after
 * 'node' in the case that 'node' is a function-like macro and
 * subsequent nodes are arguments).
 *
 * Returns NULL if node is a simple token with no expansion.
 *
 * Otherwise, returns the token list that results from the expansion
 * and sets *last to the last node in the list that was consumed by
 * the expansion. Specifically, *last will be set as follows:
 *
 *   As 'node' in the case of object-like macro expansion.
 *
 *   As the token of the closing right parenthesis in the case of
 *   function-like macro expansion.
 *
 * See the documentation of _glcpp_parser_expand_token_list for a description
 * of the "mode" parameter.
 */
static token_list_t *
_glcpp_parser_expand_node(glcpp_parser_t *parser, token_node_t *node,
                          token_node_t **last, expansion_mode_t mode)
{
   token_t *token = node->token;
   const char *identifier;
   macro_t *macro;

   /* We only expand identifiers */
   if (token->type != IDENTIFIER) {
      return NULL;
   }

   *last = node;
   identifier = token->value.str;

   /* Special handling for __LINE__ and __FILE__, (not through
    * the hash table). */
   if (strcmp(identifier, "__LINE__") == 0)
      return _token_list_create_with_one_integer(parser, node->token->location.first_line);

   if (strcmp(identifier, "__FILE__") == 0)
      return _token_list_create_with_one_integer(parser, node->token->location.source);

   /* Look up this identifier in the hash table. */
   macro = hash_table_find(parser->defines, identifier);

   /* Not a macro, so no expansion needed. */
   if (macro == NULL)
      return NULL;

   /* Finally, don't expand this macro if we're already actively
    * expanding it, (to avoid infinite recursion). */
   if (_parser_active_list_contains (parser, identifier)) {
      /* We change the token type here from IDENTIFIER to OTHER to prevent any
       * future expansion of this unexpanded token. */
      char *str;
      token_list_t *expansion;
      token_t *final;

      str = ralloc_strdup(parser, token->value.str);
      final = _token_create_str(parser, OTHER, str);
      expansion = _token_list_create(parser);
      _token_list_append(expansion, final);
      return expansion;
   }

   if (! macro->is_function) {
      token_list_t *replacement;

      /* Replace a macro defined as empty with a SPACE token. */
      if (macro->replacements == NULL)
         return _token_list_create_with_one_space(parser);

      replacement = _token_list_copy(parser, macro->replacements);
      _glcpp_parser_apply_pastes(parser, replacement);
      return replacement;
   }

   return _glcpp_parser_expand_function(parser, node, last, mode);
}

/* Push a new identifier onto the parser's active list.
 *
 * Here, 'marker' is the token node that appears in the list after the
 * expansion of 'identifier'. That is, when the list iterator begins
 * examining 'marker', then it is time to pop this node from the
 * active stack.
 */
static void
_parser_active_list_push(glcpp_parser_t *parser, const char *identifier,
                         token_node_t *marker)
{
   active_list_t *node;

   node = ralloc(parser->active, active_list_t);
   node->identifier = ralloc_strdup(node, identifier);
   node->marker = marker;
   node->next = parser->active;

   parser->active = node;
}

static void
_parser_active_list_pop(glcpp_parser_t *parser)
{
   active_list_t *node = parser->active;

   if (node == NULL) {
      parser->active = NULL;
      return;
   }

   node = parser->active->next;
   ralloc_free (parser->active);

   parser->active = node;
}

static int
_parser_active_list_contains(glcpp_parser_t *parser, const char *identifier)
{
   active_list_t *node;

   if (parser->active == NULL)
      return 0;

   for (node = parser->active; node; node = node->next)
      if (strcmp(node->identifier, identifier) == 0)
         return 1;

   return 0;
}

/* Walk over the token list replacing nodes with their expansion.
 * Whenever nodes are expanded the walking will walk over the new
 * nodes, continuing to expand as necessary. The results are placed in
 * 'list' itself.
 *
 * The "mode" argument controls the handling of any DEFINED tokens that
 * result from expansion as follows:
 *
 *   EXPANSION_MODE_IGNORE_DEFINED: Any resulting DEFINED tokens will be
 *      left in the final list, unevaluated. This is the correct mode
 *      for expanding any list in any context other than a
 *      preprocessor conditional, (#if or #elif).
 *
 *   EXPANSION_MODE_EVALUATE_DEFINED: Any resulting DEFINED tokens will be
 *      evaluated to 0 or 1 tokens depending on whether the following
 *      token is the name of a defined macro. If the DEFINED token is
 *      not followed by an (optionally parenthesized) identifier, then
 *      an error will be generated. This the correct mode for
 *      expanding any list in the context of a preprocessor
 *      conditional, (#if or #elif).
 */
static void
_glcpp_parser_expand_token_list(glcpp_parser_t *parser, token_list_t *list,
                                expansion_mode_t mode)
{
   token_node_t *node_prev;
   token_node_t *node, *last = NULL;
   token_list_t *expansion;
   active_list_t *active_initial = parser->active;

