qbit/go
1
0
Fork 0
mirror of https://github.com/golang/go synced 2024-11-12 09:50:21 -07:00
Code Releases Activity

cmd/cgo: document C.sizeof_T and zero-sized field restriction

Browse Source 
Update #9401.
Update #11925.
Update #13919.

Change-Id: I52c679353693e8165b2972d4d3974ee8bb1207ef
Reviewed-on: https://go-review.googlesource.com/18542
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
This commit is contained in:
Ian Lance Taylor 2016-01-12 07:03:28 -08:00
parent eca3618fd3
commit 505fa7b423
1 changed files with 8 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
src/cmd/cgo/doc.go
View File

@ -125,11 +125,19 @@ The C types __int128_t and __uint128_t are represented by [16]byte.
To access a struct, union, or enum type directly, prefix it with
struct_, union_, or enum_, as in C.struct_stat.
The size of any C type T is available as C.sizeof_T, as in
C.sizeof_struct_stat.
As Go doesn't have support for C's union type in the general case,
C's union types are represented as a Go byte array with the same length.
Go structs cannot embed fields with C types.
Go code can not refer to zero-sized fields that occur at the end of
non-empty C structs. To get the address of such a field (which is the
only operation you can do with a zero-sized field) you must take the
address of the struct and add the size of the struct.
Cgo translates C types into equivalent unexported Go types.
Because the translations are unexported, a Go package should not
expose C types in its exported API: a C type used in one Go package