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Date: Tue, 17 Jul 2018 16:50:28 -0300
From: Eduardo Habkost <ehabkost@redhat.com>
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Subject: [Qemu-devel] Why do we typedef every struct on QEMU?
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To: qemu-devel@nongnu.org
Cc: Philippe =?iso-8859-1?Q?Mathieu-Daud=E9?= <f4bug@amsat.org>, Markus Armbruster <armbru@redhat.com>, "Dr. David Alan Gilbert" <dgilbert@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Peter Maydell <peter.maydell@linaro.org>

I have been looking at patches that touch typedefs.h and
wondering: why do we make typedefs.h necessary at all?  Why do we
always add typedefs for every struct and union type in QEMU?

Why do we prefer to write this:

----- qemu/typedefs.h:
typedef struct SomeType SomeType;
----------------------

----- qemu/somecode.h:
#include <qemu/typedefs.h>

int some_function(SomeType *a);
----------------------


...instead of simply writing this:?

----- qemu/somecode.h:
struct SomeType;
int some_function(struct SomeType *a);
----------------------

Is the maintenance burden of typedefs.h worth it?

-- 
Eduardo