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/*
* Copyright (c) 2026, Apollo Telephone Laboratories.
* Provided under the BSD-3 clause.
*/
#include "defconf/parser.h"
#include "defconf/lexer.h"
#include "defconf/token.h"
#include "defconf/data.h"
#include "defconf/emit.h"
#include "defconf/trace.h"
/* Symbolic token */
#define SYMTOK(TOKSTR) \
"[" TOKSTR "]"
/* Literal token */
#define TOKLIT(TOKSTR) \
"'" TOKSTR "'"
/* Safe macro to convert token type to string */
#define TOKSTR(TT) \
((TT) >= _TT_MAX) \
? "bad" \
: toktab[(TT)]
/* Token to string table */
static const char *toktab[_TT_MAX] = {
[TT_NONE] = SYMTOK("none"),
[TT_DEFINE] = SYMTOK("define"),
[TT_TRUE] = TOKLIT("true"),
[TT_FALSE] = TOKLIT("false"),
[TT_INTLIT] = SYMTOK("int"),
[TT_IDENT] = SYMTOK("ident")
};
static int
token_to_data(struct token *tok, struct data_value *result)
{
if (tok == NULL || result == NULL) {
return -1;
}
switch (tok->type) {
case TT_TRUE:
result->v = 1;
result->type = DATA_TYPE_INT;
return 0;
case TT_FALSE:
result->v = 0;
result->type = DATA_TYPE_INT;
return 0;
case TT_INTLIT:
result->v = tok->v;
result->type = DATA_TYPE_INT;
return 0;
default:
return -1;
}
return -1;
}
/*
* Assert that the next token is of a specific type
*
* @state: Defconf state
* @tok: Last token
* @exp: Expected token
*/
static int
parse_expect(struct defconf_state *state, struct token *tok, tt_t exp)
{
int error;
if (state == NULL || tok == NULL) {
return -1;
}
/* Try to grab the next token */
if ((error = lexer_scan(state, tok)) < 0) {
trace_fatal(state, "expected '%s', got eof\n", TOKSTR(exp));
return error;
}
if (tok->type != exp) {
trace_fatal(state, "expected '%s', got %s instead\n",
TOKSTR(exp), TOKSTR(tok->type));
return -1;
}
return 0;
}
/*
* Parse a define directive
*
* @state: Defconf state
* @tok: Last token
*
* Returns zero on success
*/
static int
parse_define(struct defconf_state *state, struct token *tok)
{
struct data_value value;
char *ident;
int error;
if (state == NULL || tok == NULL) {
return -1;
}
/* Expect an identifier */
if ((error = parse_expect(state, tok, TT_IDENT)) < 0) {
return error;
}
/* Save the identifier */
ident = tok->s;
/* Scan the value */
if ((error = lexer_scan(state, tok)) < 0) {
trace_fatal(state, "expected value, got eof\n");
return error;
}
/* Convert token to data */
if ((error = token_to_data(tok, &value)) < 0) {
trace_fatal(state, "got bad data [%s]\n", TOKSTR(tok->type));
return error;
}
/* Emit the define */
if ((error = emit_data(ident, &value)) < 0) {
return error;
}
return 0;
}
int
parse_begin(struct defconf_state *state)
{
struct token tok;
int error;
if (state == NULL) {
return -1;
}
while (lexer_scan(state, &tok) == 0) {
switch (tok.type) {
case TT_DEFINE:
if ((error = parse_define(state, &tok)) < 0) {
return error;
}
break;
default:
trace_fatal(state, "got unexpected token: %s\n", TOKSTR(tok.type));
return -1;
}
}
return 0;
}
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