parser.c

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <stdarg.h>
#include <math.h>
#include <stdint.h>
#include "citrine.h"

char* ctr_cparse_current_program;

/**
 * CTRParserEmitErrorUnexpected
 *
 * Emits a parser error and adds the file and
 * position where the error has occurred.
 * Optionally you can pass a hint to this method to
 * add some details to the error message.
 */
void ctr_cparse_emit_error_unexpected( int t, char* hint )
{
	char* message = ctr_clex_tok_describe( t );
	fprintf(stderr, "Parse error, unexpected %s ( %s: %d )\n", message,  ctr_cparse_current_program, ctr_clex_line_number+1);
	if (hint) {
		fprintf(stderr, "%s", hint );
	}
	exit(1);
}

/**
 * CTRParserCreateNode
 *
 * Creates a parser node and adds it to the source map.
 */
ctr_tnode* ctr_cparse_create_node( int type ){
	ctr_tnode* node = (ctr_tnode*) ctr_heap_allocate_tracked( sizeof( ctr_tnode ) );
	if (ctr_source_mapping) {
		ctr_source_map* m = (ctr_source_map*) ctr_heap_allocate_tracked( sizeof( ctr_source_map ) );
		m->line = ctr_clex_line_number;
		m->node = node;
		if (ctr_source_map_head) {
			m->next = ctr_source_map_head;
			ctr_source_map_head = m;
		} else {
			ctr_source_map_head = m;
		}
	}
	return node;
}

/**
 * CTRParserMessage
 *
 * Creates the AST nodes for sending a message.
 *
 * - precedence mode 0: no argument (allows processing of unary message, binary message and keyword message)
 * - precedence mode 1: as argument of keyword message (allows processing of unary message and binary message)
 * - precedence mode 2: as argument of binary message (only allows processing of unary message)
 */
ctr_tnode* ctr_cparse_message(int mode) {
	long msgpartlen; /* length of part of message string */
	ctr_tnode* m;
	int t;
	char* s;
	char* msg;
	ctr_tlistitem* li;
	ctr_tlistitem* curlistitem;
	int lookAhead;
	int isBin;
	int first;
	ctr_size ulen;
	t = ctr_clex_tok();
	msgpartlen = ctr_clex_tok_value_length();
	if ((msgpartlen) > 255) {
		ctr_cparse_emit_error_unexpected( t, "Message too long\n" );
	}
	m = ctr_cparse_create_node( CTR_AST_NODE );
	m->type = -1;
	s = ctr_clex_tok_value();
	msg = ctr_heap_allocate_tracked( 255 * sizeof( char ) );
	memcpy(msg, s, msgpartlen);
	ulen = ctr_getutf8len(msg, msgpartlen);
	isBin = (ulen == 1);
	if (mode == 2 && isBin) {
		ctr_clex_putback();
		return m;
	}
	if (isBin) {
		m->type = CTR_AST_NODE_BINMESSAGE;
		m->value = msg;
		m->vlen = msgpartlen;
		li = (ctr_tlistitem*) ctr_heap_allocate_tracked( sizeof(ctr_tlistitem) );
		li->node = ctr_cparse_expr(2);
		m->nodes = li;
		return m;
	}
	lookAhead = ctr_clex_tok(); ctr_clex_putback();
	if (lookAhead == CTR_TOKEN_COLON) {
		if (mode > 0) {
			ctr_clex_putback();
			return m;
		 }
		*(msg + msgpartlen) = ':';
		msgpartlen += 1;
		if ((msgpartlen) > 255) {
			ctr_cparse_emit_error_unexpected( t, "Message too long\n" );
		}
		m->type = CTR_AST_NODE_KWMESSAGE;
		t = ctr_clex_tok();
		first = 1;
		while(1) {
			li = (ctr_tlistitem*) ctr_heap_allocate_tracked( sizeof(ctr_tlistitem) );
			li->node = ctr_cparse_expr(1);
			if (first) {
				m->nodes = li;
				curlistitem = m->nodes;
				first = 0;
			} else {
				curlistitem->next = li;
				curlistitem = li;
			}
			t = ctr_clex_tok();
			if (t == CTR_TOKEN_DOT) break;
			if (t == CTR_TOKEN_FIN) break;
			if (t == CTR_TOKEN_CHAIN) break;
			if (t == CTR_TOKEN_PARCLOSE) break;
			if (t == CTR_TOKEN_REF) {
				long l = ctr_clex_tok_value_length(); 
				if ((msgpartlen + l) > 255) {
					ctr_cparse_emit_error_unexpected( t, "Message too long\n" );
				}
				memcpy( (msg+msgpartlen), ctr_clex_tok_value(), l);
				msgpartlen = msgpartlen + l;
				*(msg + msgpartlen) = ':';
				msgpartlen ++;
				t = ctr_clex_tok();
				if (t != CTR_TOKEN_COLON) {
					ctr_cparse_emit_error_unexpected( t, "Expected colon.\n" );
				}
			}
		}
		ctr_clex_putback(); /* not a colon so put back */
		m->value = msg;
		m->vlen = msgpartlen;
	} else {
		m->type = CTR_AST_NODE_UNAMESSAGE;
		m->value = msg;
		m->vlen = msgpartlen;
	}
	return m;
}

