The EINA_MODINFO must export the symbols in the current module, and it
is not used for importing symbols so we can use EXPORTAPI to export
without needing to know what is being built.
Patch from a series of patches to rename EAPI symbols to specific
library DSOs.
= The Rationale =
This patch is from a series of patches to rename EAPI symbols to
specific library DSOs.
EAPI was designed to be able to pass
`__attribute__ ((visibility ("default")))` for symbols with
GCC, which would mean that even if -fvisibility=hidden was used
when compiling the library, the needed symbols would get exported.
MSVC __almost__ works like GCC (or mingw) in which you can
declare everything as export and it will just work (slower, but
it will work). But there's a caveat: global variables will not
work the same way for MSVC, but works for mingw and GCC.
For global variables (as opposed to functions), MSVC requires
correct DSO visibility for MSVC: instead of declaring a symbol as
export for everything, you need to declare it as import when
importing from another DSO and export when defining it locally.
With current EAPI definitions, we get the following example
working in mingw and MSVC (observe it doesn't define any global
variables as exported symbols).
Example 1:
dll1:
```
EAPI void foo(void);
EAPI void bar()
{
foo();
}
```
dll2:
```
EAPI void foo()
{
printf ("foo\n");
}
```
This works fine with API defined as __declspec(dllexport) in both
cases and for gcc defining as
`__atttribute__((visibility("default")))`.
However, the following:
Example 2:
dll1:
```
EAPI extern int foo;
EAPI void foobar(void);
EAPI void bar()
{
foo = 5;
foobar();
}
```
dll2:
```
EAPI int foo = 0;
EAPI void foobar()
{
printf ("foo %d\n", foo);
}
```
This will work on mingw but will not work for MSVC. And that's why
LIBAPI is the only solution that works for MSVC.
Co-authored-by: João Paulo Taylor Ienczak Zanette <jpaulotiz@gmail.com>
Co-authored-by: Lucas Cavalcante de Sousa <lucks.sousa@gmail.com>
Co-authored-by: Ricardo Campos <ricardo.campos@expertise.dev>
Summary:
These macros allow you to define module informations like
author/description/version/license
e.g.
// Use "Name <email id>" or just "Name"
EINA_MODULE_AUTHOR("Enlightenment Community");
// Mention license
EINA_MODULE_LICENSE("GPL v2");
// What your module does
EINA_MODULE_DESCRIPTION("This is what this module does");
// Module version
EINA_MODULE_VERSION("0.1");
Now eina_modinfo can show these informations to users
$ eina_modinfo module.so
version: 0.1
description: Entry test
license: GPLv2
author: Enlightenment Community
@feature
Reviewers: cedric, tasn, raster, jpeg
Subscribers: seoz
Differential Revision: https://phab.enlightenment.org/D4257
Felipe Magno de Almeida
Xavi Artigas
Amitesh Singh