gmqcc/parse.c

/*
 * Copyright (C) 2012 
 * 	Dale Weiler
 *
 * 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 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 <limits.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "gmqcc.h"

/* compile-time constant for type constants */
typedef struct {
	char *name;
	int   type;
	float value[3];
	char *string; /* string value if constant is string literal */
} constant;
VECTOR_MAKE(constant, compile_constants);

/*
 * Generates a parse tree out of the lexees generated by the lexer.  This
 * is where the tree is built.  This is where valid check is performed.
 */
int parse_gen(struct lex_file *file) {	
	int     token = 0;
	while ((token = lex_token(file)) != ERROR_LEX      && \
		    token                    != ERROR_COMPILER && \
		    token                    != ERROR_INTERNAL && \
		    token                    != ERROR_PARSE    && \
		    token                    != ERROR_PREPRO   && file->length >= 0) {
		switch (token) {
			case TOKEN_TYPEDEF: {
				char *f; /* from */
				char *t; /* to   */
				
				token = lex_token(file); 
				token = lex_token(file); f = util_strdup(file->lastok);
				token = lex_token(file); 
				token = lex_token(file); t = util_strdup(file->lastok);
				
				typedef_add(f, t);
				mem_d(f);
				mem_d(t);
				
				token = lex_token(file);
				if (token == ' ')
					token = lex_token(file);
					
				if (token != ';')
					error(ERROR_PARSE, "%s:%d Expected a `;` at end of typedef statement\n", file->name, file->line);
					
				token = lex_token(file);
				break;
			}
			
			case TOKEN_VOID:   goto fall;
			case TOKEN_STRING: goto fall;
			case TOKEN_VECTOR: goto fall;
			case TOKEN_ENTITY: goto fall;
			case TOKEN_FLOAT:  goto fall;
			{
			fall:;
				char *name = NULL;
				int   type = token; /* story copy */
				
				/* skip over space */
				token = lex_token(file);
				if (token == ' ')
					token = lex_token(file);
				
				/* save name */
				name = util_strdup(file->lastok);
				
				/* skip spaces */
				token = lex_token(file);
				if (token == ' ')
					token = lex_token(file);
					
				if (token == ';') {
					/*
					 * Definitions go to the defs table, they don't have
					 * any sort of data with them yet.
					 */
				} else if (token == '=') {
					token = lex_token(file);
					if (token == ' ')
						token = lex_token(file);
					
					/* strings are in file->lastok */
					switch (type) {
						case TOKEN_VOID:
							return error(ERROR_PARSE, "%s:%d Cannot assign value to type void\n", file->name, file->line);
							
						/* TODO: Validate (end quote), strip quotes for constant add, name constant */
						case TOKEN_STRING:
							if (*file->lastok != '"')
								error(ERROR_PARSE, "%s:%d Expected a '\"' (quote) for string constant\n", file->name, file->line);
							/* add the compile-time constant */
							compile_constants_add((constant){
								.name   = util_strdup(name),
								.type   = TYPE_STRING,
								.value  = {0,0,0},
								.string = util_strdup(file->lastok)
							});
							break;
						/* TODO: name constant, old qc vec literals, whitespace fixes, name constant */
						case TOKEN_VECTOR: {
							float compile_calc_x = 0;
							float compile_calc_y = 0;
							float compile_calc_z = 0;
							int   compile_calc_d = 0; /* dot?        */
							int   compile_calc_s = 0; /* sign (-, +) */
							
							char  compile_data[1024];
							char *compile_eval = compile_data;
							
							if (token != '{')
								error(ERROR_PARSE, "%s:%d Expected initializer list `{`,`}` for vector constant\n", file->name, file->line);	
							