/**
 * CTRParserMessages
 * 
 * Manages the creation of nodes to send a message, uses CTRParserMessage
 * to create the actual nodes.
 */
ctr_tlistitem* ctr_cparse_messages(ctr_tnode* r, int mode) {
	int t = ctr_clex_tok();
	ctr_tlistitem* pli;
	ctr_tlistitem* li;
	ctr_tlistitem* fli;
	int first = 1;
	ctr_tnode* node;
	/* explicit chaining (,) only allowed for keyword message: Console write: 3 factorial, write: 3 factorial is not possible otherwise. */
	while ((t == CTR_TOKEN_REF || (t == CTR_TOKEN_CHAIN && node && node->type == CTR_AST_NODE_KWMESSAGE))) {
		if (t == CTR_TOKEN_CHAIN) {
			t = ctr_clex_tok();
			if (t != CTR_TOKEN_REF) {
				ctr_cparse_emit_error_unexpected( t, "Expected message.\n" );
			}
		}
		li = (ctr_tlistitem*) ctr_heap_allocate_tracked( sizeof(ctr_tlistitem) );
		ctr_clex_putback();
		node = ctr_cparse_message(mode);
		if (node->type == -1) {
			if (first) {
				return NULL;
			}
			ctr_clex_tok();
			break;
		}
		li->node = node;
		if (first) {
			first = 0;
			pli = li;
			fli = li;
		} else {
			pli->next = li;
			pli = li;
		}
		t = ctr_clex_tok();
	}
	ctr_clex_putback();
	return fli;
}


/**
 * CTRParserPOpen
 *
 * Generates a set of nested nodes.
 */
ctr_tnode* ctr_cparse_popen() {
	ctr_tnode* r;
	ctr_tlistitem* li;
	int t;
	ctr_clex_tok();
	r = ctr_cparse_create_node( CTR_AST_NODE );
	r->type = CTR_AST_NODE_NESTED;
	li = (ctr_tlistitem*) ctr_heap_allocate_tracked( sizeof(ctr_tlistitem) );
	r->nodes = li;
	li->node = ctr_cparse_expr(0);
	t = ctr_clex_tok();
	if (t != CTR_TOKEN_PARCLOSE) {
		ctr_cparse_emit_error_unexpected( t, "Expected ).\n" );
	}
	return r;
}

