mirror of
https://gitlab.gnome.org/GNOME/glib.git
synced 2024-12-26 23:46:15 +01:00
f722f11e57
GTK lost it's '+' suffix back in 2019, according to <https://mail.gnome.org/archives/gtk-devel-list/2019-February/msg00000.html> This commit can be re-generated with: git grep -l GTK+ \ | grep -v -e ^NEWS -e ^glib/tests/collate.c \ | xargs sed -i 's/GTK+/GTK/g' Most of the changes are in comments and documentation.
169 lines
5.1 KiB
Markdown
169 lines
5.1 KiB
Markdown
Toolchain/Compiler requirements
|
||
===
|
||
|
||
GLib requires a toolchain that supports C99.
|
||
|
||
GLib contains some fall back code that allows supporting toolchains that are not
|
||
fully C99-compatible.
|
||
|
||
GLib makes some assumptions about features of the C library and C preprocessor,
|
||
compiler and linker that may go beyond what C99 mandates. We will use features
|
||
beyond C99 if they are substantially useful and if they are supported in a wide
|
||
range of compilers.
|
||
|
||
In general, we are primarily interested in supporting these four compilers:
|
||
|
||
* GCC on *nix
|
||
* Clang (LLVM)
|
||
* MSVC
|
||
* mingw32-w64
|
||
|
||
This is in keeping with our goal of primarily targetting GNU/Linux, Windows and
|
||
Mac OS, along with Free Software POSIX-compliant operating systems. See
|
||
[Supported platforms](./supported-platforms.md) for a bit more information and
|
||
rationale about that.
|
||
|
||
In particular, we are interested in MSVC because, although there are other
|
||
compilers which target Windows, they do not output debugging information that is
|
||
compatible with MSVC. In interest of usability, we want users of GLib to be
|
||
able to debug GLib along with their own code while using MSVC as their
|
||
development environment.
|
||
|
||
At any given time, GLib may work with mingw32 (from mingw.org) but it is not
|
||
specifically supported. Politics aside, it seems that mingw.org is mostly
|
||
dormant and, at this point, all of the big distributions have switched over to
|
||
mingw32-w64. In several cases, mingw.org has been missing APIs that we’ve
|
||
wanted to use and upstream has not been responsive about adding them.
|
||
|
||
GLib will attempt to remain compatible with other compilers, but some ‘extra
|
||
features’ are assumed. Those are detailed below.
|
||
|
||
GLib additionally requires Python 3 to build.
|
||
|
||
C99 Varargs macros
|
||
---
|
||
|
||
_Hard requirement._
|
||
|
||
GLib requires C99 ``__VA_ARG__`` support for both C and C++ compilers.
|
||
|
||
Symbol visibility control
|
||
---
|
||
|
||
_Not a hard requirement._
|
||
|
||
When available, GLib uses `__attribute__((visibility("hidden")))` and the
|
||
`-fvisibility=hidden` compiler option to control symbol visibility, and the
|
||
`-Bsymbolic-functions` linker flag.
|
||
|
||
Builtin atomic operations
|
||
---
|
||
|
||
_Not a hard requirement._
|
||
|
||
GLib will fall back to using a mutex-based implementation if atomic builtins are
|
||
not available.
|
||
|
||
C99 printf and positional parameters
|
||
---
|
||
|
||
_Not a hard requirement._
|
||
|
||
GLib can be built with an included printf implementation (from GNUlib) if the
|
||
system printf is deficient.
|
||
|
||
Constructors and destructors
|
||
---
|
||
|
||
_Hard requirement._
|
||
|
||
GLib can work with pragma-based, as well as with attribute-based constructor
|
||
support. There is a fallback for MSVC using a `DllMain()` instead.
|
||
|
||
`va_list` pass-by-reference
|
||
---
|
||
|
||
_Hard requirement._
|
||
|
||
GLib depends on the ability to pass-by-reference a `va_list`, as mandated in
|
||
C99 § 7.15: “It is permitted to create a pointer to a `va_list` and pass that
|
||
pointer to another function, in which case the original function may make
|
||
further use of the original list after the other function returns.”
|
||
|
||
Support for `static inline`
|
||
---
|
||
|
||
_Hard requirement._
|
||
|
||
GLib depends on implementation of the `inline` keyword as described by
|
||
C99 § 6.7.4.
|
||
|
||
GLib further assumes that functions appearing in header files and marked
|
||
`static inline`, but not used in a particular compilation unit will:
|
||
|
||
* not generate warnings about being unused
|
||
* not be emitted in the compiler’s output
|
||
|
||
It is possible that a compiler adheres to C99 § 6.7.4 but not to GLib’s further
|
||
assumptions. Such compilers may produce large numbers of warnings or large
|
||
executables when compiling GLib or programs based on GLib.
|
||
|
||
Support for `alloca()`
|
||
---
|
||
|
||
_Hard requirement._
|
||
|
||
Your compiler must support `alloca()`, defined in `<alloca.h>` (or `<malloc.h>`
|
||
on Windows) and it must accept a non-constant argument.
|
||
|
||
(C11) support for type redefinition
|
||
---
|
||
|
||
**This requirement has been temporarily suspended (on account of OpenBSD
|
||
carrying an old version of gcc) but it will probably return in the future.**
|
||
|
||
Your compiler must allow “a typedef name [to] be redefined to denote the same
|
||
type as it currently does”, as per C11 §6.7, item 3.
|
||
|
||
‘Big’ enums
|
||
---
|
||
|
||
_Hard requirement._
|
||
|
||
Some of our enum types use `1<<31` as a value. We also use negative values in
|
||
enums. We rely on the compiler to choose a suitable storage size for the enum
|
||
that can accommodate this.
|
||
|
||
Selected C99 features
|
||
---
|
||
|
||
_Hard requirement._
|
||
|
||
Starting with GLib 2.52 and GTK 3.90, we will be using the following C99
|
||
features where appropriate:
|
||
|
||
* Compound literals
|
||
* Designated initializers
|
||
* Mixed declarations
|
||
|
||
Function pointer conversions
|
||
---
|
||
|
||
_Hard requirement._
|
||
|
||
GLib heavily relies on the ability to convert a function pointer to a `void*`
|
||
and back again losslessly. Any platform or compiler which doesn’t support this
|
||
cannot be used to compile GLib or code which uses GLib. This precludes use of
|
||
the `-pedantic` GCC flag with GLib.
|
||
|
||
`stdint.h`
|
||
---
|
||
|
||
_Hard requirement since GLib 2.67.x._
|
||
|
||
GLib [requires a C99 `stdint.h`](https://gitlab.gnome.org/GNOME/glib/-/merge_requests/1675)
|
||
with all the usual sized integer types (`int8_t`, `uint64_t` and so on),
|
||
believed to be supported by all relevant Unix platforms/compilers, as well as
|
||
Microsoft compilers since MSVC 2013.
|
||
|