ORCA/C previously allowed struct/union members to be declared with incomplete type. Because of this, it allowed C99-style flexible array members to be declared, albeit by accident rather than by design. In some basic testing, these seem to work correctly, except that they could be initialized and that would give rise to odd behavior.
I have restricted it to allowing flexible array members only in the cases allowed by C99/C11, and otherwise disallowing members with incomplete type. I have also prohibited initializing flexible array members.
Also, generate better code for zero-initializing small arrays.
The problem was that the code would call the library routine ~ZERO with a size of 1, but it only works properly with a size of 2 or more. While adding a check here, I also changed it to not call ~ZERO for other small arrays (<=10 bytes), since it is generally more efficient to just initialize them directly.
The initializations in the following are examples that could trigger the problem:
int main(void)
{
struct { int i; char s[1]; } foo = {1, 0};
char arr[2][1] = {2};
}
This may be someone trying to use a C11-style anonymous struct/union, which should be flagged as an error until and unless those are supported. Otherwise, it probably just indicates that the programmer is confused. In any case, an error should be flagged for it.
C89 restricts bit fields to (signed) int and unsigned int only, although later standards note that additional types may be supported. ORCA/C supports the other integer types as an extension.
This fixes the compco01.c test case.
This patch should also permit the union initialization code to handle unions containing bit fields, but for the time being they are still prohibited by code elsewhere in the compiler.
The case label values are converted to the promoted type of the expression being switched on, as if by a cast. In practice, this means discarding the high bits of a 32-bit value to produce a 16-bit one.
Code requiring this is dubious and would be a good candidate for a warning or a lint error, but it's allowed under the C standards.
The following code demonstrates the issue:
#include <stdio.h>
int main(void)
{
int i = 0x1234;
switch (i) {
case 0xABCD1234:
puts("good");
break;
default:
puts("bad");
}
}
Stephen Heumann
mikew50