bool lexer_lookahead_matches_special(lexer_state_t* lex, const char* special) {
if ( lex->error || lexer_lookahead(lex) == NULL ) return NULL;
token_t* token = lexer_lookahead(lex);
if ( token->type == special_token ) {
return strcmp((char*) token->value, special) == 0;
}
return false;
}
static void
parse_actions(struct action_context *ctx)
{
/* "drop;" by itself is a valid (empty) set of actions, but it can't be
* combined with other actions because that doesn't make sense. */
if (ctx->lexer->token.type == LEX_T_ID
&& !strcmp(ctx->lexer->token.s, "drop")
&& lexer_lookahead(ctx->lexer) == LEX_T_SEMICOLON) {
lexer_get(ctx->lexer); /* Skip "drop". */
lexer_get(ctx->lexer); /* Skip ";". */
if (ctx->lexer->token.type != LEX_T_END) {
action_syntax_error(ctx, "expecting end of input");
}
return;
}
while (ctx->lexer->token.type != LEX_T_END) {
if (ctx->lexer->token.type != LEX_T_ID) {
action_syntax_error(ctx, NULL);
break;
}
enum lex_type lookahead = lexer_lookahead(ctx->lexer);
if (lookahead == LEX_T_EQUALS || lookahead == LEX_T_EXCHANGE
|| lookahead == LEX_T_LSQUARE) {
parse_set_action(ctx);
} else if (lexer_match_id(ctx->lexer, "next")) {
parse_next_action(ctx);
} else if (lexer_match_id(ctx->lexer, "output")) {
emit_resubmit(ctx, ctx->output_ptable);
} else if (lexer_match_id(ctx->lexer, "ip4.ttl")) {
if (lexer_match(ctx->lexer, LEX_T_DECREMENT)) {
struct expr *e = expr_parse_string("ip4", ctx->symtab,
&ctx->error);
ctx->prereqs = expr_combine(EXPR_T_AND, ctx->prereqs, e);
ofpact_put_DEC_TTL(ctx->ofpacts);
} else {
action_syntax_error(ctx, "expecting `--'");
}
} else if (lexer_match_id(ctx->lexer, "ct_next")) {
emit_ct(ctx, true, false);
} else if (lexer_match_id(ctx->lexer, "ct_commit")) {
emit_ct(ctx, false, true);
} else {
action_syntax_error(ctx, "expecting action");
}
if (!lexer_match(ctx->lexer, LEX_T_SEMICOLON)) {
action_syntax_error(ctx, "expecting ';'");
}
if (ctx->error) {
return;
}
}
}
static bool
parse_action(struct action_context *ctx)
{
if (ctx->lexer->token.type != LEX_T_ID) {
action_syntax_error(ctx, NULL);
return false;
}
enum lex_type lookahead = lexer_lookahead(ctx->lexer);
if (lookahead == LEX_T_EQUALS || lookahead == LEX_T_EXCHANGE
|| lookahead == LEX_T_LSQUARE) {
parse_set_action(ctx);
} else if (lexer_match_id(ctx->lexer, "next")) {
parse_next_action(ctx);
} else if (lexer_match_id(ctx->lexer, "output")) {
emit_resubmit(ctx, ctx->ap->output_ptable);
} else if (lexer_match_id(ctx->lexer, "ip.ttl")) {
if (lexer_match(ctx->lexer, LEX_T_DECREMENT)) {
add_prerequisite(ctx, "ip");
ofpact_put_DEC_TTL(ctx->ofpacts);
} else {
action_syntax_error(ctx, "expecting `--'");
}
} else if (lexer_match_id(ctx->lexer, "ct_next")) {
emit_ct(ctx, true, false);
} else if (lexer_match_id(ctx->lexer, "ct_commit")) {
emit_ct(ctx, false, true);
} else {
action_syntax_error(ctx, "expecting action");
}
if (!lexer_match(ctx->lexer, LEX_T_SEMICOLON)) {
action_syntax_error(ctx, "expecting ';'");
}
return !ctx->error;
}
static struct ast_node *ast_parser_acc_return_statement(struct ast_parser *p)
{
struct token *tok;
struct ast_node *expr;
struct ast_node *n = NULL;
const struct inplocation_mark *start;
tok = lexer_lookahead(parser_lexer(p), 1);
if (!tok) {
return NULL;
}
if (tok->type != TOKEN_KW_RETURN) {
return NULL;
}
start = token_get_start(tok);
//consume the return keyword