/**
 * CTRParserBlock
 *
 * Generates a set of AST nodes to represent a block of code.
 */
ctr_tnode* ctr_cparse_block() {
	ctr_tnode* r;
	ctr_tlistitem* codeBlockPart1;
	ctr_tlistitem* codeBlockPart2;
	ctr_tnode* paramList;
	ctr_tnode* codeList;
	ctr_tlistitem* previousListItem;
	ctr_tlistitem* previousCodeListItem;
	int t;
	int first;
	ctr_clex_tok();
	r = ctr_cparse_create_node( CTR_AST_NODE );
	r->type = CTR_AST_NODE_CODEBLOCK;
	codeBlockPart1 = (ctr_tlistitem*) ctr_heap_allocate_tracked( sizeof(ctr_tlistitem) );
	r->nodes = codeBlockPart1;
	codeBlockPart2 = (ctr_tlistitem*) ctr_heap_allocate_tracked( sizeof(ctr_tlistitem) );
	r->nodes->next = codeBlockPart2;
	paramList = ctr_cparse_create_node( CTR_AST_NODE );
	codeList  = ctr_cparse_create_node( CTR_AST_NODE );
	codeBlockPart1->node = paramList;
	codeBlockPart2->node = codeList;
	paramList->type = CTR_AST_NODE_PARAMLIST;
	codeList->type = CTR_AST_NODE_INSTRLIST;
	t = ctr_clex_tok();
	first = 1;
	while(t == CTR_TOKEN_COLON) {
		/* okay we have new parameter, load it */
		t = ctr_clex_tok();
		ctr_tlistitem* paramListItem = (ctr_tlistitem*) ctr_heap_allocate_tracked( sizeof(ctr_tlistitem) );
		ctr_tnode* paramItem = ctr_cparse_create_node( CTR_AST_NODE );
		long l = ctr_clex_tok_value_length();
		paramItem->value = ctr_heap_allocate_tracked( sizeof( char ) * l );
		memcpy(paramItem->value, ctr_clex_tok_value(), l);
		paramItem->vlen = l;
		paramListItem->node = paramItem;
		if (first) {
			paramList->nodes = paramListItem;
			previousListItem = paramListItem;
			first = 0;
		} else {
			previousListItem->next = paramListItem;
			previousListItem = paramListItem;
		}
		t = ctr_clex_tok();
	}
	first = 1;
	while((first || t == CTR_TOKEN_DOT)) {
		ctr_tlistitem* codeListItem;
		ctr_tnode* codeNode;
		if (first) {
			ctr_clex_putback();
		}
		t = ctr_clex_tok();
		if (t == CTR_TOKEN_BLOCKCLOSE) break;
		ctr_clex_putback();
		codeListItem = (ctr_tlistitem*) ctr_heap_allocate_tracked( sizeof(ctr_tlistitem) );
		codeNode = ctr_cparse_create_node( CTR_AST_NODE );
		if (t == CTR_TOKEN_RET) {
			codeNode = ctr_cparse_ret();
		} else {
			codeNode = ctr_cparse_expr(0);
		}
		codeListItem->node = codeNode;
		if (first) {
			codeList->nodes = codeListItem;
			previousCodeListItem = codeListItem;
			first = 0;
		} else {
			previousCodeListItem->next = codeListItem;
			previousCodeListItem = codeListItem;
		}
		t = ctr_clex_tok();
		if (t != CTR_TOKEN_DOT) {
			ctr_cparse_emit_error_unexpected( t, "Expected a dot (.).\n" );
		}
	}
	return r;
}

