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.
Clang docs say:
> Like -MMD, but also implies -E and writes to stdout by default.
Previously, Zig handled this option by forwarding it directly to Clang,
and disabling depfiles. However this did not adhere to Clang's documented
behavior of these flags.
Now, in addition to being forwarded directly to Clang, `-MM` also
sets c_out_mode = .preprocessor, just like `-E`.
Another issue I noticed is that Zig did not recognize the aliases for
-MG, -MM, or -MMD. The aliases are now recognized.
The presence of ZIG_VERBOSE_LINK now enables --verbose-link.
The presence of ZIG_VERBOSE_CC now enables --verbose-cc.
These are useful when debugging usage of `zig cc` which does not have
CLI flags for these options, since they are not valid C compiler flags.
* 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.
Currently `// zig fmt: off` does not work as there are two spaces
after the `//` instead of one. This can cause confusion, so allow
arbitrary whitespace before the `zig fmt: (off|on)` in the comment but
trim this whitespace to the canonical single space in the output.
Let's follow the road paved by the removal of 'z'/'Z', the Formatter
pattern is nice enough to let us remove the remaining four special cases
and declare u8 slices free from any special casing!
LLVM 12 included a patch that changed the way availability annotations
are specified. We now have to define the _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS
flag to make sure that we tell the c++ headers that we don't use
visibility annotations.
Related LLVM patch: D90843
