/* Exercise the parser used for DESCRIPTION and PACKAGES metadata. */

#include <stdint.h>

#include <string.h>

#include "common.h"

#define FUZZ_MAX_INPUT (1024 * 64)

static SEXP input_string;

static SEXP calls[2];

static SEXP make_wrapper(const char *source)

{

    ParseStatus status;

    SEXP text, parsed, wrapper;

    Rf_protect(text = Rf_mkString(source));

    Rf_protect(parsed = R_ParseVector(text, -1, &status, R_NilValue));

    if (status != PARSE_OK || XLENGTH(parsed) != 1)

        abort();

    wrapper = Rf_eval(VECTOR_ELT(parsed, 0), R_BaseEnv);

    Rf_unprotect(2);

    return wrapper;

}

int LLVMFuzzerInitialize(int *argc, char ***argv)

{

    (void)argc;

    (void)argv;

    fuzz_init_r();

    static const char source[] =

        "function(x, all) { con <- textConnection(x); "

        "on.exit(close(con)); read.dcf(con, all = all) }";

    SEXP wrapper, false_value, true_value;

    Rf_protect(wrapper = make_wrapper(source));

    Rf_protect(input_string = Rf_allocVector(STRSXP, 1));

    Rf_protect(false_value = Rf_ScalarLogical(FALSE));

    Rf_protect(true_value = Rf_ScalarLogical(TRUE));

    Rf_protect(calls[0] = Rf_lang3(wrapper, input_string, false_value));

    Rf_protect(calls[1] = Rf_lang3(wrapper, input_string, true_value));

    return 0;

}

int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)

{

    if (size < 2 || size > FUZZ_MAX_INPUT || memchr(data + 1, '\0', size - 1))

        return 0;

    char buffer[FUZZ_MAX_INPUT];

    memcpy(buffer, data + 1, size - 1);

    buffer[size - 1] = '\0';

    if (!fuzz_set_string(input_string, buffer))

        return 0;

    fuzz_eval_silent(calls[data[0] & 1], R_GlobalEnv);

    return 0;

}