/**
 * CTRParserReference
 *
 * Generates the nodes to respresent a variable or property.
 */
ctr_tnode* ctr_cparse_ref() {
	ctr_tnode* r;
	char* tmp;
	ctr_clex_tok();
	r = ctr_cparse_create_node( CTR_AST_NODE );
	r->type = CTR_AST_NODE_REFERENCE;
	r->vlen = ctr_clex_tok_value_length();
	tmp = ctr_clex_tok_value();
	if (strncmp(ctr_clex_keyword_my, tmp, ctr_clex_keyword_my_len)==0 && r->vlen == ctr_clex_keyword_my_len) {
		int t = ctr_clex_tok();
		if (t != CTR_TOKEN_REF) {
			ctr_cparse_emit_error_unexpected( t, "'My' should always be followed by a property name!\n");
		}
		tmp = ctr_clex_tok_value();
		r->modifier = 1;
		r->vlen = ctr_clex_tok_value_length();
	}
	if (strncmp(ctr_clex_keyword_my_icon, tmp, ctr_clex_keyword_my_icon_len)==0 && r->vlen == ctr_clex_keyword_my_icon_len) {
		int t = ctr_clex_tok();
		if (t != CTR_TOKEN_REF) {
			ctr_cparse_emit_error_unexpected( t, "'My' (icon) should always be followed by a property name!\n");
		}
		tmp = ctr_clex_tok_value();
		r->modifier = 1;
		r->vlen = ctr_clex_tok_value_length();
	}
	if (strncmp(ctr_clex_keyword_var, tmp, ctr_clex_keyword_var_len)==0 && r->vlen == ctr_clex_keyword_var_len) {
		int t = ctr_clex_tok();
		if (t != CTR_TOKEN_REF) {
			ctr_cparse_emit_error_unexpected( t, "Keyword 'var' should always be followed by property name!\n");
		}
		tmp = ctr_clex_tok_value();
		r->modifier = 2;
		r->vlen = ctr_clex_tok_value_length();
	}
	if (strncmp(ctr_clex_keyword_var_icon, tmp, ctr_clex_keyword_var_icon_len)==0 && r->vlen == ctr_clex_keyword_var_icon_len) {
		int t = ctr_clex_tok();
		if (t != CTR_TOKEN_REF) {
			ctr_cparse_emit_error_unexpected( t, "Keyword 'var (icon)' should always be followed by property name!\n");
		}
		tmp = ctr_clex_tok_value();
		r->modifier = 2;
		r->vlen = ctr_clex_tok_value_length();
	}
	r->value = ctr_heap_allocate_tracked( r->vlen );
	memcpy(r->value, tmp, r->vlen);
	return r;
}

/**
 * CTRParserString
 *
 * Generates a node to represent a string.
 */
ctr_tnode* ctr_cparse_string() {
	ctr_tnode* r;
	char* n;
	ctr_size vlen;
	ctr_clex_tok();
	r = ctr_cparse_create_node( CTR_AST_NODE );
	r->type = CTR_AST_NODE_LTRSTRING;
	n = ctr_clex_readstr();
	vlen = ctr_clex_tok_value_length();
	r->value = ctr_heap_allocate_tracked( sizeof( char ) * vlen );
	memcpy(r->value, n, vlen);
	r->vlen = vlen;
	ctr_clex_tok(); /* eat trailing quote. */
	return r;
}


/**
 * CTRParserNumber
 *
 * Generates a node to represent a number.
 */
void ctr_internal_debug_tree(ctr_tnode* ti, int indent);
ctr_tnode* ctr_cparse_number() {
	char* n;
	ctr_tnode* r;
	long l;
	ctr_clex_tok();
	r = ctr_cparse_create_node( CTR_AST_NODE );
	r->type = CTR_AST_NODE_LTRNUM;
	n = ctr_clex_tok_value();
	l = ctr_clex_tok_value_length();
	r->value = ctr_heap_allocate_tracked( sizeof( char ) * l );
	memcpy(r->value, n, l);
	r->vlen = l;
	return r;
}

/**
 * CTRParserBooleanFalse
 *
 * Generates a node to represent a boolean False.
 */
ctr_tnode* ctr_cparse_false() {
	ctr_tnode* r;
	ctr_clex_tok();
	r = ctr_cparse_create_node( CTR_AST_NODE );
	r->type = CTR_AST_NODE_LTRBOOLFALSE;
	r->value = ctr_heap_allocate_tracked( sizeof( char ) * 4 );
	memcpy( r->value, "False", 5 );
	r->vlen = 5;
	return r;
}

