Re: [Qemu-devel] [PATCH 03/24] qemu-common.h: comment about usage rules
On Mon, Nov 12, 2012 at 10:57:42PM +0100, Andreas Färber wrote: > Am 09.11.2012 15:56, schrieb Eduardo Habkost: > > Every time we make a tiny change on a header file, we often find > > circular header dependency problems. To avoid this nightmare, we need to > > stop including qemu-common.h on other headers, and we should gradually > > "from other headers" as below? Both forms sounds equivalent, to my non-native-speaker ears. :-) But I guess "including from other headers" is better. > > > move the declarations from the catchall qemu-common.h header to their > > specific headers. > > > > This simply adds a comment documenting the rules about qemu-common.h, > > hoping that people will see it before including qemu-common.h from other > > header files, and before adding more declarations to qemu-common.h. > > This reminds me that I had once posted a patch moving a declaration I > had once added for Cocoa to a new ui/ui.h... seems it never made it to > master, I'll go search, maybe we can smuggle that in now. ;) > > > > > Signed-off-by: Eduardo Habkost > > --- > > qemu-common.h | 11 ++- > > 1 file changed, 10 insertions(+), 1 deletion(-) > > > > diff --git a/qemu-common.h b/qemu-common.h > > index ac9985c..ea43bfa 100644 > > --- a/qemu-common.h > > +++ b/qemu-common.h > > @@ -1,5 +1,14 @@ > > > > -/* Common header file that is included by all of qemu. */ > > +/* Common header file that is included by all of qemu. > > "QEMU", while at it. > > > + * > > + * This file is supposed to be included only by .c files. No header file > > should > > + * depend on qemu-common.h, as this would easily lead to circular header > > + * dependencies. > > + * > > + * If a header files uses a definition from qemu-common.h, that definition > > "a header file" Oops. Thanks. > > > + * must be moved to a separate header file, and the header that uses it > > + * must include that header. > > + */ > > #ifndef QEMU_COMMON_H > > #define QEMU_COMMON_H > > > > I'll fix this up myself to spare you a resend and me another full review. Thanks! > > Regards, > Andreas > > -- > SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany > GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg > -- Eduardo
Re: [Qemu-devel] [PATCH 03/24] qemu-common.h: comment about usage rules
Am 09.11.2012 15:56, schrieb Eduardo Habkost: > Every time we make a tiny change on a header file, we often find > circular header dependency problems. To avoid this nightmare, we need to > stop including qemu-common.h on other headers, and we should gradually "from other headers" as below? > move the declarations from the catchall qemu-common.h header to their > specific headers. > > This simply adds a comment documenting the rules about qemu-common.h, > hoping that people will see it before including qemu-common.h from other > header files, and before adding more declarations to qemu-common.h. This reminds me that I had once posted a patch moving a declaration I had once added for Cocoa to a new ui/ui.h... seems it never made it to master, I'll go search, maybe we can smuggle that in now. ;) > > Signed-off-by: Eduardo Habkost > --- > qemu-common.h | 11 ++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/qemu-common.h b/qemu-common.h > index ac9985c..ea43bfa 100644 > --- a/qemu-common.h > +++ b/qemu-common.h > @@ -1,5 +1,14 @@ > > -/* Common header file that is included by all of qemu. */ > +/* Common header file that is included by all of qemu. "QEMU", while at it. > + * > + * This file is supposed to be included only by .c files. No header file > should > + * depend on qemu-common.h, as this would easily lead to circular header > + * dependencies. > + * > + * If a header files uses a definition from qemu-common.h, that definition "a header file" > + * must be moved to a separate header file, and the header that uses it > + * must include that header. > + */ > #ifndef QEMU_COMMON_H > #define QEMU_COMMON_H > I'll fix this up myself to spare you a resend and me another full review. Regards, Andreas -- SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg
[Qemu-devel] [PATCH 03/24] qemu-common.h: comment about usage rules
Every time we make a tiny change on a header file, we often find circular header dependency problems. To avoid this nightmare, we need to stop including qemu-common.h on other headers, and we should gradually move the declarations from the catchall qemu-common.h header to their specific headers. This simply adds a comment documenting the rules about qemu-common.h, hoping that people will see it before including qemu-common.h from other header files, and before adding more declarations to qemu-common.h. Signed-off-by: Eduardo Habkost --- qemu-common.h | 11 ++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/qemu-common.h b/qemu-common.h index ac9985c..ea43bfa 100644 --- a/qemu-common.h +++ b/qemu-common.h @@ -1,5 +1,14 @@ -/* Common header file that is included by all of qemu. */ +/* Common header file that is included by all of qemu. + * + * This file is supposed to be included only by .c files. No header file should + * depend on qemu-common.h, as this would easily lead to circular header + * dependencies. + * + * If a header files uses a definition from qemu-common.h, that definition + * must be moved to a separate header file, and the header that uses it + * must include that header. + */ #ifndef QEMU_COMMON_H #define QEMU_COMMON_H -- 1.7.11.7
[Qemu-devel] [PATCH 03/24] qemu-common.h: comment about usage rules
Every time we make a tiny change on a header file, we often find circular header dependency problems. To avoid this nightmare, we need to stop including qemu-common.h on other headers, and we should gradually move the declarations from the catchall qemu-common.h header to their specific headers. This simply adds a comment documenting the rules about qemu-common.h, hoping that people will see it before including qemu-common.h from other header files, and before adding more declarations to qemu-common.h. Signed-off-by: Eduardo Habkost --- qemu-common.h | 11 ++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/qemu-common.h b/qemu-common.h index ac9985c..ea43bfa 100644 --- a/qemu-common.h +++ b/qemu-common.h @@ -1,5 +1,14 @@ -/* Common header file that is included by all of qemu. */ +/* Common header file that is included by all of qemu. + * + * This file is supposed to be included only by .c files. No header file should + * depend on qemu-common.h, as this would easily lead to circular header + * dependencies. + * + * If a header files uses a definition from qemu-common.h, that definition + * must be moved to a separate header file, and the header that uses it + * must include that header. + */ #ifndef QEMU_COMMON_H #define QEMU_COMMON_H -- 1.7.11.4
[Qemu-devel] [PATCH 03/24] qemu-common.h: comment about usage rules
Every time we make a tiny change on a header file, we often find circular header dependency problems. To avoid this nightmare, we need to stop including qemu-common.h on other headers, and we should gradually move the declarations from the catchall qemu-common.h header to their specific headers. This simply adds a comment documenting the rules about qemu-common.h, hoping that people will see it before including qemu-common.h from other header files, and before adding more declarations to qemu-common.h. Signed-off-by: Eduardo Habkost --- qemu-common.h | 11 ++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/qemu-common.h b/qemu-common.h index b54612b..630bfa0 100644 --- a/qemu-common.h +++ b/qemu-common.h @@ -1,5 +1,14 @@ -/* Common header file that is included by all of qemu. */ +/* Common header file that is included by all of qemu. + * + * This file is supposed to be included only by .c files. No header file should + * depend on qemu-common.h, as this would easily lead to circular header + * dependencies. + * + * If a header files uses a definition from qemu-common.h, that definition + * must be moved to a separate header file, and the header that uses it + * must include that header. + */ #ifndef QEMU_COMMON_H #define QEMU_COMMON_H -- 1.7.11.7
