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Diffstat (limited to 'docs/syscall_descriptions_syntax.md')
| -rw-r--r-- | docs/syscall_descriptions_syntax.md | 27 |
1 files changed, 25 insertions, 2 deletions
diff --git a/docs/syscall_descriptions_syntax.md b/docs/syscall_descriptions_syntax.md index 68abd1f71..cf03350e0 100644 --- a/docs/syscall_descriptions_syntax.md +++ b/docs/syscall_descriptions_syntax.md @@ -129,8 +129,31 @@ structname "{" "\n" ``` Fields can have attributes specified in parentheses after the field, independent -of their type. The only attribute is direction (`in/out/inout`). For the field for -which it is specified, the direction attributes on the upper levels are overridden. +of their type. `in/out/inout` attribute specify per-field direction, for example: + +``` +foo { + field0 const[1, int32] (in) + field1 int32 (inout) + field2 fd (out) +} +``` + +`out_overlay` attribute allows to have separate input and output layouts for the struct. +Fields before the `out_overlay` field are input, fields starting from `out_overlay` are output. +Input and output fields overlap in memory (both start from the beginning of the struct in memory). +For example: + +``` +foo { + in0 const[1, int32] + in1 flags[bar, int8] + in2 ptr[in, string] + out0 fd (out_overlay) + out1 int32 +} +``` + Structs can have attributes specified in square brackets after the struct. Attributes are: |