   if (list == NULL)
      return;

   _token_list_trim_trailing_space (list);

   node_prev = NULL;
   node = list->head;

   if (mode == EXPANSION_MODE_EVALUATE_DEFINED)
      _glcpp_parser_evaluate_defined_in_list (parser, list);

   while (node) {

      while (parser->active && parser->active->marker == node)
         _parser_active_list_pop (parser);

      expansion = _glcpp_parser_expand_node (parser, node, &last, mode);
      if (expansion) {
         token_node_t *n;

         if (mode == EXPANSION_MODE_EVALUATE_DEFINED) {
            _glcpp_parser_evaluate_defined_in_list (parser, expansion);
         }

         for (n = node; n != last->next; n = n->next)
            while (parser->active && parser->active->marker == n) {
               _parser_active_list_pop (parser);
            }

         _parser_active_list_push(parser, node->token->value.str, last->next);

         /* Splice expansion into list, supporting a simple deletion if the
          * expansion is empty.
          */
         if (expansion->head) {
            if (node_prev)
               node_prev->next = expansion->head;
            else
               list->head = expansion->head;
            expansion->tail->next = last->next;
            if (last == list->tail)
               list->tail = expansion->tail;
         } else {
            if (node_prev)
               node_prev->next = last->next;
            else
               list->head = last->next;
            if (last == list->tail)
               list->tail = NULL;
         }
      } else {
         node_prev = node;
      }
      node = node_prev ? node_prev->next : list->head;
   }

   /* Remove any lingering effects of this invocation on the
    * active list. That is, pop until the list looks like it did
    * at the beginning of this function. */
   while (parser->active && parser->active != active_initial)
      _parser_active_list_pop (parser);

   list->non_space_tail = list->tail;
}

void
_glcpp_parser_print_expanded_token_list(glcpp_parser_t *parser,
                                        token_list_t *list)
{
   if (list == NULL)
      return;

   _glcpp_parser_expand_token_list (parser, list, EXPANSION_MODE_IGNORE_DEFINED);

   _token_list_trim_trailing_space (list);

   _token_list_print (parser, list);
}

static void
_check_for_reserved_macro_name(glcpp_parser_t *parser, YYLTYPE *loc,
                               const char *identifier)
{
   /* Section 3.3 (Preprocessor) of the GLSL 1.30 spec (and later) and
    * the GLSL ES spec (all versions) say:
    *
    *     "All macro names containing two consecutive underscores ( __ )
    *     are reserved for future use as predefined macro names. All
    *     macro names prefixed with "GL_" ("GL" followed by a single
    *     underscore) are also reserved."
    *
    * The intention is that names containing __ are reserved for internal
    * use by the implementation, and names prefixed with GL_ are reserved
    * for use by Khronos.  Since every extension adds a name prefixed
    * with GL_ (i.e., the name of the extension), that should be an
    * error.  Names simply containing __ are dangerous to use, but should
    * be allowed.
    *
    * A future version of the GLSL specification will clarify this.
    */
   if (strstr(identifier, "__")) {
      glcpp_warning(loc, parser, "Macro names containing \"__\" are reserved "
                    "for use by the implementation.\n");
   }
   if (strncmp(identifier, "GL_", 3) == 0) {
      glcpp_error (loc, parser, "Macro names starting with \"GL_\" are reserved.\n");
   }
   if (strcmp(identifier, "defined") == 0) {
      glcpp_error (loc, parser, "\"defined\" cannot be used as a macro name");
   }
}

static int
_macro_equal(macro_t *a, macro_t *b)
{
   if (a->is_function != b->is_function)
      return 0;

   if (a->is_function) {
      if (! _string_list_equal (a->parameters, b->parameters))
         return 0;
   }

   return _token_list_equal_ignoring_space(a->replacements, b->replacements);
}

void
_define_object_macro(glcpp_parser_t *parser, YYLTYPE *loc,
                     const char *identifier, token_list_t *replacements)
{
   macro_t *macro, *previous;

