CODEWITHSUNDEEP
c++gccc++14
user654789384
user654789384

Reputation: 395

GCC - Unused Variable Warning inside Structs

I am searching for a solution where GCC (Arm-Embedded Version) is able to tell me if a variable is not existing at all, when allocated as part of a struct.

The current examples do not warn at all, which i would like to change.

Example 1:

Example 1 has 3 variables from a sturct: var1: assigned but never referenced elsewhere, therefore i want to remove it var2: not even assigned, makes no sense to waste ram here, remove it return: assigned and referenced, everything ok.

therefore i would like to get 2 warnings here.

struct mydummy_t
{
    bool var1;
    bool var2;
    int return;
};

static mydummy_t dummy;

int main()
{
    dummy.var1 = true;
    dummy.return = 15;
    return dummy.return;
}

Example 2:

same as example one but now we have a class constructor which initially addresses every variable, but again, not all of them are referenced.

struct mydummy_t
{
    mydummy_t() : var1(false), var2(true), return(-1) {}
    bool var1;
    bool var2;
    int return;
};

static mydummy_t dummy;

int main()
{
    dummy.var1 = true;
    dummy.return = 15;
    return dummy.return;
}

Upvotes: 0

Views: 464

Answers (1)

TonyK
TonyK

Reputation: 17114

You are asking too much of the compiler. How is it to know that this structure is not used in other compilation units, which might reference any or all of those members? (Also, return is a reserved word in C++.)

Upvotes: 1

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