Re: ObjC/ObjC++: Move ObjC callbacks into their own header to fix pointless rebuilds of lots of files when they change

[Paolo Bonzini <bonzini at gnu dot org>]

On 12/04/2010 01:29 AM, Nicola Pero wrote:
> This patch fixes a problem I keep having when working on the
> Objective-C/Objective-C++ frontends, which is that any,
> no-matter-how-trivial, change to the ObjC callbacks triggers a
> rebuild of a mass of completely unrelated files (such as i386.c,
> tree-ssa-mudflap.c, etc).

I only found these files to include c-common.h, c-lang.h or c-tree.h in 
my tree:

c-aux-info.c
c-convert.c
c-decl.c
c-errors.c
c-lang.c
c-objc-common.c
c-parser.c
c-typeck.c
config/darwin.c
config/darwin-c.c
config/sol2-c.c
config/arm/arm-c.c
config/avr/avr-c.c
config/i386/i386-c.c
config/i386/msformat-c.c
config/ia64/ia64-c.c
config/m32c/m32c-pragma.c
config/microblaze/microblaze-c.c
config/rs6000/rs6000-c.c
config/spu/spu-c.c

This is a bug in the case of config/darwin.c (CCing Jack...), but it 
means that modifying c-common.h should not cause the rebuild of i386.c.

So, this is actually a bug of the Makefiles, which have extra 
unnecessary dependencies on $(C_COMMON_H).  Unfortunately I don't have 
time to look at it, but maybe someone else can.

Paolo