/**
 * CTRParserBooleanTrue
 *
 * Generates a node to represent a boolean True.
 */
ctr_tnode* ctr_cparse_true() {
	ctr_tnode* r;
	ctr_clex_tok();
	r = ctr_cparse_create_node( CTR_AST_NODE );
	r->type = CTR_AST_NODE_LTRBOOLTRUE;
	r->value = ctr_heap_allocate_tracked( sizeof( char ) * 4 );
	memcpy( r->value, "True", 4 );
	r->vlen = 4;
	return r;
}

/**
 * CTRParserNil
 *
 * Generates a node to represent Nil
 */
ctr_tnode* ctr_cparse_nil() {
	ctr_tnode* r;
	ctr_clex_tok();
	r = ctr_cparse_create_node( CTR_AST_NODE );
	r->type = CTR_AST_NODE_LTRNIL;
	r->value = "Nil";
	r->vlen = 3;
	return r;
}

/**
 * CTRParserReceiver
 *
 * Generates a node to represent a receiver (of a message).
 */
ctr_tnode* ctr_cparse_receiver() {
	int t;
	t = ctr_clex_tok();
	ctr_clex_putback();
	switch(t){
		case CTR_TOKEN_NIL:
			return ctr_cparse_nil();
		case CTR_TOKEN_BOOLEANYES:
			return ctr_cparse_true();
		case CTR_TOKEN_BOOLEANNO:
			return ctr_cparse_false();
		case CTR_TOKEN_NUMBER:
			return ctr_cparse_number();
		case CTR_TOKEN_QUOTE:
			return ctr_cparse_string();
		case CTR_TOKEN_REF:
			return ctr_cparse_ref();
		case CTR_TOKEN_BLOCKOPEN:
			return ctr_cparse_block();
		case CTR_TOKEN_PAROPEN:
			return ctr_cparse_popen();
		default:
			/* This function always exits, so return a dummy value. */
			ctr_cparse_emit_error_unexpected( t, "Expected a message recipient.\n" );
			return NULL;
	}
}

/**
 * CTRParserAssignment
 *
 * Generates a node to represent an assignment.
 */
ctr_tnode* ctr_cparse_assignment(ctr_tnode* r) {
	ctr_tnode* a;
	ctr_tlistitem* li;
	ctr_tlistitem* liAssignExpr;
	ctr_clex_tok();
	a = ctr_cparse_create_node( CTR_AST_NODE );
	li = (ctr_tlistitem*) ctr_heap_allocate_tracked( sizeof(ctr_tlistitem) );
	liAssignExpr = (ctr_tlistitem*) ctr_heap_allocate_tracked( sizeof(ctr_tlistitem) );
	a->type = CTR_AST_NODE_EXPRASSIGNMENT;
	a->nodes = li;
	li->node = r;
	liAssignExpr->node =   ctr_cparse_expr(0);  
	li->next = liAssignExpr;
	return a;
}

/**
 * CTRParserExpression
 *
 * Generates a set of nodes to represent an expression.
 */
ctr_tnode* ctr_cparse_expr(int mode) {
	ctr_tnode* r;
	ctr_tnode* e;
	int t2;
	ctr_tlistitem* nodes;
	ctr_tlistitem* rli;
	r = ctr_cparse_receiver();
	t2 = ctr_clex_tok();
	ctr_clex_putback();

