Ensures that if an assignment statement is the sole statement within a
C if statement, for loop, do loop, or do while loop, then when translated
it resides within a block, even though it does not in the original C.
Fixes the following invalid translation:
`if (1) if (1) 2;` -> `if (true) if (true) _ = @as(c_int, 2);`
To this:
```zig
if (true) if (true) {
_ = @as(c_int, 2);
};
```
Fixes#8159
* translate-c: Use [N:0] arrays when initializer is a string literal
Translate incomplete arrays as [N:0] when initialized by a string literal.
This preserves a bit more of the type information from the original C program.
Fixes#8215
Fixes#2820
After reading the source code, the first two bytes are inspected, and
if they correspond to a UTF-16 BOM in little-endian order, the source
code is converted to UTF-8.
Given a pointer operand `ptr` and a signed integer operand `idx`
`ptr + idx` and `idx + ptr` -> ptr + @bitCast(usize, @intCast(isize, idx))
`ptr - idx` -> ptr - @bitCast(usize, @intCast(isize, idx))
Thanks @LemonBoy for pointing out that we can take advantage of wraparound
to dramatically simplify the code.
* Now it supports being an lvalue (see additional lines in the test
case).
* Properly handles a pointer result location (see additional lines in
the test case that assign the result of the orelse to a variable
rather than a const).
* Properly sets the result location type when possible, so that type
inference of an `orelse` operand expression knows its result type.
We can now codegen optionals! This includes the following instructions:
- is_null
- is_null_ptr
- is_non_null
- is_non_null_ptr
- optional_payload
- optional_payload_ptr
- br_void
Also includes a test for optionals.
Add support for OffsetOfExpr that contain exactly 1 component, when that component
is a field.
For example, given:
```c
struct S {
float f;
double d;
};
struct T {
long l;
int i;
struct S s[10];
};
```
Then:
```c
offsetof(struct T, i) // supported
offsetof(struct T, s[2].d) // not supported currently
```
When two pointers are subtracted, both shall point to elements of the
same array object, or one past the last element of the array object;
the result is the difference of the subscripts of the two array elements.
The size of the result is implementation-defined, and its type
(a signed integer type) is ptrdiff_t defined in the <stddef.h> header.
If the result is not representable in an object of that type,
the behavior is undefined.
See C Standard, ยง6.5.6 [ISO/IEC 9899:2011]
Fixes#7216
If the type is a reference to a global declaration that has not yet
been translated we need to use the global scope for translation
so that other functions can also reference it.
