nordic-dev.net/vulkano
nordic-dev.net/vulkano
2
0
Fork 0
mirror of https://github.com/vulkano-rs/vulkano.git synced 2024-11-25 00:04:15 +00:00
Code Issues Packages Projects Releases Wiki Activity

Fix final struct padding

Browse Source
This commit is contained in:
Pierre Krieger 2016-04-16 14:26:17 +02:00
parent 8e3c191cd1
commit 9755ad5412
1 changed files with 53 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

75
vulkano-shaders/src/structs.rs
View File

@ -40,6 +40,7 @@ fn write_struct(doc: &parse::Spirv, struct_id: u32, members: &[u32]) -> String {
let mut current_rust_offset = Some(0);
for (num, &member) in members.iter().enumerate() {
// Compute infos about the member.
let (ty, rust_size, rust_align) = type_from_id(doc, member);
let member_name = ::member_name_from_id(doc, struct_id, num as u32);
@ -49,6 +50,7 @@ fn write_struct(doc: &parse::Spirv, struct_id: u32, members: &[u32]) -> String {
return String::new();
}
// Finding offset of the current member, as requested by the SPIR-V code.
let spirv_offset = doc.instructions.iter().filter_map(|i| {
match *i {
parse::Instruction::MemberDecorate { target_id, member,
@ -64,20 +66,6 @@ fn write_struct(doc: &parse::Spirv, struct_id: u32, members: &[u32]) -> String {
None
}).next();
let spirv_stride = doc.instructions.iter().filter_map(|i| {
match *i {
parse::Instruction::Decorate { target_id,
decoration: enums::Decoration::DecorationArrayStride,
ref params } if target_id == member =>
{
return Some(params[0]);
},
_ => ()
};
None
}).next();
// Some structs don't have `Offset` decorations, in the case they are used as local
// variables only. Ignoring these.
let spirv_offset = match spirv_offset {
@ -98,7 +86,7 @@ fn write_struct(doc: &parse::Spirv, struct_id: u32, members: &[u32]) -> String {
if spirv_offset != *current_rust_offset {
let diff = spirv_offset.checked_sub(*current_rust_offset).unwrap();
members_defs.push(format!("_dummy: [u8; {}]", diff)); // FIXME: fix name if there are multiple dummies
members_defs.push(format!("pub _dummy: [u8; {}]", diff)); // FIXME: fix name if there are multiple dummies
*current_rust_offset += diff;
}
}
@ -110,8 +98,45 @@ fn write_struct(doc: &parse::Spirv, struct_id: u32, members: &[u32]) -> String {
current_rust_offset = None;
}
members_defs.push(format!("pub {name}: {ty} /* offset: {offset}, stride: {stride:?} */",
name = member_name, ty = ty, offset = spirv_offset, stride = spirv_stride));
members_defs.push(format!("pub {name}: {ty} /* offset: {offset} */",
name = member_name, ty = ty, offset = spirv_offset));
}
// Try determine the total size of the struct in order to add padding at the end of the struct.
let spirv_req_total_size = doc.instructions.iter().filter_map(|i| {
match *i {
parse::Instruction::Decorate { target_id,
decoration: enums::Decoration::DecorationArrayStride,
ref params } =>
{
for inst in doc.instructions.iter() {
match *inst {
parse::Instruction::TypeArray { result_id, type_id, .. }
if result_id == target_id && type_id == struct_id =>
{
return Some(params[0]);
},
parse::Instruction::TypeRuntimeArray { result_id, type_id }
if result_id == target_id && type_id == struct_id =>
{
return Some(params[0]);
},
_ => ()
}
}
None
},
_ => None
}
}).fold(None, |a, b| if let Some(a) = a { assert_eq!(a, b); Some(a) } else { Some(b) });
// Adding the final padding members.
if let (Some(cur_size), Some(req_size)) = (current_rust_offset, spirv_req_total_size) {
let diff = req_size.checked_sub(cur_size as u32).unwrap();
if diff >= 1 {
members_defs.push(format!("pub _dummy: [u8; {}]", diff)); // FIXME: fix name if there are multiple dummies
}
}
// We can only derive common traits if there's no unsized member in the struct.
@ -122,8 +147,8 @@ fn write_struct(doc: &parse::Spirv, struct_id: u32, members: &[u32]) -> String {
};
format!("#[repr(C)]\n{derive}\
pub struct {name} {{\n\t{members}\n}}\n",
derive = derive, name = name, members = members_defs.join(",\n\t"))
pub struct {name} {{\n\t{members}\n}} /* total_size: {t:?} */\n",
derive = derive, name = name, members = members_defs.join(",\n\t"), t = spirv_req_total_size)
}
/// Returns true if a `BuiltIn` decorator is applied on a struct member.
@ -150,15 +175,21 @@ fn type_from_id(doc: &parse::Spirv, searched: u32) -> (String, Option<usize>, us
for instruction in doc.instructions.iter() {
match instruction {
&parse::Instruction::TypeBool { result_id } if result_id == searched => {
return ("bool".to_owned(), Some(mem::size_of::<bool>()), mem::align_of::<bool>())
#[repr(C)] struct Foo { data: bool, after: u8 }
let size = unsafe { (&(&*(0 as *const Foo)).after) as *const u8 as usize };
return ("bool".to_owned(), Some(size), mem::align_of::<Foo>())
},
&parse::Instruction::TypeInt { result_id, width, signedness } if result_id == searched => {
// FIXME: width
return ("i32".to_owned(), Some(mem::size_of::<i32>()), mem::align_of::<i32>())
#[repr(C)] struct Foo { data: i32, after: u8 }
let size = unsafe { (&(&*(0 as *const Foo)).after) as *const u8 as usize };
return ("i32".to_owned(), Some(size), mem::align_of::<Foo>())
},
&parse::Instruction::TypeFloat { result_id, width } if result_id == searched => {
// FIXME: width
return ("f32".to_owned(), Some(mem::size_of::<f32>()), mem::align_of::<f32>())
#[repr(C)] struct Foo { data: f32, after: u8 }
let size = unsafe { (&(&*(0 as *const Foo)).after) as *const u8 as usize };
return ("f32".to_owned(), Some(size), mem::align_of::<Foo>())
},
&parse::Instruction::TypeVector { result_id, component_id, count } if result_id == searched => {
debug_assert_eq!(mem::align_of::<[u32; 3]>(), mem::align_of::<u32>());