[RSPEC-1912] Non-reentrant POSIX functions should be replaced with their reentrant versions - SonarSource

Details

Type: Code Smell Detection
Status: Active
Resolution: Unresolved
Labels:
- multi-threading

Message:
Replace this call to the non-reentrant "{0}" with a call to "{0}_r"
List of parameters:
Hide

key = nonReentrantFunctionList

description = List of non-reentrant functions

default = asctime,crypt,ctermid,ctime,fgetgrent,fgetpwent,fgetspent,getgrent,getgrgid,getgrnam,gethostbyaddr,gethostbyname,gethostbyname2,gethostent,getlogin,getnetbyaddr,getnetbyname,getnetent,getnetgrent,getprotobyname,getprotobynumber,getprotoent,getpwent,getpwnam,getpwuid,getrpcbyname,getrpcbynumber,getrpcent,getservbyname,getservbyport,getservent,getspent,getspnam,gmtime,localtime,sgetspent,strtok,ttyname

type = STRING
Show
key = nonReentrantFunctionList description = List of non-reentrant functions default = asctime,crypt,ctermid,ctime,fgetgrent,fgetpwent,fgetspent,getgrent,getgrgid,getgrnam,gethostbyaddr,gethostbyname,gethostbyname2,gethostent,getlogin,getnetbyaddr,getnetbyname,getnetent,getnetgrent,getprotobyname,getprotobynumber,getprotoent,getpwent,getpwnam,getpwuid,getrpcbyname,getrpcbynumber,getrpcent,getservbyname,getservbyport,getservent,getspent,getspnam,gmtime,localtime,sgetspent,strtok,ttyname type = STRING
Default Severity:
Blocker
Impact:
High
Likelihood:
High
Default Quality Profiles:

Sonar way
Legacy Key:
NonReentrantFunction
Covered Languages:

C, C++, Objective-C
Remediation Function:
Constant/Issue
Constant Cost:
30min

CPPCheck:
nonreentrantFunctions.*

Description

A function is called reentrant if it can be interrupted in the middle of its execution and then safely called again ("re-entered") before its previous invocations complete execution.

It is especially important that multi-threaded applications do not call the same non-reentrant function from different threads.

This rule will trigger an issue each time a function in the configurable list is invoked.

Noncompliant Code Example

Given a function that includes localtime:

#include <stdio.h>
#include <time.h>

void print_date_and_time(struct tm *time_ptr)
{
  printf(
    "Current date and time: %d/%02d/%02d %02d:%02d:%02d\n",
    time_ptr->tm_year + 1900,
    time_ptr->tm_mon,
    time_ptr->tm_mday,
    time_ptr->tm_hour,
    time_ptr->tm_min,
    time_ptr->tm_sec);
}

void print_unix_epoch_date_and_time()
{
  time_t unix_epoch_time = (time_t)0;
  struct tm *local_time_ptr = localtime(&unix_epoch_time); // Noncompliant, call to the non-reentrant localtime() function
  print_date_and_time(local_time_ptr);
}

int main(int argc, char* argv[])
{
  time_t current_time;
  struct tm *local_time_ptr;

  time(&current_time);

  local_time_ptr = localtime(&current_time); // Noncompliant, call to the non-reentrant localtime() function

  // As expected, this will print: Current date and time: 1970/00/01 01:00:00
  print_unix_epoch_date_and_time();

  // This will actually also print Current date and time: 1970/00/01 01:00:00
  // Indeed, localtime() is non-reentrant, and always returns the same pointer
  print_date_and_time(local_time_ptr);

  return 0;
}

Compliant Solution

#include <stdio.h>
#include <time.h>

void print_date_and_time(struct tm *time_ptr)
{
  printf(
    "Current date and time: %d/%02d/%02d %02d:%02d:%02d\n",
    time_ptr->tm_year + 1900,
    time_ptr->tm_mon,
    time_ptr->tm_mday,
    time_ptr->tm_hour,
    time_ptr->tm_min,
    time_ptr->tm_sec);
}

void print_unix_epoch_date_and_time()
{
  time_t unix_epoch_time = (time_t)0;
  struct tm local_time;
  localtime_r(&unix_epoch_time, &local_time); // Compliant
  print_date_and_time(&local_time);
}

int main(int argc, char* argv[])
{
  time_t current_time;
  struct tm local_time;

  time(&current_time);

  localtime_r(&current_time, &local_time); // Compliant

  // As expected, this will print: Current date and time: 1970/00/01 01:00:00
  print_unix_epoch_date_and_time();

  // As expected, this will print the current date and time
  print_date_and_time(&local_time);

  return 0;
}

Attachments

Issue Links

is implemented by

CPP-139 Rule: Non reentrant POSIX function should be replaced by reentrant one (CPP Check migration)

Closed

CPP-707 Create Objective-C rules repository containing targeted rules

Closed

is related to

CPP-2820 S1912: fix FP recommending using deprecated functions

Closed

Options

Progress

Sub-Tasks

1.

C-Family

RSPEC-4379

Active

Unassigned

Non-reentrant POSIX functions should be replaced with their reentrant versions