glib-init: Statically assert more facts about standard types

This is a step towards glib#1484. We officially require a C99 toolchain,
so we can statically assert that our artisanal hand-crafted integer
types are compatible with the ones we would like to recommend people
use instead.

If there are *still* platforms where <stdint.h> is problematic, these
static assertions can act as an early-warning that future GLib releases
will make a C99-compliant <stdint.h> a hard requirement, in ways that
are less straightforward to avoid (see glib#1484 and glib!1300).

Signed-off-by: Simon McVittie <smcv@collabora.com>
This commit is contained in:
Simon McVittie 2020-10-02 15:06:09 +01:00
parent f01ca92821
commit bd1e2a984e

View File

@ -31,6 +31,11 @@
#include <stdio.h> #include <stdio.h>
#include <ctype.h> #include <ctype.h>
/* Deliberately not checking HAVE_STDINT_H here: we officially require a
* C99 toolchain, which implies <stdint.h>, int8_t and so on. If your
* toolchain does not have this, now would be a good time to upgrade. */
#include <stdint.h>
/* This seems as good a place as any to make static assertions about platform /* This seems as good a place as any to make static assertions about platform
* assumptions we make throughout GLib. */ * assumptions we make throughout GLib. */
@ -67,6 +72,71 @@ G_STATIC_ASSERT (G_ALIGNOF (TestChar) == G_ALIGNOF (int));
G_STATIC_ASSERT (G_ALIGNOF (TestShort) == G_ALIGNOF (int)); G_STATIC_ASSERT (G_ALIGNOF (TestShort) == G_ALIGNOF (int));
G_STATIC_ASSERT (G_ALIGNOF (TestInt) == G_ALIGNOF (int)); G_STATIC_ASSERT (G_ALIGNOF (TestInt) == G_ALIGNOF (int));
G_STATIC_ASSERT (sizeof (gchar) == 1);
G_STATIC_ASSERT (sizeof (guchar) == 1);
G_STATIC_ASSERT (sizeof (gint8) * CHAR_BIT == 8);
G_STATIC_ASSERT (sizeof (guint8) * CHAR_BIT == 8);
G_STATIC_ASSERT (sizeof (gint16) * CHAR_BIT == 16);
G_STATIC_ASSERT (sizeof (guint16) * CHAR_BIT == 16);
G_STATIC_ASSERT (sizeof (gint32) * CHAR_BIT == 32);
G_STATIC_ASSERT (sizeof (guint32) * CHAR_BIT == 32);
G_STATIC_ASSERT (sizeof (gint64) * CHAR_BIT == 64);
G_STATIC_ASSERT (sizeof (guint64) * CHAR_BIT == 64);
G_STATIC_ASSERT (sizeof (void *) == GLIB_SIZEOF_VOID_P);
G_STATIC_ASSERT (sizeof (gintptr) == sizeof (void *));
G_STATIC_ASSERT (sizeof (guintptr) == sizeof (void *));
G_STATIC_ASSERT (sizeof (long) == GLIB_SIZEOF_LONG);
G_STATIC_ASSERT (G_HAVE_GINT64 == 1);
G_STATIC_ASSERT (sizeof (size_t) == GLIB_SIZEOF_SIZE_T);
/* Not a typo: ssize_t is POSIX, not Standard C, but if it exists then
* it's the same size as size_t. */
G_STATIC_ASSERT (sizeof (size_t) == GLIB_SIZEOF_SSIZE_T);
G_STATIC_ASSERT (sizeof (gsize) == GLIB_SIZEOF_SSIZE_T);
G_STATIC_ASSERT (sizeof (gsize) == sizeof (size_t));
/* Again this is size_t not ssize_t, because ssize_t is POSIX, not C99 */
G_STATIC_ASSERT (sizeof (gssize) == sizeof (size_t));
G_STATIC_ASSERT (G_ALIGNOF (gsize) == G_ALIGNOF (size_t));
G_STATIC_ASSERT (G_ALIGNOF (gssize) == G_ALIGNOF (size_t));
/* goffset is always 64-bit, even if off_t is only 32-bit
* (compiling without large-file-support on 32-bit) */
G_STATIC_ASSERT (sizeof (goffset) == sizeof (gint64));
G_STATIC_ASSERT (G_ALIGNOF (goffset) == G_ALIGNOF (gint64));
G_STATIC_ASSERT (sizeof (gfloat) == sizeof (float));
G_STATIC_ASSERT (G_ALIGNOF (gfloat) == G_ALIGNOF (float));
G_STATIC_ASSERT (sizeof (gdouble) == sizeof (double));
G_STATIC_ASSERT (G_ALIGNOF (gdouble) == G_ALIGNOF (double));
G_STATIC_ASSERT (sizeof (gintptr) == sizeof (intptr_t));
G_STATIC_ASSERT (sizeof (guintptr) == sizeof (uintptr_t));
G_STATIC_ASSERT (G_ALIGNOF (gintptr) == G_ALIGNOF (intptr_t));
G_STATIC_ASSERT (G_ALIGNOF (guintptr) == G_ALIGNOF (uintptr_t));
G_STATIC_ASSERT (sizeof (gint8) == sizeof (int8_t));
G_STATIC_ASSERT (sizeof (guint8) == sizeof (uint8_t));
G_STATIC_ASSERT (G_ALIGNOF (gint8) == G_ALIGNOF (int8_t));
G_STATIC_ASSERT (G_ALIGNOF (guint8) == G_ALIGNOF (uint8_t));
G_STATIC_ASSERT (sizeof (gint16) == sizeof (int16_t));
G_STATIC_ASSERT (sizeof (guint16) == sizeof (uint16_t));
G_STATIC_ASSERT (G_ALIGNOF (gint16) == G_ALIGNOF (int16_t));
G_STATIC_ASSERT (G_ALIGNOF (guint16) == G_ALIGNOF (uint16_t));
G_STATIC_ASSERT (sizeof (gint32) == sizeof (int32_t));
G_STATIC_ASSERT (sizeof (guint32) == sizeof (uint32_t));
G_STATIC_ASSERT (G_ALIGNOF (gint32) == G_ALIGNOF (int32_t));
G_STATIC_ASSERT (G_ALIGNOF (guint32) == G_ALIGNOF (uint32_t));
G_STATIC_ASSERT (sizeof (gint64) == sizeof (int64_t));
G_STATIC_ASSERT (sizeof (guint64) == sizeof (uint64_t));
G_STATIC_ASSERT (G_ALIGNOF (gint64) == G_ALIGNOF (int64_t));
G_STATIC_ASSERT (G_ALIGNOF (guint64) == G_ALIGNOF (uint64_t));
/** /**
* g_mem_gc_friendly: * g_mem_gc_friendly:
* *