	/* user tries to put colon directly after recipient */
	if ( t2 == CTR_TOKEN_COLON ) {
		ctr_cparse_emit_error_unexpected( t2, "Recipient cannot be followed by colon.\n" );
	}

	if ( t2 == CTR_TOKEN_ASSIGNMENT ) {
		if ( r->type != CTR_AST_NODE_REFERENCE ) {
			ctr_cparse_emit_error_unexpected( t2, "Invalid left-hand assignment.\n" );
			exit(1);
		}
		e = ctr_cparse_assignment(r);
	} else if (
		t2 != CTR_TOKEN_DOT &&
		t2 != CTR_TOKEN_PARCLOSE &&
		t2 != CTR_TOKEN_CHAIN
	) {
		e = ctr_cparse_create_node( CTR_AST_NODE );
		e->type = CTR_AST_NODE_EXPRMESSAGE;
		nodes = ctr_cparse_messages(r, mode);
		if (nodes == NULL) {
			ctr_clex_tok();
			ctr_clex_putback();
			return r; /* no messages, then just return receiver (might be in case of argument). */
		}
		rli = (ctr_tlistitem*) ctr_heap_allocate_tracked( sizeof(ctr_tlistitem) );
		rli->node = r;
		rli->next = nodes;
		e->nodes = rli;
	} else {
		return r;
	}
	return e;
}

/**
 * CTRParserReturn
 *
 * Generates a node to represent a return from a block of code.
 */
ctr_tnode* ctr_cparse_ret() {
	ctr_tlistitem* li;
	ctr_tnode* r;
	ctr_clex_tok();
	r = ctr_cparse_create_node( CTR_AST_NODE );
	r->type = CTR_AST_NODE_RETURNFROMBLOCK;
	li = (ctr_tlistitem*) ctr_heap_allocate_tracked( sizeof(ctr_tlistitem) );
	r->nodes = li;
	li->node = ctr_cparse_expr(0);
	return r;
}

/**
 * CTRParserFin
 *
 * Generates a node to represent the end of a program.
 */
ctr_tnode* ctr_cparse_fin() {
	ctr_tnode* f;
	ctr_clex_tok();
	f = ctr_cparse_create_node( CTR_AST_NODE );
	f->type = CTR_AST_NODE_ENDOFPROGRAM;
	return f;
}

/**
 * CTRParserStatement
 *
 * Generates a set of nodes representing a statement.
 */
ctr_tlistitem* ctr_cparse_statement() {
	ctr_tlistitem* li = (ctr_tlistitem*) ctr_heap_allocate_tracked( sizeof(ctr_tlistitem) );
	int t = ctr_clex_tok();
	ctr_clex_putback();
	if (t == CTR_TOKEN_FIN) {
		li->node = ctr_cparse_fin();
		return li;
	} else if (t == CTR_TOKEN_RET) {
		li->node = ctr_cparse_ret();
	} else {
		li->node = ctr_cparse_expr(0);
	}
	t = ctr_clex_tok();
	if (t != CTR_TOKEN_DOT) {
		ctr_cparse_emit_error_unexpected( t, "Expected a dot (.).\n" );
	}
	return li;
}

/**
 * CTRParserProgram
 *
 * Generates the nodes to represent the entire program
 * as an Abstract Syntax Tree (AST).
 */
ctr_tnode* ctr_cparse_program() {
	ctr_tnode* program = ctr_cparse_create_node( CTR_AST_PROGRAM );
	ctr_tlistitem* pli;
	int first = 1;
	while(1) {
		ctr_tlistitem* li = ctr_cparse_statement();
		if (first) {
			first = 0;
			program->nodes = li;
		} else {
			pli->next = li;
		}
		if (li->node->type == CTR_AST_NODE_ENDOFPROGRAM) break;
		pli = li;
	}
	return program;
}

/**
 * CTRParserStart
 *
 * Begins the parsing stage of a program.
 */
ctr_tnode*  ctr_cparse_parse(char* prg, char* pathString) {
	ctr_tnode* program;
	ctr_clex_load(prg);
	ctr_cparse_current_program = pathString;
	program = ctr_cparse_program();
	program->value = pathString;
	program->vlen = strlen(pathString);
	program->type = CTR_AST_NODE_PROGRAM;
	return program;
}