| Issue |
129851
|
| Summary |
Why Isn't `-Wsign-conversion` Included in `-Wall` and `-Wextra`?
|
| Labels |
new issue
|
| Assignees |
|
| Reporter |
PikachuHyA
|
I find it puzzling that the `-Wsign-conversion` flag is not included in `-Wall -Wextra`. Is there a specific reason for this?
Here's a simple example:
```c
// demo.c
#include <stdio.h>
int main() {
unsigned long a = 1;
signed long b = 2;
printf("%llu\n", (long long unsigned int)(a + b));
return 0;
}
```
Testing it with the latest Clang compiler:
```
$ ./bin/clang demo.c -Wall -Wextra
$ ./bin/clang demo.c -Wsign-conversion
demo.c:6:49: warning: implicit conversion changes signedness: 'long' to 'unsigned long' [-Wsign-conversion]
6 | printf("%llu\n", (long long unsigned int)(a + b));
| ~ ^
1 warning generated.
$ ./bin/clang demo.c -Werror -Wsign-conversion
demo.c:6:49: error: implicit conversion changes signedness: 'long' to 'unsigned long' [-Werror,-Wsign-conversion]
6 | printf("%llu\n", (long long unsigned int)(a + b));
| ~ ^
1 error generated.
```
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