lexer_curr_token_advance(parser_lexer(p));
expr = ast_parser_acc_expression(p);
if (!expr) {
parser_synerr(p, lexer_last_token_end(parser_lexer(p)), NULL,
"Expected an expression for the return statement");
goto end;
}
n = ast_returnstmt_create(start, ast_node_endmark(expr), expr);
if (!n) {
RF_ERROR("Could not create a return statement during parsing");
}
end:
return n;
}
struct ast_node *parser_acc_fnimpl(struct parser *p)
{
struct ast_node *n;
struct ast_node *decl;
struct ast_node *body;
struct token *tok;
decl = parser_acc_fndecl(p, FNDECL_PARTOF_IMPL);
if (!decl) {
return NULL;
}
tok = lexer_lookahead(p->lexer, 1);
if (!tok) {
goto fail_free_decl;
}
if (tok->type == TOKEN_SM_OCBRACE) {
// normal function body
body = parser_acc_block(p, true);
if (!body) {
parser_synerr(p, ast_node_endmark(decl), NULL,
"Expected a body for \""RF_STR_PF_FMT"\" function "
"implementation", RF_STR_PF_ARG(ast_fndecl_name_str(decl)));
goto fail_free_decl;
}
} else {
// attempt to find a headless match expression as the function body
body = parser_acc_matchexpr(p, false, true);
if (!body) {
parser_synerr(p, ast_node_endmark(decl), NULL,
"Expected a body for \""RF_STR_PF_FMT"\" function "
"implementation", RF_STR_PF_ARG(ast_fndecl_name_str(decl)));
goto fail_free_decl;
}
// now set the matchexpr's fn_args since this is a headless matchexpr
ast_matchexpr_set_fnargs(body, ast_fndecl_args_get(decl));
}
n = ast_fnimpl_create(ast_node_startmark(decl),
ast_node_endmark(body),
decl,
body);
if (!n) {
RF_ERRNOMEM();
ast_node_destroy(body);
ast_node_destroy(decl);
return NULL;
}
return n;
fail_free_decl:
ast_node_destroy(decl);
return NULL;
}
enum parser_fnimpl_list_err parser_acc_fnimpl_list(struct parser *p,
struct ast_node *parent)
{
struct ast_node *impl;
struct token *tok;
tok = lexer_lookahead(p->lexer, 1);
if (!tok || tok->type != TOKEN_KW_FUNCTION) {
return PARSER_FNIMPL_LIST_EMPTY;
}
while (tok && tok->type == TOKEN_KW_FUNCTION) {
impl = parser_acc_fnimpl(p);
if (!impl) {
return PARSER_FNIMPL_LIST_FAILURE;
}
ast_node_add_child(parent, impl);
tok = lexer_lookahead(p->lexer, 1);
}
return PARSER_FNIMPL_LIST_SUCCESS;
}
enum parser_fndecl_list_err parser_acc_fndecl_list(struct parser *p,
struct ast_node *parent,
int fndecl_position)
{
struct ast_node *decl;
struct token *tok;
tok = lexer_lookahead(p->lexer, 1);
if (!tok || tok->type != TOKEN_KW_FUNCTION) {
return PARSER_FNDECL_LIST_EMPTY;
}
while (tok && tok->type == TOKEN_KW_FUNCTION) {
decl = parser_acc_fndecl(p, fndecl_position);
if (!decl) {
return PARSER_FNDECL_LIST_FAILURE;
}
ast_node_add_child(parent, decl);
tok = lexer_lookahead(p->lexer, 1);
}
return PARSER_FNDECL_LIST_SUCCESS;
}
static struct ast_node *ast_parser_acc_expr_statement(struct ast_parser *p)
{
struct token *tok;
struct ast_node *n = NULL;
tok = lexer_lookahead(parser_lexer(p), 1);
if (TOKEN_IS_BLOCK_START(tok)) {
n = ast_parser_acc_block(p, true);
} else if (TOKEN_IS_TYPEDECL_START(tok)) {
n = ast_parser_acc_typedecl(p);
} else if (TOKEN_IS_RETURNSTMT_START(tok)) {
n = ast_parser_acc_return_statement(p);
}
return n;
}
static void
parse_actions(struct action_context *ctx)
{
/* "drop;" by itself is a valid (empty) set of actions, but it can't be
* combined with other actions because that doesn't make sense. */
if (ctx->lexer->token.type == LEX_T_ID
&& !strcmp(ctx->lexer->token.s, "drop")
