Sometimes we use the 'struct' keyword in headers to help us reduce dependencies between header files. Document that practice.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> Signed-off-by: Eduardo Habkost <ehabk...@redhat.com> --- Changes v1 -> v2: * Use paragraphs written by Paolo Bonzini at https://www.mail-archive.com/qemu-devel@nongnu.org/msg586214.html * Fix typos spotted by Thomas Huth --- HACKING | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/HACKING b/HACKING index 0fc3e0fc04..035276e668 100644 --- a/HACKING +++ b/HACKING @@ -100,7 +100,19 @@ pointer, you're guaranteed that it is used to modify the storage it points to, or it is aliased to another pointer that is. 2.3. Typedefs -Typedefs are used to eliminate the redundant 'struct' keyword. + +Typedefs are used to eliminate the redundant 'struct' keyword, since type +names have a different style than other identifiers ("CamelCase" versus +"snake_case"). Each struct should have a CamelCase name and a +corresponding typedef. + +Since certain C compilers choke on duplicated typedefs, you should avoid +them and declare a typedef only in one header file. For common types, +you can use "include/qemu/typedefs.h" for example. However, as a matter +of convenience it is also perfectly fine to use forward struct +definitions instead of typedefs in headers and function prototypes; this +avoids problems with duplicated typedefs and reduces the need to include +headers from other headers. 2.4. Reserved namespaces in C and POSIX Underscore capital, double underscore, and underscore 't' suffixes should be -- 2.21.0
