warning: 'sscanf' used to convert a string to a floating-point value, but function will not report conversion errors; consider using 'strtod' instead [cert-err34-c]

[ClausKlein]

/usr/local/opt/llvm/bin/clang-tidy -checks=-*,cert-* -p=build /Users/clausklein/Workspace/c/tests/cJSON-src/test.c
4618 warnings generated.
Suppressed 4618 warnings (4618 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
/usr/local/opt/llvm/bin/clang-tidy -checks=-*,cert-* -p=build /Users/clausklein/Workspace/c/tests/cJSON-src/cJSON.c
/Users/clausklein/Workspace/c/tests/cJSON-src/cJSON.c:583:14: warning: 'sscanf' used to convert a string to a floating-point value, but function will not report conversion errors; consider using 'strtod' instead [cert-err34-c]
  583 |         if ((sscanf((char*)number_buffer, "%lg", &test) != 1) || !compare_double((double)test, d))
      |              ^
5033 warnings generated.
Suppressed 5032 warnings (5032 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
bash-5.2$ 

[ljluestc]

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <math.h>
#include <string.h>
#include "cJSON.h"

// Compare floating point values with small tolerance
static int compare_double(double a, double b) {
    return fabs(a - b) < DBL_EPSILON;
}

// Updated number parsing function using strtod()
static cJSON_bool parse_number(cJSON *item, const unsigned char *num) {
    char *endptr;
    errno = 0;  // Reset error state

    double test = strtod((const char *)num, &endptr);
    if (errno != 0 || num == (unsigned char *)endptr) {
        return false;  // Failed conversion
    }

    if (!compare_double(test, item->valuedouble)) {
        return false;  // Value mismatch
    }

    item->valuedouble = test;
    item->valueint = (int)test;  // Store integer part if applicable
    return true;
}

// Example Usage
void example_usage() {
    cJSON *root = cJSON_CreateObject();
    cJSON_AddNumberToObject(root, "pi", 3.141592653589793);
    cJSON_AddNumberToObject(root, "negative", -42.789);
    cJSON_AddNumberToObject(root, "integer", 12345);

    char *json_str = cJSON_Print(root);
    printf("JSON Output: %s\n", json_str);

    // Clean up
    free(json_str);
    cJSON_Delete(root);
}

int main() {
    example_usage();
    return 0;
}