&& lexer_lookahead(ctx->lexer) == LEX_T_SEMICOLON) {
lexer_get(ctx->lexer); /* Skip "drop". */
lexer_get(ctx->lexer); /* Skip ";". */
if (ctx->lexer->token.type != LEX_T_END) {
action_syntax_error(ctx, "expecting end of input");
}
return;
}
while (ctx->lexer->token.type != LEX_T_END) {
if (!parse_action(ctx)) {
return;
}
}
}
bool lexer_lookahead_matches(lexer_state_t* lex, token_types_t tokentype) {
if ( lex->error || lexer_lookahead(lex) == NULL ) return NULL;
return lexer_lookahead(lex)->type == tokentype;
}
struct ast_node *ast_parser_acc_block(struct ast_parser *p, bool expect_braces)
{
struct ast_node *n;
struct token *tok;
struct ast_node *element;
const struct inplocation_mark *start = NULL;
const struct inplocation_mark *end = NULL;
lexer_push(parser_lexer(p));
tok = lexer_lookahead(parser_lexer(p), 1);
if (!tok) {
goto err;
}
if (expect_braces) {
if (tok->type != TOKEN_SM_OCBRACE) {
goto err;
}
// consume '{'
lexer_curr_token_advance(parser_lexer(p));
start = token_get_start(tok);
}
if (!(n = ast_block_create())) {
goto err;
}
//try to parse the first element
if (!(element = ast_parser_acc_block_element(p))) {
if (!expect_braces) {
goto err_free_block;
}
//else just find the terminating '}' and return
tok = lexer_lookahead(parser_lexer(p), 1);
if (!tok || tok->type != TOKEN_SM_CCBRACE) {
parser_synerr(
p,
lexer_last_token_end(parser_lexer(p)),
NULL,
"Expected an expression or a '}' at block end"
);
goto err_free_block;
}
//consume the '}'
lexer_curr_token_advance(parser_lexer(p));
ast_node_set_start(n, start);
ast_node_set_end(n, token_get_end(tok));
return n; //empty block
}
if (!start) {
start = ast_node_startmark(element);
}
end = ast_node_endmark(element);
ast_block_add_element(n, element);
// now add elements to the block
while ((element = ast_parser_acc_block_element(p))) {
ast_block_add_element(n, element);
end = ast_node_endmark(element);
}
if (expect_braces) {
tok = lexer_lookahead(parser_lexer(p), 1);
if (!tok || tok->type != TOKEN_SM_CCBRACE) {
parser_synerr(
p,
lexer_last_token_end(parser_lexer(p)),
NULL,
"Expected an expression or a '}' at block end"
);
goto err_free_block;
}
//consume the '}'
lexer_curr_token_advance(parser_lexer(p));
end = token_get_end(tok);
}
ast_node_set_start(n, start);
ast_node_set_end(n, end);
lexer_pop(parser_lexer(p));
return n;
err_free_block:
ast_node_destroy(n);
err:
lexer_rollback(parser_lexer(p));
return NULL;
}
struct ast_node *parser_acc_fncall(struct parser *p, bool expect_it)
{
struct ast_node *n;
struct token *tok;
struct ast_node *name;
struct ast_node *genr = NULL;
struct ast_node *args = NULL;
lexer_push(p->lexer);
name = parser_acc_identifier(p);
if (!name) {
goto err;
}
genr = parser_acc_genrattr(p, false);
if (!genr && parser_has_syntax_error(p)) {
// name is an identifier and even in failure does not need to get destroyed here
goto err;
}
tok = lexer_lookahead(p->lexer, 1);
if (!tok || tok->type != TOKEN_SM_OPAREN) {
if (expect_it) {
parser_synerr(p, lexer_last_token_start(p->lexer), NULL,
"Expected '('");
}
goto err_free_genr;
}
//consume '('
lexer_next_token(p->lexer);
args = parser_acc_expression(p);
if (!args) {
if (parser_has_syntax_error(p)) {
parser_synerr(p, lexer_last_token_start(p->lexer), NULL,
"Expected argument expression for function call");
goto err_free_genr;
}
}
tok = lexer_lookahead(p->lexer, 1);