							/*
							 * This parses a single vector element: x,y & z.  This will handle all the
							 * complicated mechanics of a vector, and can be extended as well.  This
							 * is a rather large macro, and is #undef'd after it's use below.
							 */
							#define PARSE_VEC_ELEMENT(NAME, BIT)                                                                                                                                   \
							    token = lex_token(file);                                                                                                                                           \
							    if (token == ' ')                                                                                                                                                  \
							        token = lex_token(file);                                                                                                                                       \
							    if (token == '.')                                                                                                                                                  \
							        compile_calc_d = 1;                                                                                                                                            \
							    if (!isdigit(token) && !compile_calc_d && token != '+' && token != '-')                                                                                            \
							        error(ERROR_PARSE,"%s:%d Invalid constant initializer element %c for vector, must be numeric\n", file->name, file->line, NAME);                                \
							    if (token == '+')                                                                                                                                                  \
							        compile_calc_s = '+';                                                                                                                                          \
							    if (token == '-' && !compile_calc_s)                                                                                                                               \
							        compile_calc_s = '-';                                                                                                                                          \
							    while (isdigit(token) || token == '.' || token == '+' || token == '-') {                                                                                           \
							        *compile_eval++ = token;                                                                                                                                       \
							        token           = lex_token(file);                                                                                                                             \
							        if (token == '.' && compile_calc_d) {                                                                                                                          \
							            error(ERROR_PARSE, "%s:%d Invalid constant initializer element %c for vector, must be numeric.\n", file->name, file->line, NAME);                          \
							            token = lex_token(file);                                                                                                                                   \
							        }                                                                                                                                                              \
							        if ((token == '-' || token == '+') && compile_calc_s) {                                                                                                        \
							            error(ERROR_PARSE, "%s:%d Invalid constant initializer sign for vector element %c\n", file->name, file->line, NAME);                                       \
							            token = lex_token(file);                                                                                                                                   \
							        }                                                                                                                                                              \
							        else if (token == '.' && !compile_calc_d)                                                                                                                      \
							            compile_calc_d = 1;                                                                                                                                        \
							        else if (token == '-' && !compile_calc_s)                                                                                                                      \
							            compile_calc_s = '-';                                                                                                                                      \
							        else if (token == '+' && !compile_calc_s)                                                                                                                      \
							            compile_calc_s = '+';                                                                                                                                      \
							    }                                                                                                                                                                  \
							    if (token == ' ')                                                                                                                                                  \
							        token = lex_token(file);                                                                                                                                       \
							    if (NAME != 'z') {                                                                                                                                                 \
							        if (token != ',' && token != ' ')                                                                                                                              \
							            error(ERROR_PARSE, "%s:%d invalid constant initializer element %c for vector (missing spaces, or comma delimited list?)\n", file->name, file->line, NAME); \
							    } else if (token != '}') {                                                                                                                                         \
							        error(ERROR_PARSE, "%s:%d Expected `}` on end of constant initialization for vector\n", file->name, file->line);                                               \
							    }                                                                                                                                                                  \
							    compile_calc_##BIT = atof(compile_data);                                                                                                                           \
							    compile_calc_d = 0;                                                                                                                                                \
							    compile_calc_s = 0;                                                                                                                                                \
							    compile_eval   = &compile_data[0];                                                                                                                                 \
							    memset(compile_data, 0, sizeof(compile_data))
							
							/*
							 * Parse all elements using the macro above.
							 * We must undef the macro afterwards.
							 */
							PARSE_VEC_ELEMENT('x', x);
							PARSE_VEC_ELEMENT('y', y);
							PARSE_VEC_ELEMENT('z', z);
							#undef PARSE_VEC_ELEMENT
							
							/* Check for the semi-colon... */
							token = lex_token(file);
							if (token == ' ')
								token = lex_token(file);
							if (token != ';')
								error(ERROR_PARSE, "%s:%d Expected `;` on end of constant initialization for vector\n", file->name, file->line);
								
							/* add the compile-time constant */
							compile_constants_add((constant){
								.name   = util_strdup(name),
								.type   = TYPE_VECTOR,
								.value  = {
									[0] = compile_calc_x,
									[1] = compile_calc_y,
									[2] = compile_calc_z
								},
								.string = NULL
							});
							break;
						}
							
						case TOKEN_ENTITY:
						case TOKEN_FLOAT: /*TODO: validate, constant generation, name constant */
							if (!isdigit(token))
								error(ERROR_PARSE, "%s:%d Expected numeric constant for float constant\n");
							compile_constants_add((constant){
								.name   = util_strdup(name),
								.type   = TOKEN_FLOAT,
								.value  = {0,0,0},
								.string = NULL
							});
							break;
					}
				} else if (token == '(') {
					printf("FUNCTION ??\n");
				}
				mem_d(name);
			}
				
			/*
			 * From here down is all language punctuation:  There is no
			 * need to actual create tokens from these because they're already
			 * tokenized as these individual tokens (which are in a special area
			 * of the ascii table which doesn't conflict with our other tokens
			 * which are higer than the ascii table.)
			 */
			case '#':
				token = lex_token(file); /* skip '#' */
				if (token == ' ')
					token = lex_token(file);
				/*
				 * If we make it here we found a directive, the supported
				 * directives so far are #include.
				 */
				if (strncmp(file->lastok, "include", sizeof("include")) == 0) {
					/*
					 * We only suport include " ", not <> like in C (why?)
					 * because the latter is silly.
					 */
					while (*file->lastok != '"' && token != '\n')
						token = lex_token(file);
					if (token == '\n')
						return error(ERROR_PARSE, "%d: Invalid use of include preprocessor directive: wanted #include \"file.h\"\n", file->line-1);
						
					char            *copy = util_strdup(file->lastok);
					struct lex_file *next = lex_include(file,   copy);
					
					if (!next) {
						error(ERROR_INTERNAL, "Include subsystem failure\n");
						exit (-1);
					}
					parse_gen(next);
					mem_d    (copy);
					lex_close(next);
				}
				/* skip all tokens to end of directive */
				while (token != '\n')
					token = lex_token(file);
				break;
				
			case LEX_IDENT:
				token = lex_token(file);
				break;
		}
	}
	lex_reset(file);
	return 1;
}