Re: [libvirt] [PATCH] Document preferred naming conventions

On Mon, Mar 06, 2017 at 10:21:28AM +0100, Bjoern Walk wrote: > Daniel P. Berrange <berrange(a)redhat.com&gt; [2017-03-03, 10:50AM +0100]: >> This documents the preferred conventions for naming files, >> structs, enums, typedefs and functions. >> >> Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com&gt; >> --- >> HACKING | 71 ++++++++++++++++++++++++++++++++++++++++++++ >> docs/hacking.html.in | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++++ >> docs/hacking2.xsl | 4 +++ >> 3 files changed, 158 insertions(+) >> >> diff --git a/HACKING b/HACKING >> index fff003b..16be5cf 100644 >> --- a/HACKING >> +++ b/HACKING >> @@ -239,6 +239,77 @@ on the subject, on Richard Jones' guide to working with open source projects >> <http://people.redhat.com/rjones/how-to-supply-code-to-open-source-project...;. >> >> >> +Naming conventions >> +================== >> +When reading libvirt code, a number of different naming conventions will be >> +evident due to various changes in thinking over the course of the project's >> +lifetime. The conventions documented below should be followed when creating >> +any entirely new files in libvirt. When working on existing files, while it is >> +desirable to apply these conventions, keeping a consistent style with existing >> +code in that particular file is generally more important. The overall guiding >> +rule is that every file, enum, struct, function, and typedef name must have a >> +'vir' or 'VIR' prefix. All local scope variable names are exempt, and global >> +variables are exempt, unless exported in a header file. >> + >> +*File names* >> + >> +File naming varies depending on the subdirectory. The preferred style is to >> +have a 'vir' prefix, followed by a name which matches the name of the >> +functions / objects inside the file. For example, a file containing an object >> +'virHashtable' is stored in files 'virhashtable.c' and 'virhashtable.h'. >> +Sometimes, methods which would otherwise be declared 'static' need to be >> +exported for use by a test suite. For this purpose a second header file should >> +be added with a suffix of 'priv'. e.g. 'virhashtablepriv.h'. USe of >> +underscores in file names is discouraged when using the 'vir' prefix style. >> +The 'vir' prefix naming applies to src/util, src/rpc and tests/ directories. >> +Most other directories do not follow this convention. >> + >> + >> + >> +*Enum type & field names* >> + >> +All enums should have a 'vir' prefix in their typedef name, and each following >> +word should have its first letter in uppercase. The enum name should match the >> +typedef name with a leading underscore. The enum member names should be in all >> +uppercase, and use an underscore to separate each word. The enum member name >> +prefix should match the enum typedef name. >> + >> + typedef enum _virSocketType virSocketType; >> + enum _virSocketType { >> + VIR_SOCKET_TYPE_IPV4, >> + VIR_SOCKET_TYPE_IPV6, >> + }; >> + >> + >> +*Struct type names* >> + >> +All structs should have a 'vir' prefix in their typedef name, and each >> +following word should have its first letter in uppercase. The struct name >> +should be the same as the typedef name with a leading underscore. A second >> +typedef should be given for a pointer to the struct with a 'Ptr' suffix. >> + >> + typedef struct _virHashTable virHashTable; >> + typedef virHashTable *virHashTablePtr; >> + struct _virHashTable { >> + ... >> + }; >> + > I personally would prefer this style: > > typedef struct _virHashTable { > ... > } virHashTable, *virHashTablePtr; > This is done for example in src/conf/device_conf.h. Subjectively, it is > much easier to read, but objectively, it is more concise and enhances > discoverability. For example, in src/conf/domain_conf.h the typedef are > at the beginning of the file separated from the definition of the > struct. If I want to look up a virDomainDiskDefPtr it requires two > jumps. We should change device_conf.h really - it is different from pretty much everywhere else in the libvirt codebase.