if (!tok || tok->type != TOKEN_SM_CPAREN) {
if (expect_it) {
parser_synerr(p, lexer_last_token_end(p->lexer), NULL,
"Expected ')' at end of "RF_STR_PF_FMT" function call",
RF_STR_PF_ARG(ast_identifier_str(name)));
}
goto err_free_args;
}
//consume ')'
lexer_next_token(p->lexer);
n = ast_fncall_create(ast_node_startmark(name), token_get_end(tok),
name, args, genr);
if (!n) {
RF_ERRNOMEM();
goto err_free_args;
}
lexer_pop(p->lexer);
return n;
err_free_args:
if (args) {
ast_node_destroy(args);
}
err_free_genr:
if (genr) {
ast_node_destroy(genr);
}
err:
lexer_rollback(p->lexer);
return NULL;
}
struct ast_node *parser_acc_fndecl(struct parser *p, int fndecl_position)
{
struct ast_node *n;
struct token *tok;
struct token *oparen_tok;
struct ast_node *name;
struct ast_node *genr = NULL;
struct ast_node *args = NULL;
struct ast_node *ret_type = NULL;
const struct inplocation_mark *start;
const struct inplocation_mark *end;
lexer_push(p->lexer);
tok = lexer_lookahead(p->lexer, 1);
if (fndecl_position != FNDECL_PARTOF_FOREIGN_IMPORT) {
if (!tok || tok->type != TOKEN_KW_FUNCTION) {
goto err;
}
//consume function keyword
lexer_next_token(p->lexer);
}
// start should be either start of fn, or start of next token (an identifier)
start = token_get_start(tok);
name = parser_acc_identifier(p);
if (!name) {
parser_synerr(p, lexer_last_token_start(p->lexer), NULL,
"Expected an identifier for the function name after 'fn'");
goto err;
}
tok = lexer_lookahead(p->lexer, 1);
if (GENRDECL_START_COND(tok)) {
genr = parser_acc_genrdecl(p);
if (!genr) {
goto err;
}
}
tok = lexer_next_token(p->lexer);
if (!tok || tok->type != TOKEN_SM_OPAREN) {
parser_synerr(p, lexer_last_token_start(p->lexer), NULL,
"Expected '(' at function declaration");
goto err_free_genr;
}
oparen_tok = tok;
args = parser_acc_typedesc(p);
if (!args && parser_has_syntax_error_reset(p)) {
parser_synerr(p, token_get_end(tok), NULL,
"Expected either a type description for the function's "
"arguments or ')' after '('");
goto err_free_genr;
}
tok = lexer_next_token(p->lexer);
if (!tok || tok->type != TOKEN_SM_CPAREN) {
if (args) {
parser_synerr(p, lexer_last_token_end(p->lexer), NULL,
"Expected ')' at function declaration after "
"type description");
} else {
parser_synerr(p, token_get_end(oparen_tok), NULL,
"Expected ')' at function declaration after '('");
}
goto err_free_args;
}
end = token_get_end(tok);
tok = lexer_lookahead(p->lexer, 1);
if (tok && tok->type == TOKEN_OP_IMPL) {
//consume '->'
lexer_next_token(p->lexer);
ret_type = parser_acc_typedesc(p);
if (!ret_type) {
parser_synerr(p, token_get_end(tok), NULL,
"Expected type description for the function's "
"return type after '->'");
goto err_free_args;
}
end = ast_node_endmark(ret_type);
}
n = ast_fndecl_create(start, end, fndecl_position, name, genr, args, ret_type);
if (!n) {
RF_ERRNOMEM();
goto err_free_rettype;
}
lexer_pop(p->lexer);
return n;
err_free_rettype:
if (ret_type) {
ast_node_destroy(ret_type);
}
err_free_args:
if (args) {
ast_node_destroy(args);
}
err_free_genr:
if (genr) {
ast_node_destroy(genr);
}
err:
lexer_rollback(p->lexer);
return NULL;
}
struct ast_node *parser_acc_typeinstance(struct parser *p)
{
struct ast_node *n = NULL;
struct token *tok;
struct ast_node *class_name;
struct ast_node *type_name;
struct ast_node *genr = NULL;
