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IAR Embedded Workbench for Arm 9.70.x

MISRAC2012-Rule-2.2_a

In this section:
Synopsis

(Required) There shall be no dead code.

Enabled by default

Yes

Severity/Certainty

Low/Medium

lowmedium.png
Full description

A statement potentially contains no side effects. This check is identical to RED-no-effect, MISRAC2004-14.2.

Coding standards
CERT MSC12-C

Detect and remove code that has no effect

CWE 482

Comparing instead of Assigning

MISRA C:2004 14.2

(Required) All non-null statements shall either have at least one side effect however executed, or cause control flow to change.

MISRA C:2012 Rule-2.2

(Required) There shall be no dead code

Code examples

The following code example fails the check and will give a warning:

void example(void) {
  int x = 1;
  x = 2;
  x < x;
}

The following code example passes the check and will not give a warning about this issue:

#include <string>

void f();
template<class T>
struct X {
  int x;
  
  int get() const {
    return x;
  }
  
  X(int y) :
    x(y) {}  
};

typedef X<int> intX;

void example(void) {
  /* everything below has a side-effect */
  int i=0;
  f();
  (void)f();
  ++i;
  i+=1;
  i++;
  char *p = "test";
  std::string s;
  s.assign(p);
  std::string *ps = &s;
  ps -> assign(p);
  intX xx(1);
  xx.get(); 
  intX(1);
}