mercurial/cffi/bdiffbuild.py

dirstate: make dirstate flags char be unsigned

Since https://phab.mercurial-scm.org/D11387, `CC='clang -Werror' make
local` has started failing like this:

```
mercurial/cext/util.h:41:50: error: implicit conversion from 'int' to 'char' changes value from 128 to -128 [-Werror,-Wconstant-conversion]
static const char dirstate_flag_rust_special = 1 << 7;
                  ~~~~~~~~~~~~~~~~~~~~~~~~~~   ~~^~~~
```

This patch fixes that by making the flags be an unsigned char. That
also matches the `bool` typedef we have in `util.h`, which seems good
since many of the `dirstate_item_c_*()` functions return a `bool`.

Differential Revision: https://phab.mercurial-scm.org/D11444

from __future__ import absolute_import

import cffi
import os

ffi = cffi.FFI()
with open(
    os.path.join(os.path.join(os.path.dirname(__file__), '..'), 'bdiff.c')
) as f:
    ffi.set_source(
        "mercurial.cffi._bdiff", f.read(), include_dirs=['mercurial']
    )
ffi.cdef(
    """
struct bdiff_line {
    int hash, n, e;
    ssize_t len;
    const char *l;
};

struct bdiff_hunk;
struct bdiff_hunk {
    int a1, a2, b1, b2;
    struct bdiff_hunk *next;
};

int bdiff_splitlines(const char *a, ssize_t len, struct bdiff_line **lr);
int bdiff_diff(struct bdiff_line *a, int an, struct bdiff_line *b, int bn,
    struct bdiff_hunk *base);
void bdiff_freehunks(struct bdiff_hunk *l);
void free(void*);
"""
)

if __name__ == '__main__':
    ffi.compile()