const struct inplocation_mark *start;
enum parser_fnimpl_list_err err;
tok = lexer_lookahead(p->lexer, 1);
if (!tok || tok->type != TOKEN_KW_TYPEINSTANCE) {
return NULL;
}
start = token_get_start(tok);
//consumer typeclass isntance keyword
lexer_next_token(p->lexer);
class_name = parser_acc_identifier(p);
if (!class_name) {
parser_synerr(p, lexer_last_token_start(p->lexer), NULL,
"Expected an identifier for the typeclass instance "
"name after 'instance'");
goto err;
}
type_name = parser_acc_identifier(p);
if (!type_name) {
parser_synerr(p, lexer_last_token_start(p->lexer), NULL,
"Expected an identifier for the name of \""RF_STR_PF_FMT"\" "
"typeclass instance",
RF_STR_PF_ARG(ast_identifier_str(class_name)));
goto err;
}
genr = parser_acc_genrdecl(p);
if (!genr && parser_has_syntax_error_reset(p)) {
parser_synerr(p, ast_node_endmark(type_name), NULL,
"Expected a generic declaration for type instance \""
RF_STR_PF_FMT"\" after type name \""RF_STR_PF_FMT"\"",
RF_STR_PF_ARG(ast_identifier_str(class_name)),
RF_STR_PF_ARG(ast_identifier_str(type_name)));
goto err;
}
tok = lexer_next_token(p->lexer);
if (!tok || tok->type != TOKEN_SM_OCBRACE) {
parser_synerr(p, ast_node_endmark(type_name), NULL,
"Expected '{' at type instance \""RF_STR_PF_FMT"\" "
"after \""RF_STR_PF_FMT"\"",
RF_STR_PF_ARG(ast_identifier_str(class_name)),
RF_STR_PF_ARG(ast_identifier_str(type_name)));
goto err_free_genr;
}
n = ast_typeinstance_create(start, NULL, class_name, type_name, genr);
if (!n) {
RF_ERRNOMEM();
goto err_free_genr;
}
err = parser_acc_fnimpl_list(p, n);
switch (err) {
case PARSER_FNIMPL_LIST_EMPTY:
parser_synerr(p, token_get_end(tok), NULL,
"Expected at least one function implementation inside "
"the body of typeinstace \""RF_STR_PF_FMT"\" for "
"\""RF_STR_PF_FMT"\" after'{'",
RF_STR_PF_ARG(ast_identifier_str(class_name)),
RF_STR_PF_ARG(ast_identifier_str(type_name)));
goto err_free_typeinstance;
break;
case PARSER_FNIMPL_LIST_FAILURE:
parser_synerr(p, lexer_last_token_end(p->lexer), NULL,
"Expected a proper function implementation inside "
"the body of typeinstace \""RF_STR_PF_FMT"\" for "
"\""RF_STR_PF_FMT"\" after'{'",
RF_STR_PF_ARG(ast_identifier_str(class_name)),
RF_STR_PF_ARG(ast_identifier_str(type_name)));
goto err_free_typeinstance;
break;
default: // SUCCESS
break;
}
tok = lexer_next_token(p->lexer);
if (!tok || tok->type != TOKEN_SM_CCBRACE) {
parser_synerr(p, lexer_last_token_end(p->lexer), NULL,
"Expected '}' at the end of \""RF_STR_PF_FMT"\" "
"typeinstance for \""RF_STR_PF_FMT"\"",
RF_STR_PF_ARG(ast_identifier_str(class_name)),
RF_STR_PF_ARG(ast_identifier_str(type_name)));
goto err_free_typeinstance;
}
ast_node_set_end(n, token_get_end(tok));
return n;
err_free_genr:
if (genr) {
ast_node_destroy(genr);
}
err_free_typeinstance:
if (n) {
ast_node_destroy(n);
}
err:
return NULL;
}
struct ast_node *parser_acc_typeclass(struct parser *p)
{
struct ast_node *n = NULL;
struct token *tok;
struct ast_node *name;
struct ast_node *genr = NULL;
const struct inplocation_mark *start;
enum parser_fndecl_list_err err;
tok = lexer_lookahead(p->lexer, 1);
if (!tok || tok->type != TOKEN_KW_TYPECLASS) {
return NULL;
}
start = token_get_start(tok);
lexer_push(p->lexer);
//consume typeclass keyword
lexer_next_token(p->lexer);
name = parser_acc_identifier(p);
if (!name) {
parser_synerr(p, lexer_last_token_start(p->lexer), NULL,
