[cfe-dev] improving detection of uninitialized arguments (the CallAndMessageChecker)

[Per Viberg]

Hi,

I'm looking into extending the check that warns for uninitialized arguments. Below I've described what should be detected. Any opinions on if it's a useful check or potential problems/drawbacks with it?.

Check: should this be detected as a warning for uninitialized argument?:"warning: Function call argument is an uninitialized value"

void doStuff(const int *p);
void f(void);

void f(void) {
      int x;
      doStuff(&x);  // ← warning?
}

My rationale behind the warning:
1. it's not possible to write to *p, because it's of type const
2. content of *p is uninitialized stack value, and shouldn't be used.
3. the value of p is of no interest, since it's an address of an stack variable.

if any of the above criteria are not fulfilled, then no warning. Thus the function prototype must state pointer to const for the argument, the variable that the function is called with must be address of local/stack variable.

currently, only this is detected:

void doStuff2(int p);
void g(void);

void g(void) {
      int y;
      doStuff2(y);  // warning: Function call argument is an uninitialized value


/Per



.......................................................................................................................
Per Viberg Senior Engineer
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