   /* We define pre-defined macros before we've started parsing the actual
    * file. So if there's no location defined yet, that's what were doing and
    * we don't want to generate an error for using the reserved names. */
   if (loc != NULL)
      _check_for_reserved_macro_name(parser, loc, identifier);

   macro = ralloc (parser, macro_t);

   macro->is_function = 0;
   macro->parameters = NULL;
   macro->identifier = ralloc_strdup (macro, identifier);
   macro->replacements = replacements;
   ralloc_steal (macro, replacements);

   previous = hash_table_find (parser->defines, identifier);
   if (previous) {
      if (_macro_equal (macro, previous)) {
         ralloc_free (macro);
         return;
      }
      glcpp_error (loc, parser, "Redefinition of macro %s\n",  identifier);
   }

   hash_table_insert (parser->defines, macro, identifier);
}

void
_define_function_macro(glcpp_parser_t *parser, YYLTYPE *loc,
                       const char *identifier, string_list_t *parameters,
                       token_list_t *replacements)
{
   macro_t *macro, *previous;
   const char *dup;

   _check_for_reserved_macro_name(parser, loc, identifier);

        /* Check for any duplicate parameter names. */
   if ((dup = _string_list_has_duplicate (parameters)) != NULL) {
      glcpp_error (loc, parser, "Duplicate macro parameter \"%s\"", dup);
   }

   macro = ralloc (parser, macro_t);
   ralloc_steal (macro, parameters);
   ralloc_steal (macro, replacements);

   macro->is_function = 1;
   macro->parameters = parameters;
   macro->identifier = ralloc_strdup (macro, identifier);
   macro->replacements = replacements;
   previous = hash_table_find (parser->defines, identifier);
   if (previous) {
      if (_macro_equal (macro, previous)) {
         ralloc_free (macro);
         return;
      }
      glcpp_error (loc, parser, "Redefinition of macro %s\n", identifier);
   }

   hash_table_insert(parser->defines, macro, identifier);
}

static int
glcpp_parser_lex(YYSTYPE *yylval, YYLTYPE *yylloc, glcpp_parser_t *parser)
{
   token_node_t *node;
   int ret;

   if (parser->lex_from_list == NULL) {
      ret = glcpp_lex(yylval, yylloc, parser->scanner);

      /* XXX: This ugly block of code exists for the sole
       * purpose of converting a NEWLINE token into a SPACE
       * token, but only in the case where we have seen a
       * function-like macro name, but have not yet seen its
       * closing parenthesis.
       *
       * There's perhaps a more compact way to do this with
       * mid-rule actions in the grammar.
       *
       * I'm definitely not pleased with the complexity of
       * this code here.
       */
      if (parser->newline_as_space) {
         if (ret == '(') {
            parser->paren_count++;
         } else if (ret == ')') {
            parser->paren_count--;
            if (parser->paren_count == 0)
               parser->newline_as_space = 0;
         } else if (ret == NEWLINE) {
            ret = SPACE;
         } else if (ret != SPACE) {
            if (parser->paren_count == 0)
               parser->newline_as_space = 0;
         }
      } else if (parser->in_control_line) {
         if (ret == NEWLINE)
            parser->in_control_line = 0;
      }
      else if (ret == DEFINE_TOKEN || ret == UNDEF || ret == IF ||
               ret == IFDEF || ret == IFNDEF || ret == ELIF || ret == ELSE ||
               ret == ENDIF || ret == HASH_TOKEN) {
         parser->in_control_line = 1;
      } else if (ret == IDENTIFIER) {
         macro_t *macro;
         macro = hash_table_find (parser->defines,
                   yylval->str);
         if (macro && macro->is_function) {
            parser->newline_as_space = 1;
            parser->paren_count = 0;
         }
      }

      return ret;
   }

   node = parser->lex_from_node;

   if (node == NULL) {
      ralloc_free (parser->lex_from_list);
      parser->lex_from_list = NULL;
      return NEWLINE;
   }

   *yylval = node->token->value;
   ret = node->token->type;

   parser->lex_from_node = node->next;

   return ret;
}

static void
glcpp_parser_lex_from(glcpp_parser_t *parser, token_list_t *list)
{
   token_node_t *node;

   assert (parser->lex_from_list == NULL);