"Expected an identifier for the typeclass "
"name after 'class'");
goto err;
}
genr = parser_acc_genrdecl(p);
if (!genr && parser_has_syntax_error_reset(p)) {
parser_synerr(p, ast_node_endmark(name), NULL,
"Expected a generic declaration for typeclass \""
RF_STR_PF_FMT"\" after identifier",
RF_STR_PF_ARG(ast_identifier_str(name)));
goto err_free_genr;
}
tok = lexer_next_token(p->lexer);
if (!tok || tok->type != TOKEN_SM_OCBRACE) {
parser_synerr(p, ast_node_endmark(name), NULL,
"Expected '{' at \""RF_STR_PF_FMT"\" typeclass "
"declaration after identifier",
RF_STR_PF_ARG(ast_identifier_str(name)));
goto err_free_genr;
}
n = ast_typeclass_create(start, NULL, name, genr);
if (!n) {
RF_ERRNOMEM();
goto err_free_genr;
}
err = parser_acc_fndecl_list(p, n, FNDECL_PARTOF_TYPECLASS);
switch (err) {
case PARSER_FNDECL_LIST_EMPTY:
parser_synerr(p, token_get_end(tok), NULL,
"Expected at least one function declaration inside "
"the body of typeclass \""RF_STR_PF_FMT"\" after '{'",
RF_STR_PF_ARG(ast_identifier_str(name)));
goto err_free_typeclass;
break;
case PARSER_FNDECL_LIST_FAILURE:
parser_synerr(p, lexer_last_token_end(p->lexer), NULL,
"Expected a proper function declaration inside "
"typeclass \""RF_STR_PF_FMT"\"",
RF_STR_PF_ARG(ast_identifier_str(name)));
goto err_free_typeclass;
break;
default: // SUCCESS
break;
}
tok = lexer_next_token(p->lexer);
if (!tok || tok->type != TOKEN_SM_CCBRACE) {
parser_synerr(p, lexer_last_token_end(p->lexer), NULL,
"Expected '}' at the end of \""RF_STR_PF_FMT"\" "
"typeclass declaration",
RF_STR_PF_ARG(ast_identifier_str(name)));
goto err_free_typeclass;
}
ast_node_set_end(n, token_get_end(tok));
lexer_pop(p->lexer);
return n;
err_free_genr:
if (genr) {
ast_node_destroy(genr);
}
err_free_typeclass:
if (n) {
ast_node_destroy(n);
}
err:
lexer_rollback(p->lexer);
return NULL;
}
struct ast_node *parser_acc_ifexpr(struct parser *p, enum token_type if_type)
{
struct ast_node *n;
struct ast_node *branch;
struct token *tok;
const struct inplocation_mark *start;
RF_ASSERT(if_type == TOKEN_KW_IF || if_type == TOKEN_KW_ELIF,
"parse_ifexp called with invalid token type");
tok = lexer_lookahead(p->lexer, 1);
if (!tok || tok->type != if_type) {
return NULL;
}
start = token_get_start(tok);
// consume 'if' or 'elif'
lexer_next_token(p->lexer);
lexer_push(p->lexer);
// parse the taken branch
branch = parser_acc_condbranch(p, tok);
if (!branch) {
goto err;
}
// create the if expression
n = ast_ifexpr_create(start, ast_node_endmark(branch),
branch, NULL);
if (!n) {
ast_node_destroy(branch);
RF_ERRNOMEM();
goto err;
}
tok = lexer_lookahead(p->lexer, 1);
while (tok && (tok->type == TOKEN_KW_ELIF || tok->type == TOKEN_KW_ELSE)) {
if (tok->type == TOKEN_KW_ELIF) {
branch = parser_acc_ifexpr(p, TOKEN_KW_ELIF);
if (!branch) {
// error reporting should already happen in parser_acc_ifexpr()
goto err_free;
}
} else { //can only be an else
lexer_next_token(p->lexer); // consume it
branch = parser_acc_block(p, true);
if (!branch) {
parser_synerr(p, token_get_end(tok), NULL,
"Expected a block after 'else'");
goto err_free;
}
}
ast_ifexpr_add_fallthrough_branch(n, branch);
ast_node_set_end(n, ast_node_endmark(branch));
tok = lexer_lookahead(p->lexer, 1);
}
lexer_pop(p->lexer);
return n;
err_free:
ast_node_destroy(n);
err:
lexer_rollback(p->lexer);
return NULL;
}