   /* Copy list, eliminating any space tokens. */
   parser->lex_from_list = _token_list_create (parser);

   for (node = list->head; node; node = node->next) {
      if (node->token->type == SPACE)
         continue;
      _token_list_append (parser->lex_from_list, node->token);
   }

   ralloc_free (list);

   parser->lex_from_node = parser->lex_from_list->head;

   /* It's possible the list consisted of nothing but whitespace. */
   if (parser->lex_from_node == NULL) {
      ralloc_free (parser->lex_from_list);
      parser->lex_from_list = NULL;
   }
}

static void
_glcpp_parser_skip_stack_push_if(glcpp_parser_t *parser, YYLTYPE *loc,
                                 int condition)
{
   skip_type_t current = SKIP_NO_SKIP;
   skip_node_t *node;

   if (parser->skip_stack)
      current = parser->skip_stack->type;

   node = ralloc (parser, skip_node_t);
   node->loc = *loc;

   if (current == SKIP_NO_SKIP) {
      if (condition)
         node->type = SKIP_NO_SKIP;
      else
         node->type = SKIP_TO_ELSE;
   } else {
      node->type = SKIP_TO_ENDIF;
   }

   node->has_else = false;
   node->next = parser->skip_stack;
   parser->skip_stack = node;
}

static void
_glcpp_parser_skip_stack_change_if(glcpp_parser_t *parser, YYLTYPE *loc,
                                   const char *type, int condition)
{
   if (parser->skip_stack == NULL) {
      glcpp_error (loc, parser, "#%s without #if\n", type);
      return;
   }

   if (parser->skip_stack->type == SKIP_TO_ELSE) {
      if (condition)
         parser->skip_stack->type = SKIP_NO_SKIP;
   } else {
      parser->skip_stack->type = SKIP_TO_ENDIF;
   }
}

static void
_glcpp_parser_skip_stack_pop(glcpp_parser_t *parser, YYLTYPE *loc)
{
   skip_node_t *node;

   if (parser->skip_stack == NULL) {
      glcpp_error (loc, parser, "#endif without #if\n");
      return;
   }

   node = parser->skip_stack;
   parser->skip_stack = node->next;
   ralloc_free (node);
}

static void
_glcpp_parser_handle_version_declaration(glcpp_parser_t *parser, intmax_t version,
                                         const char *es_identifier,
                                         bool explicitly_set)
{
   if (parser->version != 0)
      return;

   parser->version = version;

   add_builtin_define (parser, "__VERSION__", version);

   parser->is_gles = (version == 100) ||
                     (es_identifier && (strcmp(es_identifier, "es") == 0));

   /* Add pre-defined macros. */
   if (parser->is_gles)
      add_builtin_define(parser, "GL_ES", 1);
   else if (version >= 150)
      add_builtin_define(parser, "GL_core_profile", 1);

   /* Currently, all ES2/ES3 implementations support highp in the
    * fragment shader, so we always define this macro in ES2/ES3.
    * If we ever get a driver that doesn't support highp, we'll
    * need to add a flag to the gl_context and check that here.
    */
   if (version >= 130 || parser->is_gles)
      add_builtin_define (parser, "GL_FRAGMENT_PRECISION_HIGH", 1);

   /* Add all the extension macros available in this context */
   if (parser->extensions)
      parser->extensions(parser->state, add_builtin_define, parser,
                         version, parser->is_gles);

   if (explicitly_set) {
      ralloc_asprintf_rewrite_tail(&parser->output, &parser->output_length,
                                   "#version %" PRIiMAX "%s%s", version,
                                   es_identifier ? " " : "",
                                   es_identifier ? es_identifier : "");
   }
}

/* GLSL version if no version is explicitly specified. */
#define IMPLICIT_GLSL_VERSION 110

/* GLSL ES version if no version is explicitly specified. */
#define IMPLICIT_GLSL_ES_VERSION 100

void
glcpp_parser_resolve_implicit_version(glcpp_parser_t *parser)
{
   int language_version = parser->api == API_OPENGLES2 ?
                          IMPLICIT_GLSL_ES_VERSION : IMPLICIT_GLSL_VERSION;

   _glcpp_parser_handle_version_declaration(parser, language_version,
                                            NULL, false);
}